Temporal lobe epilepsy; Seizure disorder
Epilepsy is a brain disorder in which a person has repeated seizures (convulsions) over time. Seizures are episodes of disturbed brain activity that cause changes in attention or behavior.
See also: Seizures
Causes, incidence, and risk factors
Epilepsy occurs when permanent changes in brain tissue cause the brain to be too excitable or jumpy. The brain sends out abnormal signals. This results in repeated, unpredictable seizures. (A single seizure that does not happen again is not epilepsy.)
Epilepsy may be due to a medical condition or injury that affects the brain, or the cause may be unknown (idiopathic).
Common causes of epilepsy include:
- Stroke or transient ischemic attack (TIA)
- Dementia, such as Alzheimer’s disease
- Traumatic brain injury
- Infections, including brain abscess, meningitis, encephalitis, and AIDS
- Brain problems that are present at birth (congenital brain defect)
- Brain injury that occurs during or near birth
- Metabolism disorders present at birth (such as phenylketonuria)
- Brain tumor
- Abnormal blood vessels in the brain
- Other illness that damage or destroy brain tissue
- Use of certain medications, including antidepressants, tramadol, cocaine, and amphetamines
Epilepsy seizures usually begin between ages 5 and 20, but they can happen at any age. There may be a family history of seizures or epilepsy.
Symptoms vary from person to person. Some people may have simple staring spells, while others have violent shaking and loss of alertness. The type of seizure depends on the part of the brain affected and cause of epilepsy.
Most of the time, the seizure is similar to the previous one. Some people with epilepsy have a strange sensation (such as tingling, smelling an odor that isn’t actually there, or emotional changes) before each seizure. This is called an aura.
For a detailed description of the symptoms associated with a specific type of seizure, see:
A.D.A.M. Medical Encyclopedia.
(Posted on line by PubMed Health.)
Signs and tests
The doctor will perform a physical exam, which will include a detailed look at the brain and nervous system.
An EEG (electroencephalogram) will be done to check the electrical activity in the brain. People with epilepsy will often have abnormal electrical activity seen on this test. In some cases, the test may show the area in the brain where the seizures start. The brain may appear normal after a seizure or between seizures.
To diagnose epilepsy or plan for epilepsy surgery:
- You may need to wear an EEG recorder for days or weeks while you go about your everyday life.
- You may need to stay in a special hospital where brain activity can be be watched on video cameras. This is called video EEG.
Tests that may be done include:
Head CT or MRI scan often done to find the cause and location of the problem in the brain.
Experts answer 7 frequently asked questions about epilepsy.
More than 2 million people in the United States have some form of epilepsy, a group of related disorders marked by recurrent seizures. WebMD asked epilepsy experts your most frequently asked questions.
How do people develop epilepsy?
In most cases — about seven in 10 people — the cause of epilepsy is unknown. In other cases, epilepsy can have a symptomatic cause, such as birth injuries, head injuries, and infectious diseases including meningitis and encephalitis. It can also be caused by genetic conditions and stroke.
“Whatever the cause, epilepsy causes too many nerve cells to fire in the brain at the same time,” says Donald Olson, MD, director of the Epilepsy Program at Lucile Packard Children’s Hospital at Stanford University Medical Center. “Depending on which part of the brain the cells are firing in, the symptoms could vary from a strange feeling, to one side of the body jerking, to a whole-body convulsion.”
How is epilepsy diagnosed?
A doctor will start by taking a medical history, followed by a physical and neurological examination of muscle strength, reflexes, eyesight, hearing, and ability to detect various sensations. Other tests include an electroencephalogram (EEG) test, which measures electrical impulses in the brain; imaging studies of the brain, often with magnetic resonance imaging (MRI); and blood tests to measure red and white blood cell counts, blood sugar, blood calcium and electrolyte levels; and to evaluate liver and kidney function.
What are the types of seizures?
Seizures are divided into two broad categories: partial and generalized.
Partial seizures affect only a specific part of the brain and are further grouped into two types: In simple partial seizures, a person may have jerking movement and abnormal sensations, such as extreme emotion or changes in taste, depending on what part of the brain the seizure affects. In complex partial seizures, a person loses awareness and may have unconscious movements such as lip smacking and fidgeting. Partial seizures that spread and become generalized are called partial seizures secondarily generalized.
Generalized seizures affect the entire brain from the beginning of the seizure and are broken down into several types: In generalized tonic-clonic seizures, the entire body stiffens and jerks and a person loses consciousness. This is also known as a grand mal seizure. Myoclonic seizures are lightning jerks of the muscle, usually on both sides of the body. In absence seizures, a person loses awareness and has a blank stare, as if he or she is looking through you. This is also known as a petit mal seizure. Atonic seizures cause the body to lose muscle tone with no warning and fall over.
What do I do if my friend has a seizure?
“It’s the generalized tonic-clonic seizure that requires the most action,” says Jacqueline French, MD, a professor of neurology at New York University Comprehensive Epilepsy Center and a fellow with the American Academy of Neurology.
What do I do if my friend has a seizure? continued…
First, gently bring the person to the ground and put something under the head so he or she doesn’t hit the floor, French explains. Then turn the person over on the left side — a better position for easier breathing and improved circulation. Turn him or her head slightly down so saliva won’t go into the lungs — and absolutely do not put anything in the person’s mouth. The seizure should end in one or two minutes, maybe even less.
When the person regains consciousness, he or she will be confused, so stay with the person until he or she is back to the person’s normal self. It’s a good idea for those with epilepsy to wear a medical bracelet. If he or she has a seizure and no one is around, the bracelet will tell others what’s happening so they can respond appropriately.
Can a seizure be life-threatening?
Yes, but very rarely. “Status epilepticus is when a seizure lasts longer than a few minutes, which can lead to brain injury and even death,” says French. So, if a seizure hits the three-minute mark, call 911 immediately.
Looking at seizures in another way, they can be life-threatening, especially for children who are not well supervised in certain situations. For instance, never leave a child who has had a seizure alone in the bathtub, explains Olson.
How is epilepsy treated?
The most common way to treat epilepsy is with medication. Specific drugs are prescribed depending on the type of epilepsy or seizure a person has. When medication doesn’t work, surgery is another treatment option. In some cases, a surgeon can remove the area of the brain producing seizures or can interrupt the nerve pathways that signal seizures. For children, a very strict meal plan called the ketogenic diet may reduce seizures.
If a patient doesn’t respond to medication and surgery is not an option, vagus nerve stimulation can help prevent seizures. It works through a battery implant in the chest that delivers small pulses of electrical energy into the brain via the vagus nerve in the neck. The downside: It doesn’t work for everyone, and it is not approved by the FDA for kids younger than age 12.
Any new treatments on the horizon?
“We have a lot of hope that some of the brain-stimulation technologies currently in development will bear fruit,” says Olson. The goal of brain stimulation is to detect and interrupt seizures before they begin, through an implanted device in the brain. New medications are also in clinical trials, such as nasal sprays with antiseizure drugs that could be used immediately when a seizure starts to help stop its progression.
Originally published in the March/April 2008 issue of WebMD the Magazine.