Sudden death is more than 20 times more common in patients with epilepsy than in the general population. Defects in cardiac and respiratory function are assumed to play a role in this phenomenon, but few studies have explored the underlying mechanisms and risk factors in human patients.
Researchers from University of Oxford and Bristol University in the UK and Purdue University in the US, investigated the effects of repeated brief epileptic seizures on cardiac rhythms in freely moving rats with an experimentally induced temporal lobe epilepsy. The authors report that in every epileptic rat, seizures were accompanied by dramatic changes in heart activity, including abnormal heart rhythms, dramatically decreased heart rate and asystole, followed by high heart rates which persisted for some time even after seizure activity had subsided.
Professor Jeffreys, FMedSci, Professor of Neuroscience, Department of Pharmacology at the University of Oxford, who presented the ground-breaking findings at the American Epilepsy Society Meeting said: “The dramatic cardiac changes caused by repeated seizures could build up over time leading to progressive damage to the heart until a final, fatal seizure-induced episode occurs”.
“These findings give us an exciting lead into understanding how epilepsy can impact the functioning of the rest of the body, and ultimately towards understanding SUDEP and informing therapeutic development.”
The authors believe that other bodily functions may be also be affected by seizures. “Our collaboration with bioengineers, led by Pedro Irazoqui at Purdue, has produced innovative miniature implantable devices that will help us find out how long-term epilepsy affects functioning of the heart, lungs and other bodily systems. We now are well placed to work out the kinds of change that can contribute to SUDEP and, in time, to predict and prevent it,” Jefferys says.
SUDEP Action Chief Executive Jane Hanna OBE commented: “We welcome this research. SUDEP Action has brought SUDEP to world attention, but it is great to see that research on SUDEP is now flourishing at Oxford University.”