The MoCA

TLDR

The study aimed to determine the diagnostic accuracy of the MoCA for detecting cognitive impairment in Parkinson disease by comparing it to SCOPA‑COG and S‑MMSE. The authors evaluated 114 Parkinson disease patients and 47 healthy controls, classifying participants into dementia, mild cognitive impairment, or normal cognition based on established criteria and neuropsychological testing. ROC analyses showed the MoCA outperformed SCOPA‑COG and S‑MMSE in distinguishing Parkinson disease dementia and mild cognitive impairment, with optimal cutoffs of <21/30 and <26/30, achieving high sensitivity and specificity.

Abstract

<h3>Objective:</h3> To establish the diagnostic accuracy of the Montreal Cognitive Assessment (MoCA) when screening externally validated cognition in Parkinson disease (PD), by comparison with a PD-focused test (Scales for Outcomes in Parkinson disease–Cognition [SCOPA-COG]) and the standardized Mini-Mental State Examination (S-MMSE) as benchmarks. <h3>Methods:</h3> A convenience sample of 114 patients with idiopathic PD and 47 healthy controls was examined in a movement disorders center. The 21 patients with dementia (PD-D) were diagnosed using Movement Disorders Society criteria, externally validated by detailed independent functional and neuropsychological tests. The 21 patients with mild cognitive impairment (PD-MCI) scored 1.5 SD or more below normative data in at least 2 measures in 1 of 4 cognitive domains. Other patients had normal cognition (PD-N). <h3>Results:</h3> Primary outcomes using receiver operating characteristic (ROC) curve analyses showed that all 3 mental status tests produced excellent discrimination of PD-D from patients without dementia (area under the curve [AUC], 87%–91%) and PD-MCI from PD-N patients (AUC, 78%–90%), but the MoCA was generally better suited across both assessments. The optimal MoCA screening cutoffs were &lt;21/30 for PD-D (sensitivity 81%; specificity 95%; negative predictive value [NPV] 92%) and &lt;26/30 for PD-MCI (sensitivity 90%; specificity 75%; NPV 95%). Further support that the MoCA is at least equivalent to the SCOPA-COG, and superior to the S-MMSE, came from the simultaneous classification of the 3 PD patient groups (volumes under a 3-dimensional ROC surface, chance = 17%: MoCA 79%, confidence interval [CI] 70%–89%; SCOPA-COG 74%, CI 62%–86%; MMSE-Sevens item 56%, CI 44%–68%; MMSE-World item 62%, CI 50%–73%). <h3>Conclusions:</h3> The MoCA is a suitably accurate, brief test when screening all levels of cognition in PD.