Additional Queen Square (QS) screening items improve the test accuracy of the Montreal Cognitive Assessment (MoCA) after acute stroke

Background: The Montreal Cognitive Assessment (MoCA) is a popular cognitive screening tool used in stroke, but lacks sensitivity for detecting impairment in stroke-relevant domains of processing speed, non-verbal memory and executive functions. Our aim was to assess whether the test accuracy of the MoCA can be improved with additional tailored screening items targeting these three domains. Methods: We included 196 patients admitted to an acute stroke unit at the National Hospital for Neurology and Neurosurgery, Queen Square (QS), London. Participants completed the MoCA as well as a series of additional QS-screening items designed to assess speed of processing, non-verbal memory and executive functions. Performance on the MoCA and QS screening items was compared with performance on "gold standard" neuropsychological assessment. Results: In our sample, 22% of patients were classified as "cognitively intact" on the traditional MoCA alone (>= 25), However, when tested on the QS-screening items, 40% of these patients failed on speed of processing, 56% failed on non-verbal memory and 26% failed on executive functions. Compared with neuropsychological assessment, the QS-screening items had good sensitivity (QS-Speed: 0.85; QS-Vis: 0.71; QS-EF: 0.73) and modest specificity (QS-Speed: 0.59; QS-Vis: 0.39; QS-EF: 0.54), regardless of stroke lateralisation. Conclusion: Additional screening items detected impairments in speed of processing, non-verbal memory and executive functions over and above those captured using the standard MoCA. The use of these QS-screening items improves the detection of post-stroke cognitive deficits in domains not adequately covered by the standard MoCA.