Positron emission tomography imaging of the cholinergic system in parkinsonian tremor

This PET imaging study compared cholinergic system function in tremor-dominant versus non-tremor-dominant Parkinson's disease patients using [11C]-donepezil binding. Results showed preserved cholinergic function in tremor-associated regions of tremor-dominant patients but decreased cholinergic binding in multiple brain regions of non-tremor-dominant patients, suggesting differential cholinergic pathology between Parkinson's disease subtypes.