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Epilepsy (also known as seizure disorder) is a neurological condition with symptoms which vary from a momentary lapse of attention to convulsions. Damage to brain cells can disrupt the normally smooth-running pattern of electrical activity in the brain by causing an electrical overload. This can create a seizure, which causes a sudden change in the individual's consciousness and/or change in motor activity. Epilepsy was one of the first brain disorders to be described. It was mentioned in ancient Babylon more than 3,000 years ago. The word epilepsy is derived from the Greek word for "attack." It was once thought that people who had epilepsy were being visited by demons or gods. However in 400 B.C., the early physician Hippocrates suggested that epilepsy was a disorder of the brain.
A seizure disorder includes any condition in which there are repeated episodes of seizures of any type. Epilepsy (idiopathic seizure disorder) is a term used when the seizure disorder has no identifiable cause such as brain disease. A seizure disorder affects about 0.5% of the population, and may affect people of any age.(1) The symptoms, frequency, intensity, and types of seizures vary greatly from person to person. Those whose condition is controlled by medication may not experience seizures at all.
In many cases, the cause of epilepsy is unknown.(2) It can occur as a result of an infection, head injury, brain tumor, hydro-cephalus, toxic reaction to drugs and alcohol, or other conditions which injure the brain and damage brain cells.(3, 4) Genetic factors may contribute to the development of a seizure disorder, but are not a primary cause.(5) It may also be associated with other neurological conditions such as cerebral palsy. The cause of the seizure correlates to some extent with the onset of age. In some people, seizures may be triggered by hormone changes such as pregnancy or menstruation. They may also be triggered by illness or by sensory stimuli such as lights, sounds, and touch. One study noted that free radicals may also be implicated in epilepsy. Plasma levels of vitamin A, vitamin C and vitamin E were normal in the control population as well as the patients with epilepsy who had been seizure free for one year. The status of these antioxidants in the blood of epileptic patients with active seizures was low compared to the control groups.(6) In many cases, no trigger is found for the seizures.
Some of the more common causes of seizures include:(7)
Idiopathic (no identifiable cause)
- Usually begin between ages 5 to 20
- May occur at any age
- No other neurologic abnormalities present
- Often a family history of epilepsy or seizures
Congenital defects and perinatal injuries
- Seizures usually begin in infancy or early childhood
Metabolic abnormalities
- May affect any age
- Diabetes mellitus complications
- Electrolyte imbalances
- Kidney failure, uremia (toxic accumulation of wastes)
- Nutritional deficiencies
- Phenylketonuria (PKU)-can rarely cause seizures in infants
- Use of or intoxication from alcohol or drugs
- Alcohol withdrawal
- Drug withdrawal
Brain injury
- May affect any age, highest incidence in young adults;
- Most likely if the brain membranes are damaged;
- Seizures usually begin within 2 years after the injury
- Early seizures (within 2 weeks of injury)-do not necessarily indicate that chronic seizures will develop
Tumors and brain lesions that occupy space (i.e. hematomas)
- May affect any age, more common after age 30
- Partial (focal) seizures most common initially
- May progress to generalized tonic-clonic seizures
Disorders affecting the blood vessels (stroke, TIA, etc…)
Most common cause of seizures after ag
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