Lack of efficacy of motor cortex stimulation for the treatment of neuropathic pain in 14 patients.
OBJECTIVE
Motor cortex stimulation has been reported as an effective treatment for medically resistant neuropathic pain. The goal of this study is to review the efficacy of this treatment in a series of 14 patients.


METHODS
The records of a consecutive series of 14 patients undergoing MCS for neuropathic pain at Stanford University Hospital and Clinics between 2002 and 2010 were retrospectively analyzed. The primary outcome measure was a visual analogue scale, which patients completed prior to surgery and following each programming session. The motor cortex was localized using 1) MR image guidance, 2) intraoperative somatosensory evoked potentials and motor response to stimulation, and 3) postoperative imaging. All patients underwent extensive stimulator programming.


RESULTS
Five patients exhibited a transient improvement of >50%. Of these, only two patients maintained >50% improvement to their last clinic visit. One of these patients died of unrelated causes, and the other complained of variable response at home. The median time from best to final VAS was 50 days. Average postoperative follow-up was 55.5 weeks. Postoperative imaging demonstrated appropriate lead placement in 12 patients. The other two patients did not undergo postoperative imaging.


CONCLUSIONS
In our cohort of 14 patients with neuropathic pain, motor cortex stimulation failed to produce acceptable long-term benefit. Possible reasons for this failure are discussed in the context of a small retrospective study.
Division of Neurosurgery, Department of Surgery, The Ottawa Hospital Research Institute, The University of Ottawa, Ottawa, Ontario, Canada.
Adam J
AJ
Sachs
Harish
H
Babu
Yu-Feng
YF
Su
Kai J
KJ
Miller
Jaimie M
JM
Henderson
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000379:methods*; D004567:Electrodes, Implanted; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009437:Neuralgia / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D038361:Neuronavigation / Q000379:methods; D010147:Pain Measurement / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome
Motor cortex stimulation; neuropathic pain