title: N-acetylaspartate reductions in the mediodorsal and anterior thalamus in men with schizophrenia verified by tissue volume corrected proton MRSI.
abstract: OBJECTIVE
  Deficits in the mediodorsal and anterior nuclei of the thalamus may contribute to the psychopathological symptoms of schizophrenia. These thalamic nuclei have been found to be abnormal in schizophrenia and have close connections with other brain structures implicated in the disorder. We therefore examined schizophrenia-related alterations in brain metabolite levels specifically in the mediodorsal and anterior thalamic subregions.
  
  
  METHODS
  We used in vivo proton magnetic resonance spectroscopic imaging ((1)H MRSI) to measure N-acetylaspartate (NAA), choline-containing compounds (Cho), and creatine+phosphocreatine (Cr) in the mediodorsal and anterior thalamus in 22 male patients with schizophrenia and 22 male controls. Magnetic resonance imaging (MRI) tissue segmentation and thalamic volume mask techniques were performed to distinguish the thalamus, extrathalamic gray and white matter, and CSF within the spectroscopic voxels.
  
  
  RESULTS
  Compared to healthy subjects, patients with schizophrenia had significantly lower NAA in the mediodorsal and anterior thalamus bilaterally. No significant differences in Cho or Cr levels were seen. NAA was significantly higher in the left thalamus relative to the right in both groups. We found a strong negative correlation between left thalamic NAA and duration of illness, even after partialling out the effect of age. Tissue segmentation and thalamic volume mask techniques detected no group or lateralized differences in tissue type or CSF percentages, demonstrating that the metabolite reductions were not an artifact of spectroscopic voxel heterogeneity.
  
  
  CONCLUSIONS
  These findings suggest diminished function and/or structure in the mediodorsal and anterior thalamus in male patients with schizophrenia and support earlier research demonstrating schizophrenia-related abnormalities in the thalamus and its circuitry.
authors.affiliation: Psychiatry Service, 116-N, Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Jakary
authors.forename: Sophia
authors.initials: S
authors.lastname: Vinogradov
authors.forename: Robert
authors.initials: R
authors.lastname: Feiwell
authors.forename: Raymond F
authors.initials: RF
authors.lastname: Deicken
mesh_terms: D000328:Adult; D020643:Anterior Thalamic Nuclei / Q000033:anatomy & histology* / Q000378:metabolism*; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D020645:Mediodorsal Thalamic Nucleus / Q000033:anatomy & histology* / Q000378:metabolism*; D011522:Protons; D012559:Schizophrenia / Q000378:metabolism*
chemical_list: D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline