A 36-year-old male, without conventional risk factors for epilepsy, developed seizure-like episodes 2 years ago, characterized by loss of awareness and convulsions, for which he was referred to the epilepsy monitoring unit (EMU) for seizure characterization. In the EMU, multiple nocturnal focal left temporal seizures without bilateral tonic–clonic evolution (Figure 1, Figure S1) were captured, characterized by prolonged ictal and post-ictal central apnea (ICA and PICA) lasting up to 52 and 25 s, respectively (Figure 1, Figures S2 and S3). Apnea was detected by the flattening of the thoracic and abdominal excursions monitored using respiratory inductance plethysmography (thoracic and abdominal belts).1 Brain MRI was normal, and serum autoimmune workup was negative. His seizures were well controlled on levetiracetam and lacosamide. Prolonged ICA and PICA have been identified as independent risk factors for sudden unexpected death in epilepsy2, 3 and ICA has been shown to be predictive of mesial temporal seizure onset.1 The authors received no financial support for the research, authorship, and/or publication of this article. The authors declare no conflict of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy or ethical restrictions. Figures S1–S4 Data S1 Data S2 Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Ictal central apnea has localization value, and it has predictive value of seizure onset. Which of the following has been verified in prospective studies as an independent risk factor for sudden unexpected death in epilepsy? Which of the following risk factors has the largest effect on the risk of sudden unexpected death in epilepsy? Answers may be found in the supporting information.
Zhao et al. (Thu,) studied this question.