Near Infrared Light for the Diagnosis of Brain Disease

With age, it is extremely common for the blood vessels in the brain to stiffen. As this stiffening develops, pressure increases and this damages the networks of small blood vessels across the brain. This damage can lead to brain diseases such as stroke and vascular dementia.

Stroke affects one in six people world-wide and impacts one Australian every ten minutes. Dementia is the second leading cause of death of Australians. If we can improve the diagnostic processes for these diseases and intervene earlier to treat them, this would lead to better outcomes and longer lives for millions of people.

Currently, the most common procedure for diagnosing changes in blood pressure using a pressure cuff on the upper arm. Blood pressure itself is a crude measure of vascular health and only conveys useful information after a long series of earlier changes in arterial structure have occurred. The stiffening of arteries is a much better early indicator of vessel damage.

A team of researchers at the University of Newcastle is developing a new non-invasive method for measuring artery stiffness in the brain. This new method involves projecting near-infrared light (NIR) through the skull. NIR can pass through the skull, the brain tissue and blood vessels, before it is reflected back and measured. Because oxygenated blood reflects the light differently, the pattern of light reflected back can show how blood is flowing through the vessels of the brain. By examining the patterns of blood flow, we can determine how healthy the blood vessels are and detect signs of stiffening. Pilot data shows that this new procedure offers significantly more accurate results than traditional diagnostic practices.

In the long term, this work will contribute to the development of a sensitive, practical and affordable measure for the early detection of blood vessel stiffening in the brain, helping us to provide early intervention treatments for diseases such as stroke and vascular dementia.