title: Targeting the affective component of chronic pain: a case series of deep brain stimulation of the anterior cingulate cortex.
abstract: BACKGROUND
  Deep brain stimulation (DBS) has shown considerable promise for relieving nociceptive and neuropathic symptoms of refractory chronic pain. Nevertheless, for some patients, standard DBS for pain remains poorly efficacious. Pain is a multidimensional experience with an affective component: the unpleasantness. The anterior cingulate cortex (ACC) is a structure involved in this affective component, and targeting it may relieve patients' pain.
  
  
  OBJECTIVE
  To describe the first case series of ACC DBS to relieve the affective component of chronic neuropathic pain.
  
  
  METHODS
  Sixteen patients (13 male and 3 female patients) with neuropathic pain underwent bilateral ACC DBS. The mean age at surgery was 48.7 years (range, 33-63 years). Patient-reported outcome measures were collected before and after surgery using a Visual Analog Scale, SF-36 quality of life survey, McGill Pain Questionnaire, and EQ-5D (EQ-5D and EQ-5D Health State) questionnaires.
  
  
  RESULTS
  Fifteen patients (93.3%) transitioned from externalized to fully internalized systems. Eleven patients had data to be analyzed with a mean follow-up of 13.2 months. Post-surgery, the Visual Analog Scale score dropped below 4 for 5 of the patients, with 1 patient free of pain. Highly significant improvement on the EQ-5D was observed (mean, +20.3%; range, +0%-+83%; P = .008). Moreover, statistically significant improvements were observed for the physical functioning and bodily pain domains of the SF-36 quality-of-life survey: mean, +64.7% (range, -8.9%-+276%; P = .015) and mean +39.0% (range, -33.8%-+159%; P = .050), respectively.
  
  
  CONCLUSIONS
  Affective ACC DBS can relieve chronic neuropathic pain refractory to pharmacotherapy and restore quality of life.
authors.affiliation: ‡Oxford Functional Neurosurgery and Experimental Neurology Group, Nuffield Departments of Clinical Neuroscience and Surgery; §Department of Psychiatry, University of Oxford, United Kingdom.
authors.forename: Sandra G J
authors.initials: SG
authors.lastname: Boccard
authors.forename: James J
authors.initials: JJ
authors.lastname: Fitzgerald
authors.forename: Erlick A C
authors.initials: EA
authors.lastname: Pereira
authors.forename: Liz
authors.initials: L
authors.lastname: Moir
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Van Hartevelt
authors.forename: Morten L
authors.initials: ML
authors.lastname: Kringelbach
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Green
authors.forename: Tipu Z
authors.initials: TZ
authors.lastname: Aziz
mesh_terms: D000328:Adult; D059350:Chronic Pain / Q000628:therapy*; D046690:Deep Brain Stimulation / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000628:therapy*; D010147:Pain Measurement / Q000379:methods; D011788:Quality of Life; D016896:Treatment Outcome