Occipital Nerve Stimulation 

Updated: Oct 11, 2018
Author: Antonios Mammis, MD; Chief Editor: Jonathan P Miller, MD 

Overview

Background

Occipital nerve stimulation (ONS) is a form of neuromodulation therapy aimed at treating headache and craniofacial pain. This therapy involves an implantable device composed of an electrode and pulse generator. The lead is placed into the subcutaneous tissues innervated by the greater and lesser occipital nerves, and the pulse generator is implanted into a subcutaneous pocket in the chest, abdomen, or back.

Prior to implantation, a trial is performed in which leads are placed under the skin and are connected to an external battery. The trial is performed under sedation, and the patient is discharged the same day. Afterward, the patient tries the therapy for 4–7 days and keeps a detailed pain diary.

A permanent device is implanted only if the patient reports significant improvements in pain and quality of life. The permanent implantation is placed under sedation or anesthesia, and the patient is discharged the same day.

The device is programmed by a clinical specialist appointed by the manufacturer.

This type of therapy has been evolving as a treatment for intractable occipital headache syndromes since the first implant in 1993, and the data to support its use are robust. Multiple authors have reported that successful neuromodulation for occipital headache syndromes can be accomplished with subcutaneous regional electrode placement. Available literature on the use of peripheral neurostimulation for headache includes occipital nerve stimulation, supraorbital nerve stimulation, and infraorbital nerve stimulation. Recently, other neurostimulatory techniques such as cervical epidural neurostimulation have been explored for cluster headaches, as well.[1]  

Neurostimulation is FDA-approved for the treatment of certain intractable pain syndromes, although it is not approved for headache, chronic migraine, and craniofacial pain and thus occipital nerve stimulation continues to represent an off-label use.

Mechanism of action

The theory of neuromodulation refers to therapeutic alteration of activity, electrically or chemically, in the central, peripheral, or autonomic nervous systems via the process of inhibition, stimulation, modification, or other forms of regulation. Occipital nerve stimulation is a form of neuromodulation that is reversible and adjustable and that can be tailored to an individual’s specific needs.

The mechanisms of action[2] for the paresthesia patterns and pain relief obtained from an occipital nerve stimulation are incompletely understood but appear to involve the following:

  • Subcutaneous electrical conduction

  • Dermatomal stimulation

  • Myotomal stimulation

  • Sympathetic stimulation

  • Local blood flow alteration

  • Peripheral nerve stimulation

  • Peripheral and central neurochemical mechanisms

  • Trigeminovascular system and Trigeminocervical tract

One prevalent theory is the involvement of the trigeminocervical system, which is the anatomic overlap of the trigeminal and occipital afferent systems at the level of C2 in the spinal cord. Trigeminal afferent pathways, and thus primary headache disorders, can be modulated at the C2 level by occipitally mediated afferents. In addition, electromodulation works to reduce blood flow to the pain-stimulating areas and to reduce abnormal excitation of the peripheral pain fibers, thus preventing central sensitization of trigeminal sensory nerve pathways, potentially reducing on-cell activity, and modulating the descending system at the level of the dorsal horn.

The gate control theory described by Melzack and Wall in 1965 (see image below) has been postulated to be one mechanism of action by which occipital nerve stimulation works for the treatment of local neuropathic pain.[3] According to this theory, stimulation activates large myelinated afferents, which “close the pain gate” in the substantia gelatinosa by enhancing the inhibitory actions of local circuit neurons in the dorsal horn on central transmission cells. Since pain states are maintained by continuous firing of unmyelinated and small myelinated afferents, a proportionately greater increase in the activation of large myelinated afferents closes the gate and stops pain transmission via presynaptic inhibition.

A schematic diagram of the gate control theory of A schematic diagram of the gate control theory of pain.

Indications

Indications for occipital nerve stimulation include the following:

  • Chronic, intractable primary headache disorder[4]

  • Chronic, intractable secondary headache disorders

  • Neuropathic pain involving the occipital or suboccipital region

Migraine affects 12% of the US population, and women account for 70% of affected individuals. It is estimated that up to 5% of persons who have migraines experience daily or near daily headaches (transformed migraine, chronic daily headaches). Furthermore, 1%–2% are so poorly responsive to medication paradigms that this failure can lead to various consequences, including narcotic dependence, severe restrictions in daily activities, failed personal and career objectives, and an overwhelming sense of hopelessness and despair.

Of patients with migraines, 3%–13% progress to chronic migraine, which is defined as headache pain more than 3–5 days per month. In many cases, the migraines are intractable to medical therapy. Patients in whom medical therapy has failed and who have headache pain that is refractory to preventive medication may benefit from occipital nerve stimulation trials.

Surgical modalities for treating the occipital nerve are reserved as a last resort after failure of medical management. The surgical modalities include decompressive, ablative, and stimulating procedure such as occipital nerve stimulation. Furthermore, occipital nerve stimulation is a nonablative procedure.

