Abstracts

Rationale: Excessive daytime sleepiness (EDS) is common in the general population. Etiologies include insufficient sleep, primary sleep disorders and medications. Due to its high prevalence, EDS is often overlooked by physicians. However, EDS may also be the presenting symptom of seizures. We report a series of three patients with nocturnal frontal lobe epilepsy (NFLE) who presented with a primary complaint of EDS. Methods: Retrospective review of clinical data, including polysomnography (PSG) and EEG. Results: Case 1: A 23 year old man presented with EDS and an elevated Epworth Sleepiness Scale (ESS) score of 13. His roommate had observed abnormal movements in sleep, including sitting up in bed and looking around the room, and bicycling movements with posturing of the left arm and leg. The patient was amnestic of these events. A sleep diary excluded insufficient sleep time. PSG was performed with a full set of EEG channels. Except for sleep fragmentation, no primary sleep disorders were seen. Multiple sleep latency testing (MSLT) was consistent with objective hypersomnia. EEG showed rhythmic, frontally predominant sharp wave activity corresponding to clinical seizures, which consisted of blinking, head turning and left arm elevation. Case 2: A 33 year old woman presented with EDS and an elevated ESS score of 18. Her husband had observed 6 episodes of sleep-related movements, which began with a moan and extension of both arms overhead, followed by confusion without event recall. Prior routine and ambulatory EEGs were nondiagnostic. A sleep diary excluded insufficient sleep time. PSG showed sleep fragmentation without evidence for other primary sleep disorders. MSLT was significant for shortened mean sleep latency. One day after PSG, the patient had an episode where she turned pale, with eyes rolling into the back of the head, followed by tonic-clonic activity and impaired consciousness. EEG during hospital admission showed interictal left frontal sharp waves. Case 3: A 23 year old man presented with EDS and an elevated ESS score of 10. During sleep, his roommates reported events consisting of limb movements associated with vocalization, during which the patient was unable to respond, and for which he had no recall. He reported a daily sleep duration of 7.5 hours. Except for EDS, there were no features suggestive of sleep disordered breathing. Inpatient video-EEG monitoring was performed. Interictal sharp waves were present in the left frontotemporal and right temporal region, and several seizures were recorded. A focal seizure of left frontotemporal onset correlated with right leg movements. In the second event, the patient's eyes opened from sleep, followed by bicycling movements, which corresponded to electrographic seizures of left frontocentrotemporal onset with secondary generalization. A third seizure of right temporal onset with rapid generalization did not exhibit clear clinical manifestations. Conclusions: EDS may present as the primary symptom of seizures. In patients with EDS and a history of stereotyped nocturnal events, clinical suspicion should be high for NFLE.