By Dr Ananya Mandal, MD
Epilepsy is a common disorder which affects 50 million people worldwide. As the disorder is not curable there is a very high prevalence or existing population with this disorder. Every year several hundreds of thousands join this pool of patients as new cases.
In the United Kingdom
In the UK one in 20 people will have a one-off epileptic seizure at some point in their lives. This does not mean that they have epilepsy. One in 50 people will have epilepsy at some time in their life. This however may not be a lifelong condition for all of these individuals. Around 75 people are diagnosed with epilepsy every day and more than half a million people in the UK have epilepsy. This means about one in every 100 has the condition.
Among adults in UK active epilepsy is seen in 5-10 cases per 1,000 but of these 5-30% are misdiagnosed as having epilepsy. Epilepsy most commonly starts in children or in people older than 60 years of age. Epilepsy is much more common in people with a learning disability and other congenital disorders affecting the brain. Over 200 genetic disorders may co-exist with epilepsy. This accounts for approximately 2% of people with epilepsy. In around 30% there is a strong family history of the condition.
In the United States of America
Epilepsy affects about 2 to 3 million people in the United States. About 10% of Americans will experience a seizure sometime during their lives. It leads to direct medical costs and indirect costs (lost or reduced earnings and productivity) to the tune of $15 to 17 billion annually. Children younger than age 2 and adults older than age 65 are particularly at risk. About 3% of Americans will receive a diagnosis of epilepsy by age 80.
Approximately 200,000 new cases of seizures and epilepsy occur each year. 300,000 people report their first convulsion every year and of these 120,000 are below 18 years of age. Around 75,000 and 100,000 of these are children under the age of 5 who have experienced a febrile seizure caused by high fever (not epilepsy). 45,000 children under the age of 15 develop epilepsy each year. Half of the new onset epileptics have generalized onset seizures. Generalized seizures are more common in children under the age of 10.
Males are slightly more likely to develop epilepsy than females. Incidence is greater in African American and socially disadvantaged populations. In 70 percent of new cases, no cause is found and it is idiopathic epilepsy.
The prevalence of existing pool of patients with epilepsy tends to increase with age groups. 326,000 children under 15 have epilepsy and more than 300,000 persons over the age of 65 have the condition. Epilepsy is seen more commonly among racial minorities than among Caucasians.
70 percent of people with epilepsy may be in remission or remain seizure free for 5 or more years after taking regular medications. Around 35 percent of people with mental retardation, cerebral palsy, or other neurological condition respond to medications. Only around 10 percent of new patients fail to respond to medications.
In Australia around one in 120 people have epilepsy. Epilepsy is more frequently seen in infancy, childhood, adolescence and old age.
Up to 70% of people are well controlled by anti-seizure medications. A small percentage of people may be eligible for surgery. Approximately 70% of people who have epilepsy surgery become seizure free.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)