Verbal fluency in Parkinson's disease patients on/off dopamine medication

► Patients with Parkinson disease (PD) commonly exhibit language difficulties assessed with verbal fluency tasks. ► PD patients off medication generate less number of words compared to PD on medication and healthy controls. ► PD patients off medication generated the highest frequency words on the action fluency task. ► Dopamine depletion could play a role into the lexico-semantic disturbing the normal processing of verbs.