A Review
by Jane Burford, Epilepsy Association Educator
Is it possible to die from epilepsy?
Even though the outlook for people with epilepsy is quite promising, there is an increased risk of death that is 2-3 times higher than the general population. About 40-50% of deaths of people who have epilepsy are related to epilepsy. (i)
It is important to remember that seizures themselves are rarely fatal. Death may occur because of accident directly related to a seizure, as a consequence of a seizure or ongoing seizures, from a condition that is causing the seizures, or there may be no clear cause as is the case with SUDEP.
Some epilepsy related causes of death include:
Accidents during and after seizures, such as drowning, burns, or trauma. Drowning remains a common cause of death.
Complications from a seizure, include choking and suffocation.
Death from a condition or disease that causes seizures such as a brain tumour, Alzheimer?s disease, or stroke.
Sudden unexpected death in epilepsy (SUDEP ? no identifiable cause)
Status epilepticus (prolonged or ongoing seizures)
Suicide rates are higher than average due to depression and issues associated with epilepsy.
It is difficult to prove any relationship between death and long term use of antiepileptic drugs. Rarely antiepileptic drugs, however, may cause fatal reactions. Generally these occur during early stages of treatment.
Rarely people with epilepsy may take intentional or non-intentional fatal overdoses of antiepileptic drugs. (ii), (iii)
What is SUDEP?
"SUDEP is the sudden, unexpected, witnessed or unwitnessed, non-traumatic and non-drowning death in patients with epilepsy, with or without evidence for a seizure, and excluding documented status epilepticus, in which post-mortem examination does not reveal a toxicological or anatomical cause for death." (iv)
It refers to people who have epilepsy and die suddenly and unexpectedly, and no cause of death can be found. The risk of this happening is very rare.
Most cases involve young people with a history of generalised tonic-clonic seizures. Frequently they are found dead in bed and the post-mortem examinations may reveal focal brain lesions causing the epilepsy but the cause of death cannot be established. Many people who have died from SUDEP have had sub-therapeutic (low) antiepileptic blood levels.
In an attempt to standardise the definition of this event, the US Food and Drug Administration (FDA) and Burroughs-Wellcome developed the following criteria for SUDEP in 1993. These criteria are now used in most SUDEP studies and are as follows:
The person has epilepsy, which is defined as recurrent unprovoked seizures.
The person died unexpectedly while in a reasonable state of health.
The death occurred suddenly (i.e., within minutes).
The death occurred during normal and benign circumstances.
An obvious medical cause of death could not be determined at autopsy.
The death was not the direct result of a seizure or status epilepticus.
Of note, evidence of a recent seizure does not exclude the diagnosis of SUDEP as long as death did not occur during the seizure.
Incidence
SUDEP may account for 8-17% of deaths in people with epilepsy.
Who is at risk?
Sex: It is almost twice as likely to occur in males than females.
Age: The incidence seems to be higher in younger adults. Most cases of SUDEP have been observed in people with epilepsy who are in their third to fifth decade, with a higher incidence at the younger end of the age range. The average age is estimated to be 28-35 years. SUDEP is very rare in children. (iii)
Other factors
Intellectual disability: SUDEP is significantly more common in this group.
Excessive alcohol consumption: is a more frequent behaviour in patients with SUDEP than in the general population of patients with epilepsy.
Seizure related risks
Seizure onset: Diagnosis of epilepsy at a young age and people who have had chronic epilepsy longer than ten years.
Type and frequency of seizures: Poor seizure control. People with frequent, severe generalised tonic-clonic ('grand mal') seizures are at greater risk especially if they occur during sleep. Being alone at the time of the seizure is also a risk factor. Seizures that are from an acquired brain injury, e.g. trauma, brain tumour, stroke, rather than seizures from an unidentifiable cause.
Medication risk factors
Blood levels: Sub-therapeutic or low blood levels of medications can increase the likelihood of SUDEP.
Number of medications: There is a greater risk for people taking multiple antiepileptic drugs.
Changes: Any recent changes or withdrawal of medication. Forgetting to take some dosages or not taking the medication at all.
When considering the risk factors remember that just because some or more of these may apply it does not mean that someone will die from SUDEP. (v)
Cause of death
Different events may contribute to SUDEP in different people, and the reason probably involves a number of factors rather than one single mechanism.
Respiratory
Breathing difficulties, including airway obstruction, apnoea (cessation of breathing), and fluid in the lungs, are probable fatal events.
Cardiac
In addition, irregular heart rate, during both the seizure and in-between seizures, leading to cardiac arrest and acute cardiac failure plays an important role. (iii)