Combined EEG–ECG Analysis of 5 Cases
R. Bartlam, R. Mohanraj, Epilepsy & Behavior, 2016; 64:212–215.
- SUDEP (sudden unexpected death in epilepsy) is sudden death of a person with epilepsy that is not associated with trauma or drowning. It is the most common cause of death in people with epilepsy.
- The exact reasons behind SUDEP are not fully known, but cardiac problems seem to play a role. Indeed, changes in heart rhythm are common during seizures, even if the seizures are not convulsive.
- The most common change is tachycardia (i.e., an increase in heart rate during the seizure). Bradycardia (a decrease in heart rate) has also been reported, though it is rare.
- Ictal bradycardia (low heart rate during a seizure) is important to consider because it may lead to ictal asystole (the absence of electrical activity, also called “flat-lining” when the heart beat stops). The outlook for asystole is very poor.
- Since ictal asystole could be a potential cause of SUDEP, the authors of this study looked at patients that had ictal asystole.
Description of study
- This study looked at 5 people who had asystole during a seizure and had a pacemaker for the heart implanted.
- Information such as age at start of epilepsy, seizure type and frequency, where seizure(s) arise from in the brain, seizure medications, EEG patterns between seizures, and electrical patterns during sleep were collected.
A summary of study findings
- Ictal asystole occurred most often in focal or partial seizures with lack of awareness.
- Seizures involved the temporal lobe in all 5 people.
- In 4 out of 5 people, ictal aystole happened in seizures during sleep.
- All patients had abnormal electrical activity that was stronger during sleep.
What does this mean?
- Often, people who die from SUDEP are found lying face down in bed. It could be that they die from ictal asystole or when the heart beat stops for unknown reasons.
- This is a very small study. More data is needed to better understand cardiac problems such as ictal aystole, and hopefully SUDEP.
Article published in Epilepsy & Behavior, November 2016.