Conjoint Professor Jeannette Lechner-Scott

Objective: An investigation was performed to determine the relevant hemodynamic parameters which could help assess vascular pathology in human diseases. Using these parameters, this study aims to assess if there are any hemodynamic differences in the cerebral veins of multiple sclerosis (MS) patients and controls which could impact the etiology of MS. Methods: 40 MS participants and 20 controls were recruited for this study. Magnetic resonance imaging (MRI) was performed to enable 3D geometries of the anatomy and the blood flow rates at the boundaries to be computed. Computational fluid dynamics (CFD) models were created for each participant and simulated using patient-specific boundary conditions. Results: The pressure drop and vascular resistance did not significantly differ between the groups. The internal jugular vein (IJV) cross-sectional area was larger in the MS group (Right IJV: p = 0.04, Left IJV: p = 0.02) and the straight sinus (ST) flow rate was higher in MS across all ages (p = 0.005) compared to controls. Vascular resistance was shown to indicate regions in the cerebral veins which could correspond to increased venous pressure. Conclusion & Significance: This study shows that the pressure and vascular resistance of the cerebral veins are unlikely to be directly related to the etiology of MS. The finding of higher ST flow could correspond to increased inflammation in the deep venous system. Resistance as a measure of vascular pathology shows promise and could be useful to holistically investigate blood flow hemodynamics in a variety of other diseases of the circulatory system.

Background: Multiple sclerosis (MS) is a chronic autoimmune/neurodegenerative disease associated with progressing disability affecting mostly women. We aim to estimate transition probabilities describing MS-related disability progression from no disability to severe disability. Transition probabilities are a vital input for health economics models. In MS, this is particularly relevant for pharmaceutical agency reimbursement decisions for disease-modifying therapies (DMTs). Methods: Data were obtained from Australian participants of the MSBase registry. We used a four-state continuous-time Markov model to describe how people with MS transition between disability milestones defined by the Expanded Disability Status Scale (scale 0¿10): no disability (EDSS of 0.0), mild (EDSS of 1.0¿3.5), moderate (EDSS of 4.0¿6.0), and severe (EDSS of 6.5¿9.5). Model covariates included sex, DMT usage, MS-phenotype, and disease duration, and analysis of covariate groups were also conducted. All data were recorded by the treating neurologist. Results: A total of N = 6369 participants (mean age 42.5 years, 75.00% female) with 38,837 person-years of follow-up and 54,570 clinical reviews were identified for the study. Annual transition probabilities included: remaining in the no, mild, moderate, and severe states (54.24%, 82.02%, 69.86%, 77.83% respectively) and transitioning from no to mild (42.31%), mild to moderate (11.38%), and moderate to severe (9.41%). Secondary-progressive MS was associated with a 150.9% increase in the hazard of disability progression versus relapsing¿remitting MS. Conclusions: People with MS have an approximately 45% probability of transitioning from the no disability state after one year, with people with progressive MS transitioning from this health state at a much higher rate. These transition probabilities will be applied in a publicly available health economics simulation model for Australia and similar populations, intended to support reimbursement of a plethora of existing and upcoming interventions including medications to reduce progression of MS.

Importance: Progression independent of relapse activity (PIRA) is a significant contributor to long-term disability accumulation in relapsing-remitting multiple sclerosis (MS). Prior studies have used varying PIRA definitions, hampering the comparability of study results. Objective: To compare various definitions of PIRA. Design, Setting, and Participants: This cohort study involved a retrospective analysis of prospectively collected data from the MSBase registry from July 2004 to July 2023. The participants were patients with MS from 186 centers across 43 countries who had clinically definite relapsing-remitting MS, a complete minimal dataset, and 3 or more documented Expanded Disability Status Scale (EDSS) assessments. Exposure: Three-hundred sixty definitions of PIRA as combinations of the following criteria: baseline disability (fixed baseline with re-baselining after PIRA, or plus re-baselining after relapses, or plus re-baselining after improvements), minimum confirmation period (6, 12, or 24 months), confirmation magnitude (EDSS score at/above worsening score or at/above threshold compared with baseline), freedom from relapse at EDSS score worsening (90 days prior, 90 days prior and 30 days after, 180 days prior and after, since previous EDSS assessment, or since baseline), and freedom from relapse at confirmation (30 days prior, 90 days prior, 30 days before and after, or between worsening and confirmation). Main Outcome and Measure: For each definition, we quantified PIRA incidence and persistence (ie, absence of a 3-month confirmed EDSS improvement over =5 years). Results: Among 87239 patients with MS, 33303 patients fulfilled the inclusion criteria; 24152 (72.5%) were female and 9151 (27.5%) were male. At the first visits, the mean (SD) age was 36.4 (10.9) years; 28052 patients (84.2%) had relapsing-remitting MS, and the median (IQR) EDSS score was 2.0 (1.0-3.0). Participants had a mean (SD) 15.1 (11.9) visits over 8.9 (5.2) years. PIRA incidence ranged from 0.141 to 0.658 events per decade and persistence from 0.753 to 0.919, depending on the definition. In particular, the baseline and confirmation period influenced PIRA detection. The following definition yielded balanced incidence and persistence: a significant disability worsening compared with a baseline (reset after each PIRA event, relapse, and EDSS score improvement), in absence of relapses since the last EDSS assessment, confirmed with EDSS scores (not preceded by relapses within 30 days) that remained above the worsening threshold for at least 12 months. Conclusion and Relevance: Incidence and persistence of PIRA are determined by the definition used. The proposed standardized definition aims to enhance comparability among studies.

This study aimed to compare computational fluid dynamics (CFD) results to those acquired in vivo with 4D Flow magnetic resonance imaging (MRI) and in vitro with a 3D printed model using pressure catheter manometry. The goal was to investigate the haemodynamics of the cerebral venous system (CVS) and assess the accuracy of the methodologies, to highlight any discrepancies between the¿techniques. One participant living with multiple sclerosis (MS) and one healthy control were recruited for this study. MRI was performed to generate 3D geometries of the anatomy and to compute blood flow rates at the boundaries, with 4D Flow MRI velocity streamlines for the control participant. CFD models were created for the two participants and simulated using the patient-specific boundary conditions. A 3D printed geometry of the MS participant was created and a flow loop experiment was conducted to measure the cerebral venous pressures. The venous pressures were found to be comparable to that observed in the CFD simulation. 4D Flow MRI velocity streamlines of the CVS were found to correspond well to the CFD findings, except for a few regions, which were likely impacted by the low resolution of the MRI. The use of all three methods enabled the successful validation of the velocity, flow features and pressure, and ensured that the haemodynamics of the CVS as resolved using CFD, were accurate. This highlights the potential for increased efficacy of the clinical outcomes of future studies that utilise such methods.

BACKGROUND: Previous studies have indicated that progression independent of relapse activity (PIRA) is uncommon in patients with aquaporin- 4 antibody-positive (AQP4-IgG) neuromyelitis optica spectrum disorder (NMOSD). However, the patterns of disability accumulation in seronegative NMOSD are unknown. This study aimed to evaluate the prevalence of PIRA and relapse-associated worsening (RAW) in seronegative NMOSD. METHODS: We conducted a retrospective, multicentre cohort study of seronegative NMOSD patients from the MSBase registry. Inclusion criteria required at least three recorded expanded disability status scale (EDSS) scores: baseline, progression, and 6 months confirmed disability progression (CDP). For those with 6-month CDP, the presence or absence of relapse between baseline and progression determined the classification as RAW or PIRA, respectively. Descriptive statistics were employed to present the data. RESULTS: This study included 93 patients, with a median follow-up duration of 5.0 years (Q1 2.8, Q3 8.4). The cohort predominantly consisted of female patients (77.4%), with a median age of onset of 33.9 years (Q1 26.1, Q3 41.2). PIRA was observed in 1 case (1.1%), whilst RAW was documented in 7 cases (7.5%). CONCLUSION: This international cohort study confirms that CDP is uncommon in seronegative NMOSD. Given more than three quarters of CDP occur due to RAW, therapeutic strategies should focus primarily on preventing relapses.

Background: In relapsing-remitting multiple sclerosis (RRMS), extended exposure to high-efficacy disease modifying therapy may increase the risk of side effects, compromise treatment adherence, and inflate medical costs. Treatment de-escalation, here defined as a switch to a lower efficacy therapy, is often considered by patients and physicians, but evidence to guide such decisions is scarce. In this study, we aimed to compare clinical outcomes between patients who de-escalated therapy versus those who continued their therapy. Methods: In this retrospective analysis of data from an observational, longitudinal cohort of 87,239 patients with multiple sclerosis (MS) from 186 centers across 43 countries, we matched treatment episodes of adult patients with RRMS who underwent treatment de-escalation from either high- to medium-, high- to low-, or medium- to low-efficacy therapy with counterparts that continued their treatment, using propensity score matching and incorporating 11 variables. Relapses and 6-month confirmed disability worsening were assessed using proportional and cumulative hazard models. Results: Matching resulted in 876 pairs (de-escalators: 73% females, median [interquartile range], age 40.2 years [33.6, 48.8], Expanded Disability Status Scale [EDSS] 2.5 [1.5, 4.0]; non-de-escalators: 73% females, age 40.8 years [35.5, 47.9], and EDSS 2.5 [1.5, 4.0]), with a median follow-up of 4.8 years (IQR 3.0, 6.8). Patients who underwent de-escalation faced an increased hazard of future relapses (hazard ratio 2.36 and 95% confidence intervals [CI] [1.79¿3.11], p < 0.001), which was confirmed when considering recurrent relapses (2.43 [1.97¿3.00], p < 0.001). It was also consistent across subgroups stratified by age, sex, disability, disease duration, and time since last relapse. Conclusions: On the basis of this observational analysis, de-escalation may not be recommended as a universal treatment strategy in RRMS. The decision to de-escalate should be considered on an individual basis, as its safety is not clearly guided by specific patient or disease characteristics evaluated in this study.

Predicting long-term prognosis and choosing the appropriate therapeutic approach in patients with Multiple Sclerosis (MS) at the time of diagnosis is crucial in view of a personalized medicine. We investigated the impact of early therapeutic response on the 5-year prognosis of patients with relapsing-remitting MS (RRMS). We recruited patients from MSBase Registry covering the period between 1996 and 2022. All patients were diagnosed with RRMS and actively followed-up for at least 5 years to explore the following outcomes: clinical relapses, confirmed disability worsening (CDW) and improvement (CDI), EDSS 3.0, EDSS 6.0, conversion to secondary progressive MS (SPMS), new MRI lesions, Progression Independent of Relapse Activity (PIRA). Predictors included demographic, clinical and radiological data, and sub-optimal response (SR) within the first year of treatment. Female sex (HR 1.27; 95 ¿% CI 1.16¿1.40) and EDSS at baseline (HR 1.19; 95 ¿% CI 1.15¿1.24) were independent risk factors for the occurrence of relapses during the first 5 years after diagnosis, while high-efficacy treatment (HR 0.78; 95 ¿% CI 0.67¿0.91) and age at diagnosis (HR 0.83; 95 ¿% CI 0.79¿0.86) significantly reduced the risk. SR predicted clinical relapses (HR ¿= ¿3.84; 95 ¿% CI 3.51¿4.19), CDW (HR ¿= ¿1.74; 95 ¿% CI 1.56¿1.93), EDSS 3.0 (HR ¿= ¿3.01; 95 ¿% CI 2.58¿3.51), EDSS 6.0 (HR ¿= ¿1.77; 95 ¿% CI 1.43¿2.20) and new brain (HR ¿= ¿2.33; 95 ¿% CI 2.04¿2.66) and spinal (HR 1.65; 95 ¿% CI 1.29¿2.09) MRI lesions. This study highlights the importance of selecting the appropriate DMT for each patient soon after MS diagnosis, also providing clinicians with a practical tool able to calculate personalized risk estimates for different outcomes.

