Journal Of Clinical Neurophysiology[JOURNAL]

Sun 200 papers

Electrophysiological Signatures of Alpha Coma.

Degano G, Misirocchi F, Rigoni I … +7 more , Kaplan PW, Quintard H, Vulliémoz S, Schaller K, Kleinschmidt A, Seeck M, De Stefano P

J Clin Neurophysiol · 2025 Nov · PMID 39785823 · Full text

PURPOSE: Recent research on quantitative EEG in coma has proposed several metrics correlating with consciousness level. However, the heterogeneous nature of coma can challenge the generalizability of these measures. This... PURPOSE: Recent research on quantitative EEG in coma has proposed several metrics correlating with consciousness level. However, the heterogeneous nature of coma can challenge the generalizability of these measures. This study investigates alpha-coma, an electroclinical pattern characterized by a widespread, nonreactive alpha rhythm often linked to poor outcomes. The aim was to quantify the electrophysiological features of alpha-coma and compare them to the alpha rhythm in awake controls, seeking clearer insights into quantitative EEG analysis in comatose states. METHODS: Fourteen alpha-coma patients were retrospectively selected from University Hospitals of Geneva and age-matched with 14 healthy control subjects from an open-source dataset. EEG data were preprocessed and analyzed to extract power spectra, spectral decay (aperiodic activity), sample entropy, and functional connectivity. RESULTS: Alpha-coma patients did not differ in alpha power but exhibited significantly higher levels of spectral decay ( p < 0.001), suggesting a convergence toward an inhibitory state. Sample entropy was significantly higher in alpha-coma patients ( p = 0.01), indicating an increase in the cortical complexity in alpha-coma compared with healthy subjects. CONCLUSIONS: Alpha-coma shows increased aperiodic activity and EEG complexity, despite similar alpha power and clustering coefficient. The increased aperiodic activity aligns with findings in other comatose patients, including those sedated or with subcortical dysfunction. However, the increased entropy contradicts existing literature, suggesting that alpha-coma may represent a state of widespread cortical dysfunction likely resulting from nonhierarchical, turbulent brain activity. This indicates that the loss of consciousness does not guarantee consistent cortical measures across the whole spectrum of EEG patterns.

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The American Clinical Neurophysiology Society Guideline on Indications for Continuous Electroencephalography Monitoring in Neonates.

Wusthoff CJ, Numis AL, Pressler RM … +12 more , Chu CJ, Massey S, Clancy RR, Nguyen S, Hahn CD, Scher MS, Pilon B, King DT, Wong HN, Tsuchida TN, Riviello JJ, Shellhaas RA

J Clin Neurophysiol · 2025 Jan · PMID 39752571 · Publisher ↗

PURPOSE: Continuous EEG (cEEG) monitoring is increasingly used in the management of neonates with seizures. There remains debate on what clinically relevant information can be gained from cEEG in neonates with suspected... PURPOSE: Continuous EEG (cEEG) monitoring is increasingly used in the management of neonates with seizures. There remains debate on what clinically relevant information can be gained from cEEG in neonates with suspected seizures, at high risk for seizures, or with definite seizures, as well as the use of cEEG for prognosis in a variety of conditions. In this guideline, we address these questions using American Clinical Neurophysiology Society structured methodology for clinical guideline development. METHODS: A working group was formed from American Clinical Neurophysiology Society membership with expertise in neonatal cEEG and a set of priority questions developed. We performed literature searches in PubMed and EMBASE to identify relevant studies. Evidence tables were compiled from extracted data and quality assessments performed. A modification of the GRADE process was used to evaluate the body of evidence and draft recommendations. RESULTS: Our working group identified six priority questions to evaluate the accuracy of cEEG for neonatal seizure diagnosis and the formulation of prognosis. An initial literature search yielded 18,167 results, which were distilled to a set of 217 articles. Overall, the quality of evidence for most priority questions was rated as very low and we provided conditional recommendations based on published literature and expert consensus. For each priority question, we also considered the benefits and harms of cEEG, with relative harms considered to be far less than the potential benefits across recommendations. CONCLUSIONS: We present evidence-based clinical guidelines regarding indications for cEEG monitoring in neonates. Considering resource utilization and feasibility, when cEEG monitoring results have a likelihood of altering clinical decision making, the authors felt the resource investment was justifiable.

Journal Of Clinical Neurophysiology[JOURNAL]

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