• Forty-one parkinsonian patients were examined for the effect of anticholinergic drugs on memory function. Nineteen were tested while both receiving and not receiving treatment, 11 while receiving treatment only, and 11 others while not receiving such medication. Significant deterioration of performance on a test for intermediate memory was observed in those receiving therapy. The group of patients as a whole compared unfavorably with healthy, untreated control subjects, particularly for intermediate memory.
Sadeh M, Braham J, Modan M. Effects of Anticholinergic Drugs on Memory in Parkinson's Disease. Arch Neurol. 1982;39(10):666-667. doi:10.1001/archneur.1982.00510220064017