Possible risk indicators of sudden death in epilepsy discovered

Researchers have discovered possible biological indicators to identify those at greatest risk of sudden death in epilepsy.

A team led by Dr Beate Diehl and first author Dr Britta Wandschneider compared brain scans of people who died of Sudden Unexpected Death in Epilepsy (SUDEP) and people already identified as at high risk of SUDEP, with scans of people people at low risk. The researchers found changes in the right hippocampal and parahippocampal areas of the brain.

BRC-supported Dr Wandschneider from the UCL Institute of Neurology said: “We wanted to use imaging to find which areas of the brain look different in people who suffered SUDEP. We looked at different groups: those who had a brain scan in the past and later died of SUDEP; those at high risk of SUDEP who had lots of seizures, specifically at night, with a long history epilepsy; and those at low risk of SUDEP.” 

Typically epilepsy patients often show reduced brain volume in the hippocampus. However the researchers found an increase in people who had died from SUDEP or were in the high risk group. As a result, the findings indicate neuro-imaging could be used to recognise certain biomarkers in those at greatest risk of SUDEP.

The findings also suggest that the increase in grey matter on the right side may influence the autonomic functions we do without thinking such as breathing and blood circulation.

Dr Wandschneider said: “It is known that epilepsy can be associated with abnormal regulation of important functions such as heart beat and respiration which may lead to dysregulation of these functions, causing a life threatening irregular heart beat for example. We do however not know which areas of the brain are specifically implicated in SUDEP, and whether abnormal regulation of these functions in SUDEP is seizure related, or more related to what goes on between seizures.”

The researchers also discovered possible similarities between structural changes in the brains of infants who die of cot death and structural changes in the brains of adults who die of SUDEP. Studies in babies who have died of Sudden Infant Death syndrome have found similar abnormalities in the same regions of the brain.

Dr Wandschneider said: “The changes in the hippocampus are interesting as we know from previous studies that children who die from sudden unexpected death have changes in the hippocampus and surrounding areas.”

People with epilepsy are 20 times more likely to die prematurely than those without the condition. SUDEP is the most common cause of premature death in people with epilepsy with 600 people dying from SUDEP each year.

The study, published in Brain, looked at 12 cases of SUDEP, 34 people at high risk of SUDEP, 19 at low risk and 15 healthy controls.

To read Structural imaging biomarkers of sudden unexpected death in epilepsy in Brain click here.