Interventional procedure consultation document

Deep brain stimulation for intractable trigeminal autonomic cephalalgias

Treating intense, difficult to control headache accompanied by other symptoms of the face and eyes using deep brain stimulation

Trigeminal autonomic cephalalgias (TACs) are characterised by frequent severe headache attacks that last for short periods. The headaches are usually accompanied by tears, sweating, flushing, and a runny nose on the same side of the head as the pain. Deep brain stimulation has been introduced to treat TACs that do not respond to other treatments. It aims to mask the pain by delivering electrical impulses to a precise area of the brain using an electrode.

The National Institute for Health and Clinical Excellence (NICE) is examining deep brain stimulation for intractable trigeminal autonomic cephalalgias 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 deep brain stimulation for intractable trigeminal autonomic cephalalgias.

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• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.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).

NICE is committed to promoting through its guidance race and disability equality and 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 guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. 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: 21 December 2010

Target date for publication of guidance: March 2011

1   Provisional recommendations

1.1  Current evidence on the efficacy of deep brain stimulation (DBS) for intractable trigeminal autonomic cephalalgias (TACs) is limited and inconsistent, and the evidence on safety shows that there are serious but well known side effects. Therefore this procedure should only be used with special arrangements for clinical governance, consent and audit or research.

1.2  Clinicians wishing to undertake DBS for intractable TACs should take the following actions:

• Inform the clinical governance leads in their Trusts.
• Ensure that patients and their carers understand the uncertainty about the procedure’s efficacy. They should be specifically informed that DBS may not control their headache symptoms and they should be fully informed about the possible risks associated with the procedure, including the small risk of death. Clinicians should provide them with clear written information. In addition, the use of NICE’s information for patients (‘Understanding NICE guidance’) is recommended (available from www.nice.org.uk/IPGXXXpublicinfo). [[details to be completed at publication]]
• Audit and review clinical outcomes of all patients having DBS for intractable TACs (see section 3.1).

1.3  Patient selection for DBS for intractable TACs should be carried out by a multidisciplinary team specialising in pain management.

1.4  Further research studies should clearly define patient selection and report the intensity and duration of stimulation, in addition to documenting the effects on headache symptoms as clearly as possible.

2   The procedure

2.1  Indications and current treatments

2.1.1  TACs (including for example cluster headaches) are characterised by relatively short-lasting but severe pain attacks associated with autonomic manifestations such as sweating, flushing, and ipsilateral rhinorrhea.

2.1.2  The first-line treatment for TACs is usually medical therapy, carried out with the aim of either preventing or limiting the duration of episodes. Surgery to interrupt the trigeminal sensory or autonomic pathways is sometimes used, but this has a risk of serious complications including diplopia and corneal ulcers.

2.2   Outline of the procedure

2.2.1  Deep brain stimulation involves stereotactic targeting of specific anatomical sites within the brain (such as the sensory thalamus or hypothalamus) to modulate the central processing of the pain signals.

2.2.2  With the patient under local anaesthesia and/or intravenous sedation, electrodes are inserted into the brain (through small holes drilled into the skull) using magnetic resonance imaging and/or computed tomography (CT). A test stimulation (or macrostimulation) is used to check for side effects. Postoperative CT scans may be used to assess the position of the electrodes and to identify complications such as local haemorrhage.

2.2.3  Following satisfactory electrode testing, a pulse generator is implanted under the chest wall and connected by tunnelled wires to the electrodes. The generator usually remains switched ‘on’.

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 overview, available at www.nice.org.uk/guidance/IP/895/overview

2.3   Efficacy

2.3.1  A crossover randomised controlled trial (RCT) of 12 patients with refractory chronic cluster headache (CH) reported that there was no significant difference between the ‘on’ and ‘off’ periods in either the ‘on–off’ group or the ‘off–on’ group for a number of outcomes including frequency of attacks, pain intensity (measured on the Likert scale, which ranges from 1 to 7, with 7 indicating worst pain), and patient satisfaction (on Patients’ Global Impression of Change 7-point scale, with 1 indicating best improvement).

2.3.2  During a 10-month open phase of the RCT of 12 patients, when all patients received DBS, the mean weekly attack frequency decreased by 48% from baseline (from a median of 14 to 8 attacks per week; p = 0.08).

2.3.3  A case series of 21 patients reported that all 16 patients treated for refractory chronic CH had relief from pain at a mean follow-up of 23 months. Time to response occurred at a mean of 42 days (range 1 to 86 days) with mean 71% of pain-free days.

2.3.4  The crossover RCT reported reduced anxiety and depression scores measured on the Hospital anxiety and depression scale (7 anxiety items and 7 depression items with scores greater than 7 indicating anxiety and depression, respectively) in the open phase only. Median anxiety scores decreased from 13 to 7.5 (p = 0.008) and median depression scores decreased from 10 to 4.5 (p = 0.052).

2.3.5  The Specialist Advisers listed key efficacy outcomes as improvement in the number of headaches, severity and duration of attacks, and quality of life, measured by headache scoring systems.

2.4   Safety

2.4.1  In a case series of 6 patients with unilateral refractory chronic CH, 1 patient died 3 days after the procedure from an intracerebral haemorrhage which developed along the lead tract a few hours after the procedure.

2.4.2  The RCT of 12 patients reported subcutaneous infection 3 weeks after surgery in 1 patient, and the case series of 21 patients reported 1 occurrence of deep infection. Both resolved after hardware removal and antibiotic treatment.

2.4.3  In the RCT of 12 patients, 1 individual developed transient loss of consciousness with hemiparesis shortly after test stimulation and subsequent severe micturition syncopes associated with a decrease in blood pressure in the standing position (no further details given).

2.4.4  The case series of 6 patients reported that all patients had diplopia and dizziness if high levels of electrical stimulation were used (above 1.5 V) and that 1 became tachypnoeic and tachycardic but symptoms resolved after the recording electrode was removed.

2.4.5  The Specialist Advisers listed anecdotal adverse events as stroke, seizures and lead migration.

2.5   Other comments

2.5.1  The Committee found interpretation of the evidence difficult: the single RCT dealt only with a subgroup of patients.

2.5.2  The Committee noted patient commentary which reported improvements in quality of life, even if pain was relieved only partially, and that some patients were no longer suicidal after treatment.

3   Further information

3.1  This guidance requires that clinicians undertaking the procedure make special arrangements for audit. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.

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

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

November 2010

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.}

 _{It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}