Clinical implications of benign epileptiform transients of sleep

One hundred electroencephalograms (EEGs) with benign epileptiform transients of sleep (BETS) were reviewed. The incidence of epileptic seizures, syncope, headaches, transient ischemic attacks (TIAs), dizziness and psychiatric complaints was determined. The incidence of these symptoms was similarly ascertained for another group of patients whose sleep EEGs had preceded (96 patients) or followed (96 patients) each of the BETS EEGs. These patients formed 2 separate internal control groups. No significant differences in the demographic composition of the 3 groups or in the incidence of symptoms or diagnoses were noted. The patients with BETS were also divided into 2 groups according to whether their EEGs were otherwise normal or abnormal. Each of these 2 groups was compared with their respective control group (pre- or post-BETS patients with normal or abnormal EEGs). No significant differences in the incidence of seizures were noted. Benign temporal epileptiform transients of sleep appear to be an occasional but clinically unimportant finding in sleep tracings.