Glossary of Epilepsy Terms
Functional hemispherectomy: a procedure in which portions of one hemisphere of the brain which is not functioning normally are removed, and the corpus callosum is split. This interrupts the communications among the various lobes and between the two hemispheres and prevents the spread of seizures.
Hemisphere: one half of the cerebrum, the largest part of the brain.
Generalized seizure: a seizure that occurs all through the brain.
Grand-mal seizure: an older term for a seizure in which the patient loses consciousness and collapses. The patient also has body stiffening and violent jerking, and then often goes into a deep sleep. Also known as a generalized convulsion.
Ketogenic diet: a treatment for epilepsy intended to maintain the starvation or fasting metabolism for a long period in order to create ketones, byproducts of fat-burning metabolism. Seizures often lessen or disappear during periods of fasting. The diet is very high in fat and low in carbohydrates and is most often recommended for children ages 2 through 12 who have been diagnosed with a generalized type of epilepsy, and who have failed to respond to a variety of medications.
Lesionectomy: surgery to remove isolated brain lesions that are responsible for seizure activity.
Lobe: one of the sections of the cerebrum, the largest part of the brain. The lobes are divided into four paired sections (frontal, parietal, occipital, and temporal). The seizure focus is usually located in one of the lobes.
Lumbar puncture: a diagnostic procedure in which the fluid surrounding the spinal cord (cerebrospinal fluid) is withdrawn through a needle and examined in a lab. Also known as a spinal tap.
Multiple subpial transection: a surgical procedure to help control seizures that begin in areas of the brain that cannot be safely removed (areas that control movements or speech). The surgeon makes a series of shallow cuts (transections) in the brain tissue to interrupt the movement of seizure impulses.
myoclonic seizure: a seizure that consists of sporadic jerks, usually on both sides of the body. Patients with these seizures may drop or involuntarily throw objects.
Neurologist: a doctor who specializes in the treatment of epilepsy and other disorders of the brain and nervous system.
Neruron: a single nerve cell. The brain is made up of billions of neurons. Many neurons malfunctioning together are necessary to produce a seizure.
Nonepileptic event: an event that resembles a seizure but is actually produced by another condition, such as Tourette syndrome or heart rhythm disturbances (arrhythmias). Certain psychological conditions can also bring on a nonepileptic event.
Partial seizure: (also know as a "focal seizure") a seizure that occurs in a limited area in only one hemisphere of the brain. This type of seizure is more amenable to treatment with surgery than are generalized seizures.