SUDEP and Life Expectancy

Children with Dravet Syndrome have an 85% likelihood of surviving into adulthood. Sadly, however, there is a significant risk of seizure-related premature mortality in children with the condition. 

Most people with Dravet Syndrome have a good life expectancy. The oldest adult known to have a Dravet diagnosis in the UK is currently in his 70s. It’s likely that there are many more adults living with Dravet Syndrome, however, we simply don’t know how many older people are living undiagnosed with the condition.

However, it is important for caregivers to be aware of the increased risks of premature mortality with Dravet Syndrome. Sudden unexpected death in epilepsy (SUDEP) is responsible for around half of all Dravet Syndrome-related deaths, and status epilepticus accounts for around one-third. It’s essential for health professionals to regularly talk to families about managing the risks of SUDEP and to make sure emergency protocols are in place for the treatment of life-threatening seizures. 

Latest research on SUDEP in Dravet Syndrome

Although SUDEP represents a large fraction of all epilepsy-related deaths, its incidence is likely underestimated because definitive postmortem signs or biomarkers of SUDEP do not exist. Both all-cause mortality and SUDEP rates are elevated in children with Dravet Syndrome compared with children with pediatric epilepsy. Two major risk factors for SUDEP are frequency of generalized tonic-clonic seizure (GTCS) and failure to adequately control treatment-resistant seizures, both of which are hallmarks of Dravet Syndrome and likely contribute to the higher incidence of SUDEP in the disease.

SUDEP is rarely studied in a clinical trial setting. A 2021 pooled analysis by Professor Helen Cross et al looked specifically at SUDEP in Dravet Syndrome, and the potential impact of fenfluramine in reducing the risks of SUDEP. The study found that Dravet Syndrome patients treated with fenfluramine experienced a substantially lower rate of all-cause and SUDEP-related mortality compared with pooled data from previous studies. Although there were limitations to the study (it’s an analysis of previous findings, it's an important contribution to the body of evidence for SUDEP in Dravet Syndrome. 

Overall, the findings are encouraging in indicating that improved seizure control can help reduce the risks of premature mortality in Dravet Syndrome. There remains urgent need for more research on this topic and for new options, like fenfluramine, to become available help improve seizure control in Dravet Syndrome, which is currently one of the most treatment-resistant epilepsies. 

Essential reading:

Helen J Cross et al. 'Impact of fenfluramine on the expected SUDEP mortality rates in patients with Dravet syndrome' Seizure 2021.


"SUDEP is a diagnosis of exclusion and is defined as the sudden death of a person with epilepsy not explained by status epilepticus, trauma, or other known causes".

Discussing SUDEP with caregivers

In a 2021 Dravet Syndrome UK survey, over a third (36%) of carers of people with the condition said their neurologist had never spoken to them about SUDEP. This is despite the fact that the risk of SUDEP in Dravet Syndrome is much higher than in other epilepsies that first present in childhood. SUDEP is responsible for around half of all Dravet-related deaths.

SUDEP tends to occur in pre-school and early primary year aged children with Dravet Syndrome. It’s important to make families aware that children with Dravet Syndrome have an increased risk of premature death from SUDEP. 

One in five (20%) carers of people with Dravet Syndrome want a great deal more information from their neurologist on the risks of SUDEP and how to manage them.

Discussing SUDEP with your patients is an important step in working towards finding the best treatment and seizure control plan for them. This needs to be a regular conversation, handled sensitively, so that families are aware of the risks and what they can do about potential triggers.

For more information about SUDEP, please visit the SUDEP Action website.