About half the people who experience just one seizure without a clear cause will eventually develop another one–usually within about 6 months. People are twice as likely to have another seizure if they have a known brain injury, or any other type of brain abnormality. Experiencing two or more seizures in a relatively short amount of time usually equates to an 80% chance of actually having some form of epilepsy.
Epilepsy can develop in any person, at any age. Up to 2% of the American population will develop epilepsy during their lifetimes, and naturally, people with certain health conditions may be at greater risk than others.
New cases of epilepsy are most common among children and individual over 50. After age 60, the rate starts to increase, as people develop strokes, brain tumors, or Alzheimer’s disease (all of these disorders can cause epilepsy).
- 1 out of 10 people will experience a seizure within their lifetimes.
- It is likely that around 50 million people in the world have epilepsy at any given time.
- Children and adolescents are more likely to have epilepsy of unknown or genetic origin than adults.
- Epilepsy can start at any age.
- Recent studies show that seizures in up to 65% of children and adults with newly diagnosed epilepsy can be controlled with medications. However, many of these people experience treatment-related side effects.
- Seizures in up to 35% of people with epilepsy cannot be stopped with currently-available medicines.
- There are more people with epilepsy than multiple sclerosis, Parkinson’s, cerebral palsy, and autism combined.
There is a fine balance in the brain between factors that cause electrical activity and those that restrict it, and there are also systems that limit the spread of such electrical activity. During a seizure, the natural limits have (for whatever reason) broken down, and abnormal electrical discharges can occur and spread to whole groups of neighboring cells at once. This linkage of discharges creates an uncontrollable “electrical storm” in the brain (otherwise known as a seizure).
- Babies who are small for their gestational age
- Babies who have seizures in the first month of life
- Babies who are born with abnormal brain structures
- Bleeding into the brain
- Abnormal blood vessels in the brain
- Serious brain injury or lack of oxygen to the brain
- Brain tumors
- Infections of the brain: abscess, meningitis, or encephalitis
- Stroke resulting from blockage of arteries
- Cerebral palsy
- Mental challenges
- Seizures occurring within days after head injury (called “early post-traumatic seizures”)
- Family history of epilepsy or fever-related seizures
- Alzheimer’s disease (late in the illness)
- Fever-related (febrile) seizures
- Use of illegal drugs such as cocaine
- Special Note: mild head injuries (such as a concussion with just a very brief loss of consciousness) do not cause epilepsy.
It may seem obvious that heredity (genetics) plays an important role in many cases of epilepsy in very young children, but it can be a factor for people of any age. For instance, not everyone who has a serious head injury (a clear cause of seizures) will develop epilepsy. Those who do develop epilepsy are more likely to have already had a history of seizures in their family. That would make it easier to develop epilepsy than for others with no genetic predisposition.
Epilepsy in which the seizures begin from both sides of the brain at the same time is called “primary generalized epilepsy”. PGE is more likely to involve genetic factors than what is called partial epilepsy, in which the seizures are limited to one area of the brain.
The risk is slightly higher than usual for siblings of children with epilepsy, not because they will “catch” it (seizure disorders are not contagious), but because there may be a genetic tendency. Epilepsy is more likely to occur in a brother or sister of a child with generalized seizures, depending on the type of epilepsy and the number of family members who are affected.
Many people who are seizure-free for two to four years can stop taking medication, but only under a doctor’s supervision. However, roughly 30% of children and 30% to 65% of adults will experience seizures again. If the decision is made to go off medication, it is best to gradually transition over the course of weeks, or months—not all at once.
Some people living with seizures that cannot be controlled with tolerable doses of anti-seizure medicine (called “intractable epilepsy”) do eventually become seizure-free. The longer one continues to experience seizures after the diagnosis of epilepsy is made, however, the lower the chance that seizures will stop.
The overall life expectancy of people who have epilepsy is the same as for anybody else if they are otherwise healthy. Some people whose epilepsy is caused by factors such as stroke or a brain tumor may pass on sooner.
A long-lasting convulsive seizure (called “tonic-clonic status epilepticus”) is a medical emergency. If not stopped within about 30 minutes, it can cause permanent injury or death. In addition, people with epilepsy can also die from inhaling vomit during, or just after, a seizure. This can be prevented if someone physically turns the individual onto his or her side when the seizure begins and ensures that any vomit completely exits the mouth. In general, however, seizures are rarely fatal, even if the person loses consciousness.