Abstract: Objective To evaluate the lateralizing value of electrical and clinical semiology in patients with bilateral extremities tonic seizure (BETS). Methods Ninety-two times of BETS were retrospectively observed from 26 patients with focal epilepsy, based on the surgery and follow-up results. The ictal electroencephalography(EEG),synchronous surface electromyography(EMG) and clinical symptoms were collected. Results The EEGs were correctly lateralizing in 59.8%(55/92)seizures.The accompanying lateral signs were correctly lateralized in 64.1%(59/92)seizures. The tonic joint movement lateralization was correct in 81.5%(75/92)seizures. The surface EMGs were 85.9%(79/92)correctly lateralized. The positivity rate of the latter two was higher than that of the first two, which was statistically significant. Conclusions Both the tonic joint movement and surface EMG have better lateralization value and guiding significance for preoperative evaluation of patients with epilepsy.

Key words: bilateral extremities tonic seizures(BETS), electrical-clinical semiology, positioning, lateralization