Epilepsy is a common and diverse set of chronic neurological disorders characterized by seizures. Some definitions of epilepsy require that seizures be recurrent and unprovoked,but others require only a single seizure combined with brain alterations which increase the chance of future seizures.
Epileptic seizures result from abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly 90% of epilepsy occurs in developing countries. Epilepsy becomes more common as people age. Onset of new cases occurs most frequently in infants and the elderly. As a consequence of brain surgery, epileptic seizures may occur in recovering patients.
Epilepsy is usually controlled, but not cured, with medication. However, over 30% of people with epilepsy do not have seizure control even with the best available medications.
Signs and symptoms
Epilepsy is characterized by a long term risk of recurrent seizures. These seizures may present in a number of different ways.
Just as there are many types of seizures, there are many types of epilepsy syndromes. Epilepsy classification includes more information about the person and the episodes than seizure type alone, such as clinical features (e.g., behavior during the seizure) and expected causes.
There are four main groups of epileptic syndrome which can be further divided into: benign Rolandic epilepsy, frontal lobe epilepsy, infantile spasms, juvenile myoclonic epilepsy, juvenile absence epilepsy, childhood absence epilepsy (pyknolepsy), hot water epilepsy, Lennox-Gastaut syndrome, Landau-Kleffner syndrome, Dravet syndrome, progressive myoclonus epilepsies, reflex epilepsy, Rasmussen's syndrome, temporal lobe epilepsy, limbic epilepsy, status epilepticus, abdominal epilepsy, massive bilateral myoclonus, catamenial epilepsy, Jacksonian seizure disorder, Lafora disease, photosensitive epilepsy, etc.
Each type of epilepsy presents with its own unique combination of seizure type, typical age of onset, EEG findings, treatment, and prognosis.
Epilepsy is usually treated with medication prescribed by a physician; primary caregivers, neurologists, and neurosurgeons all frequently care for people with epilepsy. However, it has been stressed that accurate differentiation between generalized and partial seizures is especially important in determining the appropriate treatment. In some cases the implantation of a stimulator of the vagus nerve, or a special diet can be helpful. Neurosurgical operations for epilepsy can be palliative, reducing the frequency or severity of seizures; or, in some patients, an operation can be curative.
The proper initial response to a generalized tonic-clonic epileptic seizure is to roll the person on the side (recovery position) to prevent ingestion of fluids into the lungs, which can result in choking and death. Should the person regurgitate, this should be allowed to drip out the side of the person's mouth. The person should be prevented from self-injury by moving them away from sharp edges, and placing something soft beneath the head. If a seizure lasts longer than 5 minutes, or if more than one seizure occurs without regaining consciousness emergency medical services should be contacted.