Background: High-efficacy disease-modifying therapies have been proven to slow disability accrual in adults with relapsing¿remitting multiple sclerosis. However, their impact on disability worsening in paediatric-onset multiple sclerosis, particularly during the early phases, is not well understood. We evaluated how high-efficacy therapies influence transitions across five disability states, ranging from minimal disability to gait impairment and secondary progressive multiple sclerosis, in people with paediatric-onset multiple sclerosis. Methods: Longitudinal data were obtained from the international MSBase registry, containing data from people with multiple sclerosis from 151 centres across 41 countries, and the Italian Multiple Sclerosis and Related Disorders Register, containing data from people with multiple sclerosis from 178 Italian multiple sclerosis centres. People younger than 18 years at the onset of multiple sclerosis symptoms were included, provided they had a confirmed diagnosis of relapsing¿remitting multiple sclerosis and at least four Expanded Disability Status Scale (EDSS) scores recorded within 12-month intervals. The primary outcome was the time to change in disability state: minimal disability (EDSS scores 0, 1·0, and 1·5), mild disability (EDSS scores 2·0 and 2·5), moderate disability (EDSS scores 3·0 and 3·5), gait impairment (EDSS scores =4·0), and clinician diagnosed secondary progressive multiple sclerosis. A multi-state model was constructed to simulate the natural course of multiple sclerosis, modelling the probabilities of both disability worsening and improvement simultaneously. The impact of high-efficacy disease-modifying therapies (alemtuzumab, cladribine, daclizumab, fingolimod, mitoxantrone, natalizumab, ocrelizumab, rituximab, or autologous haematopoietic stem cell transplantation) and low-efficacy disease-modifying therapies (dimethyl fumarate, glatiramer acetate, interferon beta, or teriflunomide), compared with no treatment, on the course of disability was assessed. Apart from recruitment, individuals with lived experience of multiple sclerosis were not involved in the design and conduct of this study. Findings: A total of 5224 people (3686 [70·6%] female and 1538 [29·4%] male) with mean age at onset of multiple sclerosis 15·24 years (SD 2·52) were included. High-efficacy therapies reduced the hazard of disability worsening across the disability states. The largest reduction (hazard ratio 0·41 [95% CI 0·31¿0·53]) was observed in participants who were treated with high-efficacy therapies while in the minimal disability state, compared with those remained untreated. The benefit of high-efficacy therapies declined with increasing disability. Young people with minimal disability who received low-efficacy therapy also experienced a reduced hazard (hazard ratio 0·65 [95% CI 0·54¿0·77]) of transitioning to mild disability, in contrast to those who remained untreated. Interpretation: Treatment of paediatric-onset relapsing-remitting multiple sclerosis with high-efficacy therapy substantially reduces the risk of reaching key disability milestones. This reduction in risk is most pronounced among young people with minimal or mild disability when treatment began. Children with relapsing-remitting multiple sclerosis should be treated early with high-efficacy therapy, before developing significant neurological impairments, to better preserve their neurological capacity. Funding: National Health and Medical Research Council, Australia; MSBase Foundation Fellowship; MS Australia Postdoctoral Fellowship.

Background: Multiple sclerosis is characterised by acute and chronic inflammation in the CNS. Diet may influence inflammation, and therefore MS outcomes. Objective: To determine whether the Dietary Inflammatory Index (DII®)) is associated with depression, anxiety, and fatigue in a prospective cohort of people with MS. Methods: People with a first clinical diagnosis of demyelination were followed over 10 years (n=223). DII and energy-adjusted DII (E-DIITM) scores were calculated from the dietary intake in the preceding 12 months measured by food frequency questionnaire. Depression and anxiety were assessed by the Hospital Anxiety and Depression Scale (HADS-A and HADS-D, respectively), and fatigue by the Fatigue Severity Scale. Results: A higher E-DII score was associated with higher levels of depression and anxiety five years later (e.g., highest vs lowest E-DII quartile, HADS-D score: ß=2.23, 95%CI=0.98,3.48, p<0.001; HADS-A score: ß=1.90, 95%CI=0.59,3.21, p<0.001). A cumulative E-DII score was associated with depression (p<0.01) and anxiety (p=0.05) at the 10-year review. No associations were seen for fatigue. Conclusion: Our findings suggest that, in people with MS, a more pro-inflammatory diet may long-term adverse impact on depression and anxiety, but not fatigue.

It is unknown whether the currently known risk factors of multiple sclerosis reflect the etiology of progressive-onset multiple sclerosis (POMS) as observational studies rarely included analysis by type of onset. We designed a case¿control study to examine associations between environmental factors and POMS and compared effect sizes to relapse-onset MS (ROMS), which will offer insights into the etiology of POMS and potentially contribute to prevention and intervention practice. This study utilizes data from the Primary Progressive Multiple Sclerosis (PPMS) Study and the Australian Multi-center Study of Environment and Immune Function (the AusImmune Study). This report outlines the conduct of the PPMS Study, whether the POMS sample is representative, and the planned analysis methods. The study includes 155 POMS, 204 ROMS, and 558 controls. The distributions of the POMS were largely similar to Australian POMS patients in the MSBase Study, with 54.8% female, 85.8% POMS born before 1970, mean age of onset of 41.44 ± 8.38¿years old, and 67.1% living between 28.9 and 39.4°¿S. The POMS were representative of the Australian POMS population. There are some differences between POMS and ROMS/controls (mean age at interview: POMS 55¿years vs. controls 40¿years; sex: POMS 53% female vs. controls 78% female; location of residence: 14.3% of POMS at a latitude = 28.9°S vs. 32.8% in controls), which will be taken into account in the analysis. We discuss the methodological issues considered in the study design, including prevalence-incidence bias, cohort effects, interview bias and recall bias, and present strategies to account for it. Associations between exposures of interest and POMS/ROMS will be presented in subsequent publications.

Background: Few studies on multiple sclerosis (MS) have explored the variability of percentage brain volume change (PBVC) measurements obtained from different clinical MRIs. In a retrospective multicentre cohort study, we quantified the variability of annualised PBVC in clinical MRIs. Methods: Clinical MRIs of relapse-onset MS patients were assessed by icobrain. Volumetric data were analysed on same-scanner and different-scanner MRI pairs if they passed quality control criteria. Alignment similarity between two images had to be comparable to same-scanner scan-rescan images. Results: Of 6826 MRIs, 85 % had appropriate volumetric sequences and 4446 serial MRI pairs were analysed. 3334 (75 %) MRI pairs from 1207 patients met the inclusions. The PBVC of included MRI pairs showed variance of 0.78 % for same-scanner pairs and 0.80 % for different-scanner pairs. Further selection of included MRI pairs with the best variance resulted in 1885 (42 %) MRI pairs with PBVC variance of 0.34 %. Excluded MRI pairs with poor alignment similarity had variances of 2.97 % for same-scanner pairs and 20.79 % for different-scanner pairs. Conclusion: Icobrain should be utilised for PBVC determination only on selected MRIs with the best alignment similarity. Applying strict selection criteria for the included MRI pairs and longitudinal imaging on the same scanner remain mandatory to reduce PBVC variability.

Rare coding variants that substantially affect function provide insights into the biology of a gene1¿3. However, ascertaining the frequency of such variants requires large sample sizes4¿8. Here we present a catalogue of human protein-coding variation, derived from exome sequencing of 983,578 individuals across diverse populations. In total, 23% of the Regeneron Genetics Center Million Exome (RGC-ME) data come from individuals of African, East Asian, Indigenous American, Middle Eastern and South Asian ancestry. The catalogue includes more than 10.4 million missense and 1.1 million predicted loss-of-function (pLOF) variants. We identify individuals with rare biallelic pLOF variants in 4,848 genes, 1,751 of which have not been previously reported. From precise quantitative estimates of selection against heterozygous loss of function (LOF), we identify 3,988 LOF-intolerant genes, including 86 that were previously assessed as tolerant and 1,153 that lack established disease annotation. We also define regions of missense depletion at high resolution. Notably, 1,482 genes have regions that are depleted of missense variants despite being tolerant of pLOF variants. Finally, we estimate that 3% of individuals have a clinically actionable genetic variant, and that 11,773 variants reported in ClinVar with unknown significance are likely to be deleterious cryptic splice sites. To facilitate variant interpretation and genetics-informed precision medicine, we make this resource of coding variation from the RGC-ME dataset publicly accessible through a variant allele frequency browser.

Cladribine (Mavenclad®) is an oral treatment for relapsing remitting MS (RRMS), but its mechanism of action and its effects on innate immune responses in unknown. This study is a prospective Phase IV study of 41 patients with RRMS, and aims to investigate the mechanism of action of cladribine on peripheral monocytes, and its impact on the P2X7 receptor. There was a significant reduction in monocyte count in vivo at week 1 post cladribine administration, and the subset of cells being most impacted were the CD14lo CD16+ 'non-classical' monocytes. Of the 14 cytokines measured in serum, CCL2 levels increased at week 1. In vitro, cladrabine induced a reduction in P2X7R pore as well as channel activity. This study demonstrates a novel mechanism of action for cladribine. It calls for studying potential benefits of cladribine in progressive forms of MS and other neurodegenerative diseases where innate immune related inflammation is implicated in disease pathogenesis.

Background: Disease modifying treatments (DMTs) for multiple sclerosis (MS) have varying levels of teratogenic potential, but whether this influences DMT prescribing patterns by sex or concurrent use of hormonal contraception in women is unknown. This study aimed to examine patterns in dispensing of DMTs in women and men with MS, and hormonal long-acting reversible contraceptive (LARC) overlap at DMT initiation among women. Methods: Population cohort study using 10% random sample of the Australian Pharmaceutical Benefits Scheme dispensing data (2007¿2021). DMT dispensing data were evaluated separately for women and men aged 18¿49 years. Hormonal LARC overlap was determined by receipt of contraceptive dispensing where the expected duration of efficacy overlapped with the DMT dispensing date. Results: DMTs with teratogenic potential (cladribine, sphingosine-1-phosphates and teriflunomide) were less likely to be commenced in women than men aged 18¿39 (OR 0.70, 0.51¿0.96), but not in those aged 40¿49 (OR 0.93, 0.60¿1.43). Hormonal LARC overlap was higher among those commenced DMTs with teratogenic potential compared with interferons (aOR 2.52, 1.14, 5.55). Conclusion: Sex and age differences in DMT utilisation were observed based on teratogenic potential. Hormonal LARC overlap appears higher in those receiving potentially teratogenic DMTs, but overall rates remain low.

