Epilepsy & Seizure Disorders

What is epilepsy?

Epilepsy is a medical condition that produces seizures affecting a variety of mental and physical functions. It’s also called a seizure disorder. When a person has two or more unprovoked seizures, they are considered to have epilepsy.

A seizure happens when a brief, strong surge of electrical activity affects part or all of the brain. 1 in 10 people will have a single seizure in their lifetime. 1 in 100 people are currently living with epilepsy. 1 in 26 will be diagnosed with epilepsy during their lifetime.


In about 60 percent of the cases, the cause is unknown. Of the remaining 40 percent, the following are the most common causes:

  • Brain tumor and/or stroke
  • Traumatic brain injury – the more severe the injury, the greater risk of developing epilepsy
  • Poisoning – lead poisoning or substance abuse
  • Infection – viral encephalitis, lupus erythematosus, meningitis
  • Maternal injury – infection or systemic illness that affects the developing brain of a fetus during pregnancy

Seizure Types

Visit our Brochures and Videos pages to learn how to identify a seizure and how you should respond.

  • Generalized tonic clonic, also known as grand mal
  • Absence, also known as petit mal
  • Complex partial, also known as psychomotor or temporal lobe
  • Atonic, also known as drop seizures
  • Myoclonic
  • Infantile spasms


Sudden Unexplained Death in Epilepsy refers to the death of a person with epilepsy without warning and where no cause of death can be found. Recent studies estimate the rate of SUDEP is about 1 per 1,000 people living with epilepsy each year. In people with frequent tonic clonic seizures (convulsions) who are poorly controlled with medications, the rate may be 1 in 100 per year.

Nonepileptic Seizures (NES)

Nonepileptic seizures or events are diagnosed in 20-30 percent of patients seen at epilepsy centers for intractable seizures. NES are attacks that may look like epileptic seizures but are not caused by abnormal brain electrical discharges. They are a manifestation of psychological distress. A physician may suspect NES when the seizures have unusual features such as type of movements, duration, triggers and frequency.