Sudden Unexpected Death in Epilepsy (SUDEP) is diagnosed when a person with epilepsy dies without a clear cause, such as an accident or drowning. For a definitive diagnosis, an autopsy must reveal no other structural or toxicological reason for the death. While rare, SUDEP is the most common cause of death directly related to epilepsy for those with uncontrolled seizures.
Most often, the individual is found in bed, and there may be signs that a seizure occurred shortly before death, though this is not required for diagnosis. The circumstances are usually benign, with no obvious external hazard present. This can leave families with many unanswered questions, as the person often seemed healthy.
Suspected Causes of SUDEP
The precise cause of SUDEP is not fully understood, but research points to factors related to the body’s response to a seizure. Leading theories center on severe disruptions to breathing, heart function, and brain control over these systems. A seizure can trigger a temporary cessation of breathing (apnea), and if prolonged, this can dangerously lower oxygen levels.
Following a seizure, the body’s systems may fail to recover properly. A seizure can induce a dangerous heart rhythm or cardiac arrest. The electrical activity can interfere with the brainstem, which regulates heartbeat and respiration, disrupting the signals for these functions.
It is thought that a cascade of events, rather than a single malfunction, leads to death. The combination of impaired breathing, an unstable heart rhythm, and a suppressed central nervous system creates a fatal scenario. Researchers are actively investigating how these systems interact during and after a seizure to better understand this sequence of events.
Primary Risk Factors
The primary risk factor for SUDEP is frequent and poorly controlled generalized tonic-clonic seizures (GTCS), which involve convulsions and a loss of consciousness. Individuals who experience three or more GTCS per year have a substantially higher risk.
Seizures that occur during sleep (nocturnal seizures) also increase a person’s risk, as many cases happen overnight when the person is alone. The position of the person during sleep may also contribute. Individuals are often found lying face down, which could obstruct their airway after a seizure.
Other factors associated with an elevated risk include a long history with epilepsy and not taking anti-seizure medication as prescribed. Failing to adhere to medication can lead to more frequent and severe seizures. While SUDEP can happen at any age, it is more common in young adults.
Approaches to Risk Reduction
The most effective way to lower SUDEP risk is achieving the best possible seizure control, particularly for GTCS. This requires a partnership with a neurology team to find an effective treatment plan. Consistent adherence to prescribed anti-seizure medication is fundamental, as missing doses can lead to breakthrough seizures.
Maintain open communication with a doctor about any seizures that occur. If seizures continue despite treatment, a physician may adjust medication, try a different one, or explore other options. For drug-resistant epilepsy, treatments like neurostimulation devices or surgery may be considered to help manage seizures.
Avoiding known seizure triggers is another practical step. Common triggers include sleep deprivation, illness, and stress; identifying and managing personal triggers can reduce seizure frequency. For those with nocturnal seizures, monitoring devices that alert others to a potential seizure may provide an additional layer of safety.