Background: Spinal cord lesions in multiple sclerosis (MS) have considerable impact on disability. High-efficacy disease-modifying treatments (hDMTs) are associated with greater reduction of relapses and new brain lesions compared to low-efficacy treatments (lDMTs). Knowledge on the impact of DMTs on cord lesion formation is limited as these outcome measures were not included in MS treatment trials. This study aims to investigate whether hDMTs reduce the formation of cord lesions more effectively than lDMTs. Methods: Patients with relapse-onset MS, a cord magnetic resonance imaging (MRI) within 6 months before/after initiation of their first DMT and =1 cord MRI at follow-up (interval > 6 months) were extracted from the MSBase registry (ACTRN12605000455662). Patients treated with hDMTs =90% or lDMTs =90% of follow-up duration were considered the hDMT and lDMT groups, respectively. Matching was performed using propensity scores. Cox proportional hazards models were used to estimate the hazards of new cord lesions, brain lesions and relapses. Results: Ninety-four and 783 satisfied hDMT and lDMT group criteria, respectively. Seventy-seven hDMT patients were matched to 184 lDMT patients. In the hDMT group there was no evidence of reduction of new cord lesions (hazard ratio [HR] 0.99 [95% CI 0.51, 1.92], p = 0.97), while there were fewer new brain lesions (HR 0.22 [95% CI 0.10, 0.49], p < 0.001) and fewer relapses (HR 0.45 [95% CI 0.28, 0.72], p = 0.004). Conclusion: A potential discrepancy exists in the effect of hDMTs over lDMTs in preventing spinal cord lesions versus brain lesions and relapses. While hDMTs provided a significant reduction for the latter when compared to lDMTs, there was no significant reduction in new spinal cord lesions.

Introduction: Newcastle, Australia, has been serially studied for MS epidemiology since 1961, showing consistently increasing prevalence estimates and incidence rates, including to our 2011 study. Objectives: To assess the 2011¿2021 epidemiology of MS in Newcastle and to compare with previous measures. Methods: Demographic and clinical data were extracted from medical records of MS cases residing in Newcastle, as identified by public and private clinicians. Prevalence (2011 and 2021) and incidence rates (2011-2021, from onset and from diagnosis) and mortality rate (2011¿2021) were estimated and age-standardised to the 2021 Australian population. Results: The 2021 prevalence was 173.1/100,000 (age-standardised = 178.7/100,000, F/M-sex-ratio = 3.3), a 42.2 % increase from 2011 (F/M-sex-ratio = 3.1), 175.0 % from 1996 (F/M-sex-ratio = 2.6), and 831.0 % from 1961 (F/M-sex-ratio = 1.2). The 2011¿21 age-standardised onset incidence rate was 3.5/100,000 person-years (F/M-sex-ratio = 2.8), a 68.7 % increase from 1971 to 81 (F/M-sex-ratio = 1.1) and 44.5 % from 1986 to 96 (F/M-sex-ratio = 2.3). The age-standardised diagnosis incidence rate was 6.1/100,000 (F/M-sex-ratio = 2.2), statistically unchanged from that in 2001¿2011 (6.8/100,000, F/M-sex-ratio = 3.2). The 2011¿21 mortality rate was 2.1/100,000 person-years (2.2 age-standardised, F/M-sex-ratio = 1.4), with a standardised mortality ratio of 1.6. Conclusion: The Newcastle region continues to be a high frequency zone for MS. The incidence rate from onset is significantly increased from previous estimates, but incidence rate from diagnosis is stable. Prevalence and incidence sex ratios have stabilised at roughly 3.0, similar to other Australian sites.

Background and purpose: Understanding predictors of changes in employment status among people living with multiple sclerosis (MS) can assist health care providers to develop appropriate work retention/rehabilitation programs. We aimed to model longitudinal transitions of employment status in MS and estimate the probabilities of retaining employment status or losing or gaining employment over time in individuals with a first clinical diagnosis of central nervous system demyelination (FCD). Methods: This prospective cohort study comprised adults (aged 18¿59 years) diagnosed with FCD (n = 237) who were followed for more than 11 years. At each review, participants were assigned to one of three states: unemployed, part-time, or full-time employed. A Markov multistate model was used to examine the rate of state-to-state transitions. Results: At the time of FCD, participants with full-time employment had an 89% chance of being in the same state over a 1-year period, but this decreased to 42% over the 10-year follow-up period. For unemployed participants, there was a 92% likelihood of remaining unemployed after 1 year, but this probability decreased to 53% over 10 years. Females, those who progressed to clinically definite MS, those with a higher relapse count, and those with a greater level of disability were at increased risk of transitioning to a deteriorated employment state. In addition, those who experienced clinically significant fatigue over the follow-up period were less likely to gain employment after being unemployed. Conclusions: In our FCD cohort, we found a considerable rate of employment transition during the early years post-diagnosis. Over more than a decade of follow-up post-FCD, we found that females and individuals with a greater disability and a higher relapse count are at higher risk of losing employment.

Cognitive impairment in multiple sclerosis (MS) affects approximately 40¿70% of patients and can have varying degrees of severity. Even mild cognitive impairment can impact on quality of life and productivity. Despite this, patients are not routinely screened or monitored for cognitive impairment in Australia due to a range of issues, with time and space being the main limiting factors. This Australian multidisciplinary perspective provides recommendations on cognition management in Australia. It gives a broad overview of cognition in MS, advice on the screening and monitoring tools available to clinicians, and strategies that can be implemented in clinics to help monitor for cognitive impairment in patients with MS. We suggest a routine baseline assessment and multidomain cognitive battery in regular intervals; a change should trigger a thorough investigation of the cause.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) that results in significant neurodegeneration in the majority of those affected and is a common cause of chronic neurological disability in young adults1,2. Here, to provide insight into the potential mechanisms involved in progression, we conducted a genome-wide association study of the age-related MS severity score in 12,584 cases and replicated our findings in a further 9,805 cases. We identified a significant association with rs10191329 in the DYSF¿ZNF638 locus, the risk allele of which is associated with a¿shortening in the median time to requiring a walking aid of a median of 3.7 years in homozygous carriers¿and with increased brainstem and cortical pathology in brain tissue. We also identified suggestive association with rs149097173 in the DNM3¿PIGC locus and significant heritability enrichment in CNS tissues. Mendelian randomization analyses suggested a potential protective role for higher educational attainment. In contrast to immune-driven susceptibility3, these findings suggest a key role for CNS resilience and potentially neurocognitive reserve in determining outcome in MS.

Background: Diet-dependent acid-base load has been associated with worsening in mental health, but to date no study has examined this in people with multiple sclerosis (PwMS). We examined the association between potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores and depression, anxiety, and fatigue in PwMS. Methods: Participants with a first clinical diagnosis of CNS demyelination were followed prospectively as part of the AusLong Study (aged 18-59 years at cohort entry). At baseline, 5- and 10-year reviews, PRAL and NEAP scores were calculated using dietary intake in the preceding 12 months calculated from a food frequency questionnaire. At 5- and 10-year reviews, the Hospital Anxiety and Depression Scale was used to assess depression and anxiety, and the Fatigue Severity Scale assessed fatigue. Results: Higher PRAL and NEAP scores were associated with increased subsequent absolute value and change in HADS depression scores over five years' follow-up (e.g., highest vs lowest PRAL quartile, 5-year change in HADS-D score: ß=+3.01, 95%CI= 1.54, 4.48, p<0.001). The level of depression at the 10-year review was determined by both the baseline dietary acid scores and baseline-5-year changes in dietary acid scores (e.g., PRAL change from baseline to 5-year review, 10-year review HADS-D score: ß=+0.09, 95%CI= 0.03, 0.15, p<0.001, NEAP change from baseline to 5-year review, 10-year review HADS-D score: ß=+0.07, 95%CI= 0.01, 0.14, p=0.03). Some associations were observed with anxiety and fatigue but were much weaker and less consistent. Conclusion: Our findings indicate that a higher dietary acid load potentially has a long-term influence on the level of depression in PwMS. The evidence is less convincing for anxiety and fatigue.

Background: Multiple sclerosis (MS) negatively affects health-related quality of life (HRQoL). Objective: To evaluate HRQoL in people with highly active relapsing MS treated with cladribine tablets (CladT; 3.5 mg/kg cumulative dose over 2 years) in CLARIFY-MS. Methods: Changes in the MS quality of life (MSQoL)-54 scores were analysed using a repeated mixed-effects linear model. Subgroup analyses were performed for participants who were pretreatment-naïve and those pretreated with disease-modifying therapies (DMTs) before initiating CladT. Safety and tolerability of CladT were also assessed. Results: MSQoL-54 physical (mean change = 4.86; 95% confidence interval (CI) = 3.18, 6.53) and mental health (4.80; 95% CI = 3.13, 6.46) composite scores (primary endpoints) showed significant improvement at Month 24 versus Baseline (p < 0.0001). Changes in the MSQoL-54 scores were consistent across the pretreatment-naïve and DMT-pretreated subgroups. No new severe or opportunistic infections occurred. Most post-baseline lymphopenia events were Grade 1¿2 in severity. Transient Grade-3 lymphopenia was observed in 19.7% (95/482) of participants. Grade-4 lymphopenia was not observed. Conclusions: CladT treatment significantly improved the mean MSQoL-54 physical and mental health composite scores over 2 years. CladT efficacy in HRQoL, relapse rates and Expanded Disability Status Scale scores demonstrates its multidimensional effects in MS treatment.

Background: Patients with relapsing-remitting multiple sclerosis (RRMS) who experience relapses on a first-line therapy (interferon, glatiramer acetate, dimethyl fumarate, or teriflunomide; collectively, "BRACETD") often switch to another therapy, including natalizumab or fingolimod. Here we compare the effectiveness of switching from a first-line therapy to natalizumab or fingolimod after =1 relapse. Methods: Data collected prospectively in the MSBase Registry, a global, longitudinal, observational registry, were extracted on February 6, 2018. Included patients were adults with RRMS with =1 relapse on BRACETD therapy in the year before switching to natalizumab or fingolimod. Included patients received natalizumab or fingolimod for =3 months after the switch. Results: Following 1:1 propensity score matching, 1000 natalizumab patients were matched to 1000 fingolimod patients. Mean (standard deviation) follow-up time was 3.02 (2.06) years after switching to natalizumab and 2.58 (1.64) years after switching to fingolimod. Natalizumab recipients had significantly lower annualized relapse rate (relative risk=0.66; 95% confidence interval [CI], 0.59¿0.74), lower risk of first relapse (hazard ratio [HR]=0.69; 95% CI, 0.60¿0.80), and higher confirmed disability improvement (HR=1.27; 95% CI, 1.03¿1.57) than fingolimod recipients. No difference in confirmed disability worsening was observed. Conclusions: Patients with RRMS switching from BRACETD demonstrated better outcomes with natalizumab than with fingolimod.

Background: Pregnancy in women with multiple sclerosis (wwMS) is associated with a reduction of long-term disability progression. The mechanism that drives this effect is unknown, but converging evidence suggests a role for epigenetic mechanisms altering immune and/or central nervous system function. In this study, we aimed to identify whole blood and immune cell-specific DNA methylation patterns associated with parity in relapse-onset MS. Results: We investigated the association between whole blood and immune cell-type-specific genome-wide methylation patterns and parity in 192 women with relapse-onset MS, matched for age and disease severity. The median time from last pregnancy to blood collection was 16.7¿years (range = 1.5¿44.4¿years). We identified 2965 differentially methylated positions in whole blood, 68.5% of which were hypermethylated in parous women; together with two differentially methylated regions on Chromosomes 17 and 19 which mapped to TMC8 and ZNF577, respectively. Our findings validated 22 DMPs and 366 differentially methylated genes from existing literature on epigenetic changes associated with parity in wwMS. Differentially methylated genes in whole blood were enriched in neuronal structure and growth-related pathways. Immune cell-type-specific analysis using cell-type proportion estimates from statistical deconvolution of whole blood revealed further differential methylation in T cells specifically (four in CD4+ and eight in CD8+ T cells). We further identified reduced methylation age acceleration in parous women, demonstrating slower biological aging compared to nulligravida women. Conclusion: Differential methylation at genes related to neural plasticity offers a potential molecular mechanism driving the long-term effect of pregnancy on MS outcomes. Our results point to a potential 'CNS signature' of methylation in peripheral immune cells, as previously described in relation to MS progression, induced by parity. As the first epigenome-wide association study of parity in wwMS reported, validation studies are needed to confirm our findings.

Background: Cladribine is a useful therapeutic option in RRMS with moderate to high disease activity. Its oral formulation and tolerability make it a useful alternative to infusion therapies. Cladribine is known to deplete CD19+ B lymphocytes, but its effect on immunoglobulin subsets is unclear. Objective: To identify whether cladribine therapy in pwMS reduces immunoglobulin subset levels as a surrogate marker of infection risk. Methods: A 'real-world' retrospective analysis of 341 pwMS presenting to a single tertiary centre between March 2017 and July 2021. Differences in immunoglobulin levels between cladribine, other disease-modifying therapies and no active treatment were assessed using a univariate ANOVA. Results: Three hundred and forty-one patients had immunoglobulin levels assessed, with 29 patients treated with cladribine. The mean IgG, IgM and IgA levels on cladribine therapy were 10.44 ± 0.40, 0.99 ± 0.09 and 2.04 ± 0.18 g/L respectively. These were not significantly different from patients not on active treatment. There was a statistically significant reduction in IgG and IgM levels for patients treated with ocrelizumab (9.37 ± 0.19 and 0.68 ± 0.04 g/L) and natalizumab (8.72 ± 0.53 and 0.69 ± 0.12 g/L) compared to patients not on treatment. Conclusion: Cladribine therapy for RRMS was not associated with immunoglobulin subset deficiencies. This is contrasted to ocrelizumab and natalizumab which demonstrate significant reductions in both IgG and IgM levels.

Background: Cognitive impairment is a common symptom of multiple sclerosis (MS). The effect of cognitive impairment in people with MS on employment, quality of life and mental health is known, however, few studies have investigated if cognitive deficits contribute to the economic burden of MS. Objective: To investigate if cognitive impairment correlates with the economic burden of MS. Methods: The client service receipt inventory was used to determine cost to the healthcare system, participant out of pocket cost, community cost and total societal cost. Quality of life was evaluated using the EuroQoL. Participants cognitive performance was assessed with the Audio Recorded Cognitive Screen and the symbol digit modalities test. Spearman's rank correlation coefficient (r) was used to gauge the strength of the correlation between domain scores and cost metrics. Results: Memory, speed of writing and the symbol digit modalities test were all negatively correlated with all aspects of cost of care (r = 0.24¿0.59, P < 0.5). This was found to be independent of other factors, such as EDSS or mental health indices. Conclusion: Cognitive deficits are independently correlated with the economic burden of MS and should be monitored as part of routine care.

Limited studies have been conducted to identify and validate multiple sclerosis (MS) genetic loci associated with disability progression. We aimed to identify MS genetic loci associated with worsening of disability over time, and to develop and validate ensemble genetic learning model(s) to identify people with MS (PwMS) at risk of future worsening. We examined associations of 208 previously established MS genetic loci with the risk of worsening of disability; we learned ensemble genetic decision rules and validated the predictions in an external dataset. We found 7 genetic loci (rs7731626: HR 0.92, P = 2.4 × 10¿5; rs12211604: HR 1.16, P = 3.2 × 10¿7; rs55858457: HR 0.93, P = 3.7 × 10¿7; rs10271373: HR 0.90, P = 1.1 × 10¿7; rs11256593: HR 1.13, P = 5.1 × 10¿57; rs12588969: HR = 1.10, P = 2.1 × 10¿10; rs1465697: HR 1.09, P = 1.7 × 10¿128) associated with risk worsening of disability; most of which were located near or tagged to 13 genomic regions enriched in peptide hormones and steroids biosynthesis pathways by positional and eQTL mapping. The derived ensembles produced a set of genetic decision rules that can be translated to provide additional prognostic values to existing clinical predictions, with the additional benefit of incorporating relevant genetic information into clinical decision making for PwMS. The present study extends our knowledge of MS progression genetics and provides the basis of future studies regarding the functional significance of the identified loci.

Background: Multiple Sclerosis (MS) is a complex neurodegenerative condition that is influenced by a combination of genetic and environmental factors. Included in these factors is the venous system, however, the extent to which it influences the etiology of MS has yet to be fully characterised. The aim of this review is to critically summarize the literature available concerning the venous system in MS, primarily concerning specific data on the venous pressure and blood flow in this system. Methods: A systematic review was conducted with the application of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The advanced search functions of both the Scopus and PubMed databases were used to conduct the literature search, resulting in 136 unique articles initially identified. Applying relevant exclusion criteria, 22 of the studies were chosen for this review. Results: The selected studies were analysed for venous pressure and blood flow related findings, with 14 studies contributing data on the internal jugular vein (IJV) flow rate, 5 on blood flows of the intracranial venous sinuses, 2 on blood flow pulsatility and 6 supplying information relevant to the venous pressure (3 studies contributed to multiple areas). The general findings of the review included that the IJV flow was not significantly different between MS patients and controls, however, there were variances between stenotic (S) and non-stenotic (NS) MS patients. Due to the limited data in the other two areas defined in this review, further research is required to establish if any variances in MS are present. Conclusion: It remains unclear if there are significant differences in many flow variables between MS patients and controls considered in this review. It would be advantageous if future work in this area focused on understanding the hemodynamics of this system, primarily concerning how the flow rate, venous pressure and vascular resistance are related, and any impact that these factors have on the etiology of MS.

Background: The variation in multiple sclerosis (MS) disease severity is incompletely explained by genetics, suggesting genetic and environmental interactions are involved. Moreover, the lack of prognostic biomarkers makes it difficult for clinicians to optimise care. DNA methylation is one epigenetic mechanism by which gene¿environment interactions can be assessed. Here, we aimed to identify DNA methylation patterns associated with mild and severe relapse-onset MS (RMS) and to test the utility of methylation as a predictive biomarker. Methods: We conducted an epigenome-wide association study between 235 females with mild (n = 119) or severe (n = 116) with RMS. Methylation was measured with the Illumina methylationEPIC array and analysed using logistic regression. To generate hypotheses about the functional consequence of differential methylation, we conducted gene set enrichment analysis using ToppGene. We compared the accuracy of three machine learning models in classifying disease severity: (1) clinical data available at baseline (age at onset and first symptoms) built using elastic net (EN) regression, (2) methylation data using EN regression and (3) a weighted methylation risk score of differentially methylated positions (DMPs) from the main analysis using logistic regression. We used a conservative 70:30 test:train split for classification modelling. A false discovery rate threshold of 0.05 was used to assess statistical significance. Results: Females with mild or severe RMS had 1472 DMPs in whole blood (839 hypermethylated, 633 hypomethylated in the severe group). Differential methylation was enriched in genes related to neuronal cellular compartments and processes, and B-cell receptor signalling. Whole-blood methylation levels at 1708 correlated CpG sites classified disease severity more accurately (machine learning model 2, AUC = 0.91) than clinical data (model 1, AUC = 0.74) or the wMRS (model 3, AUC = 0.77). Of the 1708 selected CpGs, 100 overlapped with DMPs from the main analysis at the gene level. These overlapping genes were enriched in neuron projection and dendrite extension, lending support to our finding that neuronal processes, rather than immune processes, are implicated in disease severity. Conclusion: RMS disease severity is associated with whole-blood methylation at genes related to neuronal structure and function. Moreover, correlated whole-blood methylation patterns can assign disease severity in females with RMS more accurately than clinical data available at diagnosis.

Background: Many people with multiple sclerosis (MS) modify their dietary intake post diagnosis, but there is little evidence that dietary modifications influence MS outcomes. Methods: People with a first clinical diagnosis of central nervous system demyelination were followed annually for 10 years. Depression, anxiety, and fatigue were assessed at the 5-and 10-year reviews using the Hospital Anxiety and Depression Scale and Fatigue Severity Scale, respectively. Dietary intake in the preceding 12 months was assessed at baseline, and 5-and 10-year reviews using a food frequency questionnaire. We used the Australian Recommended Food Score (ARFS) and the Diet Quality Tracker (DQT) to assess diet quality. Results: A higher diet quality in the previous 12 months using the ARFS score, but not the DQT, was associated with lower levels of depression (e.g., highest vs lowest quartile: ß=-1.35,95%CI=-2.44,-0.26,p=0.01), but neither score was associated with anxiety or fatigue. After assessing diet quality prospectively with outcomes five years later, we found that higher ARFS score, but not DQT score, was associated with lower levels of subsequent anxiety and depression (highest vs lowest quartile; Anxiety: ß=-1.61,95%CI=-2.76,-0.46,p=0.01, Depression: ß=-1.25,95%CI=-2.44,-0.07,p=0.04), but not fatigue. No associations were observed between diet quality and subsequent change in depression and anxiety over five years, although an association was observed between diet quality and change in fatigue (e.g., highest vs lowest DQT quartile: ß=-1.06,95%CI=-1.92,-0.21,p=0.02). When examining the cumulative effect of diet quality across the study period with our 10-year outcomes, only the cumulative DQT score was associated with depression but not anxiety or fatigue. Conclusion: We found significant inverse associations between diet quality and depression and anxiety, but the effect sizes were modest and there was a lack of consistency between the two diet quality measures (ARFS and DQT). A diet measure that correlates with diet quality might underlie our observed associations.

