title: MRSI correlates of cognitive-behavioral therapy in pediatric obsessive-compulsive disorder.
abstract: BACKGROUND
  The brain mechanisms of cognitive-behavioral therapy (CBT), a highly effective treatment for pediatric obsessive-compulsive disorder (OCD), are unknown. Neuroimaging in adult OCD indicates that CBT is associated with metabolic changes in striatum, thalamus, and anterior cingulate cortex. We therefore probed putative metabolic effects of CBT on these brain structures in pediatric OCD using proton magnetic resonance spectroscopic imaging (1H MRSI).
  
  
  METHODS
  Five unmedicated OCD patients (4 ♀, 13.5±2.8) and 9 healthy controls (7 ♀, 13.0±2.5) underwent MRSI (1.5 T, repetition-time/echo-time=1500/30 ms) of bilateral putamen, thalamus and pregenual anterior cingulate cortex (pACC). Patients were rescanned after 12 weeks of exposure-based CBT. The Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) of OCD symptoms was administered before and after CBT.
  
  
  RESULTS
  Four of 5 patients responded to CBT (mean 32.8% CY-BOCS reduction). Multiple metabolite effects emerged. Pre-CBT, N-acetyl-aspartate+N-acetyl-aspartyl-glutamate (tNAA) in left pregenual anterior cingulate cortex (pACC) was 55.5% higher in patients than controls. Post-CBT, tNAA (15.0%) and Cr (23.9%) in left pACC decreased and choline compounds (Cho) in right thalamus increased (10.6%) in all 5 patients. In left thalamus, lower pre-CBT tNAA, glutamate+glutamine (Glx), and myo-inositol (mI) predicted greater post-CBT drop in CY-BOCS (r=0.98) and CY-BOCS decrease correlated with increased Cho.
  
  
  CONCLUSIONS
  Interpretations are offered in terms of the Glutamatergic Hypothesis of Pediatric OCD. Similar to 18FDG-PET in adults, objectively measurable regional MRSI metabolites may indicate pediatric OCD and predict its response to CBT.
authors: Division of Child & Adolescent Psychiatry, Semel Institute for Neurosciences, Department of Radiological Sciences, UCLA School of Medicine, Los Angeles, CA 90024-1759, United States. joneill@mednet.ucla.edu
authors: Joseph
authors: J
authors: O'Neill
authors: John C
authors: JC
authors: Piacentini
authors: Susanna
authors: S
authors: Chang
authors: Jennifer G
authors: JG
authors: Levitt
authors: Michelle
authors: M
authors: Rozenman
authors: Lindsey
authors: L
authors: Bergman
authors: Noriko
authors: N
authors: Salamon
authors: Jeffry R
authors: JR
authors: Alger
authors: James T
authors: JT
authors: McCracken
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D015928:Cognitive Behavioral Therapy / Q000379:methods; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D059906:Neuroimaging / Q000379:methods; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy*; D010865:Pilot Projects