Self-awareness of deficits in Parkinson disease.

Anosognosia is an unawareness or denial of deficits. While it has mainly been associated with damage to cortical brain regions, anosognosia has also been reported in patients with subcortical brain disease. The present study investigated whether anosognosia is a feature of Parkinson disease. Forty-eight Parkinson disease patients with predominantly left- (N = 16) or right-sided (N = 32) motor symptoms who eventually underwent right or left pallidotomies, and 48 individuals identified as caregivers completed questionnaires rating severity of PD. There was no discrepancy in report between patients and caregivers as a function of pallidotomy side. However, as a group, patients rated themselves as significantly less impaired on 2 measures of activities of daily living, indicating that basal ganglia dysfunction may alter insight into severity of illness. Patients and caregivers in the left-symptom PD group differed significantly on selected measures of functional independence. This suggests the potential interaction of laterality and handedness. The importance of future investigations in PD patients with more severe cognitive impairment is stressed.