Abstract TP095: Post-Stroke Cognitive Impairment is Associated with Deficits in Working Memory and Reduced Prefrontal Activation

Post-stroke cognitive impairment (PSCI) affects up to 60% of stroke survivors and is strongly associated with poor long-term outcomes. However, the neural mechanisms underlying PSCI remain poorly understood. This study aims to evaluate cognitive performance and cortical activation in stroke survivors using cognitive assessments and simultaneous functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG). This ongoing study aims to enroll 70 participants: 35 ischemic stroke survivors and 35 cognitively normal (CN) age- and sex-matched controls. Stroke participants are recruited at least 30 days post-event from the University of Oklahoma Health Sciences. All participants undergo simultaneous fNIRS-EEG during a working memory task (n-back recordings), alongside standardized cognitive testing using the NIH Toolbox Cognition Battery. Hemodynamic responses were assessed using GLM-based analysis of HbO concentration changes, and EEG preprocessing is ongoing. We recruited 19 cognitively normal older adults (CN) and 6 stroke survivors. Stroke survivors showed significantly reduced performance across most cognitive domains compared to CN, particularly in cognitive flexibility, attention, and working memory. In the n-back task, fNIRS contrast maps revealed robust bilateral prefrontal activation in CN during the 2-back condition, consistent with load-dependent engagement of working memory circuits. In contrast, stroke survivors exhibited attenuated and spatially restricted activation patterns, with some regions demonstrating negative contrast values relative to rest. Notably, stroke participants failed to show increased activation from 1-back to 2-back conditions, suggesting impaired neural recruitment under higher cognitive demands. These preliminary findings provide converging behavioral and hemodynamic evidence of impaired working memory and neurovascular dysfunction in PSCI. Ongoing multimodal integration with EEG will further clarify the neuronal underpinnings of these deficits and may support the development of targeted interventions to improve cognitive outcomes post-stroke.