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Epilepsy and Seizures

Diagnosing EpilepsyTesting for Epilepsy

S teve was fourteen years old when he had his first seizure. He was in the garage, working on his car, when he lost consciousness. He fell to the ground and had a convulsion. Afterward, he didn't remember anything that had hap pened. His parents took him to the hospital, where several tests were done. All the test results were normal.

“The doctors kept asking questions. I felt as if I was getting the third degree. They asked questions like, did I remember if the garage was hot or smelly and did I feel anything strange before the seizure. They wanted to know if I had any aller gies, if I was getting enough sleep, what my eating habits were like, and whether I was taking any medications. They even asked if I used drugs! I got kind of annoyed and scared at the same time. I started to feel like I was weird or defective.”

Not all seizures are indicative of epilepsy. As you now know, seizures can be caused by a variety of things, including fever, illness, and head injury People are diagnosed with epilepsy when they experience two or more seizures when they are not ill and do not have a fever. Doctors will rule out many possible conditions before saying for certain that someone has epilepsy.

If you have had two or more seizures, you should seek medical treatment. The doctor will ask for a detailed description of exactly what happened during each seizure. Knowing if you had a headache, head injury, or jerking movements in any part of your body before the seizure will help the medical professional find the location of the irregular activity in the brain. He or she will also ask you what happened and how you felt immediately before the seizure. There will be questions about your health in general and about your family's medical history.

The reason that medical professionals ask so many questions is to learn as much as possible so that they can treat you correctly. In particular, they want to know if you have any warning that a seizure is starting. These warnings are called auras, and they may be something like a strange feeling of fear or sickness, or a sudden odd smell or taste. Sometimes people have auras without having a seizure afterward, but an aura means that some abnormal electrical activity in the brain is beginning. Sometimes this abnormal electrical activity tapers off, and at other times it spreads and leads to severe seizures.

Testing for Epilepsy

Several doctors and other health care workers may examine you. Your family doctor, pediatrician, or nurse practitioner may be the first person you meet with. Then there are specialists such as neurologists, who have received specialized training in how the brain works. The diagnosis of epilepsy relies heavily on the person's descriptions of what happened. A physical examination and several other tests will follow.

During the physical examination, the doctor or nurse practitioner will check your lungs, heart rate, blood pressure, height and weight, and the reflexes in your arms and legs, and he or she will shine a light into your eyes to check them. Then you will be given a series of tests. Blood and urine tests will be done to detect medical problems like anemia, diabetes, toxins (poisons) in the body, or kidney disease. Other tests may include an electro-encephalogram (EEG), computerized tomography (CT), and magnetic resonance imaging (MRI).

The Electroencephalogram (EEG)

The EEG measures the electricity given off by brain cells. This test, which takes approximately an hour, does not hurt. A technician will paste tiny wires to your head. These are connected to a machine called an electro-encephalograph, which measures and records the electrical activity in the brain. The record of the activity appears on paper in wavy patterns. Sharp waves or spikes on the EEG mean that there is extra, abnormal electrical activity in the brain. If a seizure occurs during the test, the machine will record it, but the EEG does not make a diagnosis of epilepsy. Some people with epilepsy have normal EEGs, and other people can have abnormal EEGs without having epilepsy. The EEG helps the doctor determine if there is abnormal activity in a specific area of the brain and decide what treatment to recommend.

Sometimes, if there is not enough information for the doctor to make a diagnosis, a person will be attached to a portable EEG machine that measures and records brain activity for twenty-four hours to monitor any changes when the person is awake or asleep. To both see and record any seizure activity, an EEG may be combined with video monitoring. This is especially useful for people who have epilepsy but have normal EEGs.

Other Tests

The CT and MRI tests can help “see” the brain and look for abnormal structures such as tumors or enlarged blood vessels. The CT uses a low-level X ray to scan the brain, then makes a computerized picture to show abnormal structures. MRIs give an even clearer picture of the brain than CT scans. During an MRI, you must lie still for approximately forty-five minutes in a tunnel-like machine that uses a magnet to produce a picture of the brain. Additional tests may be used to measure other changes in the brain and to learn more about seizure activity. There is no single test to diagnose epilepsy. In most cases, unfortunately, none of these tests will explain the cause of someone's seizures.

“So far, they haven't found a cause for my seizures,” Steve explains. “They're things that just happened. I have not had any seizures since I've been taking the medication that my doctor pre scribed. I don't like having this seizure disorder or epilepsy or whatever, but I'm glad there's nothing wrong with me mentally, and I'm not contagious.”

Additional topics

Science EncyclopediaEpilepsy