The National Institute for Clinical Excellence is examining vagus nerve stimulation for refractory epilepsy in children and will publish guidance on its safety and efficacy to the NHS in England and Wales. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about vagus nerve stimulation for refractory epilepsy in children.

This document has been prepared for public consultation. It summarises the procedure and sets out the provisional recommendation made by the Advisory Committee.

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

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

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendation in the light of the comments received during consultation.
• The Advisory Committee will then prepare the Final Interventional Procedures Document (FIPD) and submit it to the Institute.
• The FIPD may be used as the basis for the Institute's guidance on the use of the procedure in the NHS in England and Wales.

For further details, see the Interim Guide to the Interventional Procedures Programme, which is available from the Institute's website (www.nice.org.uk/ip).

Closing date for comments: 27 May 2003
Target date for publication of guidance: 27 August 2003

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation

Provisional recommendation

Current evidence on the safety and efficacy of vagus nerve stimulation for refractory epilepsy in children does not appear adequate to support the use of this procedure without special arrangements for consent and for audit or research. Clinicians wishing to undertake vagus nerve stimulation for refractory epilepsy in children should ensure that children who are competent, and their parents and carers, are fully involved in giving their informed consent. Clinicians should ensure that the uncertainty about the procedure's safety and efficacy is understood by the parent or carer and, where possible, the child. They should inform the clinical governance leads in their Trusts and ensure that appropriate arrangements are in place for clinical audit or research. Publication of safety and efficacy outcomes will be useful in reducing the current uncertainty. NICE is not undertaking further investigation at present.

The Interventional Procedures Advisory Committee also made the following recommendations.

• Vagus nerve stimulation should be undertaken only by specialist paediatric epilepsy teams.
• All patients treated with vagus nerve stimulation should be entered on a registry. At least one commercial registry exists, maintained by a manufacturer of a vagus nerve stimulator.

The procedure

Indications

Outline of the procedure

A battery-powered pulse-generating device is implanted under the skin of the upper left chest. A wire is tunnelled under the skin and connected to the left vagus nerve in the neck. The stimulation parameters (pulse width and frequency, current intensity, on/off cycles) are programmed into the pulse generator via a programming wand. Patients or carers can then switch the stimulator on and off by passing a magnet over the generator. The battery lasts 3-5 years and can be replaced under local anaesthesia. A typical treatment regimen might comprise intermittent stimulation for 30 seconds every 5 to 10 minutes throughout the day and night.

Efficacy

The Committee considered a systematic review published in 1998 that concluded that the efficacy of this procedure was yet to be established in children. Studies published since the review was completed indicated a reduction in seizure frequency of between 19 and 58%. The reduction in seizure frequency seemed to increase with time, that is, children seemed to experience fewer seizures the longer they had the device. Other improvements reported in one study included increased alertness, improved verbal communication in post-ictal periods, higher school achievement, and improved memory and ambulation. For more details refer to the overview (see Appendix A).

The Specialist Advisors agreed that approximately 50% of patients having this procedure had a reduction in seizure frequency of around 50%. One Specialist Advisor believed that these figures were true for adults, and although the outcomes seemed similar in children, not enough data had been published.

Safety

A systematic review published in 1998 concluded that safety was yet to be established in children. The type and frequency of reported complications varied between the studies published since the review was completed, which was a cause of concern. Some studies reported numerous side effects, including voice alteration (affecting between 22 and 58% of patients), coughing, fever, headache, vomiting, nausea and pharyngitis. For more details refer to the overview (see Appendix A).

The Specialist Advisors believed that this is a safe procedure with no major complications.

Other comments

The high drop-out rate of patients in some studies made evidence from these difficult to interpret.