Most of those with the disorder (80%) are in low income populations or the developing world.The estimated prevalence of active epilepsy (as of 2012) is in the range 3–10 per 1,000, with active epilepsy defined as someone with epilepsy who has had a least one unprovoked seizure in the last five years. Epilepsy begins each year in 40–70 per 100,000 in developed countries and 80–140 per 100,000 in developing countries. Poverty is a risk and includes both being from a poor country and being poor relative to others within ones country. In the developed world epilepsy most commonly starts either in the young or in the old. In the developing world its onset is more common in older children and young adults due to the higher rates of trauma and infectious diseases. In developed countries the number of cases a year has decreased in children and increased among the elderly between the 1970s and 2003. This has been attributed partly to better survival following strokes in the elderly. History
The oldest medical records show that epilepsy has been affecting people at least since the beginning of recorded history. Throughout ancient history, the disease was thought to be a spiritual condition. The worlds oldest description of an epileptic seizure comes from a text in Akkadian (a language used in ancient Mesopotamia) and was written around 2000 BC. The person described in the text was diagnosed as being under the influence of a moon god, and underwent an exorcism.
A cry may be heard due to contraction of the chest muscles, followed by a shaking of the limbs in unison (clonic phase). Tonic seizures produce constant contractions of the muscles. A person often turns blue as breathing is stopped. In clonic seizures there is shaking of the limbs in unison. After the shaking has stopped it may take 10–30 minutes for the person to return to normal; this period is called the "postictal state" or "postictal phase." Loss of bowel or bladder control may occur during a seizure. People experiencing a seizure may bite their tongue, either the tip or on the sides; in tonic-clonic seizure, bites to the sides are more common. Tongue bites are also relatively common in psychogenic non-epileptic seizures.Myoclonic seizures involve very brief spasms of muscles in either a few areas or all over. These sometimes cause the person to fall, which can cause injury. Absence seizures can be subtle with only a slight turn of the head or eye blinking with impaired consciousness; typically, the person does not fall over and returns to normal right after it ends. Atonic seizures involve losing muscle activity for greater than one second, typically occurring on both sides of the body. Rarer seizure types can cause involuntary unnatural laughter (gelastic), crying (dyscrastic), or more complex experiences such as déjà vu.About 6% of those with epilepsy have seizures that are often triggered by specific events and are known as reflex seizures. Those with reflex epilepsy have seizures that are only triggered by specific stimuli.