Cognition in a patient with very mild right-sided hemiparkinsonism

Non-demented patients with Parkinson's disease (PD), especially if they are high functioning and early in the course of their disease, usually exhibit mild deficits in anterograde recall memory for verbal and non-verbal material, visuospatial reasoning, visuomotor construction, temporal ordering and sequencing. Impairments in problem solving and verbal fluency tests may also occur. PD patients with predominantly right-sided symptoms usually exhibit more severe difficulties with verbal than with non-verbal tasks. We report a case of a highly educated right-handed man with very mild right-sided hemiparkinsonism who never received anti-Parkinsonian or other psychoactive medication. Our patient showed anterograde and retrograde amnesia for faces and spatial locations and difficulties on complex visuospatial tasks that required manual responses, but normal to above average performance on all other cognitive tests. The specific pattern of cognitive loss early in PD may depend on which spatial, facial or verbal pre-frontal striatal circuits are deprived of their dopaminergic inputs.