Early Cognitive Assessment Following Acute Stroke: Feasibility and Comparison between Mini-Mental State Examination and Montreal Cognitive Assessment

Objectives: Cognitive assessment is not performed routinely in the acute stroke setting. We investigated factors associated with cognitive impairment and the differences between the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores in patients with acute stroke.

Methods: In this prospective study, 881 consecutive patients (median age, 73 years) with acute stroke were enrolled. Clinical characteristics, such as education, vascular risk factors, premorbid cognitive status using the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), and stroke severity, were assessed. Cognitive performance was measured using MMSE and MoCA within 5 days of stroke onset.

Results: Both MMSE and MoCA were feasible in 621 (70.5%) patients. Factors independently associated with nonfeasibility were age (odds ratio [OR]: 1.05; 95% confidence interval [CI]: 1.02-1.08), IQCODE score (OR: 1.02; 95%CI: 1.00-1.04), and National Institutes of Health Stroke Scale (NIHSS) score (OR, 1.16; 95%CI, 1.12-1.20). Impaired MoCA (with a cut-off <26/30) performance was observed in 544 of 621 (87.6%) patients. Factors independently associated with cognitive impairment were age (OR: 1.06; 95%CI: 1.03-1.10) and NIHSS score (OR: 1.34; 95%CI: 1.14-1.57). Eighty percent of patients with normal MMSE scores had an impaired MoCA score (MMSE-MoCA mismatch). The differences were highest in the visuospatial (94.8% versus 65.3%; P < .0001), recall (76.6% versus 35.6%; P < .0001), abstraction (82.5% versus 49.8%; P < .0001), and language (72.3% versus 65.9%; P < .0001) domains between the normal MMSE and MoCA group and MMSE-MoCA mismatch group.

Conclusions: The MoCA can be particularly useful in patients with cognitive deficits undetectable on the MMSE in the acute stroke phase.