Overview

Epilepsy — also known as a seizure disorder — is a brain condition that causes recurring seizures. There are many types of epilepsy. In some people, the cause can be identified. In others, the cause is not known.

Epilepsy is common. It's estimated that 1.2% of people in the United States have active epilepsy, according to the Centers for Disease Control and Prevention. Epilepsy affects people of all genders, races, ethnic backgrounds and ages.

Seizure symptoms can vary widely. Some people may lose awareness during a seizure while others don't. Some people stare blankly for a few seconds during a seizure. Others may repeatedly twitch their arms or legs, movements known as convulsions.

Having a single seizure doesn't mean you have epilepsy. Epilepsy is diagnosed if you've had at least two unprovoked seizures at least 24 hours apart. Unprovoked seizures don't have a clear cause.

Treatment with medicines or sometimes surgery can control seizures for most people with epilepsy. Some people require lifelong treatment. For others, seizures go away. Some children with epilepsy may outgrow the condition with age.

Symptoms

Seizure symptoms vary depending on the type of seizure. Because epilepsy is caused by certain activity in the brain, seizures can affect any brain process. Seizure symptoms may include:

  • Temporary confusion.
  • A staring spell.
  • Stiff muscles.
  • Uncontrollable jerking movements of the arms and legs.
  • Loss of consciousness.
  • Psychological symptoms such as fear, anxiety or deja vu.

Sometimes people with epilepsy may have changes in their behavior. They also may have symptoms of psychosis.

Most people with epilepsy tend to have the same type of seizure each time. Symptoms are usually similar from episode to episode.

Warning signs of seizures

Some people with focal seizures have warning signs in the moments before a seizure begins. These warning signs are known as aura.

Warning signs might include a feeling in the stomach. Or they might include emotions such as fear. Some people might feel deja vu. Auras also might be a taste or a smell. They might even be visual, such as a steady or flashing light, a color, or a shape. Some people may experience dizziness and loss of balance. And some people may see things that aren't there, known as hallucinations.

Seizures are classified as either focal or generalized, based on how and where the brain activity causing the seizure begins.

When seizures appear to result from activity in just one area of the brain, they're called focal seizures. These seizures fall into two categories:

  • Focal seizures without loss of consciousness. Once called simple partial seizures, these seizures don't cause a loss of awareness, also known as consciousness. They may alter emotions or change the way things look, smell, feel, taste or sound. Some people experience deja vu. This type of seizure also may result in involuntary jerking of a body part, such as an arm or a leg. And focal seizures may cause sensory symptoms such as tingling, dizziness and flashing lights.
  • Focal seizures with impaired awareness. Once called complex partial seizures, these seizures involve a change or loss of consciousness. This type of seizure may seem like being in a dream. During a focal seizure with impaired awareness, people may stare into space and not respond in typical ways to the environment. They also may perform repetitive movements, such as hand rubbing, chewing, swallowing or walking in circles.

Symptoms of focal seizures may be confused with other neurological conditions, such as migraine, narcolepsy or mental illness. A thorough exam and testing are needed to tell if symptoms are the result of epilepsy or another condition.

Focal seizures may come from any lobe of the brain. Some types of focal seizures include:

  • Temporal lobe seizures. Temporal lobe seizures begin in the areas of the brain called the temporal lobes. The temporal lobes process emotions and play a role in short-term memory. People who have these seizures often experience an aura. The aura may include sudden emotion such as fear or joy. It also may be a sudden taste or smell. Or an aura may be a feeling of deja vu, or a rising sensation in the stomach. During the seizure, people may lose awareness of their surroundings. They also may stare into space, smack their lips, swallow or chew repeatedly, or have movements of their fingers.
  • Frontal lobe seizures. Frontal lobe seizures begin in the front of the brain. This is the part of the brain that controls movement. Frontal lobe seizures cause people to move their heads and eyes to one side. They won't respond when spoken to and may scream or laugh. They might extend one arm and flex the other arm. They also might make repetitive movements such as rocking or bicycle pedaling.
  • Occipital lobe seizures. These seizures begin in the area of the brain called the occipital lobe. This lobe affects vision and how people see. People who have this type of seizure may have hallucinations. Or they may lose some or all of their vision during the seizure. These seizures also might cause eye blinking or make the eyes move.

Generalized seizures

Seizures that appear to involve all areas of the brain are called generalized seizures. Generalized seizures include:

  • Absence seizures. Absence seizures, previously known as petit mal seizures, typically occur in children. Symptoms include staring into space with or without subtle body movements. Movements may include eye blinking or lip smacking and only last 5 to 10 seconds. These seizures may occur in clusters, happening as often as 100 times a day, and cause a brief loss of awareness.
  • Tonic seizures. Tonic seizures cause stiff muscles and may affect consciousness. These seizures usually affect muscles in the back, arms and legs and may cause the person to fall to the ground.
  • Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control. Since this most often affects the legs, it often causes sudden falls to the ground.
  • Clonic seizures. Clonic seizures are associated with repeated or rhythmic jerking muscle movements. These seizures usually affect the neck, face and arms.
  • Myoclonic seizures. Myoclonic seizures usually appear as sudden brief jerks or twitches and usually affect the upper body, arms and legs.
  • Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the most dramatic type of epileptic seizure. They can cause a sudden loss of consciousness and body stiffening, twitching and shaking. They sometimes cause loss of bladder control or biting of the tongue.

When to see a doctor

Seek immediate medical help if any of the following occurs with a seizure:

  • The seizure lasts more than five minutes.
  • Breathing or consciousness doesn't return after the seizure stops.
  • A second seizure follows immediately.
  • You have a high fever.
  • You're pregnant.
  • You have diabetes.
  • You've injured yourself during the seizure.
  • You continue to have seizures even though you've been taking anti-seizure medicine.

