title: Long-term outcomes of deep brain stimulation for neuropathic pain.
abstract: BACKGROUND
  Deep brain stimulation (DBS) to treat neuropathic pain refractory to pharmacotherapy has reported variable outcomes and has gained United Kingdom but not USA regulatory approval.
  
  
  OBJECTIVE
  To prospectively assess long-term efficacy of DBS for chronic neuropathic pain in a single-center case series.
  
  
  METHODS
  Patient reported outcome measures were collated before and after surgery, using a visual analog score, short-form 36-question quality-of-life survey, McGill pain questionnaire, and EuroQol-5D questionnaires (EQ-5D and health state).
  
  
  RESULTS
  One hundred ninety-seven patients were referred over 12 years, of whom 85 received DBS for various etiologies: 9 amputees, 7 brachial plexus injuries, 31 after stroke, 13 with spinal pathology, 15 with head and face pain, and 10 miscellaneous. Mean age at surgery was 52 years, and mean follow-up was 19.6 months. Contralateral DBS targeted the periventricular gray area (n = 33), the ventral posterior nuclei of the thalamus (n = 15), or both targets (n = 37). Almost 70% (69.4%) of patients retained implants 6 months after surgery. Thirty-nine of 59 (66%) of those implanted gained benefit and efficacy varied by etiology, improving outcomes in 89% after amputation and 70% after stroke. In this cohort, >30% improvements sustained in visual analog score, McGill pain questionnaire, short-form 36-question quality-of-life survey, and EuroQol-5D questionnaire were observed in 15 patients with >42 months of follow-up, with several outcome measures improving from those assessed at 1 year.
  
  
  CONCLUSIONS
  DBS for pain has long-term efficacy for select etiologies. Clinical trials retaining patients in long-term follow-up are desirable to confirm findings from prospectively assessed case series.
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom. sandra.boccard@dpag.ox.ac.uk
authors.forename: Sandra G J
authors.initials: SG
authors.lastname: Boccard
authors.forename: Erlick A C
authors.initials: EA
authors.lastname: Pereira
authors.forename: Liz
authors.initials: L
authors.lastname: Moir
authors.forename: Tipu Z
authors.initials: TZ
authors.lastname: Aziz
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Green
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000523:psychology / Q000628:therapy*; D010147:Pain Measurement; D011788:Quality of Life; D016896:Treatment Outcome