Investigating the neuroinflammatory basis of cognitive impairment in Parkinson's disease using PET neuroimaging

Summary

Parkinson's disease (PD) typically causes problems such as difficulty walking and tremor. However, many patients also develop dementia, which has a major impact on quality of life and care requirements, but cannot be effectively treated.

Dementia in PD is associated with protein deposits called Lewy bodies throughout the brain, but other factors are also likely to be involved. In particular, our previous research suggests that inflammation might play an important role in the development of PD dementia, and build-up of a protein called tau may also be involved. This is important to establish, as it could lead to the development of anti-inflammatory drugs and/or drugs to lower tau levels for the prevention of dementia in PD.

This study aims to establish whether inflammation and tau aggregation in the brain are involved in the earliest stages of PD dementia, by studying these processes in patients with newly-diagnosed PD as well as healthy volunteers. Participants will undergo brain scanning using a technique called positron emission tomography (PET) to measure inflammation and tau. They will also have a blood test, and in some cases a lumbar puncture for collection of cerebrospinal fluid (CSF). Markers of inflammation and levels of key proteins will be measured in these blood and CSF samples. We will then continue to follow participants with clinical assessments for up to 10 years. We will investigate the relationship between levels of brain inflammation, abnormal tau aggregation, and dementia risk in PD, and make comparisons with healthy controls.

We hope to establish that changes in inflammation and tau protein aggregation are involved at an early stage in those at high risk of PD dementia, and if so, this will have important implications for developing treatments to prevent this complication of the disease. 

Participation: For this study we recruited 40 volunteers from the Cambridge BioResource.

Organisation: This study was organised by Dr Caroline Williams Gray from the University of Cambridge.