Alternative Names seizure disorder, convulsive disorder, recurrent seizures, fits
Definition Epilepsy is a disorder of the nervous system 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? Excitable brain cells give off a high-voltage electrical discharge. These cells are located in the cerebral cortex or deep in the brainstem or spinal cord.
What are the signs and symptoms of the condition? There are several kinds of seizures.
In generalised tonic-clonic seizures, also called grand mal seizures, the person will suddenly lose consciousness. Sometimes there is an aura (sensation that things are not quite right) or warning, followed by stiffening of the whole body, which is known as the tonic phase. There may also be tongue biting or loss of bladder control. This is followed by jerking of the arms and legs, which is known as the clonic phase. These seizures last 2 to 5 minutes. A period of unresponsiveness follows, lasting 5 to 20 minutes.
Partial seizures, or focal seizures, last a few minutes and affect one arm or leg or one side of the body. These seizures may be sensory, with numbness or tingling, or they may be motor, with jerking or twitching.
In complex partial seizures, which used to be known as temporal lobe or psychomotor seizures, symptoms vary from so-called "deja vu" spells to periods of altered consciousness. There may be spaciness, confusion and inability to remember the spells, and the spaciness or confusion can last several minutes.
Absence seizures produce sudden "spacing out." This lasts only a few seconds and almost never more than 20 seconds. The person will not remember that anything happened.
Myoclonic seizures may produce sudden flinging or jerking of arms or legs or the whole body. Sometimes the person falls, but does not lose consciousness.
What are the causes and risks of the condition? There are many possible causes, ranging from inheritance to scars on the brain. These scars can result from head trauma, strokes, tumours, or vascular malformations (blood vessel abnormalities in the brain). Often no underlying abnormality or family history is found.
What can be done to prevent the condition? There is no known way to prevent epilepsy but medication can help control the seizures.
How is the condition diagnosed? Epilepsy is usually diagnosed from a description of the seizure condition and through electrical recordings of brain wave activity (electroencephalograms or EEGs).
What are the long-term effects of the condition? Seizures can lead to physical injury from falling. Frequent seizures may interfere with school or ability to work. Uncontrolled, they can also damage the brain and death can occur.
What are the risks to others? If seizures are not well controlled, driving or work-related accidents might put others at risk.
What are the treatments for the condition? Epilepsy may be treated with anticonvulsant drugs such as phenytoin, carbamazepine, lamotrigine, valproate, topiramate, and tiagabine, surgery or stimulation of the vagal nerve (nerve that controls swallowing and heart rate). Triggers that make seizures more likely, such as alcohol and lack of sleep, must be avoided. Treating tumours, malformed blood vessels (abnormalities in the arteries or veins of the brain), or other underlying problems in the brain may also lessen or stop seizures.
What are the side effects of the treatments? Many drugs used to treat epilepsy have side effects, including drowsiness, skin rash, liver abnormalities and changes of the gums.
How is the condition monitored? Blood is tested regularly to monitor the levels of anticonvulsant drugs. Full blood counts or liver function tests may also be done.
Author: Michael Curiel, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
