Epilepsy
Epilepsy is a brain disorder involving recurrent seizures.

Causes, incidence, and risk factors
Epilepsy is a disorder involving repeated seizures of any type. Seizures (“fits”) are episodes of disturbed brain function that cause changes in attention and/or behavior. They are caused by abnormal electrical excitation 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 such cases, repeated seizures may not recur once the underlying problem is corrected.

In other cases, injury to the brain (e.g., 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 some cases, no cause at all can be identified.

Some of the more common causes of seizures include:
• Idiopathic (no identifiable cause)
• Developmental or genetic conditions present at birth, or injuries near birth – in this case, the seizures usually begin in infancy or early childhood.
• Metabolic abnormalities
• Brain injury
- may affect any age, highest incidence in young adults
- most likely to occur 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 (epilepsy) will develop
- Tumors and brain lesions that occupy space (such as hematomas)
- Disorders affecting the blood vessels (such as stroke and TIA)
- Degenerative disorders (senile dementia Alzheimer type, or similar organic brain syndromes) mostly affect older people
- Infections

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

Symptoms

The severity of symptoms can vary greatly from simple staring spells to loss of consciousness and violent convulsions. For many patients, the event is stereotyped (the same thing over and over) while some patients have many different types of seizures that cause different symptoms each time.

The type of seizure a person experiences depends on a variety of factors, such as the part of the brain affected, the cause, and individual response.

An aura consisting of a strange sensation (such as tingling, smell, or emotional changes) occurs in some people prior to each seizure. Seizures may occur repeatedly without explanation.

Symptoms of Generalized Seizures
Generalized seizures affect all or most of the brain. They include petit mal and grand mal seizures.

Symptoms of Partial Seizures
Partial seizures affect only a portion of the brain.

The diagnosis of epilepsy and seizure disorders requires a history of recurrent seizures of any type. A physical examination (including a detailed neuromuscular examination) may be normal, or it may show abnormal brain function related to specific areas of the brain.

An electroencephalograph (EEG), a reading of the electrical activity in the brain, may confirm the presence of various types of seizures. It may, in some cases, indicate the location of the lesion causing the seizure. EEGs can often be normal in between seizures, so it may be necessary to do prolonged EEG monitoring.

Treatment
Oral anti-convulsants may reduce the number of future seizures. Response is individual, and the medication used and dosage may have to be adjusted repeatedly. The type of medicine used depends on the seizure type, as some seizure types respond well the one medication and may respond poorly (or even be made worse) by others.

The need for follow-up depends on the seizure type and medications used. Some medications need to be monitored for side effects and blood levels.

For some patients, the use of several medications may still be inadequate. This is called refractory epilepsy. Some such people may benefit from brain surgery to remove the abnormal brain cells that are causing the seizures. For others, a vagal nerve stimulator is implanted in the chest, which can help reduce the number of seizures.