Lack of Accurate Self-appraisal is Equally Likely in MCI from Parkinson's Disease and Alzheimer's Disease.

Background: How accurate are mild cognitive impairment (MCI) patients in assessing their cognitive and functional deficit is often unclear to the clinician. The accuracy of patient self-appraisal in Parkinson's disease-MCI (PD-MCI) has received less attention than amnestic MCI (a-MCI) often associated with Alzheimer's disease. We evaluated if PD-MCI patients demonstrate accurate self-appraisal of their cognitive deficits compared to patients with amnestic a-MCI or non-amnestic MCI (na-MCI).

Methods: This cross-sectional cohort study included, 30 PD-MCI, 33 a-MCI, and 17 na-MCI patients. Self-appraisal was assessed by comparing responses of caregivers and patients on a validated self-rating questionnaire of cognitive and functional impairments. All patients completed a full neuropsychological evaluation and depression screening measure. Univariate ANOVA, regression, and correlational analyses were employed to identify group differences in self-appraisal scores and relationships between cognitive and functional impairment, depression measures, and self-appraisal scores.

Results: Self-appraisal scores for PD-MCI did not differ significantly from a-MCI and na-MCI. In the PD-MCI group, higher depression scores were associated with lower self-appraisal scores (i.e, patients assessed cognition as worse than caregivers). In a stepwise regression model with self-appraisal scores as the dependent variable, only the depression score was significant predictor among PD-MCI and accounted for 50% of the variance.

Conclusions: Our findings suggest that impaired patient self-appraisal is equally likely to occur in PD-MCI as in a-MCI and na-MCI patients. Among PD-MCI, depression was the strongest predictor of impaired patient self-appraisal. Impaired insight into cognitive impairment and depression should be considered in both care and research with PD patients.