Event-based prospective memory in newly diagnosed, drug-naive Parkinson's disease patients

The present study investigated memory for intention in individuals with Parkinson's disease (PD) who were newly diagnosed and not yet treated to avoid the effect of therapy as a potential confounding variable. A comprehensive neuropsychological battery and an event-based prospective memory task were administered to 41 subjects with de novo PD and 40 control subjects. Separate scores were computed for correct execution of intended action (prospective component) and recall of intention (retrospective component). PD patients performed marginally worse (p =.053) than controls on the prospective component of the task. On the other hand, the performance of the two groups was comparable for the retrospective component. Neuropsychological findings revealed lower performance of the PD group in episodic memory and in some measures of executive functions. These results suggested a subtle prospective memory dysfunction present at the initial stage of PD, which may be related to disruption of fronto-striatal circuitry.