Use of the Montreal Cognitive Assessment and Alzheimer's Disease-8 as cognitive screening measures in Parkinson's disease

Objective To examine the sensitivity and specificity of the Montreal Cognitive Assessment (MoCA), a brief cognitive screening measure previously validated for use in Parkinson's disease (PD), and Alzheimer's Disease-8 (AD8), an eight-item informant report used to screen for dementia, but not yet validated for use in PD, to identify cognitive impairment in a sample of 111 patients with PD. Methods Cognitive impairment was determined based on a battery of neuropsychological measures, excluding the MoCA and AD8. Classification rates of both the MoCA and AD8 in identifying cognitive impairment were examined using logistic regression and receiver operator characteristic (ROC) analysis. Optimal cutoff scores were determined to maximize sensitivity and specificity. Results The MoCA correctly classified 78.4% of participants (p < 0.001), and ROC analysis yielded an area under the curve (AUC) of 0.82. A MoCA cutoff score of <25 yielded optimal sensitivity (0.77) and specificity (0.79) for identifying PD patients with cognitive impairment. Similar analyses for the AD8 were statistically nonsignificant, although the classification rate was 70.5%, with an AUC of 0.50. Conclusions These results provide additional support for the MoCA, but not the AD8, in identifying cognitive impairment in patients with PD.