title: Transcranial direct current stimulation to lessen neuropathic pain after spinal cord injury: a mechanistic PET study.
abstract: BACKGROUND
  It is suggested that transcranial direct current stimulation (tDCS) can produce lasting changes in corticospinal excitability and can potentially be used for the treatment of neuropathic pain. However, the detailed mechanisms underlying the effects of tDCS are unknown.
  
  
  OBJECTIVE
  We investigated the underlying neural mechanisms of tDCS for chronic pain relief using [(18)F]-fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET).
  
  
  METHODS
  Sixteen patients with neuropathic pain (mean age 44.1 ± 8.6 years, 4 females) due to traumatic spinal cord injury received sham or active anodal stimulation of the motor cortex using tDCS for 10 days (20 minutes, 2 mA, twice a day). The effect of tDCS on regional cerebral glucose metabolism was evaluated by [(18)F]FDG-PET before and after tDCS sessions.
  
  
  RESULTS
  There was a significant decrease in the numeric rating scale scores for pain, from 7.6 ± 0.5 at baseline to 5.9 ± 1.8 after active tDCS (P = .016). We found increased metabolism in the medulla and decreased metabolism in the left dorsolateral prefrontal cortex after active tDCS treatment compared with the changes induced by sham tDCS. Additionally, an increase in metabolism after active tDCS was observed in the subgenual anterior cingulate cortex and insula.
  
  
  CONCLUSIONS
  The results of this study suggest that anodal stimulation of the motor cortex using tDCS can modulate emotional and cognitive components of pain and normalize excessive attention to pain and pain-related information.
authors.affiliation: 1Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Yoon
authors.forename: Yu Kyeong
authors.initials: YK
authors.lastname: Kim
authors.forename: Hye-Ri
authors.initials: HR
authors.lastname: Kim
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Kim
authors.forename: Youngjo
authors.initials: Y
authors.lastname: Lee
authors.forename: Hyung Ik
authors.initials: HI
authors.lastname: Shin
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D059350:Chronic Pain / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D004599:Electric Stimulation Therapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology; D009437:Neuralgia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy*; D059408:Pain Management / Q000379:methods; D010147:Pain Measurement; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: FDG-PET; neuropathic pain; spinal cord injury; transcranial direct current stimulation