Prevalence and Incidence
Posted on 12/01/2011
About 2.5 million people in the United States have epilepsy, and as many as 9 percent of the entire population may experience a seizure at some point in their lives. Epileptic seizures may be tied to a brain injury or genetics, but most of the time the cause is unknown. New cases of epilepsy are diagnosed most commonly in the first year of life. The rate of new cases in children gradually declines until about age 10, and then stabilizes. After age 55 or 60, the rate starts to increase, as people develop strokes, brain tumors, or Alzheimer's disease, all of which may cause epilepsy.
About 2.7 million Americans have been treated for epilepsy in the past five years. More men than women have epilepsy. New cases of epilepsy are most common among children, especially during the first year of life. Up to 5 percent of the world’s population may have a single seizure at some time in their lives. It is likely that around 50 million people in the world have epilepsy at any one time. Children and adolescents are more likely to have epilepsy of unknown or genetic origin. Brain injury or infection can cause epilepsy at any age. Recent studies show that up to 70 percent of children and adults with newly diagnosed epilepsy can be successfully treated. About 10 percent of children with epilepsy have seizures that do not respond to treatment. The proportion of adults is higher, up to 15 percent.
The reasons why epilepsy begins are different for people of different ages. But what is known is that the cause is undetermined for about half of all individuals with epilepsy, irregardless of age. Children may be born with a defect in the structure of their brain, or they may suffer a head injury or infection that causes their epilepsy. Severe head injury is the most common known cause in young adults. In middle age, strokes, tumors, and injuries are more frequent. In people age 65 and older, stroke is the most common known cause, followed by degenerative conditions such as Alzheimer's disease. Often seizures do not begin immediately after a person has an injury to the brain. Instead, a seizure may occur many months later.
· Epilepsy risk factors
· Premature birth or low birth weight
· Trauma during birth (such as lack of oxygen)
· Seizures in the first month of life
· Abnormal brain structures at birth
· Bleeding into the brain
· Abnormal blood vessels in the brain
· Serious brain injury or lack of oxygen to the brain
· Brain tumors
· Infections of the brain such as meningitis or encephalitis
· Stroke resulting from blockage of arteries
· Cerebral palsy
· Mental disabilities
· Seizures occurring within days after head injury
· Family history of epilepsy or fever-related seizures
· Alzheimer's disease (late in the illness)
· Lengthy fever-related (febrile) seizures
· Alcohol or drug abuse
