Sudden Unexpected Death in Epilepsy (SUDEP)

What is SUDEP?

If a person with epilepsy dies suddenly and no other cause can be found, it is called ‘Sudden Unexpected Death in Epilepsy' or SUDEP.1  It is unclear exactly what causes SUDEP in all situations, but experts believe it is probably related to patients having cardiorespiratory difficulties following a seizure.2

  • 1. Gayatri et al. (2010). Parental and physician beliefs regarding the provision and content of written sudden unexpected death in epilepsy (SUDEP) information. Epilepsia; 51: 777-782.
  • 2. Camfield. P. & Camfield, C. (2005). Sudden Unexpected Death in People with Epilepsy: A Pediatric Perspective. Sem Ped Neurol, 12:10-14.


How common is it?

It may be confronting when you first find out about SUDEP, but reassuringly, research suggests SUDEP in children is very rare.

In a study of a group of children with epilepsy1 who were followed for twenty years, the researchers found that the overall incidence of SUDEP was 0.1 children per every 1000 patient-years. Importantly, the researchers found that:

  • For those children with a serious neurological handicap, the chance of death over the next 20 years can approach 25%, but death in these cases is usually caused by complications relating to neurological deficits, rather than seizures. 

The incidence of SUDEP in children has been recently re-evaluated utilising cohorts from Ontario Canada and Sweden. The overall incidence was 1.1/1000 patient-years, similar to adult populations.2 3  This incidence is higher than the figure given above from earlier research.


Don’t be afraid to ask your doctor about SUDEP. If you would like to read more about SUDEP, you may find the following resources helpful:

  • 1. Camfield. P. & Camfield, C. (2005). Sudden Unexpected Death in People with Epilepsy: A Pediatric Perspective. Sem Ped Neurol, 12:10-14.
  • 2. Sveinsson et al. (2017). The incidence of SUDEP. A nationwide population-based cohort study. Neurology, 89, 170-177.
  • 3. Keller at al. (2018). Incidence of sudden unexpected death in epilepsy in children is similar to adults. Neurology, 91(2), e107-e111.

Risks and risk reduction

What are the risk factors for SUDEP?

  • When the age of epilepsy onset is less than 16 years. 1
  • When the patient has had epilepsy for more than 15 years.2
  • Where the patient has frequent generalised tonic-clonic seizures.3
  • Where the patient has nocturnal seizures.4
  • Patients who sleep alone and have generalised tonic-clonic seizures are at risk for SUDEP.5

What can you do to reduce the risk of SUDEP?

The following suggestions may help reduce the risk of your child suffering from SUDEP:

  • Preventing seizures is the most effective way to prevent epilepsy-related deaths, in particular SUDEP. Ensuring your child takes their medication every day and is compliant helps prevent seizures and therefore, may help reduce their risk of SUDEP.
  • Nocturnal Supervision (e.g. sharing a bedroom, using a listening device).6
  • One possible intervention may include seizure alerting devices.
  • There are increasingly available seizure detection devices based on a variety of biomarkers. With improved technology, this is a rapidly moving field. Although there are false alarms and the devices are not perfect in detecting all seizures, there is increasing data that certain wearable devices can frequently detect generalised tonic-clonic seizures. Discussion with your doctor may be helpful. 

Key message

While it may seem confronting at first, it is good to discuss SUDEP with your Doctor and to understand that it is very rare in children with a new epilepsy diagnosis or where epilepsy is well controlled. Information from the North American SUDEP Registry does show however, that there is some risk for all epilepsy syndromes, hence discussion and precautions are relevant to each patient with epilepsy. 

As the child grows into an adult, if their epilepsy is long-standing the risk continues. Compliance with treatment and best possible control of seizures is the best way of reducing risk of SUDEP.

Literature supports information sharing with families at the time of diagnosis. It is recognised that families want information. It also enables discussion of potential risk modification. 



Information last reviewed: 18/08/2021.
  • 1. Shorvon & Tomson (2011). Sudden unexpected death in epilepsy. Lancet, 378:2028-2038.
  • 2. Shorvon & Tomson (2011). Sudden unexpected death in epilepsy. Lancet, 378:2028-2038.
  • 3. Shorvon & Tomson (2011). Sudden unexpected death in epilepsy. Lancet, 378:2028-2038.
  • 4. Lambers et al (2012). Epilepsia, 53(2): 253-257. Langan et al (2005). Neurology, 64: 1131-1133. Nashef et al (1995). Epilepsia, 36: 1187-1194.
  • 5. Sveinsson et al (2020). Clinical risk factors in SUDEP. A nationwide population-based case-control study. Neurology: 94(4): e419-e429.
  • 6. Langan et al. (2005). Case-control study of SUDEP. Neurology, 64: 1131-33.