title: Assessment of non-motor hearing symptoms in hemifacial spasm using magnetoencephalography.
abstract: BACKGROUND
  Hemifacial spasm patients often suffer from non-motor symptoms such as tinnitus. These non-motor symptoms are known to be associated with changes in cortical activity. Magnetoencephalography (MEG) is a technique that can record brain activity noninvasively. To determine the usefulness of MEG in assessing changes in cortical activity associated with non-motor hearing symptoms in hemifacial spasm patients.
  
  
  METHODS
  We used MEG to evaluate the reactivity of the auditory cortex in 26 hemifacial spasm patients. We divided patients into a subjective tinnitus group (n = 10) and a non-tinnitus group (n = 16). The latency and amplitude of the most prominent deflection, N100m, was compared between the two groups.
  
  
  RESULTS
  There was a significant difference in the pure tone audiogram on the spasm side compared with the non-spasm side. After stimulation on the spasm side, the amplitude of the N100m peak in the contralateral hemisphere was lower in the subjective tinnitus group than in the non-tinnitus group.
  
  
  CONCLUSIONS
  Our results indicate that MEG can detect differences in cortical activity between hemifacial spasm patients with and without tinnitus. This suggests that MEG can identify changes in cortical activity associated with non-motor symptoms.
authors: Department of Neurosurgery, Yonsei University College of Medicine, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul, Korea.
authors: Young Seok
authors: YS
authors: Park
authors: Bong Soo
authors: BS
authors: Kim
authors: Dong Kyu
authors: DK
authors: Lee
authors: Seung-Koo
authors: SK
authors: Lee
authors: Hyuk Chan
authors: HC
authors: Kwon
authors: Kiwoong
authors: K
authors: Kim
authors: Yong Ho
authors: YH
authors: Lee
authors: Jin Woo
authors: JW
authors: Chang
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D019569:Hemifacial Spasm / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D014012:Tinnitus / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology