Domain-specific versus generalized cognitive screening in acute stroke

Abstract

Cognitive assessments after stroke are typically short form tests developed for dementia that generates pass/fail classifications (e.g. the MoCA). The Oxford Cognitive Screen (OCS) provides a domain-specific cognitive profile designed for stroke survivors. This study compared the use of the MoCA and the OCS in acute stroke with respect to symptom specificity and aspects of clinical utility. A cross-sectional study with a consecutive sample of 200 stroke patients within 3 weeks of stroke completing MoCA and OCS. Demographic data, lesion side and Barthel scores were recorded. Inclusivity was assessed in terms of completion rates and reasons for non-completion were evaluated. The incidence of cognitive impairments on both the MoCA and OCS sub-domains was calculated and differences in stroke specificity, cognitive profiles and independence of the measures were addressed. The incidence of acute cognitive impairment was high: 76 % of patients were impaired on MoCA, and 86 % demonstrated at least one impairment on the cognitive domains assessed in the OCS. OCS was more sensitive than MoCA overall (87 vs 78 % sensitivity) and OCS alone provided domain-specific information on prevalent post-stroke cognitive impairments (neglect, apraxia and reading/writing ability). Unlike the MOCA, the OCS was not dominated by left hemisphere impairments but gave differentiated profiles across the contrasting domains. The OCS detects important cognitive deficits after stroke not assessed in the MoCA, it is inclusive for patients with aphasia and neglect and it is less confounded by co-occurring difficulties in these domains.

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

“…The poor performance of left hemisphere stroke patients on the MoCA most likely reflect the demand of the MoCA subtests on both receptive and expressive language abilities as well as verbal working memory abilities, which are commonly affected following a left hemisphere stroke. Although our findings suggest the MoCA is effective in detecting gross impairment following left hemisphere stroke, the large language component to most of the subtests, even those that are not specifically testing language functions, may reduce the test accuracy of the MoCA for detecting domain specific impairments or indeed non-impairments (22). The large language burden of the MoCA may reduce the clinical utility in detecting non-language based cognitive impairments for left hemisphere stroke patients.…”

“…Further work is needed to improve the MoCA's sensitivity for use within the stroke population. The recent development of stroke-specific cognitive screens show promise (22). Alternatively, clinicians could consider supplementing the MoCA with additional screening items or brief assessment tools to overcome some of the limitations identified.…”

“…Alternatively, it may be that the MoCA is more sensitive to detecting left hemisphere stroke impairments. Indeed, it has been shown that left hemisphere stroke patients are more likely to have difficulty completing, and score lower, on the MoCA compared with right hemisphere strokes, due to the high language demands of most MoCA subtests (22,23). Neuropsychological assessment data was not available in the study for comparison.…”

Cognitive function in stroke survivors: A 10-year follow-up study

“…11,12,18,28,33 Nevertheless, the cognitive testing performance may have been confounded by frequent post-stroke sequelae such as neglect, apraxia, agnosia, or mild-to-moderate language impairments, as these deficits were not assessed. 34 In particular, such undetected deficiencies in larger network functions may negatively have impacted the performance on the visuoexecutive subtests with subsequent lower scoring results. Also, age-and education-corrected MMSE and MoCA cutoffs derived from normative data could have been used instead of predefined cutoffs, 35,36 but attempts to increase sensitivity with this method generally decrease specificity and vice versa.…”

Depressão e prejuízo cognitivo pós-acidente vascular cerebral: avaliação expandida no Estudo de Mortalidade e Morbidade do AVC (EMMA), São Paulo, Brasil

“…biomarcadores específicos, as características das lesões neuroanatômicas pós-AVC, tais como a lateralidade do AVC, a localização e anormalidades microestruturais também são descritas como fatores de risco para DPA (Robinson e Jorge, 1984;Bhogal et al, 2004;Carod-Artal et al, 2006;Douven et al, 2017;Mitchell et al, 2017) e PC (Zekry et al, 2003;Wong et al, 2015;Demeyere et al, 2016;Chan et al, 2017;Sivakumar et al, 2017).…”