Background: Screening for cognitive impairment is recommended in patients with cerebrovascular disease. We sought to establish the incidence of cognitive impairment using the Montreal Cognitive Assessment (MoCA) in a cohort of consecutive patients attending our stroke prevention clinic (SPC), and to determine whether a subset of the MoCA could be derived for use in this busy clinical setting.
Methods: The MoCA was administered to 102 patients. Incidence of cognitive impairment was compared to presenting complaint and final diagnosis. extent of cerebral white matter changes (WMC) was rated using the Age Related White Matter Changes (ARWMC) scale in 80 patients who underwent neuroimaging. A subset of the three most predictive test elements of the MoCA was derived using regression analysis.
Results: 63.7% of patients scored <26/30 on the MoCA, in keeping with cognitive impairment. This was unrelated to the final diagnosis or extent of WMC, although a trend for lower MoCA scores was observed in older patients. A mini-MoCA subscore combining the clock drawing test, five-word delayed recall, and abstraction was highly correlated with the final MoCA score (R=0.901). A score of <7/10 using this 10-point mini-MoCA identified cognitive impairment as defined by the MoCA with a sensitivity of 98.5%, and a specificity of 77.6%.
Conclusions: Two-thirds of SPC patients demonstrated evidence for cognitive impairment, irrespective of their final diagnosis or the presence of WMC. A mini-MoCA comprised of the clock drawing test, five-word delayed recall, and abstraction represents a potential alternative to the full MoCA in this population.