Prediction of post-stroke cognitive impairment by Montreal Cognitive Assessment (MoCA) performances in acute stroke: comparison of three normative datasets

Aging Clin Exp Res. 2022 Aug;34(8):1855-1863. doi: 10.1007/s40520-022-02133-9. Epub 2022 Apr 20.

Abstract

Background: Cognitive assessment in acute stroke is relevant for identifying patients at risk of persistent post-stroke cognitive impairment (PSCI). Despite preliminary evidence on MoCA accuracy, there is no consensus on its optimal score in the acute stroke setting to predict PSCI.

Aims: (1) To explore whether the application of different normative datasets to MoCA scores obtained in the acute stroke setting results in variable frequency of patients defined as cognitively impaired; (2) to assess whether the normality cut-offs provided by three normative datasets predict PSCI at 6-9 months; (3) to calculate alternative MoCA cut-offs able to predict PSCI.

Methods: Consecutive stroke patients were reassessed at 6-9 months with extensive neuropsychological and functional batteries for PSCI determination.

Results: Out of 207 enrolled patients, 118 (57%) were followed-up (mean 7.4 ± 1.7 months), and 77 of them (65%) received a PSCI diagnosis. The application of the normality thresholds provided by the 3 normative datasets yielded to variable (from 28.5% to 41%) rates of patients having an impaired MoCA performance, and to an inadequate accuracy in predicting PSCI, maximizing specificity instead of sensitivity. In ROC analyses, a MoCA score of 22.82, adjusted according to the most recent normative dataset, achieved a good diagnostic accuracy in predicting PSCI.

Conclusions: The classification of acute stroke patients as normal/impaired based on MoCA thresholds proposed by general population normative datasets underestimated patients at risk of persistent PSCI. We calculated a new adjusted MoCA score predictive of PSCI in acute stroke patients to be further tested in larger studies.

Keywords: Acute stroke; Montreal Cognitive Assessment; Neuropsychology; Normality cut-off; Post-stroke cognitive impairment.

MeSH terms

  • Cognitive Dysfunction* / diagnosis
  • Cognitive Dysfunction* / etiology
  • Cognitive Dysfunction* / psychology
  • Humans
  • Mental Status and Dementia Tests
  • Neurologic Examination
  • Neuropsychological Tests
  • ROC Curve
  • Stroke* / complications
  • Stroke* / epidemiology