Thyrotoxic Periodic Paralysis : Electrophysiologic Studies During? Paralytic Attack in Two Patients

J Korean Neurol Assoc > Volume 13(3); 1995 > Article

Journal of the Korean Neurological Association 1995;13(3): 671-675.

갑상선중독 주기성마비 : 마비시의 전기생리학적 검사 2례

양대웅, 이상암, 김광국

울산대학교 신경과

Thyrotoxic Periodic Paralysis : Electrophysiologic Studies During? Paralytic Attack in Two Patients

Dae Woong Yong, M.D., Sang Ahm Lee, M.D., Kwang Kuk Kim, M.D.

Department of Neurology, College of Medicine, University of Ulsan, Asan Medical Center

Abstract

The precise nature of the underlying disturbance responsible for TTP is unknown, but recent work suggests that abnormalities of sodium channels play an important role. There are only a few electrophysiologic studies reported during an attack of paralysis of TTP and the electrophysiologic studies during paralytic attack in our two patients showed the following results, different only in severity. 1.Nerve conduction studies were normal in all the tested sensory nerves. Motor nerves showed normal conduction velocities, but low amplitudes of CMAPs except for median nerve. 2.Needle EMG showed markedly decreased insertional activities, and lowamplitude, short-duration, and polyphasic MUAPS, The recruitment patterns on maximal efforts were markedly reduced. There were no spontaneous activities. 3.Repetitive nerve stimulation of ulnar nerve showed significant incremental responses on digiti quinti muscle, marked during the early phase of stimulation. The degree of incremental responses was proportional to the frequency of stimulation.