Journal article
Prolonged Postictal hypercapnia is associated with Delayed Recovery of Consciousness after Generalized Convulsive Seizure
Seizure (London, England)
07/03/2026
DOI: 10.1016/j.seizure.2026.07.006
Abstract
•Interictal central CO2 chemosensitivity as measured by the hypercapnic ventilatory response is negatively associated with the severity of postictal hypercapnia following GCS.•Duration of postictal hypercapnia is associated with longer latency to early signs of recovery of consciousness (ROC) following GCS.•Preictal hypercapnia and longer PGES duration are associated with a longer duration of postictal immobility (PI) following GCS.•An impaired HCVR, delayed ROC and prolonged duration of PI should be further studied as potential biomarkers for SUDEP.
Postictal impairment of breathing and arousal is a significant contributor in many SUDEP cases. Central CO2 chemoreception, which mediates ventilatory response, is often blunted after generalized convulsive seizures (GCS). It is plausible that the central chemoreceptors that mediate arousal in response to hypercapnia are similarly impaired after GCS, thereby contributing to delayed recovery of consciousness (ROC). Therefore, we hypothesized that greater severity of postictal hypercapnia is associated with longer latency to early signs of ROC following GCS.
Epilepsy patients were monitored with video-EEG, respiratory effort and airflow, transcutaneous (Tc) CO2, and pulse oximetry. Primary outcomes were latency to early signs of ROC and duration of postictal immobility (PI). The interictal hypercapnic ventilatory response (HCVR) was measured in a subset of patients. Univariable and multivariable generalized linear models were created.
A total of 149 GCS were recorded from 86 of 351 participants. Evaluable peri-ictal TcCO2 and video-EEG data were available in 47 GCS in 38 participants (Female = 50%). In multivariable models, duration of postictal hypercapnia and temporal lobe seizures were significantly associated with prolonged latency to early signs of ROC, while preictal TcCO₂ level and postictal generalized EEG suppression (PGES) duration were significantly associated with PI duration. Interictal HCVR slope was negatively associated with postictal hypercapnia.
Interictal HCVR is negatively associated with postictal hypercapnia, and the latter is associated with delayed ROC. In addition, preictal TcCO2 and PGES duration are associated with PI duration. The significance of these findings should be examined in future studies as potential risk markers for SUDEP.
Details
- Title: Subtitle
- Prolonged Postictal hypercapnia is associated with Delayed Recovery of Consciousness after Generalized Convulsive Seizure
- Creators
- Rup K. Sainju - Department of Neurology, University of Iowa, Iowa City, IAPaula K. Lee - University of IowaDeidre N. Dragon - University of IowaHarold B. Winnike - University of IowaJustin D. Kuhn - University of IowaJeni I. Michelson - University of IowaEduardo Bravo - University of IowaJohnson P. Hampson - The University of Texas Health Science Center at HoustonSamden Lhatoo - The University of Texas Health Science Center at HoustonLinder H. Wendt - University of IowaPatrick Ten Eyck - Institute for Clinical and Translational Science, University of Iowa, Iowa City, IAGordon F. Buchanan - Department of Neurology, University of Iowa, Iowa City, IABrian K. Gehlbach - University of IowaGeorge B. Richerson - Department of Neurology, University of Iowa, Iowa City, IA
- Resource Type
- Journal article
- Publication Details
- Seizure (London, England)
- DOI
- 10.1016/j.seizure.2026.07.006
- ISSN
- 1059-1311
- Publisher
- Elsevier Ltd
- Language
- English
- Electronic publication date
- 07/03/2026
- Academic Unit
- Neurology; Molecular Physiology and Biophysics; Pulmonary, Critical Care, and Occupational Medicine; Clinical Research Unit; Iowa Neuroscience Institute; Biostatistics; Neurosurgery; Internal Medicine; Design Biostat and Ethics
- Record Identifier
- 9985180789502771
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