Screening for cognitive impairment with the MoCA in young patients with minor stroke: findings from a prospective observational study.

Background and aims: About half of all stroke patients under the age of 50 have cognitive deficits. If these are subtle, they may escape routine neurological examination. The aim of this study was to investigate whether the Montreal Cognitive Assessment (MoCA), an internationally recommended screening tool for cognitive assessment in stroke patients, is suitable for detecting cognitive deficits in younger stroke patients with a minor stroke.
Methods: Patients aged 18 to 55 years with a minor (NIHSS ≤5) ischemic stroke were eligible for inclusion in this prospective observational study. The primary endpoint was to assess the sensitivity of the MoCA. Secondary endpoints were specificity, positive and negative predictive value. A comprehensive neuropsychological assessment (CNA) and the MoCA were completed at least 3 days after stroke. The CNA assessed memory, attention, language, visuospatial and executive functions with multiple tasks for each domain.
Results: Of 121 patients who met the inclusion criteria between April 2021 and December 2023, 34 were enrolled. Median age was 48 years (41; 52) and 35% were female. The median interval between stroke and screening was 5 days (4; 7). Half of the patients scored 1.5 standard deviations below the population norm in at least one cognitive domain. The MoCA detected this impairment in only four cases (cut-off <26), giving a sensitivity of 24%. The specificity, positive predictive value and negative predictive value were 88%, 66% and 54% respectively.
Conclusions: Our data suggest that the MoCA is not sensitive to cognitive impairment in young minor stroke patients.