What questions did the research examine in this study?

Previous studies on SUDEP have found several main risk factors. These include poor control of seizures with antiseizure medications, frequent seizures, and convulsive seizures. Often the death occurs at night. Several recent studies report more breathing abnormalities with seizures that occur from sleep. Many of the individuals who die of SUDEP are found face down, so a possible effect of suffocation has been considered.

Research on SUDEP is difficult—unlike studies that can examine effect by a trial, studies on death, including SUDEP, can only use proxy measures such as abnormalities of heart and breathing. The alternative is to examine patients' history and medical records. Historical—or retrospective—research is complicated by much loss of data. For example, information may be lost when patients are seen in multiple different hospitals or move to multiple different places. This results in limited information. This makes the current study especially helpful because the national health system in Sweden allows a reliable review of health history preceding the death of a patient in a comprehensive and reliable way.

The researchers of this study examined a large national database in Sweden comparing individuals who had died of SUDEP and individuals who were alive and had epilepsy.

What are the main findings of the study?

The authors identified 255 SUDEP cases and compared risk factors to those of 1,148 patients with epilepsy who were of the same sex and still alive. The most striking finding was that the risk of SUDEP was increased 15 times in those who had convulsions at night within the previous year. Furthermore, those who lived alone had a 5 times greater risk of dying.

Other risks included using recreational drugs and alcohol. These findings confirm prior reports of the dangers of frequent convulsions, particularly those that occur at night. The authors found that more than two-thirds of the deaths of those who live alone could potentially be prevented if the patient had someone to help.

What does this mean for patients with epilepsy and their loved ones?

Currently we do not have any way to prevent SUDEP but taking certain steps may lower risk. Avoidance of recreational drugs and alcohol is one important measure that may be at least partially helpful. Patients should be careful to take their antiepileptic medications as prescribed without missing any doses.

The study highlights the often-underestimated risk from seizures that occur in sleep. It explains why these seizures may be dangerous, even though the patient appears to be protected while in bed. More importantly, it emphasizes the role of a caregiver.

Since being alone at the time of seizure was a strong risk factor for death, it can be inferred that basic care from someone who is near a patient having a convulsion can be life-saving. Simple first aid measures can include removing sharp or hazardous objects around the individual and, if possible, turning the patient on his or her side to avoid breathing in saliva (aspiration). Calling an ambulance may be appropriate if the event is unexpected, if the convulsions are multiple, if there are injuries, or if the patient is having trouble breathing or is otherwise ill. Seizure bracelets with information about medications and any allergies are often helpful. Other studies have examined wearable technology including alerting devices.