Quantitative EEG analysis related to coma and prognosis in acute severe cerebral infarction

INTRODUCTION: While electroencephalographic (EEG) abnormalities in acute cerebral infarction are increasingly documented, their neuroanatomical specificity and underlying pathophysiology remain poorly understood. This study investigated how lesion topography (cortical vs. brainstem) shapes distinct cortical oscillatory patterns and their clinical correlates in severe infarction with impaired consciousness. METHODS: We analyzed EEG recordings from 15 large hemispheric infarction (LHI) patients, 13 brainstem infarction (BSI), and 14 healthy control subjects. Quantitative EEG (qEEG) metrics included absolute/relative band power (ABP/RBP) and functional connectivity (FC) across delta (δ), theta (θ), alpha (α), and beta (β) bands. Correlations between quantitative EEG (qEEG) parameters and clinical outcomes were also assessed. RESULTS: The BSI group exhibited significantly elevated δ-band ABP/RBP alongside attenuated α/β-band power compared to LHI group (all p < 0.001). Notably, in the non-ipsilesional occipital region, enhanced δ/β-band activity demonstrated positive correlations with favorable clinical outcomes, whereas increased θ/α bands activities showed inverse prognostic associations. Furthermore, LHI patients exhibited stronger δ-band functional connectivity between the non-ipsilesional frontal-occipital networks (p < 0.01). CONCLUSIONS: This study delineates distinctive EEG signatures characterizing severe cerebral infarction, establishing non-ipsilesional occipital qEEG parameters as pivotal biomarkers for both consciousness evaluation and outcome prediction. These objective electrophysiological markers not only differentiate LHI from BSI through network-level neural reorganization patterns, but also demonstrate clinical applicability. The findings provide empirical support for qEEG integration into neurocritical care for acute stroke with impaired consciousness.