American Medical Association Family Medical Guide - American Medical Association [428]
Epilepsy
Epilepsy is abnormal electrical activity in the brain that causes miscommunication among brain cells. In a healthy person, brain cells communicate with one another by sending electrical signals back and forth but, in a person who has epilepsy, the signals from one group of brain cells occasionally become so strong that they temporarily overwhelm nearby parts of the brain. This sudden, excessive electrical activity causes seizures (uncontrolled movements or temporary loss of consciousness or memory).
Generalized seizures—grand mal seizures or petit mal (or absence) seizures—affect the entire brain. Partial seizures affect a specific area of the brain. Partial seizures can be either simple partial seizures (during which the person remains aware) or complex partial seizures (during which the person loses touch with his or her surroundings and, sometimes, loses consciousness).
In most people with epilepsy, the cause is unknown. In some cases, the disorder can result from a problem such as a brain tumor, stroke, severe head injury, a brain infection, or a blood vessel malformation. Pesticide poisoning, withdrawal from alcohol or other drugs, drug overdose, or a chemical imbalance in the body can also trigger epilepsy. Between 1 and 2 percent of Americans have some form of epilepsy. The disease may run in families and affects men and women in equal numbers. Petit mal seizures occur mainly in children. Isolated, nonrecurring seizures (called febrile seizures) can occur in infants and toddlers as a result of a high fever from an infection. A child who has febrile seizures does not have epilepsy, but the seizures may increase his or her risk of developing the disorder later in life.
In people who have epilepsy, seizures can occur spontaneously or, occasionally, can be triggered by flickering or flashing lights, loud noises, or monotonous sounds. The risk of having a seizure increases with stress, lack of sleep, fatigue, or hunger, or when a person does not take his or her antiseizure medication properly.
Symptoms
Many people who have epilepsy experience a warning of an oncoming seizure called an aura, which may occur just before or as much as several hours before a seizure. An aura may be a vague feeling of tension or unease, or it may be a recognizable sensory change such as a specific sound, disturbing odor, physical sensation, or visual disturbance.
Grand mal seizure
During a grand mal seizure, a person experiences loss of balance and coordination, loss of consciousness, and uncontrollable twitching and jerking body movements. Some people may also lose bladder and bowel control. A seizure normally lasts 1 or 2 minutes, after which the person is usually disoriented and exhausted and does not remember the seizure.
Petit mal seizure
During a petit mal seizure, a person (usually a child) suddenly stops whatever he or she is doing and becomes unaware and inattentive, staring blankly for a few seconds to half a minute. Some people may also experience brief confusion, slight muscle twitching, or rapid eye movements. The symptoms are subtle, and the person is not aware of the seizure. Children who have petit mal seizures are sometimes thought to be daydreaming. The seizures can occur hundreds of times throughout the day, interfering with a child’s ability to concentrate or to complete simple tasks.
Simple partial seizure
A simple partial seizure does not cause loss of consciousness. It usually begins with sudden, uncontrollable muscle twitching in one part of the body, which gradually spreads to other parts of the body.