The benefits of occipital nerve stimulation have been described in a number of conditions, including the following:

  • Occipital neuralgia (intractable)[5]

  • Occipital headaches

  • Migraine (intractable)[6, 7]

  • Cervicogenic headache

  • Postherpetic neuralgia

  • Tension headache

  • Cluster headaches

  • Posttraumatic pain

  • Posttraumatic headache

  • Chronic daily headaches (transformed migraine)

  • Chronic headache attributed to whip lash

  • New daily persistent headache

  • Hemicranias continua

  • Headache secondary to idiopathic intracranial hypertension

Contraindications

If the patient’s quality of life does not improve during the trial period (see Pre-Procedure Planning), the device is not implanted. 

If there is concern that the patient’s headaches are due to either medication overuse or opioid use, this may disqualify them from implantation, despite quality-of-life improvement during the trial period.[8]

 

 

Technical Considerations

Complications of occipital nerve stimulation placement are avoidable by taking certain necessary steps, as follows:

  • Anchoring leads to fascia at retromastoid incision

  • Swabbing all candidates to rule out methicillin-resistant Staphylococcus aureus (MRSA) colonization.

  • Preoperative (prior to implantation) antibiotic treatment to eliminate MRSA colonization

  • Trimming patient's occipital region hair with clippers

  • Sterile surgical technique to help reduce the incidence of infection

Procedure Planning

Prior to implantation, a trial is performed in which leads are placed under the skin and are connected to an external battery. The trial is performed under sedation, and the patient is discharged the same day. Afterward, the patient tries the therapy for 4–7 days and keeps a detailed pain diary.

A permanent device is implanted only if the patient reports significant improvements in pain and quality of life. 

Positive response to transcutaneous electric nerve stimulation is also a good predictor for repsonse to ONS for treatment of occipital headache.[9]

Complication prevention

Complications of occipital nerve stimulation placement are avoidable by taking certain necessary steps, as follows:

  • Choosing the right candidate for surgery; this is an elective surgery, and patients should be medically optimized (eg, good control of diabetes)

  • Good sterile intraoperative surgical technique

  • Swabbing all candidates to rule out MRSA colonization

  • Anchoring leads to fascia at retromastoid incision

  • Preoperative antibiotic treatment to eliminate MRSA colonization prior to implantation.

Outcomes

Several studies with long-term follow-up (>10 years) demonstrate that, in more than 150 patients with implants, approximately 75% of patients rated either good or excellent long-term pain relief, with a 15% fair rating and a 10% poor rating.[2]  

A 2011 study by Mogilner and Mammis found that 82% patients who underwent implantation reported continued significant benefit from stimulator use.[10]

The ONSTIM trial published data in 2011 showing that at 3 months 39% of patients reported at least 50% reduction in headache days per month or a 3-point reduction in pain intensity with adjustable stimulation, compared with 0% in the medically managed group.[11]

In 2012, Silberstein et al. published results from their multicenter, double-blind, randomized controlled trial evaluating occipital nerve stimulation for migraine. They reported that significantly more patients achieved 30% pain reduction, a reduction in headache days per month, and reductions in migraine-related disability when compared to sham stimulation.[12]

In their 2017 single center, double-blind, randomized controlled trial Mekhail et al. reported a signifciant reduction in headache days, pain intensity, and migraine-related disability in patients utilizing occipital nerve stimulation for chronic migraine.[13]

Complications

Placement of an occipital nerve stimulator is a relatively safe procedure with a low complication rate. The specific complications include the following:[14, 15, 16]

  • Lead migration or fracture

  • Surgical site infection

  • Wound erosion

  • Revision surgery for other reasons (primarily elective cosmetic adjustments to the leads) 

  • Hardware malfunction 

  • Battery failures

  • Inadequacy of stimulation-related coverage

  • Seromas

  • Hematomas

  • Pain and numbness at lead sites

Few major complications have been reported, and the minor complications are easily treatable and usually do not affect the efficacy of the therapy. The most common device related complications include migration, erosion, and infection.[17]

Compared with other forms of peripheral nerve stimulation, ONS generally has higher rates of complication, especially related to lead migration and infection. The long wire course from lead placement to the pulse generator, thin subcutaneous tissue in the scalp, and flexion, extension, and rotation of the head can lead to dislodgement of the leads.[18]

 

Periprocedural Care

Patient Education and Consent

Elements of Informed Consent

Occipital nerve stimulation (ONS) for headache and craniofacial pain is not FDA-approved and thus represents an off-label use of this technology. Insurance companies may or may not cover the cost of occipital nerve stimulation placement, and patients are encouraged to contact their insurances to see if they qualify as candidates and if insurance will cover it.

Patients who are interested in participating in one of several clinical trials are referred to ClinicalTrials.gov.

Equipment

Occipital nerve stimulation involves an implantable device composed of an electrode and pulse generator. 

