Motor cortex stimulation (MCS) has been used to treat various chronic refractory pain conditions such as atypical facial pain, post-stroke pain (PSP), and other nerve/brain injury pain syndromes. It entails implantation of electrodes over the primary motor cortex. One or more electrodes are placed extra-durally over the motor cortex via a burr hole or a small craniotomy, and these electrodes are then connected to an implantable, battery-powered, neurostimulator. This procedure is usually performed in two separate operations: computer-aided neuro-navigation techniques and magnetic resonance imaging (MRI) images are used to guide implantation of electrode(s); and a second operation is performed for implantation of a neurostimulator if stimulation of the motor cortex is successful in alleviating the patient's pain. The neurostimulator is placed subcutaneously near the clavicle, and is connected to the electrode(s). An external radio transmitter is used to adjust the electrical impulses depending on the level of pain. Researchers have suggested that MCS-related pain relief is probably due to MCS-induced release of endogenous opioids in brain structures involved in the processing of pain. |