Background Multiple sclerosis (MS) is a chronic disabling disease that is associated with negative effects on health-related quality of life (HRQoL) due to reduced physical and psychosocial functioning. Cladribine tablets 10 mg (3.5 mg/kg cumulative dose over 2 years) have been approved for the treatment of adult patients with highly active relapsing multiple sclerosis (RMS). The ongoing CLARIFY-MS study (NCT03369665; EudraCT number: 2017-002632-17) aims to assess the effect of cladribine tablets 3.5 mg/kg on HRQoL of patients with highly active RMS. Objective To report on the design of the CLARIFY-MS study, baseline patient characteristics, and results of a pre-planned interim analysis focusing on treatment satisfaction, safety, and tolerability that includes all data reported till 6 months after start of treatment. Methods The CLARIFY-MS study is a 2-year, open-label, single-arm, prospective, multicenter, phase IV study. Eligible patients with highly active RMS were assigned to receive cladribine tablets 3.5 mg/kg over 2 years. Treatment satisfaction was assessed using the Treatment Satisfaction Questionnaire for Medication (TSQM, v1.4; scale range from 0 to 100, higher values indicating higher satisfaction). Safety assessments, including occurrence of treatment-emergent adverse events (TEAEs; any adverse event reported after drug administration), serious adverse events (SAEs), and lymphocyte counts, were summarized descriptively. Results A total of 482 patients from 85 sites in Europe were treated with cladribine tablets. Mean patient age was 37.4 years, 338 (70.1%) were women, median EDSS was 2.5, and 345 (71.6%) were prior users of disease-modifying therapy (DMT). During the first 6 months after the start of treatment, and before reaching the full dose of cladribine tablets, mean TSQM global satisfaction score for the overall population was 70.4 (standard deviation, ± 18.48). The side effects score was 91.9 (± 17.68), convenience scored 86.6 (± 13.57), and effectiveness was 65.8 (± 21.14). A total of 275 patients (57.1%) reported at least one TEAE and 9 patients (1.9%) had a SAE. The majority of observed lymphopenia cases were of grade 1 or 2; 33 (6.8%) of the total study cohort had grade 3 lymphopenia, and no grade 4 lymphopenia was reported. Conclusion Patients reported high treatment satisfaction (TSQM) with cladribine tablets in this pre-planned interim analysis at 6 months. Few serious, and no unexpected, adverse events were reported, and there were no instances of grade 4 lymphopenia over the first 6 months. These preliminary data indicate good tolerability and convenience of administration of cladribine tablets in patients with highly active RMS.

Background: Perceived cognitive impairment in MS is associated with adverse changes in employment capacity, sexual function, and aspects of daily living. Studies have shown relationships between perceived cognitive impairment and objective neuropsychological functioning and mood. Subjective cognitive performance in people with MS has not previously been compared to their objective performance on a computerised cognitive battery. Methods: All participants completed at least 6-monthly serial testing on the MSReactor computerised cognitive testing platform consisting of 3 reaction time tasks. These measure psychomotor processing speed (simple reaction time), attention (choice reaction time) and working memory (One back task). In addition, we collected subjective cognitive performance and patient reported outcomes of depression, anxiety and quality of life. The strength and direction of the relationships between subjective and objective performance on the cognitive tasks were examined using Kendalls rank coefficient at year 1 and year 2. We calculated partial correlation estimates where subjective performance was also associated with patient reported outcomes. Results: Subjective overall performance correlated weakly with the working memory task (Tau -0.10; (95% confidence interval (CI) -0.19, -0.01). Subjective performance also correlated weakly with depression but not anxiety or quality of life. Subjective reaction speed correlated weakly with psychomotor processing speed (Tau -0.10; CI -0.19, -0.01); and subjective accuracy correlated weakly with the attention (Tau 0.12; CI 0.03, 0.21) and working memory (Tau 0.15; CI 0.05, 0.24) tasks, respectively. Conclusion: Participants' perceived performance on the MSReactor tests correlated only weakly with objective changes. Depression was associated with subjective cognitive performance reports. These results suggest that a person with MS' perception of their cognitive performance is only weakly associated with cognitive changes detected using MSReactor.

Conventional genome-wide association studies (GWASs) of complex traits, such as Multiple Sclerosis (MS), are reliant on per-SNP p-values and are therefore heavily burdened by multiple testing correction. Thus, in order to detect more subtle alterations, ever increasing sample sizes are required, while ignoring potentially valuable information that is readily available in existing datasets. To overcome this, we used penalised regression incorporating elastic net with a stability selection method by iterative subsampling to detect the potential interaction of loci with MS risk. Through re-analysis of the ANZgene dataset (1617 cases and 1988 controls) and an IMSGC dataset as a replication cohort (1313 cases and 1458 controls), we identified new association signals for MS predisposition, including SNPs above and below conventional significance thresholds while targeting two natural killer receptor loci and the well-established HLA loci. For example, rs2844482 (98.1% iterations), otherwise ignored by conventional statistics (p = 0.673) in the same dataset, was independently strongly associated with MS in another GWAS that required more than 40 times the number of cases (~45 K). Further comparison of our hits to those present in a large-scale meta-analysis, confirmed that the majority of SNPs identified by the elastic net model reached conventional statistical GWAS thresholds (p < 5 × 10-8 ) in this much larger dataset. Moreover, we found that gene variants involved in oxidative stress, in addition to innate immunity, were associated with MS. Overall, this study highlights the benefit of using more advanced statistical methods to (re-)analyse subtle genetic variation among loci that have a biological basis for their contribution to disease risk.

Background: Increasingly, people with relapsing-remitting multiple sclerosis (RRMS) are switched to highly effective disease-modifying therapies (DMTs) such as ocrelizumab. Objective: To determine predictors of relapse and disability progression when switching from another DMT to ocrelizumab. Methods: Patients with RRMS who switched to ocrelizumab were identified from the MSBase Registry and grouped by prior disease-modifying therapy (pDMT; interferon-ß/glatiramer acetate, dimethyl fumarate, teriflunomide, fingolimod or natalizumab) and washout duration (<1 month, 1¿2 months or 2¿6 months). Survival analyses including multivariable Cox proportional hazard regression models were used to identify predictors of on-ocrelizumab relapse within 1 year, and 6-month confirmed disability progression (CDP). Results: After adjustment, relapse hazard when switching from fingolimod was greater than other pDMTs, but only in the first 3 months of ocrelizumab therapy (hazard ratio (HR) = 3.98, 95% confidence interval (CI) = 1.57¿11.11, p = 0.004). The adjusted hazard for CDP was significantly higher with longer washout (2¿6 m compared to <1 m: HR = 9.57, 95% CI = 1.92¿47.64, p = 0.006). Conclusion: The risk of disability worsening during switch to ocrelizumab is reduced by short treatment gaps. Patients who cease fingolimod are at heightened relapse risk in the first 3 months on ocrelizumab. Prospective evaluation of strategies such as washout reduction may help optimise this switch.

The cross-sectional area of the superior sagittal sinus (SSS) is larger in multiple sclerosis than normal and correlates with disease severity and progression. The sinus could be enlarged due to a decrease in the pressure difference between the lumen and the subarachnoid space, an increase in wall thickness or increased wall stiffness. The cross-sectional area of the SSS and straight sinus (ST) were measured in 103 patients with multiple sclerosis and compared to 50 controls. The cross-sectional area of the SSS and ST were increased by 20% and 13% compared to the controls (p = 0.005 and 0.02 respectively). The deflection of the wall of the sinus was estimated. The change in pressure gradient, wall thickness or elastic modulus between groups was calculated by modelling the walls as simply supported beams. To account for these findings, the modelling suggests either a 70% reduction in transmural venous pressure or a 2.4 fold increase in SSS wall stiffness plus an 11% increase in wall thickness or a combination of changes. An increase in sinus pressure, although the most straight forward possibility to account for the change in sinus size may exist in only a minority of patients. An increase in sinus wall stiffness and thickness may need further investigation.

Background: Neuromyelitis optica spectrum disorder (NMOSD) is associated with significant morbidity and mortality. Several therapies have been recommended for NMOSD and more recently clinical trials have demonstrated efficacy for three monoclonal antibody therapies. We present a retrospective observational study of treatment response in NMOSD. Methods: This was a retrospective, unblinded, observational study of treatment efficacy for rituximab and traditional immunosuppressive therapy in patients with AQP4 antibody positive NMOSD. Treatment efficacy was assessed using annualised relapse rates (ARR), time to first relapse and expanded disability status scale (EDSS) scores. Results: Complete relapse and treatment data were available for 43/68 (63%) of AQP4 antibody positive NMOSD cases covering 74 episodes of treatment. In a time to first relapse analysis rituximab showed a risk ratio of 0.23 (95% CI 0.08 ¿ 0.65) when compared with no treatment and there was a non-significant reduction in ARR of 35% compared to pre-treatment. ß-interferon (p = 0.0002) and cyclophosphamide (p = 0.0034) were associated with an increased ARR compared to pre-treatment. Rituximab (median 4.0 [range 0.0 ¿ 7.0]; p = 0.042) and traditional immunosuppressive therapy (median 4.0 [range 0.0 ¿ 8.0]; p = 0.016) were associated with a lower final EDSS compared to ß-interferon (median 6.0 [range 4.0 ¿ 7.5]). Conclusions: These data provide additional support for the use of rituximab in preference to traditional immunosuppressive agents and MS disease modifying therapies as first line treatment of NMOSD.

Background and Purpose: Fingolimod has been shown to be more effective in reducing relapse rate and disability than injectable therapies in clinical trials. An increase in N-acetylaspartate (NAA) as measured by MR spectroscopy is correlated with maintaining axonal metabolic functions. This study compared the neurometabolic and volumetric changes in relapsing-remitting multiple sclerosis (RRMS) patients on fingolimod or injectable therapies with healthy controls (HCs). Methods: Ninety-eight RRMS (52 on fingolimod, 46 on injectable therapies (27 on glatiramer acetate and 19 on interferon) were age and sex-matched to 51 HCs. RRMS patients underwent cognitive, fatigue, and mental health assessments, as well as an Expanded disability status scale (EDSS). MRI/S was acquired from the hippocampus, posterior cingulate gyrus (PCG), and prefrontal cortex (PFC). Volumetric and neurometabolic measures were compared across cohorts using a univariate general linear model and correlated with clinical severity and neuropsychological scores. Results: Clinical parameters, MR-volumetric, and neurometabolic profiles showed no differences between treatment groups (p¿>.05). Compared to HCs, both RRMS cohorts showed volume changes in white matter (-13%), gray matter (-16%), and cerebral spinal fluid (CSF) (+17-23%), as well as reduced NAA (-17%, p =.001, hippocampus), (-7%, p =.001, PCG), and (-9%, p =.001, PFC). MRI/S metrics in three regions were moderately correlated with cognition and fatigue functions. Conclusion: While both treatment arms showed overall similar volumetric and neurometabolic profiles, longitudinal studies are warranted to clarify neurometabolic changes and associations with treatment efficacy.

Background: We studied the prevalence of neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) in Indigenous populations of Australia and New Zealand with the aim of assessing potential differences. Methods: Cases of possible NMOSD and MS were collected from Australia and New Zealand. Clinical details, MR imaging, and serologic results were used to apply 2015 IPND diagnostic criteria for NMOSD and 2010 McDonald criteria for MS. Frequencies of self-determined ethnic ancestry were calculated for confirmed NMOSD, suspected NMOSD, and MS. Prevalence rates for NMOSD and MS according to ancestry were compared. Results: There were 75 cases with NMOSD, 89 with suspected NMSOD, and 101 with MS. NMOSD cases were more likely to have Asian, Indigenous, or Other ancestry compared to suspected NMOSD or MS. There were no differences in the clinical phenotype of NMOSD seen in Indigenous compared to European ancestry populations. Per 100,000, the prevalence estimate for NMOSD in people with Maori ancestry was 1.50 (95% CI 0.52¿2.49) which was similar to those with Asian ancestry 1.57 (95% CI 1.15¿1.98). NMOSD prevalence in Australian Aboriginal and Torres Strait Islander populations was 0.38 (95% CI 0.00¿0.80) per 100,000. Conclusion: The prevalence of NMOSD in the Maori population is similar to South East Asian countries, reflecting their historical origins. The prevalence of MS in this group is intermediate between those with South East Asian and European ancestry living in New Zealand. Both NMOSD and particularly MS appear to be uncommon in the Indigenous populations of Australia.

