Abstracts

Rationale: Pulmonary edema (PE) is one factor that may lead to sudden unexpected death in epilepsy (SUDEP). PE has been reported after seizures in several case reports. PE is invariably present in cases of SUDEP coming to autopsy. PE is present in almost all baboons dying of presumed SUDEP. However, several recent reviews on SUDEP suggest that PE following seizures is mild, infrequent and not likely a cause of SUDEP. We investigated the incidence of PE following generalized convulsions (GC) in patients admitted to the epilepsy monitoring unit (EMU). Methods: Chest X-Rays (CXR) following GC were obtained in consecutive patients admitted to the EMU. Delay to CXR following GC, seizure lateralization and localization, seizure duration, duration and severity of ictal/postictal oxygen desaturation (SpO2), ictal apnea duration and duration of postictal generalized EEG suppression (PGES), when present, were recorded. Logistic regression was used to study the relationship between presence or absence of CXR abnormalities and seizure/patient characteristics. Results: Forty two CXR were obtained in 24 patients after GC. Eleven of the 24 patients had at least 1 abnormal CXR following a GC. In this group of 11 patients, a total of 22 CXR were obtained following GC and abnormalities were present in 15 CXR. Abnormalities included pulmonary edema/congestion in 7 patients, of which 2 also had focal infiltrates. Focal infiltrates only were present in 4 patients. No abnormalities were present in 13 patients on any CXR following a GC. There was no significant difference in mean delay to CXR following GC in the group of GC with abnormal CXR (225 min) versus those with normal CXR (196 min). The duration of ictal/postictal apnea, duration of oxygen desaturation, SpO2 nadir or PGES duration were not significantly different in GC with abnormal CXR versus those with normal CXR. The mean seizure duration was significantly longer (p=0.002) in the group of GC with postictal abnormal CXR (259.7 sec) versus those with normal CXR (101.2 sec). The odds-ratio for presence of CXR abnormality was 20.46 (p=0.0059) when seizure duration was greater than 100 sec versus seizures less than 100 sec. On multivariable analysis, only the seizure duration was a significant predictor of CXR abnormality (p=0.015). Conclusions: Radiographic abnormalities are not uncommon following GC. The presence of CXR abnormality is significantly associated with the duration of the preceding GC. Severe, untreated pulmonary edema may be relevant to the pathophysiology of SUDEP.