Interventional procedure consultation document

Occipital nerve stimulation for intractable chronic migraine

Treating intractable chronic migraine by nerve stimulation

A migraine is a severe headache usually felt as a throbbing pain at the front or on one side of the head. Some people also have other symptoms, such as nausea and sensitivity to light. Intractable means that the migraine does not respond to treatment. Occipital nerve stimulation involves implanting electrodes, a neurostimulator (a battery-powered device that delivers electrical stimulation to the nerves) and connecting insulated wires under the skin. The electrodes are implanted near the occipital nerve located just beneath the skin at the back of the head. The neurostimulator is usually implanted in the torso (trunk). The patient uses a remote control to deliver electrical impulses to the occipital nerve with the aim of masking the pain of the migraine.

The National Institute for Health and Clinical Excellence (NICE) is examining occipital nerve stimulation for intractable chronic migraine and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about occipital nerve stimulation for intractable chronic migraine.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination and promote equality and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 17 December 2012

Target date for publication of guidance: 27 March 2013

1                      Provisional recommendations

1.1                  The evidence on occipital nerve stimulation (ONS) for intractable chronic migraine shows some efficacy in the short term but there is very little evidence about long-term outcomes. With regard to safety, there is a risk of complications, which often need further surgery. Therefore this procedure should only be used with special arrangements for clinical governance, consent and audit or research.

1.2                  Clinicians wishing to undertake ONS for intractable chronic migraine should take the following actions: 

·      Inform the clinical governance leads in their Trusts.

Ensure that patients understand the uncertainty about the procedure’s safety and efficacy and provide them with clear written information. In addition, the use of NICE’s information for the public is recommended. [[URL to be added at publication]]

1.3                  Selection of patients for treatment using ONS for intractable chronic migraine should be done by a multidisciplinary team, including specialists in headache, pain management and functional neurosurgery.

1.4                  Clinicians should enter details about all patients undergoing ONS for intractable chronic migraine onto the UK Neuromodulation Register [web link] when access to that database is available. They should audit and review clinical outcomes locally and should document and consider their relationship to patient characteristics. 

1.5                  NICE encourages publication of further information from comparative studies and from collaborative data collection to guide future use of this procedure and to provide patients with the best possible advice. Publications should include full details of any complications and of adjunctive or subsequent treatments. Outcomes should include measures of pain, function and quality of life, particularly in the long-term.

1.6                  NICE may review the procedure on publication of further evidence.

2                      The procedure

2.1                  Indications and current treatments

2.1.1              Migraine is a severe headache, often accompanied by sensitivity to light, sleep disruption and depression. It may be preceded by an aura, consisting of perception of an unusual light, an unpleasant smell or, occasionally, confusing thoughts or experiences.

2.1.2              Current treatment for patients with migraine aims to prevent or stop episodes using drugs such as painkillers, anti-emetics and triptans. If medical treatment fails, invasive treatments such as nerve blocks or acupuncture are sometimes used.

2.2                  Outline of the procedure

2.2.1              ONS for intractable chronic migraine is usually done in 2 stages. In the first, trial stage, using local anaesthesia and usually with fluoroscopic guidance, electrodes are passed through a subcutaneous tunnel and placed over the occipital nerve(s) around the level of C1. Correct placement of electrodes is verified by intra-operative stimulation before they are sutured to subcutaneous tissue. A lead is tunnelled under the skin from the electrode to an exit site in the posterior cervical region where it is connected by an external extension lead to a hand-held neurostimulator.

2.2.2              The second stage is carried out if the trial is successful. With the patient under general anaesthesia, an implantable neurostimulator is secured in a subcutaneous pocket, usually in the infraclavicular region or the abdominal wall. A lead is tunnelled from the electrode to the implantable neurostimulator. The patient uses a remote control to stimulate the occipital nerves when needed.

Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the systematic review, available at www.nice.org.uk/guidance/IP/1048/systematic review

2.3                  Efficacy

2.3.1                A randomised controlled trial (RCT) of 157 patients compared ONS (active stimulation, n=105) against sham stimulation (n=52). It reported a significantly greater decrease in the ‘Migraine disability assessment score’ (MIDAS), which takes into account headache days and their impact on the patient’s life (maximum score 200), at 12-week follow-up for the ONS group than for the sham stimulation group (64.6 and 20.4 reduction respectively, p=0.001).

2.3.2              An RCT of 67 patients comparing ONS (n=33) against sham stimulation (n=17) or medical management (n=17) reported a responder rate (defined as a reduction in headache days per month of 50% or more or a 3-point or greater reduction in average overall pain intensity compared with baseline at 3 months) of 39% (11/28) in the ONS group, 6% (1/16) in the sham stimulation group and 0% (0/17) in the medication group (p value not reported).

2.3.3              A case series of 25 patients reported that headache frequency per 90 days reduced from 75.56 (standard deviation [SD] 26.81) before implantation to 37.45 (SD 7.49) over a mean follow-up of 18 months (p<0.001).

2.3.4              The RCT of 157 patients reported no significant difference between the groups in the proportion of patients whose pain reduced by 50% or more (measured on a visual analogue scale) (17% for ONS and 14% for sham stimulation, p=0.55) at 12‑week follow‑up.

2.3.5              The case series of 25 patients reported a significant reduction in headache severity (0–10 scale) from a baseline of 9.32 (SD 1.28) to 5.72 (SD 3.31) over a mean follow-up of 18 months (p<0.001).

2.3.6              The Specialist Advisers listed key efficacy outcomes as migraine or headache days, headache severity, frequency and duration, reductions in disability (measured by MIDAS), quality of life (SF-36) and reduced medication use.

2.4                  Safety

2.4.1              Infections at the implant site were reported in 14% (7/51) of patients in the RCT of 67 patients at 3‑month follow‑up. Infection was reported in 4% (4/105) of patients in the ONS group and 6% (3/52) of patients in the sham stimulation group in the RCT of 157 patients at 12 week follow up (no further details available).

2.4.2              Skin erosion was reported in 4% (4/105) of patients in the ONS group and 4% (2/52) of patients in the sham stimulation group in the RCT of 157 patients at 12-week follow-up.

2.4.3              Lead migration or dislodgement was reported in 10% (5/52) of patients in the sham stimulation group and 14% (15/105) of patients in the ONS group in the RCT of 157 patients after 3 months; and in 24% (12/51) of patients in the RCT of 67 patients at 3‑month follow‑up. Lead migration was reported in 36% (9/25) of patients in the case series of 25 patients at mean 18-month follow-up.

2.4.4              Problems with ineffective device programming and ineffective leads were reported in 12% (6/51) and 4% (2/51) of patients, respectively, in the RCT of 67 patients at 3 month follow‑up.

2.4.5              Persistent pain or numbness at the implant site was reported in 13% (14/105) of patients in the ONS group and 17% (9/52) of patients in the sham stimulation group in the RCT of 157 patients at 12 week follow‑up. Loss of motor or musculoskeletal control was reported in 1% (1/105) of patients in the ONS group in the same RCT (timing not reported).

2.4.6              Unintended stimulation effect (no further details available) was reported in 6% (6/105) of patients in the ONS group and 2% (1/52) of patients in the sham stimulation group in the RCT of 157 patients.

2.4.7              In addition to the above, the Specialist Advisers listed haemorrhage, nerve damage and lead fracture as theoretical adverse events.

2.5                  Other comments

2.5.1              The Committee recognised that patients being considered for ONS for intractable chronic migraine commonly have very distressing and chronic symptoms, which other methods of treatment have failed to control.

2.5.2              The Committee recognised that research in this area is difficult because of the complex and heterogeneous nature of chronic migraine. Currently there are not enough good-quality comparative studies to be able confidently to evaluate the procedure’s efficacy. This underpins the recommendations in section 1.

3                      Further information

3.1                  For related NICE guidance see www.nice.org.uk

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

November, 2012