Sudden unexpected death in epilepsy was not always recognised as a distinct clinical problem. Its modern history is a story of case recognition, definition, epidemiology, family advocacy and growing attention to modifiable risk.
Before the term SUDEP
Sudden deaths in people with epilepsy were described long before modern terminology existed, but they were often attributed to asphyxia, accident or an undefined effect of a seizure.
Without consistent definitions, studies could not be compared reliably.
The modern research era
From the late twentieth century onward, researchers increasingly separated sudden unexpected deaths from drowning, trauma, status epilepticus and known structural causes.
The term SUDEP became established as standardised definitions were developed.
Why definitions mattered
Clear case definitions allowed researchers to estimate incidence, identify risk factors and compare cohorts.
They also made it possible to distinguish definite, probable and possible cases in research.
Generalised tonic-clonic seizures emerge as the strongest clinical risk factor
Over time, studies consistently found that frequent generalised tonic-clonic seizures carry the clearest modifiable clinical association with SUDEP.
This shifted prevention discussions toward seizure control, medication adherence and nocturnal safety where appropriate.
Monitoring studies changed the mechanistic picture
Recorded deaths in epilepsy monitoring units showed that postictal respiratory and autonomic dysfunction can be central to the terminal sequence.
That evidence moved the field beyond older ideas that SUDEP was simply a primary cardiac arrhythmia problem.
Families and advocacy changed clinical communication
Bereaved families and advocacy organisations pushed for better awareness and more open discussion of risk.
Modern epilepsy care increasingly recognises that people should receive clear, individualised information without sensationalising the risk.
Related reading
Sources and further reading
Evidence checked: September 2026.