Efficacy of motor cortex stimulation in the treatment of neuropathic pain: a randomized double-blind trial

Object In this study the authors used a double-blind protocol to assess the efficacy of motor cortex stimulation (MCS) for treating neuropathic pain. Methods Eleven patients with unilateral neuropathic pain (visual analog scale [VAS] score 8–10) of different origins and topography were selected for MCS. A 20-contact grid was implanted through a craniotomy centered over the motor cortex contralateral to the painful area. The motor cortex strip was identified using neuroimages, somatosensory evoked potentials, acute electrical stimulation, and corticocortical evoked potentials. Subacute therapeutic stimulation trials allowed the authors to determine the most efficient pair of contacts to use for long-term MCS. The grid was replaced with a 4-contact electrode connected to an internalized stimulator. Bipolar stimulation at a 40-Hz frequency, 90-μsec pulse width, amplitude 2–7 V, and 1 hour in “ON” and 4 hours in “OFF” mode was used. Pain was evaluated using the VAS, Bourhis, and McGill pain scales applied eac...