In ONS programming, a wide array of electrodes is used in order to increase stimulation of the terminal branches of the occipital nerves.

A fluoroscopic images of occipital leads in the su A fluoroscopic images of occipital leads in the supraorbital (A), infraorbital (B), and occipital (C) region in a patient with intractable cluster headache
A fluoroscopic images of occipital leads showing s A fluoroscopic images of occipital leads showing stacked left-sided occipital leads in a woman with hemicrania continua.

Patient Preparation

Anesthesia

Local anesthesia is used at the incision site only.

Positioning

The patient may be positioned laterally or prone depending on the incision entry point.

Monitoring & Follow-up

The device is programmed by a clinical specialist, appointed by the manufacturer.

Device Programming and Maintenance

Most patients currently opt for the implantable pulse generator system, which is currently an off-label application for peripheral use. The life of the battery varies depending on the amplitude used and the number of hours the device is left on during the day. With the voltage settings usually required for occipital stimulation, the primary cell lithium ion battery can last 3–5 years, while the rechargeable may last 7–9 years before replacement.

Preprocedural Planning

Prior to implantation, a trial is performed in which leads are placed under the skin and are connected to an external battery. The patient may be positioned laterally or prone, based on the location of the incision. The head is placed on a horseshoe headrest and the cervical spine is slightly flexed. A percutaneous lead is introduced under fluoroscopic guidance, and with the patient under sedation. The entry point should be approximately 1 cm superior to the tip of the mastoid process, and the trajectory is towards the tip of the odontoid process. Trajectories superior to this are often times used and are well tolerated as well. The electrode should be placed in the superficial aspect of the subcutaneous fat. Care should be taken to not place the lead in the dermis, nor too close to the fascia. The leads are secured to the skin with a 2-0 nylon drain stitch.

The leads are then inserted into the trialing cable, and programming commences. Stimulation is applied using a temporary radiofrequency (RF) transmitter to various select electrode combinations; this enables the patient to report the stimulation location, intensity, and overall sensation. Most patients have reported an immediate stimulation in the selected occipital nerve distribution with 1 to 4 volts with midrange pulse widths and frequencies.

The trial period is typically 4 to 7 days, and patients are encouraged to maintain a headache or pain diary. Trial success is defined as greater than 50% improvement in pain on the visual analog scale, or significant reduction in headache days, or improvement in quality of life. A permanent device is implanted only if the patient reports significant improvements in pain and quality of life.

Alternatively, positive response to transcutaneous electric nerve stimulation has also been used as a good predictor for repsonse to ONS for treatment of occipital headache.[9]  

 

Technique

Approach Considerations

Complications of occipital nerve stimulation (ONS) placement are avoidable by taking certain necessary steps, as follows:

  • Anchoring leads to fascia at retromastoid incision

  • Swabbing all candidates to rule out methicillin-resistant Staphylococcus aureus (MRSA) colonization

  • Preoperative (prior to implantation) antibiotic treatment to eliminate MRSA colonization

  • Trimming patient's occipital region hair with clippers

  • Sterile surgical technique to help reduce the incidence of infection

Occipital Nerve Stimulator Implantation

Upon a successful trial of neurostimulation, permanent implantation may be considered. Permanent implantation is performed under general anesthesia. The patient is positioned supine with the head turned towards the left.

A vertical 2-cm incision is made under fluoroscopic control at the level of the C1 lamina, either medial and inferior to the mastoid process or in the midline posteriorly, extending to but not into the cervicodorsal fascia.

The subcutaneous tissues immediately lateral to the incision are undermined sharply to accept a loop of electrode created after placement and tunneling to prevent electrode migration. A Tuohy needle is gently curved to conform to the transverse posterior cervical curvature (bevel concave) and, without further dissection, is passed transversely in the subcutaneous space across the base of the affected greater and/or lesser occipital nerves, which, at the level of C1, are located within the cervical musculature and overlying fascia.

After lead placement, stimulation is applied using a temporary neurostimulator to various select electrode combinations, enabling the patient to report on the table the stimulation location, intensity, and overall sensation. Most patients have reported an immediate stimulation in the selected occipital nerve distribution with voltage settings from 1 to 4 volts with midrange pulse widths and frequencies.

Three options are available for the system power source: an external radiofrequency transmitter/receiver system, a primary cell implantable pulse generator, and a rechargeable implantable pulse generator.

Typical implant locations include the following:

  • Upper buttock: Facilitates single-stage electrode and generator placement in the prone position

  • Abdomen: Usually performed the patient in the lateral position

  • Upper chest: Lateral or supine positions favor this location

The 3 primary manufacturers of neurostimulation devices include Medtronic, Advanced Neuromodulation Systems/St. Jude, and Advanced Bionics/Boston Scientific.

The device is programmed by a clinical specialist appointed by the manufacturer.

 

Questions & Answers