Background: Computer-aided diagnosis can facilitate the early detection and diagnosis of multiple sclerosis (MS) thus enabling earlier interventions and a reduction in long-term MS-related disability. Recent advancements in the field of artificial intelligence (AI) have led to the improvements in the classification, quantification and identification of diagnostic patterns in medical images for a range of diseases, in particular, for MS. Importantly, data generated using AI techniques are analyzed automatically, which compares favourably with labour-intensive and time-consuming manual methods. Objective: The aim of this review is to assist MS researchers to understand current and future developments in the AI-based diagnosis and prognosis of MS. Methods: We will investigate a variety of AI approaches and various classifiers and compare the current state-of-the-art techniques in relation to lesion segmentation/detection and prognosis of disease. After briefly describing the magnetic resonance imaging (MRI) techniques commonly used, we will describe AI techniques used for the detection of lesions and MS prognosis. Results: We then evaluate the clinical maturity of these AI techniques in relation to MS. Conclusion: Finally, future research challenges are identified in a bid to encourage further improvements of the methods.

Background: In a previous study, multiple sclerosis (MS) was found to be associated with an increase in intracranial arterial pulsation volume and a reduction in venous sinus compliance, affecting pulsation dampening. There was a suggestion that the reduction in compliance of the sagittal sinus in MS was caused by an increase in venous pressure, secondary to transverse sinus stenosis. Some differences were noted depending on the gender of the patients, however, the original study was relatively underpowered for further sub-classification. The purpose of the current study is to enroll a larger number of patients to allow sub-classification on gender and disease type to further evaluate the markers of possible venous pressure alteration. Methods: 103 patients with MS were prospectively recruited from an MS clinic and compared to 50 matched non-MS patients. Using 3DT1 post contrast images, the sagittal sinus cross-sectional area was measured. The narrowest portion of the transverse sinuses was located and the cross sectional areas and wetted circumferences were measured to calculate the minimum hydraulic and effective diameters. The jugular bulb heights were measured. Voxel wise brain morphometry was performed to evaluate atrophy. Statistical analysis was performed using non-parametric methods and was assessed using a=0.05. Results: Compared to controls, the MS patients' sagittal sinuses were 23% larger in cross-section (p<0.0001), the transverse sinuses had an average effective stenosis of 39% by area (p<0.0001) and there was a 62% increase in jugular bulb height (p=0.0001). The MS patients showed a reduction in normalized grey matter volume of 2.8% (p= 0.0001). Males with MS showed worse outcomes compared to females, with an increased EDSS and grey matter loss and had a 23% larger sagittal sinus area (p=0.02), 22% higher jugular bulb height (p=0.03) but a lower transverse sinus stenosis percentage (19% vs 48%, p<0.0001). Progressive forms of MS also had worse outcomes and had a 19% larger sagittal sinus area (p=0.04) compared to relapsing remitting MS. Conclusion: In this larger cohort, worse outcomes in both males and progressive forms of MS were associated with larger sagittal sinuses. The possible cause of the altered sinus pressure in females was narrower transverse sinuses. In males, higher jugular bulbs may be associated with increased venous sinus pressure.

Background and Objectives: Research in Multiple Sclerosis (MS) has recently focused on extracting knowledge from real-world clinical data sources. This type of data is more abundant than data produced during clinical trials and potentially more informative about real-world clinical practice. However, this comes at the cost of less curated and controlled data sets. In this work we aim to predict disability progression by optimally extracting information from longitudinal patient data in the real-world setting, with a special focus on the sporadic sampling problem. Methods: We use machine learning methods suited for patient trajectories modeling, such as recurrent neural networks and tensor factorization. A subset of 6682 patients from the MSBase registry is used. Results: We can predict disability progression of patients in a two-year horizon with an ROC-AUC of 0.85, which represents a 32% decrease in the ranking pair error (1-AUC) compared to reference methods using static clinical features. Conclusions: Compared to the models available in the literature, this work uses the most complete patient history for MS disease progression prediction and represents a step forward towards AI-assisted precision medicine in MS.

Purpose: Fatigue is a common symptom in patients with multiple sclerosis (MS) with unknown pathophysiology. Dysfunction of the GABAergic/glutamatergic pathways involving inhibitory and excitatory neurotransmitters such as ¿-aminobutyric acid (GABA) and glutamine + glutamate pool (Glx) have been implicated in several neurological disorders. This study is aimed to evaluate the potential role of GABA and Glx in the origin of central fatigue in relapse remitting MS (RRMS) patients. Methods: 24 RRMS patients and 16 age- and sex-matched healthy controls (HC) were scanned using Mescher-Garwood point resolved spectroscopy (MEGA-PRESS) with a 3 T system to quantify GABA+ and Glx from prefrontal (PFC) and sensorimotor (SMC) cortices. Self-reported fatigue status was measured on all participants using the Modified Fatigue Impact Scale (MFIS). Results: RRMS patients had higher fatigue scores relative to HC (p = 0.05). Compared to HC, Glx levels in RRMS patients were significantly decreased in SMC (p = 0.04). Significant correlations were found between fatigue scores and GABA+ (r = -0.531, p = 0.008) and Glx (r = 0.511, p = 0.018) in PFC. Physical fatigue was negatively correlated with GABA+ in SMC and PFC (r = -0.428 and -0.472 respectively, p = 0.04) and positively with PFC Glx (r = 0.480, p = 0.028). Conclusion: The associations between fatigue and GABA + and Glx suggest that there might be dysregulation of GABAergic/glutamatergic neurotransmission in the pathophysiological mechanism of central fatigue in MS.

Background: Dietary patterns and their association with subsequent clinical course have not been well studied in early multiple sclerosis (MS). Objectives: To describe dietary patterns in people in 5 years following first clinical demyelination and assess associations with MS conversion and relapse. Methods: This study included baseline food frequency questionnaire dietary intake (entry to the Ausimmune Study) and 5-year follow-up; iterated principal factor analysis was applied. MS conversion and relapse risks were assessed by Cox proportional hazards models, adjusted for age, sex, study site, education, body mass index (BMI), smoking and omega-3 supplement use. Results: In cases with a first clinical diagnosis of central nervous system (CNS) demyelination, we identified three major dietary patterns, 'Prudent', 'High-Vegetable' and 'Mixed', explaining 43%, 37% and 24% of diet variance in dietary intake, respectively. Fruits, vegetables, fish, wholegrains and nuts loaded highly on the Prudent pattern, starchy vegetables and legumes on the High-Vegetable pattern, and meats and alcohol on the Mixed pattern. Diet factor scores were not associated with MS conversion risk. Those with baseline Prudent scores above the median had significantly lower relapse risk (adjusted hazard ratio = 0.54, 95% confidence interval (CI) 0.37, 0.81) with some evidence of a plateau effect. Conclusion: Prudent diet factor score above the median was prospectively associated with lower relapse risk in the 5 years following the first clinical demyelinating event.

Background: A delayed onset of treatment effect, termed therapeutic lag, may influence the assessment of treatment response in some patient subgroups. Objectives: The objective of this study is to explore the associations of patient and disease characteristics with therapeutic lag on relapses and disability accumulation. Methods: Data from MSBase, a multinational multiple sclerosis (MS) registry, and OFSEP, the French MS registry, were used. Patients diagnosed with MS, minimum 1 year of exposure to MS treatment and 3 years of pre-treatment follow-up, were included in the analysis. Studied outcomes were incidence of relapses and disability accumulation. Therapeutic lag was calculated using an objective, validated method in subgroups stratified by patient and disease characteristics. Therapeutic lag under specific circumstances was then estimated in subgroups defined by combinations of clinical and demographic determinants. Results: High baseline disability scores, annualised relapse rate (ARR) ¿ 1 and male sex were associated with longer therapeutic lag on disability progression in sufficiently populated groups: females with expanded disability status scale (EDSS) < 6 and ARR < 1 had mean lag of 26.6 weeks (95% CI = 18.2¿34.9), males with EDSS < 6 and ARR < 1 31.0 weeks (95% CI = 25.3¿36.8), females with EDSS < 6 and ARR ¿ 1 44.8 weeks (95% CI = 24.5¿65.1), and females with EDSS ¿ 6 and ARR < 1 54.3 weeks (95% CI = 47.2¿61.5). Conclusions: Pre-treatment EDSS and ARR are the most important determinants of therapeutic lag.

Background: Cerebellar and brainstem symptoms are common in early stages of multiple sclerosis (MS) yet their prognostic values remain unclear. Objective: The aim of this study was to investigate long-term disability outcomes in patients with early cerebellar and brainstem symptoms. Methods: This study used data from MSBase registry. Patients with early cerebellar/brainstem presentations were identified as those with cerebellar/brainstem relapse(s) or functional system score ¿ 2 in the initial 2 years. Early pyramidal presentation was chosen as a comparator. Andersen-Gill models were used to compare cumulative hazards of (1) disability progression events and (2) relapses between patients with and without early cerebellar/brainstem symptoms. Mixed effect models were used to estimate the associations between early cerebellar/brainstem presentations and expanded disability status scale (EDSS) scores. Results: The study cohort consisted of 10,513 eligible patients, including 2723 and 3915 patients with early cerebellar and brainstem symptoms, respectively. Early cerebellar presentation was associated with greater hazard of progression events (HR = 1.37, p < 0.001) and EDSS (ß = 0.16, p < 0.001). Patients with early brainstem symptoms had lower hazard of progression events (HR = 0.89, p = 0.01) and EDSS (ß = -0.06, p < 0.001). Neither presentation was associated with changes in relapse risk. Conclusion: Early cerebellar presentation is associated with unfavourable outcomes, while early brainstem presentation is associated with favourable prognosis. These presentations may be used as MS prognostic markers and guide therapeutic approach.

Objective: To compare the clinical effectiveness of high- and low-efficacy treatments in patients with recently active and inactive secondary progressive multiple sclerosis (SPMS) after accounting for therapeutic lag. Methods: Patients treated with high-efficacy (natalizumab, alemtuzumab, mitoxantrone, ocrelizumab, rituximab, cladribine, fingolimod) or low-efficacy (interferon beta, glatiramer acetate, teriflunomide) therapies after SPMS onset were selected from MSBase and Observatoire Français de la Sclérose en Plaques (OFSEP), 2 large observational cohorts. Therapeutic lag was estimated for each patient from their demographic and clinical characteristics. Propensity score was used to match patients treated with high- and low-efficacy therapies. Outcomes after the period of therapeutic lag was disregarded were compared in paired, pairwise-censored analyses. Results: One thousand patients were included in the primary analysis. Patients with active SPMS treated with high-efficacy therapy experienced less frequent relapses than those on low-efficacy therapy (hazard ratio [HR] 0.7, p = 0.006). In patients with inactive SPMS, there was no evidence for a difference in relapse frequency between groups (HR 0.8, p = 0.39). No evidence for a difference in the risk of disability progression was observed. Conclusion: In treated patients with SPMS, high-efficacy therapy is superior to low-efficacy therapy in reducing relapses in patients with active but not those with inactive SPMS. However, more potent therapies do not offer an advantage in reducing disability progression in this patient group.

