Late-onset nocturnal intractable seizure during sleep: what is the origin?

A 54-year-old man was admitted to the Sleep Laboratory, Hospital of Kaunas University of Medicine, for assessment of nocturnal seizures of unknown origin during sleep. This patient complained of increasing daytime sleepiness, morning headaches. Before the admission to the Sleep Laboratory, the treatment with depakine and clonazepam had been prescribed. Despite the treatment, the frequency of nocturnal seizures and daytime sleepiness increased. Full night polysomnography was performed. Ten central apneas were registered during all night. Two central sleep apneas with deep desaturation followed by generalized tonicclonic seizures were documented. First sleep apnea lasted for 180 seconds and was terminated by epileptic tonic-clonic seizures. The second central sleep apnea with oxygen desaturation of 65% was detected 20 minutes later. It lasted for 200 seconds and was also terminated by epileptic tonic-clonic seizures. The conclusion was drawn that the patient had epileptic seizures caused by central sleep apneas with deep oxygen desaturation. The treatment with nasal continuous positive airway pressure device was started. The seizures disappeared completely. Clonazepam was stopped. Depakine was gradually withdrawn during the two weeks. One-year follow-up showed very good compliance, no seizures, and diminished daytime sleepiness.