Multiple: Seizure Disorder
Multiple: Seizure Disorder
Seizure disorder, also called epilepsy, is a disorder of the brain in which there is an abnormal brief surge of the electrical impulses that travel between brain cells. Instead of the normal pattern of signal transmission, the nerve cells misfire as many as 500 times a second, much faster than usual. The affected person's symptoms may range from a few seconds of blank staring to several minutes of convulsions, loss of consciousness, or muscle spasms.
One in every ten adults around the world will have a seizure at some point in his or her life. To be diagnosed with seizure disorder, however, a person must have two or more seizures.
Seizure disorder has been known to doctors for thousands of years. The loss of control, strange movements, and unpredictable behaviors of people having seizures caused some ancient writers to wonder whether they were possessed by demons. Eventually, however, Hippocrates in the fifth century BCE attributed seizures to a problem within the brain. His insight proved to be correct. It is important to keep in mind that seizure disorder is not caused by a mental disorder or by mental retardation. Although some mentally retarded people do have seizures, having seizures does not mean that the affected person is or will become mentally retarded.
Doctors divide seizures into four large categories:
- Generalized seizures (sometimes called grand mal seizures) affect both sides of the brain and include: absence seizures, in which the person stares into space briefly; atonic seizures, in which the person goes limp or falls down; and tonic-clonic seizures, in which the person may lose consciousness, stiffen the body, or make jerking movements of the arms and legs.
- Focal seizures occur in only one part of the brain and affect about 60 percent of people diagnosed with seizure disorder. In focal seizures, the person may have hallucinations or other sensory
- disturbances or experience sudden but intense emotions. In some cases, a person having a focal seizure may perform repetitious movements like eye blinking, mouth twitching, or walking in a circle.
- Nonepileptic seizures may look like focal or generalized seizures, but are not caused by electrical disruptions in the brain. They may be caused by a high fever, strong drugs, general anesthesia, or certain complications of pregnancy.
- Status epilepticus is the medical term for an ongoing seizure that lasts longer than five minutes or seizures that follow each other without the individual waking up. It is potentially life-threatening and needs emergency treatment.
It is possible for a person with seizure disorder to have more than one type of seizure.
Some people with seizure disorder find that their seizures are triggered by certain conditions or activities; others do not have recognizable triggers. The most common trigger for a seizure is failure to take prescribed antiseizure medication. Other triggers include heavy drinking, lack of sleep, emotional stress, or (in women) hormonal changes associated with the menstrual cycle. Seizure triggers do not cause seizures in the strict sense, they simply set them off.
Doctors estimate that about one person in every 100 around the world, or about 50 million people in all, has seizure disorder. In the United States, about 200,000 people are diagnosed with seizure disorder each year, 45,000 of them children below the age of fifteen. There is no apparent cause of the seizures in over half of newly diagnosed cases.
About half of newly diagnosed patients have generalized seizures. Generalized seizures are more common in children under the age of ten than in adults.
Risk factors for seizure disorder include:
- Age: Children younger than two years and adults over sixty-five are more likely to develop the condition.
- Sex: Males are slightly more likely to develop seizure disorder than females.
- Race: African Americans are more likely to develop seizure disorder than members of other racial groups.
The rate of seizure disorder is higher in those with other disorders that affect the nervous system:
- 10 percent of patients with Alzheimer disease
- 22 percent of patients with stroke
- 10 percent of children with cerebral palsy
- 10 percent of children with mental retardation
- 8.7 percent of children whose mothers have seizure disorder
- 2.4 percent of children whose fathers have seizure disorder
First Aid for a Seizure
A generalized seizure can be frightening for onlookers to see; however, most are not medical emergencies. The Epilepsy Foundation recommends the following steps to help a person having a seizure:
- Stay calm and calm down other people nearby.
- Do not try to hold the person or stop his or her movements.
- Time the seizure with a nearby clock or watch.
- Remove any hard or sharp objects near the person.
- Loosen his or her tie or collar.
- Put a folded towel or sweater under the person's head and turn the head to one side to keep the airway clear.
- Do not try to force the person's mouth open.
- Do not try to give the person artificial respiration.
- Stay with the person until he or she regains normal consciousness.
- Be friendly and reassuring.
- Offer to call a taxi or family member to take him or her home.
If the seizure lasts longer than five minutes, the person stops breathing, the seizure happened in the water, or the person appears to be injured in any way, call 911 at once.
Seizure disorder can have a number of different possible causes. A few rare types of epilepsy have been traced to specific genes; a few other types are
known to run in families, though they have not been linked to specific genes. In some cases, seizures are a result of head injuries, cerebral palsy, autism, Alzheimer disease, alcohol abuse, brain tumors, AIDS, and other infectious diseases that affect the brain. In about 50 percent of cases, however, doctors cannot identify a specific cause of the patient's seizure disorder.
