Disney star Cameron Boyce died on July 6, 2019. The 20-year-old began his acting career at age 9 and had already starred in the feature films "Eagle Eye," "Grown Ups," and "Grown Ups 2," as well as the Disney Channel series "Jesse" and "The Descendants."
Boyce was found unresponsive in his home and pronounced dead at the scene. His family that the actor had "passed away in his sleep due to a seizure which was a result of an ongoing medical condition for which he was being treated." An autopsy report released by the Los Angeles County Department of Medical Examiner-Coroner this week that the cause of death was "sudden unexpected death in epilepsy," or SUDEP. The manner of death was certified as natural.
To honor their son, his family started the Cameron Boyce Foundation. According to the foundation's , it "provides young people artistic and creative outlets as alternatives to violence and negativity and uses resources and philanthropy for positive change in the world."
What is SUDEP?
Mortality due to epilepsy is a serious concern. Those with epilepsy have a significantly higher mortality rate than the general population. Approximately 40% of deaths in patients with epilepsy are epilepsy related. The causes can include underlying neurologic disorders, accidents during a seizure, status epilepticus, suicide, treatment-related deaths, and SUDEP.
According to the , SUDEP "is said to occur when a person with epilepsy dies unexpectedly and was previously in their usual state of health. The death is not known to be related to an accident or seizure emergency such as status epilepticus. When an autopsy is done, no other cause of death can be found."
Although estimates vary, studies suggest that SUDEP accounts for 8%-17% of deaths in people with epilepsy.
To standardize the definition of SUDEP, the FDA and Burroughs-Wellcome developed criteria for SUDEP in 1993. These criteria, now used in most SUDEP studies, are as follows:
- The patient has epilepsy, which is defined as recurrent, unprovoked seizures
- The patient 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
Evidence of a recent seizure does not exclude the diagnosis of SUDEP as long as death did not occur during the seizure.
What are the risk factors for SUDEP?
The main risk factors for SUDEP are:
- Uncontrolled or frequent seizures
- Tonic-clonic seizures
Other possible risk factors may include:
- Seizures that begin at a young age; most reported cases of SUDEP occur in patients ages 18-40
- Possible genetic predisposition (see below)
- Male sex
- Many years of living with epilepsy
- Poor patient compliance with medication
- Alcoholism
Is the cause of SUDEP known?
The exact cause is not known, but the following factors may play a role in SUDEP, either alone or in combination:
Respiratory
Respiratory problems are commonly seen in patients with seizures and have been reported in patients with SUDEP and near-SUDEP. Both can cause a significant fall in oxygen saturation. Apnea can occur, with either a central or obstructive cause. Electrical impulses during a seizure can extend into the respiratory center of the brain causing apnea.
Obstructive apnea has been postulated to contribute to SUDEP, especially in patients found in a prone position. Physical obstruction of the upper respiratory tract, and increased risk of aspiration are both associated with prone positioning.
In addition, neurogenic pulmonary edema has been found on autopsy in a large number of patients with SUDEP. Neurogenic pulmonary edema is characterized by the acute onset of pulmonary edema following a significant central nervous system (CNS) insult. The etiology is thought to be a surge of catecholamines that results in cardiopulmonary dysfunction. However, the degree of edema may not be sufficient to cause death.
Cardiovascular
Cardiac arrhythmias may play a role in SUDEP. Fatal arrhythmias have been reported during and between seizures. Tachycardia has been documented in many seizure attacks, but in a small number of patients, bradycardia accompanies a seizure and may persist beyond the end of the seizure.
Another proposed mechanism of SUDEP has to do with prolonged QT interval, either seizure-induced or due to autonomic instability predisposing a patient to a malignant arrhythmia. Researchers have suggested that since genetic mutations in ion channels underlie some forms of epilepsy, syndromes associated with cardiac arrhythmias, such as congenital long QT syndrome may play a role in SUDEP. There seems to be some support to this theory as genetic studies have found genes (such as KCNQ1, SCN1A, LQTS, KCNH2, and SCN5A) in patients with SUDEP. These are genes frequently found in patients with long QT syndrome.
Neurogenic cardiopulmonary dysfunction
A multicenter international study called MORTEMUS evaluated records of patients with SUDEP, near-SUDEP, and non-SUDEP deaths that occurred in epilepsy monitoring units. A from that study concluded that "SUDEP in epilepsy monitoring units primarily follows an early postictal, centrally mediated, severe alteration of respiratory and cardiac function induced by generalised tonic-clonic seizure, leading to immediate death or a short period of partly restored cardiorespiratory function followed by terminal apnoea then cardiac arrest."
Medication-associated risk factors
Subtherapeutic levels of antiepileptic drugs have been found in patients with SUDEP. Whether this is due to poor patient compliance or inadequate dosing in not known.
Withdrawal from medications may contribute to SUDEP. Patients on multiple antiepileptic drugs have a higher incidence of SUDEP than those patients who are not.
The anti-seizure drugs carbamazepine and lamotrigine may have sodium channel modulating effects which can cause heart rate variability.
What can be done to reduce the risk of SUDEP?
According to the , ways to reduce the risk of SUDEP include:
- The most important way to lessen the risk of SUDEP is to work towards having as few seizures as possible, particularly generalized tonic-clonic seizures
- Take prescribed seizure medications consistently
- Identify and avoid seizure triggers
- Keep regular appointments with health care providers
Consider other epilepsy treatments, such as surgery, when medications are not working to control seizures.
Michele R. Berman, MD, and Mark S. Boguski, MD, PhD, are a wife and husband team of physicians who have trained and taught at some of the top medical schools in the country, including Harvard, Johns Hopkins, and Washington University in St. Louis. Their mission is both a journalistic and educational one: to report on common diseases affecting uncommon people and summarize the evidence-based medicine behind the headlines.