title: Hypogyrification in obsessive-compulsive disorder.
abstract: BACKGROUND
  Previous studies hypothesized that neurodevelopmental risk factors may play a role in the pathogenesis of obsessive-compulsive disorder (OCD). Cortical folding has been shown to be a reliable indicator for normal and altered neurodevelopment, but in OCD it has barely been investigated up to now. The present study investigates whether alterations in gyrification are detectable in OCD and, if so, how these are associated with clinical characteristics.
  
  
  METHODS
  We compared the local Gyrification Index (lGI) between 75 OCD patients and 75 matched healthy subjects across the whole brain. In addition, for those regions exhibiting an altered lGI in patients we explored a potential relationship to symptom severity, age of onset, and influence of medication.
  
  
  RESULTS
  OCD patients had a significantly decreased lGI in right parietal, precentral but also insula, temporal, pars triangularis and rostral middle frontal regions compared to healthy subjects. A positive association with age of onset was found but no association with symptom severity. There was no effect of co-morbidity or medication.
  
  
  CONCLUSIONS
  The reduced gyrification found in OCD confirms previous findings in other psychiatric disorders and suggests that alterations may already occur during early stages of brain development. Our findings support the idea that altered cortical folding might represent a trait characteristic of the disorder although longitudinal studies are needed to clarify the trajectory of this morphological measure in OCD.
authors.affiliation: Department of Neuroradiology,Klinikum rechts der Isar, Technische Universität München,Munich,Germany.
authors.forename: O G
authors.initials: OG
authors.lastname: Rus
authors.affiliation: Department of Neuroradiology,Klinikum rechts der Isar, Technische Universität München,Munich,Germany.
authors.forename: T J
authors.initials: TJ
authors.lastname: Reess
authors.affiliation: Department of Psychiatry and Psychotherapy,Jena University Hospital,Jena,Germany.
authors.forename: G
authors.initials: G
authors.lastname: Wagner
authors.affiliation: Windach Institute and Hospital of Neurobehavioural Research and Therapy (WINTR),Windach,Germany.
authors.forename: M
authors.initials: M
authors.lastname: Zaudig
authors.affiliation: Department of Neuroradiology,Klinikum rechts der Isar, Technische Universität München,Munich,Germany.
authors.forename: C
authors.initials: C
authors.lastname: Zimmer
authors.affiliation: Department of Neuroradiology,Klinikum rechts der Isar, Technische Universität München,Munich,Germany.
authors.forename: K
authors.initials: K
authors.lastname: Koch
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000000981:diagnostic imaging / Q000473:pathology*; D055815:Young Adult
keywords: Cortical folding; freesurfer; gyrification OCD; local gyrification index; obsessive compulsive disorder