Trigeminal Neuropathic Pain

Abstract

Motor cortex stimulation is a surgical treatment for medically refractory trigeminal neuropathic pain, a syndrome often caused by nerve injury due to trauma, dental work, or previous surgery for trigeminal neuralgia. Preoperative planning includes pain assessment scales, psychological clearance, and functional magnetic resonance imaging (fMRI) to map the motor cortex. The patient undergoes a craniotomy with trial placement of an epidural electrode array, assisted by neuronavigation, phase reversal monitoring, and somatosensory evoked potential recordings. Less commonly, the electrodes are placed in the subdural space. Postoperative seizure is the most common complication, additionally there are risks for infection and hemorrhage. Programming of the device is performed and the patient undergoes permanent implantation of the system if they achieve a greater than 50% reduction in their pain. Further research is necessary to determine which patients will have the best response to therapy.