Background/objective: Observational clinical data from cladribine-treated patients with relapsing forms of multiple sclerosis (MS) were recorded in the Australian MS registry powered by the MSBase registry platform (5-year follow-up) and analysed to complement information from the pivotal cladribine clinical trials in MS. Methods: A cohort of 90 cladribine-treated patients with follow-up data reported by treating physicians and recorded in the Australian MSBase registry (database lock February 2016) were examined. Clinical data included Expanded Disability Status Scale (EDSS) scores, relapses and other disease-modifying drugs (DMDs) administered before and after cladribine treatment. Results: Mean age on starting cladribine was 47 years; mean age at MS onset was 34 years, and median baseline EDSS score was 5.25. Disability trajectories in patients with sufficient follow-up suggested an overall increasing trend prior to cladribine treatment which was reduced during the 2-year post-treatment. Approximately 80% of patients were EDSS progression-free, 65% remained relapse-free after 2 years and median time to next DMD was 1.7 years. Conclusion: These observational data suggest a disease-modifying effect in this cohort of relapsing MS patients characterised by older and more disabled patients. Since these data represent a single-arm cohort, clinical trials and larger comparative post-marketing studies are needed to validate and extend these findings.

Objective To investigate pregnancy-related disease activity in a contemporary multiple sclerosis (MS) cohort. Methods Using data from the MSBase Registry, we included pregnancies conceived after December 31, 2010, in women with relapsing-remitting MS or clinically isolated syndrome. Predictors of intrapartum relapse and postpartum relapse and disability progression were determined by clustered logistic regression or Cox regression analyses. Results We included 1,998 pregnancies from 1,619 women with MS. Preconception annualized relapse rate (ARR) was 0.29 (95% confidence interval 0.27-0.32), fell to 0.19 (0.14-0.24) in the third trimester, and increased to 0.59 (0.51-0.67) in early postpartum. Among women who used fingolimod or natalizumab, ARR before pregnancy was 0.37 (0.28-0.49) and 0.29 (0.22-0.37), respectively, and increased during pregnancy. Intrapartum ARR decreased with preconception dimethyl fumarate use. ARR spiked after delivery across all DMT groups. Natalizumab continuation into pregnancy reduced the odds of relapse during pregnancy (odds ratio 0.76 per month [0.60-0.95], p = 0.017). DMT reinitiation with natalizumab protected against postpartum relapse (hazard ratio [HR] 0.11 [0.04-0.32], p < 0.0001). Breastfeeding women were less likely to relapse (HR 0.61 [0.41-0.91], p = 0.016). We found that 5.6% of pregnancies were followed by confirmed disability progression, predicted by higher relapse activity in pregnancy and postpartum. Conclusion Intrapartum and postpartum relapse probabilities increased among women with MS after natalizumab or fingolimod cessation. In women considered to be at high relapse risk, use of natalizumab before pregnancy and continued up to 34 weeks gestation with early reinitiation after delivery is an effective option to minimize relapse risks. Strategies of disease-modifying therapy use have to be balanced against potential fetal/neonatal complications.

Background: Natalizumab and fingolimod were the first preparations recommended for disease breakthrough in priorly treated relapsing-remitting multiple sclerosis. Of three published head-to-head studies two showed that natalizumab is the more effective to prevent relapses and EDSS worsening. Methods: By re-analyzing original published results from MSBase, France, and Denmark using uniform methodologies, we aimed at identifying the effects of differences in methodology, in the MS-populations, and at re-evaluating the differences in effectiveness between the two drugs. We gained access to copies of the individual amended databases and pooled all data. We used uniform inclusion/exclusion criteria and statistical methods with Inverse Probability Treatment Weighting. Results: The pooled analyses comprised 968 natalizumab- and 1479 fingolimod treated patients. The on-treatment natalizumab/fingolimod relapse rate ratio was 0.77 (p=0.004). The hazard ratio (HR) for a first relapse was 0.82 (p=0.030), and the HR for sustained EDSS improvement was 1.4 (p=0.009). There were modest differences between each of the original published studies and the replication study, but the conclusions of the three original studies remained unchanged: in two of them natalizumab was more effective, but in the third there was no difference between natalizumab and fingolimod. Conclusion: The results were largely invariant to the epidemiological and statistical methods but differed between the MS populations. Generally, the advantage of natalizumab was confirmed.

Our inability to reliably predict disease outcomes in multiple sclerosis remains an issue for clinicians and clinical trialists. This study aims to create, from available clinical, genetic and environmental factors; a clinical-environmental-genotypic prognostic index to predict the probability of new relapses and disability worsening. The analyses cohort included prospectively assessed multiple sclerosis cases (N=253) with 2858 repeated observations measured over 10 years. N=219 had been diagnosed as relapsingonset, while N=34 remained as clinically isolated syndrome by the 10th-year review. Genotype data were available for 199 genetic variants associated with multiple sclerosis risk. Penalized Cox regression models were used to select potential genetic variants and predict risk for relapses and/or worsening of disability. Multivariable Cox regression models with backward elimination were then used to construct clinical-environmental, genetic and clinical-environmental-genotypic prognostic index, respectively. Robust timecourse predictions were obtained by Landmarking. To validate our models, Weibull calibration models were used, and the Chisquare statistics, Harrell's C-index and pseudo-R2 were used to compare models. The predictive performance at diagnosis was evaluated using the Kullback-Leibler and Brier (dynamic) prediction error (reduction) curves. The combined index (clinical-environmental- genotypic) predicted a quadratic time-dynamic disease course in terms of worsening (HR=2.74, CI: 2.00-3.76; pseudo- R2=0.64; C-index=0.76), relapses (HR=2.16, CI: 1.74-2.68; pseudo-R2=0.91; C-index=0.85), or both (HR=3.32, CI: 1.88- 5.86; pseudo-R2 = 0.72; C-index=0.77). The Kullback-Leibler and Brier curves suggested that for short-term prognosis (_5 years from diagnosis), the clinical-environmental components of disease were more relevant, whereas the genetic components reduced the prediction errors only in the long-term (_5 years from diagnosis). The combined components performed slightly better than the individual ones, although their prognostic sensitivities were largely modulated by the clinical-environmental components. We have created a clinical-environmental-genotypic prognostic index using relevant clinical, environmental, and genetic predictors, and obtained robust dynamic predictions for the probability of developing new relapses and worsening of symptoms in multiple sclerosis. Our prognostic index provides reliable information that is relevant for long-term prognostication and may be used as a selection criterion and risk stratification tool for clinical trials. Further work to investigate component interactions is required and to validate the index in independent data sets.

Importance: Multiple sclerosis (MS) is usually diagnosed in women during their childbearing years. Currently, no consensus exists on whether pregnancy can delay the first episode of demyelination or clinically isolated syndrome (CIS). Objective: To investigate the association of pregnancy with time to CIS onset. Design, Setting, and Participants: This multicenter cohort study collected reproductive history (duration of each pregnancy, date of delivery, length of breastfeeding) on all participants between September 1, 2016, and June 25, 2019. Adult women being treated at the MS outpatient clinics of 4 tertiary hospitals in 2 countries (Charles University and General University Hospital in Prague, Czech Republic; Royal Melbourne Hospital in Melbourne, Australia; Alfred Hospital in Melbourne, Australia; and John Hunter Hospital in Newcastle, Australia) were recruited to participate in the study. Preexisting data (date of CIS onset, date of birth, sex, date of clinical onset, and Expanded Disability Status Scale result) were collected from MSBase, an international registry of long-term prospectively collected data on patients with MS. Data analyses were performed from June 1, 2019, to February 3, 2020. Exposures: Gravida (defined as any pregnancy, including pregnancy that ended in miscarriage and induced abortion) and parity (defined as childbirth after gestational age of more than 20 weeks, including livebirth and stillbirth) before CIS onset. Main Outcomes and Measures: Time to CIS onset. The following were assessed: (1) whether women with previous pregnancies and childbirths had a delayed onset of CIS compared with those who had never been pregnant and those who had never given birth, and (2) whether a dose response existed, whereby a higher number of gravidity and parity was associated with a later onset of CIS. Results: Of the 2557 women included in the study, the mean (SD) age at CIS onset was 31.5 (9.7) years. Of these women, before CIS onset, 1188 (46%) had at least 1 pregnancy and 1100 (43%) had at least 1 childbirth. The mean (SD) age at first pregnancy was 23.3 (4.5) years and at first childbirth was 23.8 (4.5) years. Women with previous pregnancies and childbirths had a later onset of CIS compared with those who had never been pregnant (HR, 0.68; 95% CI, 0.62-0.75; P <.001), with a median delay of 3.3 (95% CI, 2.5-4.1) years. Women who had given birth also had a later CIS onset compared with women who had never given birth (HR 0.68; 95% CI, 0.61-0.75; P <.001), with a similar median delay of 3.4 (95% CI, 1.6-5.2) years. A higher gravidity and parity number was not associated with delay in CIS onset. Conclusions and Relevance: This study suggests an association between previous pregnancies and childbirths and timing of CIS onset, but having more pregnancies or childbirths did not appear to be associated with a later CIS onset. Further studies are needed to help explain the mechanisms behind the associations between pregnancy and onset of multiple sclerosis 2020 American Medical Association. All rights reserved.

Background: Multiple sclerosis (MS) is a disease in which biomarker identification is fundamental to predict response to treatments and to deliver the optimal drug to patients. We previously found an association between rs7298096, a polymorphism upstream to the NINJ2 gene, and the 4-year response to interferon-ß (IFNß) treatment in MS patients. Objectives: To analyse the association between rs7298096 and time to first relapse (TTFR) during IFNß therapy in MS patients and to better investigate its functional role. Methods: Survival analysis was applied in three MS cohorts from different countries (n = 1004). We also studied the role of the polymorphism on gene expression using GTEx portal and a luciferase assay. We interrogated GEO datasets to explore the relationship between NINJ2 expression, IFNß and TTFR. Results: Rs7298096AA patients show a shorter TTFR than rs7298096G-carriers (Pmeta-analysis = 3 × 10-4, hazard ratio = 1.41). Moreover, rs7298096AA is associated with a higher NINJ2 expression in blood (p = 7.0 × 10-6), which was confirmed in vitro (p = 0.009). Finally, NINJ2 expression is downregulated by IFNß treatment and related to TTFR. Conclusions: Rs7298096 could influence MS disease activity during IFNß treatment by modulating NINJ2 expression in blood. The gene encodes for an adhesion molecule involved in inflammation and endothelial cells activation, supporting its role in MS.

Neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) show overlap in their clinical features. We performed an analysis of relapses with the aim of determining differences between the two conditions. Cases of NMOSD and age- and sex-matched MS controls were collected from across Australia and New Zealand. Demographic and clinical information, including relapse histories, were recorded using a standard questionnaire. There were 75 cases of NMOSD and 101 MS controls. There were 328 relapses in the NMOSD cases and 375 in MS controls. Spinal cord and optic neuritis attacks were the most common relapses in both NMOSD and MS. Optic neuritis (p < 0.001) and area postrema relapses (P = 0.002) were more common in NMOSD and other brainstem attacks were more common in MS (p < 0.001). Prior to age 30 years, attacks of optic neuritis were more common in NMOSD than transverse myelitis. After 30 this pattern was reversed. Relapses in NMOSD were more likely to be treated with acute immunotherapies and were less likely to recover completely. Analysis by month of relapse in NMOSD showed a trend toward reduced risk of relapse in February to April compared to a peak in November to January (P = 0.065). Optic neuritis and transverse myelitis are the most common types of relapse in NMOSD and MS. Optic neuritis tends to occur more frequently in NMOSD prior to the age of 30, with transverse myelitis being more common thereafter. Relapses in NMOSD were more severe. A seasonal bias for relapses in spring-summer may exist in NMOSD.

