title: Absence of auditory M100 source asymmetry in schizophrenia and bipolar disorder: a MEG study.
abstract: BACKGROUND
  Whether schizophrenia and bipolar disorder are the clinical outcomes of discrete or shared causative processes is much debated in psychiatry. Several studies have demonstrated anomalous structural and functional superior temporal gyrus (STG) symmetries in schizophrenia. We examined bipolar patients to determine if they also have altered STG asymmetry.
  
  
  METHODS
  Whole-head magnetoencephalography (MEG) recordings of auditory evoked fields were obtained for 20 subjects with schizophrenia, 20 with bipolar disorder, and 20 control subjects. Neural generators of the M100 auditory response were modeled using a single equivalent current dipole for each hemisphere. The source location of the M100 response was used as a measure of functional STG asymmetry.
  
  
  RESULTS
  Control subjects showed the typical M100 asymmetrical pattern with more anterior sources in the right STG. In contrast, both schizophrenia and bipolar disorder patients displayed a symmetrical M100 source pattern. There was no significant difference in the M100 latency and strength in bilateral hemispheres within three groups.
  
  
  CONCLUSIONS
  Our results indicate that disturbed asymmetry of temporal lobe function may reflect a common deviance present in schizophrenia and bipolar disorder, suggesting the two disorders might share etiological and pathophysiological factors.
authors: Medical Imaging Center, First Affiliated Hospital of Jinan University, Guangzhou, China ; Clinical Experimental Center, First Affiliated Hospital of Jinan University, Guangzhou, China.
authors: Ying
authors: Y
authors: Wang
authors: Yigang
authors: Y
authors: Feng
authors: Yanbin
authors: Y
authors: Jia
authors: Yanping
authors: Y
authors: Xie
authors: Wensheng
authors: W
authors: Wang
authors: Yufang
authors: Y
authors: Guan
authors: Shuming
authors: S
authors: Zhong
authors: Dan
authors: D
authors: Zhu
authors: Li
authors: L
authors: Huang
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000503:physiopathology*; D001714:Bipolar Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*