ABSTRACT
BACKGROUND: Prosopagnosia, the selective inability to recognize known faces, has been described in Alzheimer's disease and fronto-temporal dementia but is not expected to occur in Parkinson's disease (PD). METHODS AND RESULTS: We report three PD patients who developed recurrent, paroxysmal and short-lasting episodes of prosopagnosia, before progressing to PD dementia (PDD). Hallucinations and other higher-order visual deficits - such as optic ataxia and micro/macropsia - were also seen. CONCLUSION: Progressive signs of temporal and parietal dysfunction have been suggested to herald dementia in PD. The observation of prosopagnosia and other higher-order visuoperceptive defects in the transition to dementia, reinforce the importance of posterior-cortical deficit in PD.