Objective: Although individuals with low stroke severity tend to recover well, cognitive impairment is common independent of stroke size or location. In this study, the patterns of recovery for individual cognitive domains and factors associated with outcome were examined. Design: A prospectively enrolled cohort of patients with minor stroke was administered cognitive testing at 1, 6, and 12 mos postinfarct. Composite T scores were generated for global cognition and well as independent cognitive domains at each time point. Paired t tests compared changes in scores over time. Regression models identified factors associated with improvement. Results: A total of 46 patients, with an average NIH Stroke Scale score of 2.7, were enrolled. Average age was 61.3 yrs. Patients improved overall between 1 and 6 mos; however, distinct patterns of recovery were seen for different cognitive domains. The most significant improvement was in spatial memory. Verbal memory scores remained low longitudinally. Motor speed and executive function increased, then plateaued. Despite a mean education of 13.6 yrs, only 36% of global cognition scores were higher than or equal to the normative mean at 12 mos, and only 57% of patients improved their global scores from 6 to 12 mos. Late recovery was associated with lower NIH Stroke Scale scores, higher 1-mo Montreal Cognitive Assessment scores, and rehabilitation. Baseline function predicted overall long-term recovery. Conclusion: Patterns of recovery are distinct for individual cognitive domains for patients with minor stroke. Stroke severity and rehabilitation influence trajectory. Premorbid baseline predicts long-term outcome.

Cortical ischemic strokes result in cognitive deficits depending on the area of affected brain. However, we have demonstrated that difficulties with attention and processing speed can occur even with small subcortical infarcts. Symptoms appear independent of lesion location, suggesting they arise from generalized disruption of cognitive networks. Longitudinal studies evaluating directional measures of functional connectivity in this population are lacking. We evaluated six patients with minor stroke exhibiting cognitive impairment 6-8 weeks post-infarct and four age-similar controls. Resting state magnetoencephalography data were collected. Clinical and imaging evaluations of both groups were repeated six and twelve months later. Network Localized Granger Causality was used to determine differences in directional connectivity between groups and across visits, which were correlated with clinical performance. Directional connectivity patterns remained stable across visits for controls. After stroke, inter-hemispheric connectivity between frontoparietal cortex and non-frontoparietal cortex significantly increased between visits 1 and 2, corresponding to uniform improvement in reaction times and cognitive scores. Initially, the majority of functional links originated from non-frontal areas contralateral to the lesion, connecting to ipsilesional brain regions. By visit 2, inter-hemispheric connections, directed from ipsilesional to contralesional cortex significantly increased. At visit 3, patients demonstrating continued favorable cognitive recovery showed less reliance on these interhemispheric connections. These changes were not observed in those without continued improvement. Our findings provide supporting evidence that the neural basis of early post-stroke cognitive dysfunction occurs at the network-level, and continued recovery correlates with evolution of inter-hemispheric connectivity.

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