Impaired self-awareness of motor deficits in Parkinson's disease: association with motor asymmetry and motor phenotypes.

Background: This study investigated impaired self-awareness of motor deficits in nondemented, nondepressed Parkinson's disease (PD) patients during a defined clinical on state.

Methods: Twenty-eight PD patients were examined. Patients' self-ratings and experts' ratings of patients' motor performance were compared. Patient-examiner discrepancies and level of impairment determined severity of impaired self-awareness. Motor exam assessed overall motor functioning, hemibody impairment, and 4 motor phenotypes. Neuropsychological tests were also conducted.

Results: Signs of impaired self-awareness were present in 17 patients (60.7%). Higher severity of impaired self-awareness correlated significantly with higher postural-instability and gait-difficulty off scores (r = .575; P = .001), overall motor off scores (r = .569; P = .002), and higher left hemibody off scores (r = .490; P = .008). In multiple linear regression analyses, higher postural-instability and gait-difficulty off scores remained as the only significant predictor of impaired self-awareness severity.

Conclusions: Postural instability and gait difficulties, disease severity, and right hemisphere dysfunction seem to contribute to impaired self-awareness.