Epilepsy

Overview, Causes, & Risk Factors

Epilepsy is a disorder of the brain in which seizures occur repeatedly. Seizures are caused by sudden, large discharges of electrical impulses from brain cells.

What is going on in the body?

Neurons are the nerve cells within the brain. They coordinate movement, thinking, personality, and sensory activities. Neurons communicate with each other through electrical discharges. A seizure occurs when excitable neurons give off abnormal electrical discharges. There are different types of seizures, depending on where the excitable neurons are located. Epilepsy is diagnosed when an individual has a repeating pattern of seizures.

Epilepsy is divided into two main types: generalized and partial. Generalized epilepsy affects the entire brain. The person loses consciousness or awareness of the environment. Partial epilepsy affects only one part of the brain. The individual usually doesn't lose consciousness.

Generalized epilepsy may cause the following types of seizures:

absence seizures

atonic seizures

clonic seizures

myoclonic seizures

tonic seizures

tonic-clonic seizures

Partial epilepsy may cause the following types of seizures:

complex partial seizures

secondary generalized seizures

simple partial seizures

What are the causes and risks of the condition?

Epilepsy may be caused by many diseases and conditions. Some of the diseases that can cause epilepsy are as follows:

advanced liver disease

Alzheimer's disease and other types of dementia

atherosclerosis, or hardening of the arteries

bleeding into the brain, such as a subarachnoid hemorrhage

infections involving the brain, including encephalitis and bacterial meningitis

brain tumors

congenital diseases or conditions

hereditary diseases

stroke

transient ischemic attack, which is also called a small stroke

Certain conditions that can cause epilepsy include the following:

abnormalities in the blood vessels of the brain

chromosomal abnormalities

craniotomy, which is brain surgery

head injury

illegal drugs, such as cocaine

injury during birth or in the uterus

lead poisoning

Symptoms & Signs

What are the signs and symptoms of the condition?

Signs and symptoms of epilepsy vary according to the type of seizure.

Absence seizures used to be called petit mal seizures. They have the following characteristics:

include small movements of the face or eyes

involve staring into space

last from a few seconds to a minute

may include dulling of consciousness

most commonly appear in children

Tonic-clonic seizures were formerly called grand mal seizures. These seizures have the following characteristics:

begin suddenly without warning

cause confusion or fatigue afterward

include jerking of the arms and legs

include loss of bladder control

involve stiffening of the body

last 1 to 2 minutes, with consciousness returning up to 15 minutes later

Following are some of the characteristics of atonic seizures:

consciousness may or may not be lost

involve a loss of muscle tone

last a few seconds

the person may drop to the ground without warning

Myoclonic seizures generally are characterized by the following:

involve quick muscle jerking

may be triggered by too much alcohol

may be triggered by lack of sleep

usually don't cause loss of consciousness

usually happen in the early morning

Clonic seizures may have the following characteristics:

cause loss of consciousness

involve muscle jerking

most common in childhood

Simple partial seizures usually can be identified by the following:

consciousness is not changed

last a few seconds

may involve body movements

may lead to a generalized tonic-clonic seizure

may result in a complex partial seizure

things may look, sound, feel, or taste differently

Complex partial seizures may include the following characteristics:

automatic behaviors, such as lip smacking

confusion after the seizure is over

loss of contact with the environment, even though the person is conscious

loss of memory for events that occur during the seizure

may go on to a generalized tonic-clonic seizure

Diagnosis & Tests

How is the condition diagnosed?

Diagnosis of epilepsy begins with a history and physical exam. The healthcare provider will ask about contributing illnesses or injuries. An electroencephalogram, or EEG, will be ordered. An EEG measures electrical activity within the brain. If a seizure occurs during the EEG, the abnormal activity can be detected. A normal EEG does not rule out epilepsy. Other tests that may be ordered include the following:

blood tests to look for diseases or conditions causing the seizures

cranial CT scan to look for abnormalities in the brain

cranial MRI to provide a closer look at brain structures

positron emission tomography, or PET scans, to identify the abnormal brain area

Prevention & Expectations

What can be done to prevent the condition?

Damage to a fetus during pregnancy and delivery may increase the risk of epilepsy. Women with high-risk pregnancies should be monitored closely.

Many childhood infections can be prevented by appropriate vaccination. Protection against lead poisoning will help prevent epilepsy. Following sports safety guidelines for children, adolescents, and adults can prevent some injuries.

Many times, there is no way to prevent epilepsy. Individuals can lower their risk of seizures by taking the following steps:

avoiding excess alcohol

avoiding illegal drugs, especially marijuana and cocaine

getting enough sleep

limiting intake of stimulants such as caffeine

recognizing and avoiding known factors that trigger their own seizures

seeking prompt treatment for fever and illness

taking all medications as prescribed

What are the long-term effects of the condition?

Seizures can lead to physical injury from falling. Epilepsy may interfere with school or work.

What are the risks to others?

Epilepsy is not contagious and poses no risk to others. Medications used to treat epilepsy can cause damage to a fetus. Women with epilepsy need careful monitoring during pregnancy.

Treatment & Monitoring

What are the treatments for the condition?

Medications used to treat epilepsy are known as anticonvulsants. Common anticonvulsants include the following:

carbamazepine, also known as Tegretol

clonazepam, also known as Frisium

diazepam, also called Valium

ethosuxamide, also known as Zarontin

gabapentin, also known as Neurontin

lamotrigine, also known as Lamictal

phenobarbital, also known as Solfoton

phenytoin, also known as Dilantin

primidone, also known as Mysoline

tiagabine, also known as Gabitril

topiramate, also known as Topamax

valproate sodium, also known as Epilim

If a person's seizures are not controlled with medicine, a vagal nerve stimulator may be used. A small pacemaker-like box is inserted under the skin of the chest. It sends regular electrical discharges to the vagus nerve. This discharge can disrupt the abnormal electrical charges. A vagal nerve stimulator does not involve any surgery on the brain.

People with severe, uncontrollable seizures may be candidates for brain surgery. The surgeon opens the skull with a craniotomy. He or she then removes the abnormal brain tissue.

Underlying problems, such as a brain tumor, may require further treatment.

A person with epilepsy may be embarrassed or depressed. Counseling about the condition may help the individual and the family. Support groups exist for those with epilepsy.

What are the side effects of the treatments?

Medications used to treat epilepsy may cause drowsiness, dental problems, and allergic reactions. Insertion of a vagal nerve stimulator involves a small risk for bleeding, infection, or allergic reaction to anesthesia. A craniotomy carries a larger risk of bleeding, infection, brain damage, or allergic reaction to anesthesia.

Many anticonvulsants decrease the effectiveness of oral contraceptives.

What happens after treatment for the condition?

Many substances interfere with the action of anticonvulsants. These include over-the-counter medicines, prescription medications, and herbal remedies. Individuals with epilepsy should consult their healthcare provider before taking any new products.

Treatment of epilepsy is lifelong. If seizures are well-controlled, the individual may live a normal lifestyle. Some people may have significant disabilities from their epilepsy.

Individuals with epilepsy may be able to drive if they are seizure-free. Laws governing driving vary from place to place. People with seizures can participate in most activities of regular life. They may be advised to avoid hazardous activities. Federal law prohibits discrimination in employment. There are also laws precluding people with epilepsy from certain jobs, such as commercial trucking.

A person with epilepsy should use an identification bracelet or card informing others of the condition.

How is the condition monitored?

Blood is tested regularly to monitor the levels of anticonvulsants. Any new or worsening symptoms should be reported to the healthcare provider.