Epilepsy Talk

Epilepsy Glossary | September 18, 2009

Even if you do have epilepsy, it doesn’t necessarily mean you know all the lingo.  (I didn’t!)  So here are some definitions of medical terms related to epilepsy…

Absence Seizure:  (previously called petit mal seizures) Frequent, brief events (5-30 seconds) with abrupt onset, impairment of consciousness, and staring followed by an abrupt return to baseline function. If a person is speaking when the absence seizure occurs, he or she will stop talking, stare and when the brief seizure is over, resume the sentence as if nothing had occurred. In fact the person usually does not even recognize that a seizure occurred.

Anticonvulsant: An antiepileptic drug used to control both convulsive and non-convulsive seizures.

Atonic Seizure: A seizure that causes a sudden loss of muscle tone, particularly in the arms and legs, and often causes the patient to fall.

Aura: A warning or initial symptom at the beginning of a seizure, experienced by the patient, but not visible to observers. (Auras might progress to become focal or even generalized seizures, or they might exist alone.)

Clonic Seizure: Repetitive, rhythmic jerks that involve all or part of the body.

Complex Partial Seizure: A seizure that includes impairment of awareness, for example, patients seem to be “out of it” or “staring into space.” (Automatisms or other movements are frequently a part of the seizure, such as in automotor seizures.)

Corpus Callosum: A band of nerve fibers located deep in the brain that connects the two halves (hemispheres) of the brain. (The corpus callosum helps the hemispheres share information.)

Corpus Callosotomy: An operation that cuts the corpus callosum and interrupts the spread of seizures from one hemisphere of the brain to the other. (Callosotomies might be complete, or might involve only a portion of the corpus callosum. Although seizures generally do not completely stop after this procedure, they usually become less severe.)

Drop Attacks: A term used by some clinicians that lumps atonic and tonic seizures together and labels them as “drop attacks.”

Epilepsy: Chronic medical condition characterized by recurrent, unprovoked seizures. Epilepsy currently afflicts an estimated 40 million people worldwide and approximately 2.3 million in the United States alone.

Epileptic Seizure: An abnormal, excessive, sudden discharge of the neurons in the brain. In essence, a seizure is like experiencing an “electrical storm of the brain.”

Epilepsy Surgery: A neurosurgical procedure to prevent further seizures, usually accomplished by resecting the epileptogenic zone. (This is successful in eliminating seizures in a large majority of patients, depending on the type of epilepsy identified during EEG-video monitoring.)

Epileptogenic Zone: The region of the brain responsible for the abnormal electrical signals that cause seizures.

EEG or Electroencephalogram: A recording of the electrical activity of the brain.  (This test helps a physician to diagnose epilepsy.)

EEG/Video Monitoring: Simultaneous EEG and video recording between and during seizures. It can be prolonged monitoring lasting from hours to days and is employed  to diagnose epilepsy and localize the seizure focus. The results are useful to determine therapy, medical or surgical.)

Electrode: A conductive disk (usually metal) attached to the scalp that conveys the electrical activity of the brain through a wire to an EEG machine. (During an electroencephalogram, typically 21 electrodes are temporarily pasted to the scalp.)

Extratemporal Cortical Resection: An operation to cut out (resect) brain tissue that contains a seizure focus (“Extratemporal” means the tissue is located in an area of the brain other than the temporal lobe, most often the frontal lobe.)

Functional Magnetic Resonance Imaging (fMRI): A type of brain scan that can be used to monitor the brain’s activity and to detect abnormalities in how it works.

Generalized Onset Seizure: Discharges that begin in one part of the brain then travel throughout the brain.

Grand-Mal Seizure: An older term for a seizure during which the patient loses consciousness and collapses. (The patient also has body stiffening and violent jerking, and then goes into a deep sleep. Also known as a generalized convulsion.)

Hemisphere: One half of the cerebrum, the largest part of the brain.

