Early Frontal qEEG Markers Predict Delayed Cognitive Recovery After Mild-to-Moderate Ischemic Stroke: A Prospective Cohort Study

Background and ObjectivePost-stroke cognitive impairment affects 30%-60% of survivors, yet predicting which patients will demonstrate delayed recovery remains challenging. We investigated whether early quantitative electroencephalography (qEEG) markers can identify patients with cognitive recovery potential during the critical 3-6 month post-stroke period.MethodsThis prospective cohort study enrolled patients with first-time supratentorial ischemic stroke (NIHSS <15). Resting-state EEG was recorded at 8 ± 1 days post-stroke to calculate regional qEEG indices: peak alpha frequency (PAF), delta + theta/alpha + beta ratio (DTABR), and theta-alpha dominant frequency variability (DFV). The Montreal Cognitive Assessment (MoCA) was administered at 3 and 6 months post-stroke. Cognitive recovery was defined as ≥2-point MoCA improvement. Stepwise logistic regression identified recovery predictors, with model performance evaluated using area under the receiver operating characteristic curve (AUC).ResultsOf 96 enrolled patients, 53 (55.2%) demonstrated cognitive recovery, with substantial improvements in delayed recall/memory, naming, abstraction, and visuospatial/executive function. Patients with recovery showed lower cognitive performance at 3 months but reached comparable levels by 6 months post-stroke. Lower frontal PAF (adjusted OR 0.29, 95% CI 0.16, 0.47), reduced frontal DTABR (adjusted OR 0.84, 95% CI 0.72, 0.96), and elevated frontal DFV (adjusted OR 4.59, 95% CI 1.27, 20.81) predicted cognitive recovery with good discriminatory ability (AUC = 0.831, 95% CI: 0.748, 0.914).ConclusionsEarly frontal qEEG measures identified stroke patients with delayed cognitive recovery potential during the 3-6 month window, despite initially poor performance. These findings suggest that early qEEG assessment could help inform personalized rehabilitation planning and identify candidates for extended cognitive rehabilitation interventions.