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Postictal generalized EEG suppression and respiratory dysfunction following generalized tonic–clonic seizures in sleep and wakefulness
Author(s) -
Peng Weifeng,
Danison Jessica L.,
Seyal Masud
Publication year - 2017
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/epi.13805
Subject(s) - wakefulness , epilepsy , anesthesia , electroencephalography , psychology , non rapid eye movement sleep , tonic (physiology) , medicine , rapid eye movement sleep , neuroscience
Summary Objective Sudden unexpected death in epilepsy ( SUDEP ) is a common cause of death in epilepsy and frequently occurs following generalized tonic–clonic seizures ( GTCS ) in sleep. Postictal generalized electroencephalography (EEG) suppression ( PGES ), postictal immobility, and periictal respiratory dysfunction are potential risk factors for SUDEP . We sought to determine whether there was a difference in respiratory dysfunction, PGES , and postictal immobility for GTCS occurring during wakefulness or sleep. Methods We retrospectively analyzed video‐ EEG telemetry data in the epilepsy‐monitoring unit. Patients’ state at seizure onset and seizure characteristics were identified. Respiratory parameters and heart rate were recorded. Presence and duration of PGES and time to first postictal nonrespiratory movement were recorded. Results There were 165 seizures in 67 patients. There was no significant difference in the duration of postictal immobility in GTCS occurring out of wakefulness or sleep (p = 0.280). Oxygen desaturation nadir (p = 0.572) and duration of oxygen desaturation were not significantly different for GTCS starting during sleep or wakefulness (p = 0.992). PGES occurred more frequently when seizure onset was in sleep than in wakefulness (p = 0.004; odds ratio [ OR ] 2.760). There was no difference in the duration of PGES between the two groups. Significance PGES occurs more commonly after GTCS in sleep than in wakefulness but, in the epilepsy‐monitoring unit ( EMU ), a patient's state at seizure onset does not affect the degree of respiratory dysfunction or duration of postictal immobility. In sleep, outside the hospital setting, GTCS are likely to go unnoticed. Postictal immobility in prone patients prevents head repositioning and unimpeded air exchange. A positive feedback cycle ensues with increasing respiratory distress, potentiating postictal immobility and PGES and eventually leading to asystole. Our findings suggest that the high incidence of nocturnal SUDEP may be related to the unsupervised environment during sleep rather than the severity of sleep‐related respiratory dysfunction or PGES duration in the immediate postictal period.