
Epilepsy is a neurological disorder that affects people of all ages; however, the incidence of seizures is higher in young children (estimated to occur in as many as 4 percent of all children) than in adults. It is unknown why the developing brain is more prone to seizures than the adult brain. When they occur repeatedly and are not provoked, a child is said to have epilepsy.
In most cases there is no specific acute cause of epilepsy. Some individuals may have minor brain injury present since birth or an inherited tendency towards having seizures. Sometimes, head trauma or a brain infection (meningitis or encephalitis) at an early age produces scarring of the brain that can cause seizures.
Seizures can cause a wide variety of symptoms such as strange sensations, changes in behavior or emotions, muscle spasms, convulsions, or a sudden loss of awareness or consciousness. When children have intractable epilepsy, they are at increased risk of physical injury during a seizure, adverse effects from antiepileptic drugs, disruption of family life, and impairment of learning and attention. Any or all of these reasons, accompanied by concerns about quality of life and future development, may lead a family to consider surgery.
Diagnostic techniques, such as electroencephalograms (EEGs), video-EEG telemetry (vEEG), computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and single photon-emission computerized tomography (SPECT) are used to assess and visualize abnormalities and structural problems associated with epilepsy that may be targets for surgery. Functional testing, including neuropsychological testing, functional magnetic resonance imaging (fMRI), and WADA testing, may be used prior to surgery to define vital regions of the brain and limit risks associated with removal of the epileptic zone.
Most children with epilepsy are well controlled with medication and develop normally with few limitations. However, some children experience uncontrolled seizures or intractable epilepsy despite aggressive treatment with antiepileptic therapy. In these children, epilepsy surgery or surgical removal of the "epileptic zone" of brain tissue is often considered. Although in the past, surgical treatment for epilepsy was considered only after a long period of seizures and multiple medication trials, individuals who will develop intractable epilepsy can now be identified earlier. A surgical evaluation will often be considered when a child has not responded to two or three antiepileptic medications. There is accumulating evidence that surgically curing epilepsy at an early age may provide a better quality of life.
There are many different types of epilepsy that are distinguished by causes, extent, and effects. Among these, there are two major types of epilepsy: generalized epilepsy, in which seizures affect the entire brain, and partial (or focal) epilepsy, in which seizures begin in a specific portion of the brain.
Generalized epilepsies have no defined area in the brain from which the seizures originate. There are two varieties of generalized epilepsies:
The seizures caused by generalized epilepsy include:
Partial (focal) epilepsy involve seizures that begin in a region of the most highly developed part of the brain’s hemispheres. While the seizures sometimes are localized, they can spread to become generalized seizures. The seizures caused by these epilepsies, which may spread and become generalized, include: