The test accuracy of the Montreal Cognitive Assessment (MoCA) by stroke lateralisation

Abstract

Background: The Montreal Cognitive Assessment (MoCA) is an increasingly popular screening tool for detecting cognitive impairment post-stroke. However its' test accuracy by stroke lateralisation is as yet unknown. Aim: Our aim was to investigate whether the test accuracy of the MoCA differs by stroke lateralisation across different cognitive domains. Methods: We retrospectively examined the cognitive profiles of 228 subacute stroke patients (86 Left, 142 Right), comparing MoCA-total and domain-specific scores with performance on detailed neuropsychological assessment. Results: The prevalence of cognitive impairment detected on neuropsychological assessment was high and relatively comparable between the right and left hemisphere stroke groups (91% and 93% respectively). Notably however, 29% of the right stroke group and 6% of the left stroke group achieved a "cognitively-intact" MoCA score (≥25). A high proportion of right stroke patients who had an overall MoCA-intact score were found to be impaired in intellectual functioning, processing speed, executive functions and non-verbal memory on neuropsychological assessment. Furthermore, a high proportion of patients who scored fullmarks within a MoCA-specified domain, irrespective of their overall score, were found to have impairment on corresponding neuropsychological assessment for both stroke groups. Conclusions: Particular care needs to be taken in interpreting MoCA-intact performance for right hemisphere patients due to its poor sensitivity to right hemisphere deficits. Scoring maximum points within a MoCA-specified domain also does not necessarily indicate intact cognitive functioning in that domain. Clinicians should consider supplementing their MoCA assessment with additional tools to increase the test accuracy of detecting relevant cognitive impairments post-stroke.

Post-stroke executive dysfunction and verbal fluency negatively correlated to IL8

“…In this study, it was found that patients with dominant hemispheric infarction exhibited poor performance with MoCA test. This finding agreed with Chan and colleagues (2017) [27] that hypothesized the poor performance of dominant hemisphere stroke patients on the MoCA most probably reflected the dependence of the MoCA constitutes on both receptive and expressive language skills as well as verbal working memory abilities, which are commonly involved following a dominant hemisphere stroke.…”

Determinants, Prevalence, and Trajectory of Long-Term Post-Stroke Cognitive Impairment: Results from a 4-Year Follow-Up of the ARCOS-IV Study

“…The MoCA has good psychometric properties and is a valid screening tool to detect post-stroke cognitive impairment [13]. Although a recent study [14] questioned the accuracy of the MoCA to assess attention and executive function by stroke lateralization, the majority of studies have shown the MoCA to be superior compared to other screening measures such as the MMSE [11, 15, 16]. While primarily considered a screening tool, the MoCA has been used as a cognitive outcome measure in longitudinal studies where lengthy neuropsychological testing is not often feasible.…”

Social participation following right hemisphere stroke: influence of a cognitive-communication disorder

“…The choice of screening tool for cognition may also require consideration to ensure that the broad range of neuropsychological deficits that may arise post RH is assessed. The prior reported concern that some patients may present with domain specific cognitive impairments, which are overlooked in favour of a composite cognitive score, is reflected in findings within this thesis (Chan, 2017).…”

“…Chan and colleagues (2017) reported that the MoCA may under-estimate cognitive impairment in RH stroke. In their study the RH patient group, with intact cognition as assessed by the MoCA, showed impairments in information processing speed (57%), executive function (46%) and non-verbal memory (31%) on neuropsychological assessment (Chan, Altendorff, Healy, Werring, Cipolotti, 2017 (Blyth, Scott, Bond &, Paul, 2012). Research in the area of RH CCD suggests a disproportionate focus in referral processes and care-pathways on swallowing and motor speech deficits may exclude communications needs from provision of services.…”