title: Neuroanatomical characteristics associated with response to dorsal anterior cingulotomy for obsessive-compulsive disorder.
abstract: OBJECTIVE
  Approximately 10% of patients with obsessive-compulsive disorder (OCD) have symptoms that are refractory to pharmacologic and cognitive-behavioral therapies. Neurosurgical interventions can be effective therapeutic options in these patients, but not all individuals respond. The mechanisms underlying this response variability are poorly understood.
  
  
  OBJECTIVE
  To identify neuroanatomical characteristics on preoperative imaging that differentiate responders from nonresponders to dorsal anterior cingulotomy, a neurosurgical lesion procedure used to treat refractory OCD.
  
  
  METHODS
  We retrospectively analyzed preoperative T1 and diffusion magnetic resonance imaging sequences from 15 patients (9 men and 6 women) who underwent dorsal anterior cingulotomy. Eight of the 15 patients (53%) responded to the procedure.
  
  
  METHODS
  We used voxel-based morphometry (VBM) and diffusion tensor imaging to identify structural and connectivity variations that could differentiate eventual responders from nonresponders. The VBM and probabilistic tractography metrics were correlated with clinical response to the cingulotomy procedure as measured by changes in the Yale-Brown Obsessive Compulsive Scale score.
  
  
  RESULTS
  Voxel-based morphometry analysis revealed a gray matter cluster in the right anterior cingulate cortex, anterior to the eventual lesion, for which signal strength correlated with poor response (P = .017). Decreased gray matter in this region of the dorsal anterior cingulate cortex predicted improved response (mean [SD] gray matter partial volume for responders vs nonresponders, 0.47 [0.03] vs 0.66 [0.03]; corresponding to mean Yale-Brown Obsessive Compulsive Scale score change, -60% [19] vs -11% [9], respectively). Hemispheric asymmetry in connectivity between the eventual lesion and the caudate (for responders vs nonresponders, mean [SD] group laterality for individual lesion seeds, -0.79 [0.18] vs -0.08 [0.65]; P = .04), putamen (-0.55 [0.35] vs 0.50 [0.33]; P = .001), thalamus (-0.82 [0.19] vs 0.41 [0.24]; P = .001), pallidum (-0.78 [0.18] vs 0.43 [0.48]; P = .001), and hippocampus (-0.66 [0.33] vs 0.33 [0.18]; P = .001) also correlated significantly with clinical response, with increased right-sided connectivity predicting greater response.
  
  
  CONCLUSIONS
  We identified features of anterior cingulate cortex structure and connectivity that predict clinical response to dorsal anterior cingulotomy for refractory OCD. These results suggest that the variability seen in individual responses to a highly consistent, stereotyped procedure may be due to neuroanatomical variation in the patients. Furthermore, these variations may allow us to predict which patients are most likely to respond to cingulotomy, thereby refining our ability to individualize this treatment for refractory psychiatric disorders.
authors.affiliation: Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York.
authors.forename: Garrett P
authors.initials: GP
authors.lastname: Banks
authors.affiliation: Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Mikell
authors.affiliation: Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York.
authors.forename: Brett E
authors.initials: BE
authors.lastname: Youngerman
authors.affiliation: College of Physicians and Surgeons, Columbia University, New York, New York.
authors.forename: Bryan
authors.initials: B
authors.lastname: Henriques
authors.affiliation: Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Kelly
authors.affiliation: Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York.
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Chan
authors.affiliation: Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York.
authors.forename: Diana
authors.initials: D
authors.lastname: Herrera
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital, Boston.
authors.forename: Darin D
authors.initials: DD
authors.lastname: Dougherty
authors.affiliation: Department of Neurosurgery, Massachusetts General Hospital, Boston.
authors.forename: Emad N
authors.initials: EN
authors.lastname: Eskandar
authors.affiliation: Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York.
authors.forename: Sameer A
authors.initials: SA
authors.lastname: Sheth
mesh_terms: D000328:Adult; D056324:Diffusion Tensor Imaging; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000601:surgery*; D017063:Outcome Assessment, Health Care; D011612:Psychosurgery / Q000379:methods*; D055815:Young Adult