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) Videos 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 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 Choi, K. -D. Articles by Kim, J. S. Search for Related Content PubMed Articles by Choi, K. -D. Articles by Kim, J. S. Related Collections Related Article

Head-shaking nystagmus in lateral medullary infarction

Patterns and possible mechanisms

From the Departments of Neurology (K.-D.C., S.-Y.O., S.-H.P., J.S.K.), Radiology (J.-H.K.), and Otolaryngology (J.-W.K.), College of Medicine, Seoul National University, Seoul National University Bundang Hospital, Seoul, Korea; and Department of Neurology (K.-D.C.), Pusan National University School of Medicine and Medical Research Institute, Pusan National University, Pusan, Korea.

Address correspondence and reprint requests to Dr. Ji Soo Kim, Department of Neurology, College of Medicine, Seoul National University, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707, Korea jisookim{at}snu.ac.kr

Objective: Horizontal head shaking at 2 to 3 Hz can induce nystagmus in patients with central as well as in patients with peripheral vestibulopathy. However, the characteristics and diagnostic value of this post-head-shaking nystagmus (HSN) have not been studied systematically in central vestibulopathy, and little is known of the mechanisms involved.

Methods: We analyzed spontaneous and HSN and the effects of baclofen, a GABA_B agonist, in 16 patients with acute lateral medullary infarction.

Results: These patients showed several characteristics of HSN unlike those observed in peripheral vestibulopathy. HSN was observed in 14 of 16 patients (87.5%), and in all cases, the horizontal component beats toward the lesion side, i.e., was ipsilesional. Even in the eight patients with contralesional spontaneous horizontal nystagmus, the HSN was opposite to the spontaneous nystagmus. Three patients showed unusually strong HSN with a maximum slow-phase velocity greater than 60 degrees/second. Visual fixation markedly suppressed HSN and baclofen reduced HSN. In most of the patients, MRI showed infarctions in the caudal or middle portion of the medulla and spared the rostral portion.

Conclusions: We propose that head-shaking nystagmus in lateral medullary infarction is due to unilaterally impaired nodulouvular inhibition of the velocity storage. This proposal is consistent with the results of neuroanatomic studies that demonstrate that Purkinje cells controlling velocity storage in the nodulus and ventral uvula project to the caudal or middle portion of the vestibular nuclei, whereas those subserving visual-vestibular interactions in the flocculus project to the more rostral portion.

Editorial, see page 1333

Supplemental data at www.neurology.org

Received December 20, 2005. Accepted in final form February 2, 2007.

Disclosure: The authors report no conflict of interest.

Related Article

Head-shaking nystagmus and new technology

Timothy C. Hain
Neurology 2007 68: 1333-1334. [Full Text] [PDF]

This article has been cited by other articles:

				T. C. Hain Head-shaking nystagmus and new technology Neurology, April 24, 2007; 68(17): 1333 - 1334. [Full Text] [PDF]