If you have a seizure for the first time, seek medical advice.

Causes

Epilepsy has no identifiable cause in about half the people with the condition. In the other half, the condition may be traced to various factors, including:

  • Genetic influence. Some types of epilepsy run in families. In these instances, it's likely that there's a genetic influence. Researchers have linked some types of epilepsy to specific genes. But some people have genetic epilepsy that isn't hereditary. Genetic changes can occur in a child without being passed down from a parent.

    For most people, genes are only part of the cause of epilepsy. Certain genes may make a person more sensitive to environmental conditions that trigger seizures.

  • Head trauma. Head trauma as a result of a car accident or other traumatic injury can cause epilepsy.
  • Factors in the brain. Brain tumors can cause epilepsy. Epilepsy also may be caused by the way blood vessels form in the brain. People with blood vessel conditions such as arteriovenous malformations and cavernous malformations can have seizures. And in adults older than age 35, stroke is a leading cause of epilepsy.
  • Infections. Meningitis, HIV, viral encephalitis and some parasitic infections can cause epilepsy.
  • Injury before birth. Before they're born, babies are sensitive to brain damage that could be caused by several factors. They might include an infection in the mother, poor nutrition or not enough oxygen. This brain damage can result in epilepsy or cerebral palsy.
  • Developmental conditions. Epilepsy can sometimes occur with developmental conditions. People with autism are more likely to have epilepsy than are people without autism. Research also has found that people with epilepsy are more likely to have attention-deficit/hyperactivity disorder (ADHD) and other developmental conditions. Having both conditions may be related to genes.

Seizure triggers

Seizures can be triggered by things in the environment. Seizure triggers don't cause epilepsy, but they may trigger seizures in people who have epilepsy. Most people with epilepsy don't have reliable triggers that always cause a seizure. However, they often can identify factors that make it easier to have a seizure. Possible seizure triggers include:

  • Alcohol.
  • Flashing lights.
  • Illicit drug use.
  • Skipping doses of antiseizure medicines or taking more than prescribed.
  • Lack of sleep.
  • Hormone changes during the menstrual cycle.
  • Stress.
  • Dehydration.
  • Skipped meals.
  • Illness.

Risk factors

Certain factors may increase your risk of epilepsy:

  • Age. The onset of epilepsy is most common in children and older adults, but the condition can occur at any age.
  • Family history. If you have a family history of epilepsy, you may be at an increased risk of seizures.
  • Head injuries. Head injuries are responsible for some cases of epilepsy. You can reduce your risk by wearing a seat belt while riding in a car. Also wear a helmet while bicycling, skiing, riding a motorcycle or doing any activities with a high risk of head injury.
  • Stroke and other vascular diseases. Stroke and other blood vessel diseases can cause brain damage. Brain damage may trigger seizures and epilepsy. You can take steps to reduce your risk of these diseases. Limit alcohol, don't smoke, eat a healthy diet and exercise regularly.
  • Dementia. Dementia can increase the risk of epilepsy in older adults.
  • Brain infections. Infections such as meningitis, which causes inflammation in the brain or spinal cord, can increase your risk.
  • Seizures in childhood. High fevers in childhood can sometimes be associated with seizures. Children who have seizures due to high fevers generally won't develop epilepsy. The risk of epilepsy increases if a child has a long fever-associated seizure, another nervous system condition or a family history of epilepsy.

Complications

Having a seizure at certain times can be dangerous to yourself or others.

  • Falling. If you fall during a seizure, you can injure your head or break a bone.
  • Drowning. People with epilepsy are 13 to 19 times more likely to drown while swimming or bathing than people without epilepsy. The risk is higher because you might have a seizure while in the water.

  • Car accidents. A seizure that causes either loss of awareness or control can be dangerous if you're driving a car or operating other equipment.

    Many states have driver's license restrictions related to a driver's ability to control seizures. In these states, there is a minimum amount of time that a driver must be seizure-free before being cleared to drive. The amount of time may range from months to years.

  • Trouble with sleep. People who have epilepsy may have trouble falling asleep or staying asleep, known as insomnia.

  • Pregnancy complications. Seizures during pregnancy pose dangers to both mother and baby. Also, certain anti-seizure medicines increase the risk of birth defects. If you have epilepsy and you're considering becoming pregnant, get medical help as you plan your pregnancy.

    Most women with epilepsy can become pregnant and have healthy babies. You need to be carefully monitored throughout pregnancy. Your medicines may need to be adjusted. It's very important that you work with your healthcare team to plan your pregnancy.

  • Memory loss. People with some types of epilepsy have trouble with memory.

Emotional health issues

People with epilepsy are more likely to have mental health conditions. They may be a result of dealing with the condition itself as well as medicine side effects. But even people with well-controlled epilepsy are at increased risk. Emotional health problems that may affect people with epilepsy include:

  • Depression.
  • Anxiety.
  • Suicidal thoughts and behaviors.

Other life-threatening complications of epilepsy are not common but may happen. These include:

  • Status epilepticus. This condition occurs if you're in a state of continuous seizure activity lasting more than five minutes. Or it may occur if you have seizures without regaining full consciousness in between them. People with status epilepticus have an increased risk of permanent brain damage and death.

  • Sudden unexpected death in epilepsy (SUDEP). People with epilepsy also have a small risk of sudden unexpected death. The cause is unknown, but some research shows that it may occur due to heart or respiratory conditions.

    People with frequent tonic-clonic seizures or people whose seizures aren't controlled by medicines may be at higher risk of SUDEP. Overall, about 1% of people with epilepsy die of SUDEP. It's most common in those with severe epilepsy that doesn't respond to treatment.

By Mayo Clinic Staff