title: Reduced brain gray matter concentration in patients with obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  To investigate differences in brain gray matter concentrations or volumes in patients with obstructive sleep apnea syndrome (OSA) and healthy volunteers.
  
  
  METHODS
  Optimized voxel-based morphometry, an automated processing technique for MRI, was used to characterize structural differences in gray matter in newly diagnosed male patients.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  The study consisted of 36 male OSA and 31 non-apneic male healthy volunteers matched for age (mean age, 44.8 years).
  
  
  METHODS
  Using the t-test, gray matter differences were identified. The statistical significance level was set to a false discovery rate P < 0.05 with an extent threshold of k(E) > 200 voxels.
  
  
  RESULTS
  The mean apnea-hypopnea index (AHI) of patients was 52.5/h. On visual inspection of MRI, no structural abnormalities were observed. Compared to healthy volunteers, the gray matter concentrations of OSA patients were significantly decreased in the left gyrus rectus, bilateral superior frontal gyri, left precentral gyrus, bilateral frontomarginal gyri, bilateral anterior cingulate gyri, right insular gyrus, bilateral caudate nuclei, bilateral thalami, bilateral amygdalo-hippocampi, bilateral inferior temporal gyri, and bilateral quadrangular and biventer lobules in the cerebellum (false discovery rate P < 0.05). Gray matter volume was not different between OSA patients and healthy volunteers.
  
  
  CONCLUSIONS
  The brain gray matter deficits may suggest that memory impairment, affective and cardiovascular disturbances, executive dysfunctions, and dysregulation of autonomic and respiratory control frequently found in OSA patients might be related to morphological differences in the brain gray matter areas.
authors.affiliation: Sleep Center, Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eun Yeon
authors.initials: EY
authors.lastname: Joo
authors.forename: Woo Suk
authors.initials: WS
authors.lastname: Tae
authors.forename: Min Joo
authors.initials: MJ
authors.lastname: Lee
authors.forename: Jung Woo
authors.initials: JW
authors.lastname: Kang
authors.forename: Hwan Seok
authors.initials: HS
authors.lastname: Park
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Minah
authors.initials: M
authors.lastname: Suh
authors.forename: Seung Bong
authors.initials: SB
authors.lastname: Hong
mesh_terms: D000328:Adult; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D004292:Dominance, Cerebral / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000502:physiology; D017286:Polysomnography; D012016:Reference Values; D020181:Sleep Apnea, Obstructive / Q000473:pathology*