The National Institute for Clinical Excellence is examining selective peripheral denervation of cervical dystonia and will publish guidance on its safety and efficacy to the NHS in England, Wales and Scotland. 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 selective peripheral denervation of cervical dystonia. 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 preliminary recommendation
• the identification of factual inaccuracies
• additional relevant evidence.

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 recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance, which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.

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: 23 March 2003

Target date for publication of guidance: June 2004

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

Current evidence on the safety and efficacy of selective peripheral denervation of cervical dystonia appears adequate to support the use of this procedure, provided that the normal arrangements are in place for consent, audit and clinical governance.

The procedure should be carried out in a specialist neurosurgical unit with a multidisciplinary team.

Patient selection for this procedure is important. Patients should only be offered the procedure when their disease has become refractory to best medical treatment.

Cervical dystonia is a condition in which the muscles of the neck contract painfully and cause twisting of the head. The head may be pulled backwards (retrocollis), forwards (anterocollis) or to the side (torticollis), depending on which muscle groups are affected. This muscle spasm may occur intermittently or continuously. The cause of cervical dystonia is not known. In children, it is sometimes associated with congenital abnormalities of the shape of the head or of the spine, but it may occur at any age. Cervical dystonia may persist for several years, or sometimes for life. Some patients recover spontaneously.

Standard treatment for cervical dystonia includes physiotherapy, drugs to reduce spasm, injections of botulinum toxin, and brain surgery. Peripheral denervation may be an alternative, especially in people who have not responded to other treatments.

Selective peripheral denervation is a surgical procedure that varies according to the muscle groups affected. It is performed under general anaesthetic and involves cutting the nerves that supply the affected muscles through a skin incision. Sometimes it may involve cutting the muscles themselves.

The evidence was limited to one systematic review and several case series studies. The review found no controlled studies and no reliable evidence to compare the procedure with other treatments. Two of the larger case series studies found very good to excellent results in 88% (228/260 and 182/207) of patients at follow-up. However, the time to follow-up and how these outcomes were assessed were not specified in either study. For more details, refer to the sources of evidence (see Appendix).

One Specialist Advisor noted that careful patient selection should improve the efficacy of the procedure.

The largest case series study identified reported the following complications: occasional tic-like pain 1% (3/260); tonsillar abscess 0.4% (1/260); transient swelling of the neck in a few patients (number not specified); and pins and needles or sensation of tightness or fullness in a few patients (number not specified). For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors listed potential adverse events as difficulty in swallowing, as well as the usual potential complications of surgery such as infection and haemorrhage.

It was noted from the evidence that almost all patients suffered some sensory loss.

There was good long-term follow-up.

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

• Interventional procedure overview of selective peripheral denervation of cervical dystonia, December 2002

Available from: www.nice.org.uk/ip083overview