Symptoms of seizure disorder vary depending on the type of seizure:
- Generalized absence seizures (sometimes called petit mal seizures): The patient stares off into space and appears to be “out of it” or inattentive.
- Generalized tonic-clonic seizures: These are the dramatic generalized seizures that many people picture in their mind when they think of a seizure. The person may fall on the ground, lose consciousness, thrash about, and lose bowel or bladder control. In these types of seizures, after the jerking ends, the patient will be asleep or drowsy, which is called the post-ictal state.
- Generalized atonic seizures: The person goes limp and may slump (if sitting) or fall down (if standing).
- Generalized myoclonic seizures: The person makes sudden jerking or twitching movements of the arms and legs.
- Simple focal seizures: In a simple focal seizure, there is no change in the patient's level of consciousness. The patient may experience a sudden strong emotion or notice changes in the way things look, sound, taste, or feel.
- Complex focal seizures: A complex focal seizure is one in which the patient loses consciousness for a few moments, although he or she may continue to make purposeless repetitive movements like lip smacking, swallowing, or picking at clothing.
Many people do not understand enough about seizure disorder and its wide range of possible symptoms to respond appropriately to a person having a seizure. It is not unusual for people having nonconvulsive seizures to be treated as if they are mentally ill. Thus widespread lack of understanding is one of the biggest social problems for people with seizure disorder.
Seizure disorder can be difficult to diagnose, because seizures can be caused by meningitis, encephalitis, or a stroke, which all need emergency
attention. The person having the seizure may not remember what happened when he or she returns to normal consciousness, and a family member or bystander may need to describe to a doctor the patient's symptoms and whether there have been previous seizures. After any necessary emergency medical treatment is given, the next step in diagnosis is a neurological examination to test the patient's reflexes, sight, hearing, muscle tone, gait, posture, balance, coordination, and ability to talk normally and answer simple questions.
The specific laboratory tests and imaging studies that may be ordered depend on the specific symptoms associated with the seizure:
- Blood tests to look for evidence of infection, diabetes, or anemia.
- Electroencephalogram (EEG) to record the patterns of electrical activity in the patient's brain. In some types of seizure disorder, the patient's brain waves will be abnormal even when he or she is not having a seizure.
- Computed tomography (CT) scan, magnetic resonance imaging (MRI), or positron emission tomography (PET) scans of the head to identify brain tumors, evidence of a stroke, or other structural abnormalities of the brain. PET can also be used to identify the parts of the brain responsible for focal seizures.
The test results are used to determine which type of seizure disorder the patient has and if possible, the likely cause of the seizures, which helps to guide treatment decisions.
Antiseizure medications are the first line of treatment for seizure disorder. Most patients need only one medication, but some may need a combination of two or more. It may take several trials of different drugs to determine which one works best and what dosage is most effective.
Some patients whose seizures are caused by a small portion of the brain may benefit from surgery, but only if the affected part of the brain does not control sight, hearing, or other vital functions.
Some patients are also helped by a vagus nerve stimulator, a device implanted beneath the collarbone near the vagus nerve in the neck. It is not clear why stimulation of this particular nerve helps to control seizures, but it is reported to lower the number of seizures by 20–40 percent in most patients.
The prognosis of seizure disorder varies according to the patient's age at the time of the first seizure as well as the type of seizure. About 80 percent of people with seizure disorder can be successfully treated with medications; the remaining 20 percent are said to have intractable (difficult-to-treat) epilepsy. About 75 percent of people who are seizure-free on medication for two to five years can be successfully withdrawn from medication. Seizure disorder does carry with it, however, an increased risk of sudden unexplained death or of status epilepticus, from which about 42,000 people die annually in the United States.
Some people with seizure disorder have difficulty finishing school and with employment. One reason is social misunderstanding; another is the effect of antiseizure drugs on a person's ability to concentrate. Employment difficulties are usually related to the restrictions that most states place on driving. Most states require a person with a history of seizure disorder to show that he or she has been seizure-free for a specified period of time before he or she can apply for a driver's license.
Seizure disorder is difficult to prevent, given that it has so many different forms and the fact that doctors cannot identify a cause in about half of all cases. The best way that patients diagnosed with the disorder can prevent seizures is to take their prescribed medications as directed.
WORDS TO KNOW
Intractable: Referring to a disease or disorder that cannot be easily treated or cured.
Status epilepticus: An ongoing seizure that lasts longer than five minutes; it is a medical emergency.
Present research on seizure disorder is focused on improving brain imaging techniques so that doctors will be better able to identify patients who can be helped by surgery as well as medications for seizure disorder. Other researchers are looking for additional genes that may be related to seizure disorder or studying the effectiveness of special diets in treating seizures.
SEE ALSO AIDS; Alcoholism; Alzheimer disease; Brain tumors; Cerebral palsy; Concussion; Encephalitis; Meningitis; Stroke
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