- Determine baseline clinical and enteric histopathologic characteristics of individuals enriched genetically (with strong family history) or clinically (with iRBD) for PD risk. 40 healthy controls, 20 iRBD, and 20 with strong PD family history will be enrolled. Hypothesis 1: The proportion of individuals with abnormal enteric alpha synuclein (a-syn) pathology is higher in at-risk populations than healthy controls.
- Determine the natural history of our at-risk study groups, over a 3-year period, using motor and non-motor (cognitive) measures. Hypothesis 2: New development of PD motor symptoms (parkinsonism), mild cognitive impairment, or dementia (determined by neuropsychological testing) will be observed at a higher rate in those with enteric a-syn pathology than those without.
- Measure resilience and progression of enteric histopathological findings in our study groups, using colon biopsies repeated after 3 years. Hypothesis 3: The proportion of individuals with enteric a-syn pathology will increase at a greater rate in at-risk study groups than in healthy controls.