Scientists at the US Case Medical Centre, in Ohio, have shown for the first time that sudden unexpected death in epilepsy (SUDEP) can occur even when a seizure has not taken place. This is a highly significant finding, and it suggests that seizure detection devices may not be the most effective tools for prevention.
SUDEP is the sudden death of a person with epilepsy for which no obvious cause can be found. It is a rare, but devastating, event that almost always follows a seizure, and most often a generalised tonic-clonic seizure. There are approximately 600 incidences of SUDEP in the UK each year.
Sometimes when SUDEP occurs, there are no physical signs that a seizure has taken place; but with no EEG recording available from the time of death, it is impossible in these cases to rule out a very subtle seizure. The team in Ohio has now found clinical evidence that a seizure is not essential for SUDEP to occur.
Their study, published in the medical journal Epilepsia, focused on three people, two of whom had suffered SUDEP and one of whom had suffered probable SUDEP. All three had been at a high risk of SUDEP, with longstanding, drug-resistant epilepsy and frequent generalized tonic-clonic seizures, and when they died they were being monitored at a specialist epilepsy clinic. This meant that there were records of their heart and breathing function, and their brain and seizure activity (via video-EEG) from the period before their deaths.
When the researchers looked at these records, they found all three people had experienced irregularities in heart rhythm and breathing patterns, and an abnormal type of brain activity called ‘suppression’ in the lead-up to death. However, none of them had shown any physical or electrical signs of a seizure just before they died.
This is the first time that monitored SUDEP, or near-SUDEP, without a seizure has been reported in scientific literature. Although it is only a study of three people, this finding is very important, especially with respect to SUDEP prevention.
The research concludes: “These cases confirm the existence of non-seizure SUDEP; such deaths may not be prevented by seizure detection-based devices.”
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In 2014 Epilepsy Research UK hosted an international expert workshop entitled ‘Time for Prevention—Evidence and Clinical Translation’, in Oxford. For a copy of the proceedings of this event, which are published in the medical journal Epilepsia, please email
The charity SUDEP Action, 01235 772850, offers support to people who have been affected by SUDEP.