Abstracts

Rationale: Many causes exist for apparent life-threatening events (ALTE) in infants, and determining the causes is important for treatment. Epilepsy, as a manifestation of an ALTE, is sometimes a diagnostic challenge. Like ALTE, cardiac abnormalities, respiratory abnormalities, and a combination of both are postulated to cause sudden unexpected death in epilepsy (SUDEP). Therefore, it is important to understand the interaction between seizures, and cardiopulmonary function. In this study, we describe two cases of temporal lobe epilepsy presenting as ALTE. Methods: We reviewed two pediatric patients at the Stollery Children's Hospital that presented with focal epilepsy as an ALTE for the first time. Both patients had extensive diagnostic work-ups including electrocardiogram (ECG), pulse oximetry, brain magnetic resonance imaging (MRI), interictal electroencephalogram (EEG), and long-term video EEG. Results: We found that, while both patients had normal ECGs, pulse oximetry studies, brain MRI, and interictal EEG, a long-term video EEG showed that the sequence of seizure for both patients began with altered level of consciousness followed by tachycardia, then oxygen desaturation followed by bradycardia and respiratory arrest. For both patients the ictal discharges originated from the left temporal areas preceding onset of arrest. Conclusions: Determining the cause of an ALTE is crucial as the treatment differs in each condition. It is also important to understand the sequence of events leading to the arrest as they may play a role crucial in identifying the cause of an ALTE. In this study, using telemetry studies, we demonstrated that the ictal left temporal lobe discharges as a manifestation of an ALTE. While an interictal routine EEG can be unreliable, a long-term telemetry study may be very valuable in identifying the sequence of events in which a diagnostic challenge exists in determining the cause of an ALTE.