Neuromyelitis optica spectrum disorders (NMOSD) are an inflammation of the central nervous system associated with autoantibodies to aquaporin-4. We have undertaken a clinic-based survey of NMOSD in the Australia and New Zealand populations with the aim of characterising the clinical features and establishing the value of recently revised diagnostic criteria. Cases of possible NMOSD and age and sex-matched controls with multiple sclerosis (MS) were referred from centres across Australia and New Zealand. Cases were classified as NMOSD if they met the 2015 IPND criteria and remained as suspected NMOSD if they did not. Clinical and paraclinical data were compared across the three groups. NMOSD was confirmed in 75 cases and 89 had suspected NMOSD. There were 101 controls with MS. Age at onset, relapse rates and EDSS scores were significantly higher in NMOSD than in MS. Lesions and symptoms referable to the optic nerve were more common in NMOSD whereas brainstem, cerebellar and cerebral lesions were more common in MS. Longitudinally extensive spinal cord lesions were seen in 48/71 (68%) of cases with NMOSD. Elevations of CSF, white cell count and protein were more common in NMOSD. We have confirmed a clinical pattern of NMOSD that has been seen in several geographical regions. We have demonstrated the clinical utility of the current diagnostic criteria. Distinct patterns of disease are evident in NMOSD and MS, but there remains a large number of patients with NMOSD-like features who do not meet the current diagnostic criteria for NMOSD and remain a diagnostic challenge.

AIMS: To systematically review the diagnostic value of the central vein sign (CVS) in multiple sclerosis (MS) and to meta-analyse the proportion of positive lesions for CVS needed to distinguish MS from non-MS mimics. MATERIALS AND METHODS: A literature review was performed and a proportion meta-analysis was performed to examine the proportion of the CVS in MS lesions. Studies reporting a threshold of the CVS containing lesions with 100% diagnostic accuracy were included in the meta-analysis. This was compared to MS mimics in order to establish the discriminative value of the CVS. RESULTS: The CVS was found to be viable at lower field strengths (3 T and 1.5 T) and automated analysis is currently less accurate than manual counting. Five studies were included for the proportional meta-analysis. From the analysis, a proportion of 45% of lesions having the CVS was suggested given that the findings that the weighted proportion was 46.4% (95% confidence interval [CI]: of 40.3%¿52.6%) with low heterogeneity (I2 = 0.0%; p=0.5). CONCLUSION: Although the CVS is a clinically relevant and viable sign, further work is needed to integrate this into the existing diagnostic criteria. As manual determination is a time-consuming process, the development of automated methods will be beneficial. With improvements in computational imaging techniques, the CVS will have an important role in the diagnosis and differentiation of MS.

Background: Monitoring and screening of cognitive function in the ambulatory setting requires simple, brief cognitive tests that are reproducible. MSReactor (MSR) is a web-based platform that screens psychomotor (processing) speed, attention and working memory using a game-like interface. The Processing Speed Test (PST) is a validated computerized version of the Symbol Digit Modalities test (SDMT) and component of the Multiple Sclerosis Performance Test (MSPT). Objective: To determine the baseline and 6-month predictive correlations between the MSReactor computerised cognitive battery and the PST. Methods: Prospectively enrolled relapsing-remitting multiple sclerosis (RRMS) patients completed the MSR and the PST during 6-monthly clinic visits. Pearson's product-moment coefficients with partial correlation adjustment were calculated between the PST and MSR reaction times for Simple reaction test (SRT), Choice reaction test (CRT) and One- back test (OBK). Results: 379 RRMS patients from six tertiary MS centres in Australia were enrolled. The mean age was 40.4 years (SD 10.3) and median Expanded Disability Status Scale (EDSS) score was 1.5 (IQR 1.0 ¿ 2.0). Most (66%) were on high efficacy disease-modifying treatment. Baseline PST scores correlated with the MSR reaction times: SRT (R=-0.40), CRT (R= -0.44) and OBK (R= -0.47), p <0.05. There was a moderate correlation between the first visit MSR and 6-month PST test for SRT (R= -0.37, p<0.001), CRT (R=-0.44, p < 0.001) and OBK (R= -0.43, p < 0.001) speed. Conclusions: MSR-measured psychomotor speed, attention and working memory at baseline moderately correlates with baseline and 6-month PST; suggesting overlapping cognitive processes are being tested. Six-month test-retest reliability was acceptable for both tests.

Background: Fatigue is a common and debilitating symptom in multiple sclerosis (MS). Over the past decade, a growing body of research has focussed on the pathophysiological mechanisms underlying central (cognitive and physical) fatigue in MS. The precise mechanisms causing fatigue in MS patients are complex and poorly understood, and may differ between patients. Advanced quantitative magnetic resonance imaging (MRI) techniques allow for objective assessment of disease pathology and have been used to characterise the pathophysiology of central fatigue in MS. Objective: To systematically review the existing literature of MRI-based studies assessing the pathophysiological mechanisms of MS-related central fatigue. Methods: A systematic literature search of four major databases (PubMed, Medline, Embase, Scopus and Google Scholar) was conducted to identify MRI-based studies of MS-related fatigue published in the past 20 years. Studies using the following MRI-based methods were included: structural (lesion load/atrophy), T1 relaxation time/magnetisation transfer ratio (MTR), diffusion tensor imaging (DTI), functional MRI (fMRI) and magnetic resonance spectroscopy (MRS). Results: A total of 92 studies were identified as meeting the search criteria and included for review. Structurally, regional gray/white matter atrophy, cortical thinning, decreased T1 relaxation times and reduced fractional anisotropy were associated with central fatigue in MS. Functionally, hyperactivity and reduced functional connectivity in several regional areas of frontal, parietal, occipital, temporal and cerebellum were suggested as causes of central fatigue. Biochemically, a reduction in N-acetyl aspartate/creatine and increased (glutamine+glutamate)/creatine ratios were correlated with fatigue severity in MS. Conclusion: Several advanced quantitative MRI methods have been employed in the study of central fatigue in MS. Central fatigue in MS is associated with macro/microstructural and functional changes within specific brain regions (frontal, parietal, temporal and deep gray matter) and specific pathways/networks (cortico-cortical and cortico-subcortical). Alternations in the cortico-striatal-thalamocortical (CSTC) loop are correlated with the development of fatigue in MS patients.

Background: Exposure to disease-modifying therapy (DMT) during early pregnancy in women with relapsing-remitting MS (RRMS) may be increasing. Objective: To retrospectively determine incidence of pregnancy, DMT exposure and pregnancy outcomes in women with RRMS. Methods: We identified all women with RRMS aged 15¿45 years in the MSBase Registry between 2005¿2016. Annualised pregnancy incidence rates were calculated using Poisson regression models. DMT exposures and pregnancy outcomes were assessed. Results: Of 9,098 women meeting inclusion criteria, 1,178 (13%) women recorded 1,521 pregnancies. The annualised incidence rate of pregnancy was 0.042 (95% CI 0.040, 0.045). A total of 635 (42%) reported pregnancies were conceived on DMT, increasing from 27% in 2006 to 62% in 2016. The median duration of DMT exposure during pregnancy was 30 days (IQR: 9, 50). There were a higher number of induced abortions on FDA pregnancy class C/D drugs compared with pregnancy class B and no DMT (p = 0.010); but no differences in spontaneous abortions, term or preterm births. Conclusions: We report low pregnancy incidence rates, with increasing number of pregnancies conceived on DMT over the past 12-years. The median duration of DMT exposure in pregnancy was relatively short at one month.

Importance: Within 2 decades of onset, 80% of untreated patients with relapsing-remitting multiple sclerosis (MS) convert to a phase of irreversible disability accrual termed secondary progressive MS. The association between disease-modifying treatments (DMTs), and this conversion has rarely been studied and never using a validated definition. Objective: To determine the association between the use, the type of, and the timing of DMTs with the risk of conversion to secondary progressive MS diagnosed with a validated definition. Design, Setting, and Participants: Cohort study with prospective data from 68 neurology centers in 21 countries examining patients with relapsing-remitting MS commencing DMTs (or clinical monitoring) between 1988-2012 with minimum 4 years' follow-up. Exposures: The use, type, and timing of the following DMTs: interferon beta, glatiramer acetate, fingolimod, natalizumab, or alemtuzumab. After propensity-score matching, 1555 patients were included (last follow-up, February 14, 2017). Main Outcome and Measure: Conversion to objectively defined secondary progressive MS. Results: Of the 1555 patients, 1123 were female (mean baseline age, 35 years [SD, 10]). Patients initially treated with glatiramer acetate or interferon beta had a lower hazard of conversion to secondary progressive MS than matched untreated patients (HR, 0.71; 95% CI, 0.61-0.81; P <.001; 5-year absolute risk, 12% [49 of 407] vs 27% [58 of 213]; median follow-up, 7.6 years [IQR, 5.8-9.6]), as did fingolimod (HR, 0.37; 95% CI, 0.22-0.62; P <.001; 5-year absolute risk, 7% [6 of 85] vs 32% [56 of 174]; median follow-up, 4.5 years [IQR, 4.3-5.1]); natalizumab (HR, 0.61; 95% CI, 0.43-0.86; P =.005; 5-year absolute risk, 19% [16 of 82] vs 38% [62 of 164]; median follow-up, 4.9 years [IQR, 4.4-5.8]); and alemtuzumab (HR, 0.52; 95% CI, 0.32-0.85; P =.009; 5-year absolute risk, 10% [4 of 44] vs 25% [23 of 92]; median follow-up, 7.4 years [IQR, 6.0-8.6]). Initial treatment with fingolimod, alemtuzumab, or natalizumab was associated with a lower risk of conversion than initial treatment with glatiramer acetate or interferon beta (HR, 0.66; 95% CI, 0.44-0.99; P =.046); 5-year absolute risk, 7% [16 of 235] vs 12% [46 of 380]; median follow-up, 5.8 years [IQR, 4.7-8.0]). The probability of conversion was lower when glatiramer acetate or interferon beta was started within 5 years of disease onset vs later (HR, 0.77; 95% CI, 0.61-0.98; P =.03; 5-year absolute risk, 3% [4 of 120] vs 6% [2 of 38]; median follow-up, 13.4 years [IQR, 11-18.1]). When glatiramer acetate or interferon beta were escalated to fingolimod, alemtuzumab, or natalizumab within 5 years vs later, the HR was 0.76 (95% CI, 0.66-0.88; P <.001; 5-year absolute risk, 8% [25 of 307] vs 14% [46 of 331], median follow-up, 5.3 years [IQR], 4.6-6.1). Conclusions and Relevance: Among patients with relapsing-remitting MS, initial treatment with fingolimod, alemtuzumab, or natalizumab was associated with a lower risk of conversion to secondary progressive MS vs initial treatment with glatiramer acetate or interferon beta. These findings, considered along with these therapies' risks, may help inform decisions about DMT selection.