HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hanajima, R. Articles by Ugawa, Y. Search for Related Content PubMed PubMed Citation Articles by Hanajima, R. Articles by Ugawa, Y. Related Collections Related Article

Intracortical inhibition of the motor cortex in Segawa disease (DYT5)

From the Department of Neurology, the University of Tokyo (R.H., Y.U.) and Segawa Neurological Clinic for Children (Y.N., M.S.), Tokyo, Japan.

Address correspondence and reprint requests to Dr. R. Hanajima, Department of Neurology, the University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan; e-mail: hanajima-tky{at}umin.ac.jp

Background: Segawa disease (autosomal dominant guanosine triphosphate cyclohydrolase I [GTP-I] deficiency, DYT5) is a hereditary dopa-responsive generalized dystonia.

Objective: To investigate the pathophysiologic mechanisms for dystonia in Segawa disease, we studied intracortical inhibition of the primary motor cortex in patients with Segawa disease.

Methods: We studied 9 patients with Segawa disease (8 genetically confirmed patients and 1 with abnormally low GTP-I activity) and 12 age-matched normal control subjects. We studied the active motor threshold (AMT) using single pulse transcranial magnetic stimulation (TMS) and the short-interval intracortical inhibition (SICI) of the motor cortex using the previously reported paired pulse TMS method. Responses were recorded from the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles.

Results: The AMT was not significantly different between the patients and normal subjects. For both studied muscles, in Segawa disease, normal amount of SICI was evoked at interstimulus intervals (ISIs) of 1 to 4 msec even though they had dystonia in those muscles.

Conclusion: Normal SICI of the motor cortex in Segawa disease stands in remarkable contrast to the previously reported reduction of SICI in focal dystonia. This suggests that the gamma-aminobutyric acid A system of the motor cortex is intact in Segawa disease. The pathophysiologic mechanisms for dystonia must be partly different between Segawa disease and focal dystonia.

Supported in part by Research Project Grant-in-aid for Scientific Research, No. 17590865 (R.H.), No. 16500194 (Y.U.), from the Ministry of Education, Science, Sports and Culture of Japan; grants for the Research Committee on rTMS Treatment of Movement Disorders, the Ministry of Health and Welfare of Japan (17231401); the Research Committee on Dystonia, the Ministry of Health and Welfare of Japan; a grant from the Committee of the Study of Human Exposure to EMF, Ministry of Public Management, Home Affairs, Post and Telecommunications; and grants from Life Science Foundation of Japan.

Disclosure: The authors report no conflicts of interest.

Received March 20, 2006. Accepted in final form November 27, 2006

Related Article

March 27 Highlights
Neurology 2007 68: 972. [Full Text] [PDF]

This article has been cited by other articles:

				E. Roze, E. Apartis, F. Clot, N. Dorison, S. Thobois, L. Guyant-Marechal, C. Tranchant, P. Damier, D. Doummar, N. Bahi-Buisson, et al. Myoclonus-dystonia: Clinical and electrophysiologic pattern related to SGCE mutations Neurology, March 25, 2008; 70(13): 1010 - 1016. [Abstract] [Full Text] [PDF]