Neuropsychological and neuroimaging markers in prediction of cognitive impairment after ischemic stroke: a prospective follow-up study

Abstract

Shima Mehrabian,1 Margarita Raycheva,1 Neli Petrova,2 Armina Janyan,3,4 Mariya Petrova,1 Latchezar Traykov1 1Clinic of Neurology, University Hospital Alexandrovska, Sofia, 2Clinic of Neurology, MHAT “Ruse”, Ruse, 3Research Center for Cognitive Science, Department of Cognitive Science and Psychology, New Bulgarian University, Sofia, Bulgaria; 4Laboratory for Cognitive Studies in Language, National Research Tomsk State University, Tomsk, Russia Background: There are few longitudinal studies with controversial results examining delayed changes in cognition after ischemic stroke and predictive values of neuropsychological and neuroimaging markers. Objective: The objectives of this study were to evaluate the delayed changes in cognition in poststroke patients and their relationship to the neuropsychological and neuroimaging markers measured during the acute poststroke phase. Methods: Eighty-five first-ever stroke inpatients (mean age 65.6±5.6 years) without previous cognitive complaints were prospectively evaluated with a comprehensive neuropsychological battery at the 5th day and the 1st, 6th, and 12th months. A wide range of clinical, radiological, and neuropsychological variables were examined. Results: Our results showed significantly poorer performance on mini–mental state examination, memory, attention/executive functions, and processing speed in patients with stroke in comparison with stroke-free cognitively intact controls. Multiple regression analysis revealed that hippocampal atrophy is the strongest predictor of delayed cognitive impairment. Secondary divided subgroups according to Isaacs Set Test (IST) score showed that patients with IST score ≤28 had different patterns of cognitive and neurological impairment after 1 year. Baseline impairments in attention/executive functions and memory were associated with development of dementia in poststroke patients. Conclusion: Executive functioning deficit appears to have a predictive power for cognitive impairment progression. The study suggests that IST as a screening test has a potential to be a reliable and quick tool for poststroke cognitive impairment evaluation and delayed cognitive and neurological outcome. Hippocampal atrophy was the strongest predictor for cognitive impairment outcome, even in poststroke cognitive impairment. The findings may set the stage for better poststroke management. Keywords: hippocampal atrophy, IST, neuropsychological predictors, poststroke dementia