Motor cortex stimulation: functional magnetic resonance imaging-localized treatment for three sources of intractable facial pain.

Neuropathic facial pain can be a debilitating condition characterized by stabbing, burning, dysesthetic sensation. With a large range of causes and types, including deafferentation, postherpetic, atypical, and idiopathic, both medicine and neurosurgery have struggled to find effective treatments that address this broad spectrum of facial pain. The authors report the use of motor cortex stimulation to alleviate 3 distinct conditions associated with intractable facial pain: trigeminal deafferentation pain following rhizotomy, deafferentation pain secondary to meningioma, and postherpetic neuralgia. Functional MR imaging was used to localize facial areas on the precentral gyrus prior to surgery. All 3 patients experienced long-lasting complete or near-complete resolution of pain following electrode implantation. Efficacy in pain reduction was achieved through variation of stimulation settings over the course of treatment, and it was assessed using the visual analog scale and narrative report. Surgical complications included moderate postsurgical incisional pain, transient cerebral edema, and intraoperative seizure. The authors' results affirm the efficacy and broaden the application of motor cortex stimulation to several forms of intractable facial pain.

Neurostimulation in headache disorders.

Although headache is a common ailment, its more severe manifestations such as intractable migraine, and trigeminal autonomic cephalagias including cluster headaches have a debilitating effect on patients resulting in chronic pain and severe functional impairment. Neurostimulation has been explored as a possible treatment option in selective drug-resistant primary headache disorders, in conducting clinical trials involving neurostimulation of deep brain structures, occipital nerves, and vagal nerves as treatment methods for refractory primary headache disorders, the selection of patients should be strictly based on pre-defined clinical criteria. The trials should be well designed, taking into account the potential risks and complications associated with such therapies.

Cortical stimulation for the rehabilitation of patients with hemiparetic stroke: a multicenter feasibility study of safety and efficacy.

OBJECT: In this prospective multicenter study the authors hypothesized that investigational epidural cortical stimulation (CS) delivered concurrently with rehabilitation therapy may enhance motor recovery following stroke. METHODS: Patients who had suffered their index stroke >or= 4 months previously were randomized into 6 weeks of rehabilitation therapy with or without CS. Cortical stimulation, targeted by functional imaging, was delivered at approximately 50% of motor movement threshold. Primary outcome measures were Upper Extremity Fugl-Meyer (UEFM [a measure of neurological and motor function]) and Arm Motor Ability Test (AMAT [a measure of activities of daily living]) scores. The primary study end point was 4 weeks following rehabilitation therapy. RESULTS: A total of 24 patients, 12 per group, completed the treatment protocol. The mean interval since the patients' index stroke was 33 months (range 4-100 months). There were no deaths or cases of neurological deterioration; 1 acute postoperative seizure occurred unrelated to the device or treatment. Patients who underwent CS experienced improved hand/arm function more than control patients. The UEFM score improved 5.5 +/- 4.4 points in patients in the CS group compared with 1.9 +/- 4.4 points for controls (p = 0.03). A 3.5-point UEFM improvement is considered clinically meaningful. The AMAT scores for the CS group improved by 0.4 +/- 0.6 points, whereas the scores in the control group improved by 0.2 +/- 0.4 points (p = 0.2). A 0.21-point improvement in AMAT score is considered clinically meaningful. In the CS group, 67% of patients had clinically meaningful improvement in UEFM scores, compared with 25% of the control group (p = 0.05). Of patients in the CS group 50% had clinically meaningful improvement in UEFM as well as AMAT scores, compared with only 8% of those in the control group (p = 0.03). CONCLUSIONS: These results suggest that subthreshold epidural CS is safe and effective during rehabilitation for recovery of arm and hand function following hemiparetic stroke. Further research in a larger cohort is needed to validate the therapeutic effect.