Neurophysiological Studies in a Patient with Hyperekplexia

J Korean Neurol Assoc > Volume 13(4); 1995 > Article

Journal of the Korean Neurological Association 1995;13(4): 970-978.

병적 놀람증 (Hyperekplexia ; pathological startle)환자에서의 ?신경생리학적 검사

이명식, 이상복, 김용덕, 김원찬, 최영철

연세대학교 영동세브란스병원 신경과

Neurophysiological Studies in a Patient with Hyperekplexia

Myung Sik Lee, M.D., Sang Bock Lee, M.D., Yong Duk Kim, M.D., Won Chan Kim, M.D., Young Cheol Choi, M.D

Department of Neurology, Severance Hoispital Yonsei University,College of Medicine

Abstract

The results of neurophysiological studies in a 20 year-old man who had pathological jumps and falls following unexpected auditory stimuli is presented. He also had action induced hemidystonia and polymyoclonus involving fingers of the both hands. Somatosensory evoked potential study showed no giant cortical wave and jerk-locked back averaging electroencephalogram showed no jerk ,related cortical event. Polymyographic study after auditory stimuli showed electromyographic (EMG) bursts recruitment pattern consistent with hyprekplexia ai)d reticular reflex myocloniis. EMG bursts spread rostrally and caudally from the sternocleidomastoid muscle via a slowly conducting neuronal pathways. These findings are compatible. With hyperekplexia. Pathologically increased gain of the brainstem reticular formation seems to cause hyperekplexia.