Independent Functional Outcomes after Prolonged Coma following Cardiac Arrest: A Mechanistic Hypothesis. Issue 4 (11th February 2020)

• Record Type: Journal Article
• Authors: Forgacs, Peter B.; Devinsky, Orrin; Schiff, Nicholas D.
• Is Part Of: Annals of neurology. Volume 87:Issue 4(2020)
• Page Start: 618
• Page End: 632
• Publication Date: 2020-02-11
• Subjects: Neurology -- Periodicals; Pediatric neurology -- Periodicals; Nervous system -- Surgery -- Periodicals; 616.8
• DOI: 10.1002/ana.25690
• Languages: English
• ISSNs: 0364-5134

Abstract

Abstract : Objective: Survivors of prolonged (>2 weeks) post–cardiac arrest (CA) coma are expected to remain permanently disabled. We aimed to investigate 3 outlier patients who ultimately achieved independent functional outcomes after prolonged post‐CA coma to identify electroencephalographic (EEG) markers of their recovery potential. For validation purposes, we also aimed to evaluate these markers in an independent cohort of post‐CA patients. Methods: We identified 3 patients with late recovery from coma (17–37 days) following CA who recovered to functionally independent behavioral levels. We performed spectral power analyses of available EEGs during prominent burst suppression patterns (BSP) present in all 3 patients. Using identical methods, we also assessed the relationship of intraburst spectral power and outcomes in a prospectively enrolled cohort of post‐CA patients. We performed chart reviews of common clinical, imaging, and EEG prognostic variables and clinical outcomes for all patients. Results: All 3 patients with late recovery from coma lacked evidence of overwhelming cortical injury but demonstrated prominent BSP on EEG. Spectral analyses revealed a prominent theta (~4–7Hz) feature dominating the bursts during BSP in these patients. In the prospective cohort, similar intraburst theta spectral features were evident in patients with favorable outcomes; patients with BSP and unfavorable outcomes showed either no features, transient burst features, or decreasing intraburst frequencies with time. Interpretation: BSP with theta (~4–7Hz) peak intraburst spectral power after CA may index a recovery potential. We discuss our results in the context of optimizing metabolic substrate availability and stimulating the corticothalamic system during recovery from prolonged post‐CA coma. ANN NEUROL 2020;87:618–632