Idiopathic: No underlying cause other than a possible inherited predisposition.

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 medicines.)

Lobe: One of the sections of the cerebrum, the largest part of the brain. (The lobes are divided into four paired sections.)

Lumbar Puncture: A diagnostic procedure during which the fluid surrounding the spinal cord (cerebrospinal fluid) is withdrawn through a needle and examined in a laboratory.  (It is also known as a spinal tap.)

Magnetic Resonance Imaging (MRI): More advanced than an x-ray, an MRI is an imaging machine that produces detailed computerized images of internal body organs and tissues.

Myoclonic Seizures: Usually bilateral (predominantly in the arms), irregular, arrhythmic, and can occur singularly or repetitively. These jerks may be so intense that some patients fall. The seizures usually occur shortly after awakening and can interfere with dressing, combing hair, brushing teeth and activities in the kitchen (e.g., dropping plates and glasses). Myoclonic seizures are often brought on by sleep deprivation, stress, alcohol or menstruation.

Neurologist: A doctor who specializes in the treatment of disorders of the brain and nervous system (such as epilepsy).

Neuron: A single nerve cell. (The brain is made up of billions of neurons. Many neurons malfunctioning together are necessary to produce a seizure.)

Neurotransmitters: Chemicals in the brain that aid in transmitting signals and messages back and forth between neurons.

Non-Epileptic Event: An event that resembles a seizure but is actually produced by another condition, such as Tourette syndrome and heart rhythm disturbances, called arrhythmias. (Certain psychological conditions can also bring on a non-epileptic event.)

Petit Mal Seizure: An older term for a form of epilepsy with very brief, unannounced lapses in consciousness which can be accompanied by blank staring.  Often, the person does not even recognize that a seizure has occurred.

Seizure: An event of altered brain function caused by abnormal or excessive electrical discharges in the brain. (Most seizures cause sudden changes in behavior or motor function.)

Seizure Focus: The area of the brain where a seizure starts.

Simple Partial Seizures: Seizures that transiently disrupt or alter speech, motor activity, vision, smell or taste. Simple partial seizures are not associated with any alteration in the level of consciousness.

Status Epilepticus: A prolonged seizure, usually defined as lasting longer than 30 minutes, or a series of repeated seizures without regaining consciousness. (Status epilepticus is a medical emergency, and medical help should be obtained immediately.)

Symptomatic: Arising from a suspected or known cause.

Tonic Seizure: A seizure that is characterized by stiffening of the muscles, sustained for more than a few seconds.

Tonic-Clonic Seizure:  (previously called grand mal seizures) Begins with stiffening of all extremities (tonic phase) followed by rhythmic jerking of all extremities (clonic phase). The tonic phase usually lasts about 30 to 60 seconds, and the clonic phase one to two minutes. The overwhelming majority of tonic-clonic seizures last less than three minutes.

Temporal Lobe Resection: A surgical procedure during which brain tissue in the temporal lobe is cut away (resected) to remove the seizure focus.

Vagus Nerve: A small cranial nerve that passes through the neck and is connected to various areas of the brain.

Vagus Nerve Stimulation: A surgical treatment for epilepsy involving implantation in the neck of an electrode on the vagus nerve. (The electrode is connected to a pacemaker that is placed under the skin in the chest. While the VNS is usually programmed to cycle continuously, the patient can turn the stimulator on, using a small magnet placed over the pacemaker, if he or she feels a seizure coming on.)

Video/EEG Monitoring: Simultaneous EEG and video recording between and during seizures. It can be prolonged monitoring lasting from hours to days.

Resources:

http://www.ehealthmd.com/library/epilepsy/EPI_kinds.htm

http://my.clevelandclinic.org/disorders/Epilepsy/hic_Epilepsy_Glossary.aspx

http://www.cincinnatichildrens.org/svc/alpha/e/epilepsy/glossary.htm

Copyright © 2009, Phylis Feiner Johnson. All rights reserved.

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