Parkinson’s disease affects about 1% of people over the age of 60 and is a progressive neurological disease, so problems with slowness of movement and walking tend to get worse over time. Although many people are aware that Parkinson’s causes tremor and difficulties with movement, what’s less well known is that about 50% of patients with the condition will also get dementia within the first 10 years. The reason why some patients develop dementia early on in the condition and others do not, is not clear. A new theory is that this is related to levels of inflammation in the brain caused by the immune system’s response to the disease.

Recently, Dr Caroline Williams-Gray, MRC Clinician Scientist at the University of Cambridge, has been investigating the link between the inflammation in the brain and dementia in Parkinson’s, with support from the Evelyn Trust.

“We need to try to establish whether there is a clear relationship between inflammation in the brain and the development of dementia in Parkinson’s. If we could do that, then we may be able to new therapies targeting brain inflammation in order to try and slow down the development of dementia in these patients. This is a really important issue, because while we can treat some of the physical symptoms of Parkinson’s using dopamine-replacing treatments such as levodopa , we currently have no therapies which make a significant impact on the dementia,” explains Caroline.

Since last year, the study has been recruiting patients with early stage disease at the Parkinson’s Research Clinic, based at the John van Geest Centre for Brain Repair in Cambridge. Study participants have clinical and memory assessments, and undergo PET scanning - a special type of brain scanning - to measure inflammation in the brain, as well as to look at deposits of a protein called tau which may also be involved in causing dementia. Participants also give blood samples and have a lumbar puncture to collect a sample of cerebrospinal fluid: the fluid which bathes the brain and spinal cord. The research team are looking at links between the scan findings, markers of inflammation in the blood and cerebrospinal fluid, and the risk of later development of dementia in these participants. Currently 16 people have agreed to take part in this study and recruitment is continuing: the cohort will total 40.

“Our work is at an early stage, but pilot data has been promising. If we can show that the inflammatory response in the brain is linked to deposition of abnormal proteins such as tau and progression to dementia, we may open up new treatment options as inflammation is potentially very treatable. We have been very fortunate recently to secure further funding from the Medical Research Council for the study. This means we can carry the study on over a longer period to track levels of inflammation and deposits of tau protein over time and look at how this is linked with changes in memory and thinking. The study is also now recruiting  healthy volunteers of a similar age from the Cambridge Bioresource to act as a ‘control group’. We’re very grateful to the Evelyn Trust for the funding that got this project off the ground.”

You can find out more about the research carried out by Dr Williams-Gray here: 

https://www.neuroscience.cam.ac.uk/directory/profile.php?chm27