OHSU

Motor Cortex Stimulation

Motor cortex stimulation is a type of surgery to reduce chronic pain. If you have trigeminal neuralgia (TN) that does not get better with other treatments, your doctor might suggest motor cortex stimulation.

With this procedure, your doctor uses small electrodes (wires that conduct mild electrical signals) to stimulate areas of your brain. The procedure stimulates areas that move your face, neck, trunk (middle of your body), arms and leg.

The procedure

Before surgery, your doctor locates the specific area of your brain that produces movements in parts of your body. He or she may use one of several different techniques to locate this area.

Motor cortex stimulation surgery is usually performed under general anesthesia (you are asleep during the procedure).

Your surgeon performs a craniotomy (opens your skull to expose your brain) and inserts an electrode into the tough membrane covering your brain. He or she uses the electrode to stimulate the part of your brain that controls movement. At the same time, your surgeon watches to see if any of your muscles contract (tighten).

The electrode stimulation during surgery may completely relieve your pain. However, you usually have a longer trial stimulation before your doctor implants a pulse generator.

After the procedure

Your doctor tests the electrode as soon as you are fully awake. You will have tests until you can always respond that stimulation reduces the pain you had before surgery by at least 50 percent (half as painful as before surgery).

You will need a second craniotomy, also under general anesthesia, for your doctor to permanently implant a pulse generator. The pulse generator is usually placed under the skin of your chest, often near your collarbone. It is permanently connected to the electrode.

Risks of motor cortex stimulation

Risks related to this procedure include:

  • Seizures during surgery
  • Infection around the stimulator or pulse generator
  • Epidural hematoma (blood buildup between the skull and brain covering)
  • Subdural effusion (fluid release under the brain covering)
  • Pain relief that gets less over time
  • Pain caused by the stimulation

Be sure to talk to your doctor about the risks of this procedure in your particular situation.