What is sudden unexpected death in epilepsy?

Sudden Unexpected Death in Epilepsy (SUDEP) is a term used when a person with epilepsy suddenly dies and the reason for the death is not known. For example, it is not due to injury or to drowning following or during a seizure, and it is not due to a prolonged and severe seizure (status epilepticus).

What causes sudden unexpected death in epilepsy?

The cause is not known. If a post-mortem examination is done on a person who dies of SUDEP, no abnormality is found to account for the death. There are various theories as to why a person with epilepsy may die suddenly. One theory is that a seizure may affect a part of the brain that controls heart or breathing function, and so the heart and/or breathing just stop during a seizure.

How common is sudden unexpected death in epilepsy?

The risk of SUDEP is small for most people with epilepsy. It is estimated to cause about 500 deaths per year in the UK. This sounds a lot; however, when you compare it to the number of people who have epilepsy, it is quite rare.

Of those who die from SUDEP, it is most common in people who have generalised tonic-clonic seizures, especially in young adults. The most important 'risk factors' seem to be poor seizure control, and seizures occurring during sleep.

Note: epilepsy is common. About 1 in 30 people in the UK develops epilepsy at some stage. Most people with epilepsy have a normal lifespan and do not die of SUDEP.

• In people with severe epilepsy (frequent and severe tonic-clonic seizures), it is estimated that about 1 in 200 dies of SUDEP each year.
• In people with mild idiopathic epilepsy (epilepsy of unknown cause), it is estimated that about 1 in 1000 dies of SUDEP each year.
• In people who are in remission, the risk of SUDEP seems to be negligible (very low). The term 'in remission' means that you have had seizures in the past, but have none or very few at present. This is either because of treatment, or because the epilepsy has settled down.

How can the risk be minimised?

If you have epilepsy, it may be possible to reduce the small risk of dying from SUDEP by:

• Preventing seizures as much as possible. This is usually by medication. In some people, surgery is used to prevent seizures when medication has not been successful in preventing seizures. However, in some cases it is not possible to stop seizures fully. (See separate leaflet called 'Epilepsy - Treatments' for details.)
• Being aware of the potential risk of night-time seizures. Some people only have seizures at night when asleep (or have them more often at night). As the risk of SUDEP is still present even for night-time seizures, if possible, you should try to prevent these seizures as much as you can. This may mean a review of medication. But again, in some people it is not possible to prevent seizures fully.

Bereavement due to sudden unexpected death in epilepsy

The sudden death of a loved one for any reason (such as due to SUDEP) is very upsetting and traumatic. If you have lost someone close due to this condition, it may be best to talk it through with your GP, or with the GP of the affected person. It is a tragic event where usually nothing could have been done to prevent it from happening. Some people find that it helps to get information and help from a support group - details of some are given below.

Further information

Epilepsy Bereaved

PO Box 112 Wantage, Oxon, OX12 8XT
Bereavement Contact Line: 01235 772 850 Web: www.sudep.org
Supports and informs people who have been affected by epilepsy and sudden death.

CRUSE (Bereavement Care)

PO Box 800, Richmond, Surrey TW9 1RG
Helpline: 0844 477 9400 Web: www.cruse.org.uk/
Cruse Bereavement Care is the largest bereavement charity in the UK.

Compassionate Friends

53 North Street, Bristol, BS3 1EN
Helpline: 0845 123 2304 Web: www.tcf.org.uk
Offers its help to parents whose son or daughter (of any age) has died from any cause.

Epilepsy Action

New Anstey House, Gateway Drive, Leeds, LS19 7XY
Helpline: 0808 800 5050 Web: www.epilepsy.org.uk

National Society For Epilepsy

Chesham Lane, Chalfont St Peter, Gerrards Cross, Bucks, SL9 0RJ
Helpline: 01494 601 400 Web: www.epilepsynse.org.uk

Epilepsy Scotland

48 Govan Road, Glasgow, Scotland, G51 1JL
Helpline: 0808 800 2200 Web: www.epilepsyscotland.org.uk

Epilepsy Wales

PO Box 4168, Cardiff, CF14 0WZ
Helpline: 0800 228 9016 Web: www.epilepsy-wales.org.uk

References

• Asadi-Pooya AA, Sperling MR; Clinical Features of Sudden Unexpected Death in Epilepsy. J Clin Neurophysiol. 2009 Aug 24. [abstract]
• Surges R, Thijs RD, Tan HL, et al; Sudden unexpected death in epilepsy: risk factors and potential pathomechanisms. Nat Rev Neurol. 2009 Sep;5(9):492-504. Epub 2009 Aug 11. [abstract]