title: Long-term follow-up of motor cortex stimulation for neuropathic pain in 23 patients.
abstract: BACKGROUND
  Motor cortex stimulation (MCS) is being offered to patients suffering from neuropathic pain. Outcome prediction, programming and especially sustaining a long-term treatment effect represent major challenges. We report a retrospective long-term analysis of our patients treated with MCS over a median follow-up of 39.1 months.
  
  
  OBJECTIVE
  To investigate the time course of the treatment effect in MCS for neuropathic pain.
  
  
  METHODS
  Twenty-three closely followed patients treated with MCS were retrospectively analyzed. Reduction in pain measured on a visual analogue scale (VAS) was defined as the primary outcome parameter. VAS pain level and adverse events were documented at the 1-, 3-, 6-, 12-, 18- and 24-month follow-ups.
  
  
  RESULTS
  The mean VAS under best medical treatment was 7.8 (SD 1.2, range 5-9) with escalation to 9.3 (SD 0.9, range 6-10) when the patients' medications were missed or delayed. About half of the patients (47.8%) experienced a satisfactory (>50%) reduction in pain during the first month of treatment. The best treatment results were seen at the 3-month follow-up (mean VAS 4.8, SD 1.9, -37.2% compared to baseline). A decline in the treatment effect was generally observed at the subsequent follow-up assessments. Six patients had their devices explanted during the follow-up period due to loss of treatment effect.
  
  
  CONCLUSIONS
  In this study, MCS failed to provide long-term pain control for neuropathic pain. Many aspects of MCS still remain unclear, especially the neural circuits involved and their response to long-term stimulation. Means must be developed to overcome the problems in this promising technique.
authors.affiliation: Department of Stereotactic and Functional Neurosurgery, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Philipp J
authors.initials: PJ
authors.lastname: Slotty
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Eisner
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Honey
authors.forename: Christian
authors.initials: C
authors.lastname: Wille
authors.forename: Jan
authors.initials: J
authors.lastname: Vesper
mesh_terms: D000328:Adult; D000368:Aged; D046690:Deep Brain Stimulation / Q000379:methods / Q000639:trends*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009437:Neuralgia / Q000175:diagnosis / Q000628:therapy*; D059408:Pain Management / Q000379:methods / Q000639:trends*; D010147:Pain Measurement / Q000379:methods / Q000639:trends; D012189:Retrospective Studies; D016896:Treatment Outcome