Definition of Epilepsy:

Epilepsy is a brain disorder involving repeated spontaneous seizures of any type.

Causes, incidence, and risk factors:

Seizures ("fits," convulsions) are episodes of disturbed brain function that cause changes in attention or behavior. They are caused by abnormally excited electrical signals in the brain.

Sometimes seizures are related to a temporary condition, such as exposure to drugs, withdrawal from certain drugs, or abnormal levels of sodium or glucose in the blood. In the repeated seizures do not happen again once the underlying problem is corrected, the person does NOT have epilepsy.

In other cases, injury to the brain (for example, stroke or head injury) causes brain tissue to be abnormally excitable. In some people, an inherited abnormality affects nerve cells in the brain, which leads to seizures. In these cases, the seizures happen spontaneously, without an immediate cause. This IS epilepsy.

Some seizures are idiopathic, which means the cause cannot be identified. These seizures usually begin between ages 5 and 20, but they can happen at any age. People with this condition have no other neurological problems, but sometimes have a family history of seizures or epilepsy.

Disorders affecting the blood vessels, such as stroke and TIA, are the most common cause of seizures after age 60. Illnesses that cause the brain to deteriorate and dementia such as Alzheimer's diesease, can also lead to seizures.

Some of the more common causes of epilepsy include:

• Problems during the development of the baby in the womb.
• Brain injury
  • Early seizures (within 2 weeks of injury) do not necessarily mean that chronic (ongoing) seizures (epilepsy) will develop
  • Most common in young adults
  • Seizures usually begin within 2 years after the injury
• Genetic conditions present at birth.
• Infections
  • Acute severe infections of any part of the body
  • Brain abscess
  • Brain infections like meningitis and encephalitis
  • Chronic infections (such as neurosyphilis)
  • Complications of AIDS or other immune disorders
  • May affect people of all ages
  • May be a reversible cause of seizures (epilepsy may stop)
• Injuries near the time of birth (seizures usually begin in infancy or early childhood)
• Metabolic abnormalities (problems with body chemistry) may affect people of any age and may be a result of
  • Kidney failure, uremia (toxic accumulation of wastes)
  • Liver Failure
  • Nutritional deficiencies
  • Phenylketonuria (PKU) -- can cause seizures in infants
  • Other metabolic diseases, such as inborn error of metabolism
• Tumors and brain lesions (such as hematomas or abnormal blood vessels)
  • May affect any age but are more common after age 30
  • May lead to generalized tonic-clonic seizures
  • Partial (focal) seizures most common to start with

About 0.5% of the population has epilepsy. Approximately 1.5-5.0% of the population may have a seizure in their lifetime. Epilepsy can affect people of any age.

Risk factors include a family history of epilepsy, head injury, or other condition that causes damage to the brain.

Some factors may present a risk for more seizures in a person with a previously well-controlled seizure disorder:

• Certain prescribed medications
• Emotional stress
• Illness, especially infection
• Lack of sleep
• Pregnancy
• Skipping doses of epilepsy medications
• Use of alcohol or other recreational drugs