Impaired Self-Awareness of Motor Disturbances in Parkinson's Disease

Traditionally, anosognosia for cognitive or motor impairments in patients with Parkinson's disease (PD) was viewed as unlikely unless the patient was demented. More recent research has suggested that a portion of non-demented PD patients (30%-50%) in fact have impaired subjective awareness (ISA) of their motor impairments (ISAm). This empirical finding has implications for the clinical neuropsychological examination of PD patients and raises theoretical questions relevant to the broader study of anosognosia seen in other patient groups. The purpose of this paper is to primarily review our own research in this area and to summarize research findings of other investigators who have examined ISA in PD patients. Our secondary goal is to demonstrate the relevance of assessing ISA when conducting a neuropsychological examination of PD patients. Our findings suggest ISAm in PD patients is related to motor signs of right hemispheric dysfunction, but the brain imaging correlates of ISA for hypokinesias appear different than those obtained for ISA for dyskinesia in this patient group.