The Lateralizing Value of Asymmetric Generalized Tonic-Clonic Seizure

J Korean Neurol Assoc > Volume 14(2); 1996 > Article

Journal of the Korean Neurological Association 1996;14(2): 408-414.

비대칭형 전신성 근간대성 경련의 간질 병소 일측화의 예측에 대한 효용성

김지수, 이상건

서울대학교 의과대학 신경과학교실

The Lateralizing Value of Asymmetric Generalized Tonic-Clonic Seizure

Ji Soo Kim, M.D., Sang Kun Lee, M.D.

Department of Neurology, College of Medicine, Seoul National University Hospital

Abstract

Background : Ictal semiology is very important in inferring the seizure generating brain structures. Asymmetric tonic posture(one elbow is extended while the other is flexed during tonic phase) may occur during generalized tonic clonic(GTC) seizure. The lateralizing value of asymmetric GTC seizure is controversial. Object : To evaluate the lateralizing value of asymmetric GTC seizure, we undertook this study. Methods : The videotapes of 148 patients who underwent video-EEG monitoring in Seoul National University Hospital Epilepsy Monitoring Unit from September 1994 to July 1995, were reviewed, The localization of seizure focus was based on the findings of interictal & ictal EEG, brain MRI, interictal & ictal SPECT, PET, cognitive function test and invasive EEG. The asymmetric tonic postures were classified into 4 classes : 1. Consistent ; the asymmetric posture lasting from the onset of seizure generalization to seizure termination 2. Initial ; the asymmetric posture starting from the onset of seizure generalization , but followed by symmetric tonic flexion or extension. 3. Terminal ; the asymmetric posture following the symmetric tonic flexion or extension. 4. Alternating ; the asymmetric posture alternating during seizure. Results : Total 747 seizures were reviewed. There were 81 asymmetric seizures in 37 patients. 3 patients (4 asymmetric seizures) had generalized onset and these patients were excluded. There were 32 consistent, 20 initial, 22 terminal and 3 alternating asymmetric GTC seizures. In 21 out of 34 patients (62%) , the extended arm was contralateral to seizure onset. Especially in the case of consistent and initial asymmetric posture, the extended arm was contralateral to seizure onset in 94% and 100% respectively. Conclusion : The consistent and initial asymmetric posture during GTC seizure provide good lateralizing information.