Background and purpose: The Montreal Cognitive Assessment (MoCA) and Addenbrooke's Cognitive Examination-Revised (ACE-R) are proposed as short cognitive tests for use after stroke, but there are few published validations against a neuropsychological battery. We studied the relationship between MoCA, ACE-R, Mini-Mental State Examination (MMSE) and mild cognitive impairment (MCI) in patients with cerebrovascular disease and mild cognitive impairment (MCI).
Methods: One hundred consecutive non-institutionalized patients had the MMSE, MoCA, ACE-R, and National Institute of Neurological Disorders and Stroke-Canadian Stroke Network Vascular Cognitive Impairment Harmonization Standards Neuropsychological Battery ≥ 1 year after transient ischemic attack or stroke in a population-based study. MCI was diagnosed using modified Petersen criteria in which subjective cognitive complaint is not required (equivalent to cognitive impairment-no dementia) and subtyped by number and type of cognitive domains affected.
Results: Among 91 nondemented subjects completing neuropsychological testing (mean/SD age, 73.4/11.6 years; 44% female; 56% stroke), 39 (42%) had MCI (amnestic multiple domain=10, nonamnestic multiple domain=9, nonamnestic single domain=19, amnestic single domain=1). Sensitivity and specificity for MCI were optimal with MoCA <25 (sensitivity=77%, specificity=83%) and ACE-R <94 (sensitivity=83%, specificity=73%). Both tests detected amnestic MCI better than nonamnestic single-domain impairment. MMSE only achieved sensitivity >70% at a cutoff of <29, mainly due to relative insensitivity to single-domain impairment.
Conclusions: The MoCA and ACE-R had good sensitivity and specificity for MCI defined using the Neurological Disorders and Stroke-Canadian Stroke Network Vascular Cognitive Impairment Battery ≥1 year after transient ischemic attack and stroke, whereas the MMSE showed a ceiling effect. However, optimal cutoffs will depend on use for screening (high sensitivity) or diagnosis (high specificity). Lack of timed measures of processing speed may explain the relative insensitivity of the MoCA and ACE-R to single nonmemory domain impairment.