A seizure is a transient occurrence of signs or symptoms caused by abnormal, excessive neuronal activity within the brain. For most people, a seizure event is brief and resolves without lasting consequence. However, the abnormal electrical activity can sometimes disrupt vital functions, creating a risk of death. Understanding the specific ways a seizure can lead to death is the first step toward implementing effective prevention and safety measures.
The Mortality Risk: Answering the Core Question
It is possible to die during or shortly after a seizure, though this is rare among all people who experience seizures. However, the overall mortality rate for people with epilepsy is significantly higher than the general population. This increased risk is primarily driven by three distinct pathways that can lead to a fatal outcome.
The most frequent cause of death directly related to epilepsy is Sudden Unexpected Death in Epilepsy (SUDEP). SUDEP involves an unexpected death in a person with epilepsy who was otherwise healthy, where a postmortem examination reveals no other clear cause of death. A second, immediate medical emergency is Status Epilepticus, which is a prolonged or continuous seizure that does not stop on its own.
The third major cause involves fatal accidents that occur when a person loses consciousness or control during a seizure. These accidents include drowning, severe falls, or burns, and the risk is highly dependent on the person’s environment at the time of the event. Controlling the underlying seizure disorder is the main factor in reducing risk across all three categories.
Primary Mechanisms of Seizure-Related Death
Sudden Unexpected Death in Epilepsy (SUDEP)
SUDEP typically occurs following a generalized tonic-clonic seizure, which affects both sides of the brain and causes full-body convulsions. The seizure disrupts the brain’s control over basic, life-sustaining functions. The primary mechanisms involve severe post-seizure respiratory depression, often followed by cardiac dysfunction.
Respiratory failure is the most common initial step in the SUDEP cascade, manifesting as postictal apnea—a prolonged pause in breathing after the seizure movements stop. This lack of oxygen causes the heart to slow dramatically, sometimes resulting in asystole (the heart stopping completely). Research suggests that seizure activity spreading to the amygdala, which regulates breathing, may be responsible for this persistent loss of respiration.
Status Epilepticus
Status Epilepticus (SE) is a neurological emergency defined as a seizure lasting longer than five minutes, or multiple seizures without a return to consciousness in between. When a convulsive seizure continues for a prolonged period, the intense and continuous muscle activity subjects the body to extreme systemic stress. This sustained overactivity triggers a massive release of stress hormones, particularly catecholamines, which can injure the heart and other organs.
The uncontrolled muscular contractions generate significant heat, leading to rapid hyperthermia that can damage the brain and other tissues. The intense metabolic demand also causes metabolic acidosis, severely disrupting the body’s acid-base balance. Furthermore, the breakdown of skeletal muscle cells (rhabdomyolysis) releases toxic compounds like myoglobin into the bloodstream. These compounds can clog the kidneys’ filtering units, leading to acute kidney injury and organ failure.
Accidental Death
Accidental death is a significant contributor to seizure-related mortality, though it is not a direct physiological result of the seizure itself. The momentary loss of consciousness or motor control during an event places the individual in immediate physical danger. A common example is drowning, which occurs if a person has a seizure while bathing or swimming and is unable to keep their airway clear.
A person experiencing a generalized seizure may fall suddenly and strike their head, resulting in a severe traumatic brain injury. Other hazards include falling down stairs, encountering traffic, or sustaining severe burns. These deaths are considered seizure-related because the loss of awareness makes the person vulnerable to environmental hazards.
Immediate Safety Protocols During a Seizure
For a bystander, the most effective prevention strategy is to follow simple first aid steps to keep the person safe until the seizure stops. The primary goal is to prevent physical injury and ensure the person can breathe. The person should be gently eased to the floor, and harmful objects, such as furniture or sharp items, should be moved away.
The person’s head should be protected by placing something soft and flat, like a folded jacket, underneath it. If the person is convulsing, they should be gently turned onto their side. This position helps keep the airway clear and allows fluids to drain from the mouth. It is also important to loosen any tight clothing around the neck, such as a collar or tie, to aid breathing.
A person should never be restrained during a seizure, as attempting to hold them down can cause musculoskeletal injuries like broken bones. It is a dangerous misconception that one should put an object in the person’s mouth to prevent them from swallowing their tongue, as this can cause dental trauma or block the airway. A bystander should stay with the person until the seizure ends, remaining calm and timing the event.
Emergency services should be called immediately if the seizure lasts five minutes or longer, which is the threshold for Status Epilepticus. Help is also needed if the person is injured, has difficulty breathing after the movements stop, or has a second seizure soon after the first. Additionally, immediate medical assistance is required for:
- A first-ever seizure.
- A seizure that occurs in water.
- A seizure involving a person who is pregnant.
Long-Term Strategies for Risk Reduction
The most significant long-term strategy for reducing the risk of seizure-related death is achieving the best possible seizure control through consistent medical management. Taking prescribed anti-seizure medication exactly as directed is the single most effective way to lower seizure frequency and reduce the risk of SUDEP. Missing even a single dose can lower the therapeutic level of the medication in the blood and increase the likelihood of a breakthrough seizure.
When medication alone is insufficient, advanced options can minimize seizure frequency. These include devices like the Vagus Nerve Stimulator, which is surgically implanted and sends electrical pulses to the brain via the vagus nerve. Responsive Neurostimulation is another advanced therapy involving an implanted device that detects abnormal brain activity and delivers an electrical impulse to stop a seizure before it spreads.
Lifestyle adjustments also play a role in proactive risk reduction by helping to avoid common seizure triggers. Maintaining a consistent sleep schedule is important, as sleep deprivation is a frequent trigger that lowers the brain’s seizure threshold. Stress management and regular exercise can help, and people with epilepsy are advised to limit or avoid alcohol and recreational drugs. For high-risk patients, monitoring devices can be used, particularly at night, to alert caregivers to a prolonged seizure event, enabling rapid intervention.