Epilepsy risk factors: causes, genes and seizure triggers

What epilepsy is

Epilepsy is a brain disorder that causes people to have recurring seizures. The seizures happen when clusters of nerve cells, or neurons, in the brain send out the wrong signals (MedlinePlus). People who have recurring seizures due to a brain disorder have epilepsy (MedlinePlus).

Having a seizure does not by itself mean a person has epilepsy. First seizures, febrile seizures, nonepileptic events and eclampsia (a life-threatening condition that can occur during pregnancy) are examples of conditions involving seizures that may not be associated with epilepsy. Whatever the type of seizure, it is important to tell your doctor when you have one (NINDS).

Who is more likely to have epilepsy

Anyone can develop epilepsy. It affects both men and women of all races, ethnic backgrounds and ages (NINDS).

Epilepsy has many possible causes, but about half of people living with epilepsy do not know the cause. In some cases, epilepsy is clearly linked to genetic factors, developmental brain abnormalities, infection, traumatic brain injury (TBI), stroke, brain tumors, or other identifiable problems (NINDS). MedlinePlus lists illness, brain injury and abnormal brain development as possible causes, and says that in many cases the cause is unknown (MedlinePlus).

Sometimes, when the brain tries to repair itself after a head injury, stroke, or other problem, it can unintentionally create nerve connection issues that lead to seizures (NINDS).

Genes and family history

Genetic changes may play a key role in the development of certain types of epilepsy. Many types affect multiple members of a family, pointing to an inherited gene or genes. In other cases, gene variations may occur spontaneously in people with no family history of the disorder (called "de novo" mutations). Researchers estimate that hundreds of genes could play a role (NINDS).

Children of parents with epilepsy have about a five percent risk of developing the condition at some point, compared to roughly one percent in a child in the general population. The risk increases if a parent has a hereditary form of the disorder, and parents who are concerned may wish to consult a genetics health care provider (NINDS).

Conditions that can lead to epilepsy

Epilepsy may develop as a result of many types of conditions that disrupt normal brain activity. Once these conditions are treated, some people may no longer have seizures. Examples include (NINDS):

• brain tumors (see brain tumor risk factors)
• head trauma
• alcoholism or alcohol withdrawal
• Alzheimer's disease (see dementia risk factors)
• strokes, heart attacks, and other conditions that deprive the brain of oxygen (see stroke risk factors)
• abnormal blood vessel formation (called arteriovenous malformations) or bleeding in the brain
• brain inflammation or swelling
• infections such as meningitis, HIV-related infections, and viral encephalitis

Cerebral palsy and other developmental disorders also may be associated with epilepsy. Epilepsy is often seen in people with other brain development disorders, for example among people with autism spectrum disorder or intellectual disabilities (NINDS).

What can trigger a seizure

Seizure triggers do not cause epilepsy but can provoke seizures in those who are susceptible. Triggers include (NINDS):

• stress
• drinking alcohol, or alcohol withdrawal
• dehydration or missing meals
• exposure to toxins or poisons, including lead, carbon monoxide, illicit drugs, and very large doses of prescription medications
• hormonal changes associated with the menstrual cycle
• sleep deprivation
• visual stimulation such as flashing lights or moving patterns

In surveys of people with epilepsy, stress is the most commonly reported seizure trigger (NINDS). More broadly, seizures can have many causes, including medicines, high fevers, head injuries and certain diseases (MedlinePlus).

When a seizure is an emergency

Most seizures last from 30 seconds to 2 minutes and do not cause lasting harm. However, it is a medical emergency if seizures last longer than 5 minutes or if a person has many seizures and does not wake up between them (MedlinePlus).

NINDS calls this status epilepticus: a potentially life-threatening condition in which a person either has an abnormally prolonged seizure (over five minutes) or does not fully regain consciousness between recurring seizures. Five minutes is enough to damage neurons and such seizures are unlikely to end on their own, so medical care is needed immediately (NINDS).

General safety advice (not part of the NIH pages): if a seizure lasts longer than 5 minutes, or a person does not wake up between seizures, call 911.

Treatment

Doctors use brain scans and other tests to diagnose epilepsy. It is important to start treatment right away. There is no cure for epilepsy, but medicines can control seizures for most people. When medicines are not working well, surgery or implanted devices such as vagus nerve stimulators may help. Special diets can help some children with epilepsy (MedlinePlus).

It is very important to keep taking antiseizure medication for as long as it is prescribed; stopping too early is one of the major reasons people who have been seizure-free start having new seizures. Stopping medication should always be done with the supervision of a health care professional (NINDS).

Common questions

Does one seizure mean I have epilepsy?

No. Having a seizure does not by itself mean a person has epilepsy, but it is important to tell your doctor when you have a seizure (NINDS).

Is epilepsy inherited?

Sometimes. Many types of epilepsy affect multiple members of a family, and children of parents with epilepsy have about a five percent risk of developing it, compared to roughly one percent in the general population (NINDS).

Can stress cause a seizure?

Stress does not cause epilepsy, but it can trigger seizures in people who are susceptible, and it is the most commonly reported trigger in surveys of people with epilepsy (NINDS).