Occipital Nerve Stimulation

Why it is done

Occipital nerve stimulation is a surgical procedure that may be useful in the treatment of chronic and severe headache disorders, such as chronic migraines, that do not respond well to other therapies.

Risks

Implantation of occipital nerve stimulation devices is a relatively safe procedure with minimal complications. Studies show that most patients report significant reduction in the pain intensity, and headache days per month.

The complications include:

• Lead dislodgement or breakage
• Wound infection
• Wound erosion (skin deterioration at the surgical site)
• Pain and numbness at the lead sites
• Hematoma
• Collection of fluid (seroma) in the incision sites
• Device malfunction
• Battery failure
• Lack of pain relief
• Insufficient stimulation coverage of pain area
• Need for revision surgery

Procedure

How It is performed

Occipital nerve stimulation is performed in two stages, usually a week apart. In the first stage, the doctor places only the electrodes in the scalp, which are operated with an external battery. The patient uses the device for four to seven days, on a trial basis. If the patient experiences significant pain relief from the occipital nerve stimulation, implantation of the pulse generator follows.

A pain specialist or a neurosurgeon performs the procedure. The trial procedure is performed using local anesthesia and mild sedation, while the implantation of the pulse generator requires general anesthesia.

Stage I: Occipital nerve stimulation trial

Preparation

• Blood and imaging tests
• Historical data noted
  • Bleeding disorders
  • High blood pressure
  • Allergies
  • Any other health problems
  • Any regular medications taken
• Hair over electrode implantation site clipped

Procedure

The doctor

• Administers sedation and injects local anesthesia in the occipital area of the scalp.
• Makes a tiny incision in the scalp.
• Inserts the electrodes into the tissues under the skin using continuous X-ray (fluoroscopy) for guidance.
• Connects the leads to an external pulse generator.
• Tests the stimulator with response from the patient to ensure that the electrodes are placed optimally.
• Closes the incision with sutures with the leads trailing out of the incision.

After the procedure

• The patient is monitored in the recovery room for a few hours.
• The leads from the scalp are connected to the external pulse generator and settings are adjusted to suit the requirement of the patient.
• The patient uses the device for the next four to seven days as needed.
• The patient performs activities and eats food that usually trigger migraines and maintains a pain diary, noting the stimulation effect.
• Implantation of the pulse generator is undertaken if the patient benefits from significant pain relief from occipital nerve stimulation.
• The trial stimulation may not prove useful with certain kinds of headaches, as the response to stimulation may take a few weeks or even months.

Stage II: Occipital nerve stimulator implantation

Preparation

• The patient must avoid eating and drinking for eight hours before the procedure.

Procedure

The doctor

• Attaches an IV line and administers general anesthesia.
• Opens the incision site in the scalp where the leads are implanted at the trial stage.
• Ensures the electrodes are firmly in place or adjusts the placement as necessary, with fluoroscopic guidance.
• Tunnels the leads subcutaneously to the pulse generator implant site.
• Creates a small pocket under the skin to implant the pulse generator.
• Connects the tunneled leads to the pulse generator.
• Tests the pulse generator to make sure it works properly.
• Places the pulse generator in the implant site and closes it with sutures.

Results

After the procedure, the patient is weaned off anesthesia and administered painkillers. The patient will be monitored in the recovery room for a few hours.

Most patients are discharged within a day or two as complete recovery may take up to six weeks. Pain relief or reduction in pain intensity from the neurostimulation can occur variably in patients. Neurostimulation effects may take weeks or even months in some patients.