title: Subcortical functioning in obsessive-compulsive disorder: an exploratory EEG coherence study.
abstract: BACKGROUND
  Given the paucity of quantitative EEG studies using coherence measures to understand the electrophysiological functional integrity of sub-cortical structures in obsessive-compulsive disorder, the current study was carried out.
  
  
  METHODS
  We obtained EEG coherence values for 20 adult OCD patients (10 males; 10 females) and 19 appropriately matched healthy controls across delta (0.5-3.5 Hz), theta (4-7.5 Hz), alpha (8-12 Hz), beta1 (12.5-20 Hz) and beta2 (20.5-30 Hz) bands. As coherence between distant brain regions reflects physiological activities at sub-cortical neural networks, we chose EEG channels at four distant brain regions - anterior interhemispheric, posterior interhemispheric, fronto-temporal and fronto-occipital.
  
  
  RESULTS
  In comparison to controls we found significant increase of theta band EEG coherence in the fronto-occipital region in OCD patients (P = 0.045) which did not correlate significantly with either medication status or disease severity.
  
  
  CONCLUSIONS
  This EEG coherence study that suggests hyperactivity at subcortical circuitry in OCD patients is in agreement with existing neuro-imaging findings. Furthermore, this finding provides external validity for sub-cortical dysfunction hypothesis of OCD.
authors.affiliation: Centre for Cognitive Neuroscience, Central Institute of Psychiatry, Ranchi, Jharkhand, India. pushpalds@yahoo.com
authors.forename: Pushpal
authors.initials: P
authors.lastname: Desarkar
authors.forename: Vinod Kumar
authors.initials: VK
authors.lastname: Sinha
authors.forename: Karuppiah
authors.initials: K
authors.lastname: Jagadheesan
authors.forename: Shamshul Haque
authors.initials: SH
authors.lastname: Nizamie
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000503:physiopathology*