Decreased intestinal acetylcholinesterase in early Parkinson disease: An (11)C-donepezil PET study.

OBJECTIVE: To investigate systemic levels of acetylcholinesterase in early Parkinson disease (PD) with (11)C-donepezil PET, a potential marker of parasympathetic innervation.

METHODS: This was a cross-sectional study with 19 patients with early-stage PD (disease duration 1.5 ± 0.6 years) and 16 age-matched controls who had clinical assessments, olfaction tests, and (11)C-donepezil PET to measure acetylcholinesterase density in peripheral organs.

RESULTS: The patients with PD showed significantly reduced (11)C-donepezil uptake in the small intestine (-14%, p = 0.018), colon (-22%, p < 0.001), and kidneys (-14%, p = 0.028). No difference in myocardial or pancreatic acetylcholinesterase levels was seen.

CONCLUSION: We found significantly decreased (11)C-donepezil signal in the intestine and kidneys of patients with early PD, suggesting that parasympathetic denervation is present early in the disease course.