2015 Pilot Project Grant in Honour of Delphine Martin

Biomarkers of Cognitive Impairment in Parkinson’s Disease

Dr. Bradley MacIntosh | University of Toronto, Sunnybrook Research Institute

$45,000 (1 year) Porridge for Parkinson’s Pilot Project in Honour of Delphine Martin

Project: Biomarkers of Cognitive Impairment in PD Using Orthostatic Hypotension, White Matter & Grey Matter fMRI Metrics: A PPMI* Study

Dr. Bradley MacIntosh is a Scientist with the Brain Sciences Research Program at the University of Toronto (Sunnybrook Research Institute). He studies the use of imaging technology to track blood flow in the brains of people living with Parkinson’s. His work focuses on the role of blood flow in the development and management of Parkinson’s disease. Specifically, his work looks at fluctuations in white matter in the brain and periods of cognitive decline, hoping to correlate those with changes in blood flow. If a correlation is found, the result could lead to diagnostic tools and also an ability to treat Parkinson’s disease through controlling blood pressure.

Dr. MacIntosh works closely with scientists in the fields of neurology and psychiatry. His areas of research interest include functional and vascular imaging techniques using magnetic resonance imaging, notably the arterial spin labelling perfusion technique, and he studies stroke and neurodegenerative diseases. In addition to using neuroimaging measurements as outcome measures for aerobic exercise trials, his laboratory is actively developing new forms of physiological images, such as cardiac pulsatility effects on the brain.

This funding supports Dr. MacIntosh’s research in using imaging technology to track volatile blood flow in the brains of people with Parkinson’s disease. In many cases, non-motor symptoms of Parkinson’s (including orthostatic hypotension, caused by blood pressure concerns) appear before the more commonly thought of motor symptoms of the disease. Correlating blood flow with fluctuations in white matter and cognitive decline contributes to the development of diagnostics to spot Parkinson’s disease early and potentially suggest ways of treating it by controlling blood pressure.

Dr. MacIntosh uses imaging technology to try to identify people with these early symptoms of Parkinson’s. MacIntosh is using functional Magnetic Resonance Imaging (fMRI) to scan the brains of people who have difficulty regulating their blood pressure. The scans track how often the brain is pulsating “ a measure of blood flow to the brain. Dr. MacIntosh believes the volatility of that blood flow is bad for the brain, and might be either depriving brain cells of oxygen or flooding them with too much oxygen, at different times.

“The brain is like Jello, and it’s pulsating with every heartbeat. Too much of this jiggling, we think, is related to blood vessels that have lost their ability to cushion the blood flow.” – Dr. MacIntosh

MacIntosh hopes to correlate rates of pulsatility with fluctuations in white matter in the brains of people who have already been diagnosed clinically as being in the early stages of Parkinson’s disease. He and his team will also test their cognitive functioning to see if that is also declining. If he can confirm an association with the volatility of blood flow to the brain, and show a cognitive decline, he will not only have developed a way to help diagnose Parkinson’s disease, he may also open up treatment avenues. Treating the volatile blood pressure early might prove beneficial.

“What we’re aiming for right now is a non-invasive diagnostic tool using information that is already out there. It’s just a matter of finding and proving that this can be helpful.” – Dr. MacIntosh


* PPMI is Parkinson’s Progression Markers Initiative