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Common Terms

Epilepsy is a complex disease and has a lot of terminology. We have put together a collection of the most important and prevalent of those terms.

Absence Seizure

A generalized seizure, usually lasting less than 20 seconds, characterized by a blank stare & sometimes blinking, eye rolling or chewing movements. Can occur many times a day. Often mistaken for daydreaming. Usually begins in childhood. Outgrown by approximately 75% of children. Formerly called petit mal.

Antiepileptic Drugs

Medication used to control seizures. Also called anticonvulsants.

Atonic Seizure

A generalized seizure characterized by sudden loss of muscle tone, causes the head or body to drop suddenly with falling & potential injury. Recovery in a few seconds to a minute. Protective helmets are helpful to protect from injury.Also called a drop attack.


A warning period at the beginning of a seizure. May sense a feeling of fear or doom, or strange sensations such as an odd smell or taste, nausea, or palpitations. Actually a simple partial seizure occurring seconds or minutes before a complex partial or secondarily generalized tonic-clonic seizure, or it may occur alone.


Purposeless, automatic & involuntary movements during a seizure, such as chewing, lip-smacking, picking at clothing or wandering around confused; may occur during complex partial & absence seizures.

Benign Rolandic Epilepsy

Epilepsy syndrome of childhood characterized by partial seizure affecting the face, causing drooling & inability to speak, may be followed by a convulsion. Typically occur at night and are usually outgrown by age 16. Also called benign partial epilepsy of childhood.

Catamenial Epilepsy

In women, the tendency for seizures to occur around the time of menstruation.

Clonic Seizure

A generalized seizure characterized by rhythmic jerking movements involving both sides of the body.

Complex Partial Seizure

A seizure that affects only part of the brain, but causes impaired consciousness or awareness. May be accompanied by automatisms, dazed behavior, and/or movements or emotional behavior that seems out of place, unfocused or mechanical. Following the seizure there will be a period of confusion & no memory of the incident.


The stiffening or jerking that accompanies a seizure.

CT or CAT Scan

Computed Tomography; a scanning technique which uses x-rays & computers to produce images of the structure of the brain to help detect abnormalities.


Electroencephalogram; a diagnostic test which records the brain’s electrical activity or “brain waves”. It does not provide a diagnosis of epilepsy, but can help distinguish types of seizures, or where seizures begin in the brain.


A chronic disorder characterized by recurrent unprovoked seizures. Also called seizure disorder.


A neurologist with specialty training in epilepsy.

Febrile Seizure

A seizure caused by high fever, common in young children under the age of 5. Only rarely are they associated with later epilepsy. Anticonvulsants are not usually needed.

Focal Seizure

An older term for partial seizure, in which the seizure starts in one part of the brain.

Gelastic Seizure

Partial seizure characterized by inappropriate laughter. The laughter may sound forced, like a bray, or similar to crying.

Generalized Seizure

Seizure that involves the entire brain and causes tonic & clonic movements or another type of generalized epilepsy such as atonic, myoclonic or absence.

Grand Mal

An older term for a generalized tonic-clonic seizure.


Surgical removal of one side, or hemisphere, of the brain; the operation is now often modified to remove a portion of the hemisphere and to disconnect the remaining portions.


Referring to the period during a sudden attack, such as seizure or stroke. A seizure, of whatever type, is referred to as an ictus.


Used to describe an epileptic seizure of unknown cause, as opposed to seizures caused by an identifiable problem in the brain.

Infantile Spasms

Clusters of rapid jerks followed by stiffening or jackknife movements. Usually starts in the first year of life & stops by the age of 4. May be associated with significant developmental delay & the development of other forms of epilepsy. It requires prompt diagnosis and treatment with specific medications.Also known as West syndrome.


Difficult to alleviate or remedy; for example, intractable seizures are difficult to control with the usual antiepileptic drug therapy.

Juvenile Myoclonic Epilepsy (JME)

An epilepsy syndrome that typically begins at puberty. Characterized by myoclonic (muscle jerk) seizures and possibly also absence or tonic-clonic seizures, generally on going to sleep or awakening. Treatment is usually very effective.

Ketogenic Diet

A high fat, low carbohydrate, low protein diet used to control seizures in children.

Landau-Kleffner Syndrome

A rare disorder beginning between the ages of 3 and 7, characterized by seizures and the loss of language ability.

Lennox-Gastaut Syndrome

A difficult-to-treat disorder beginning in childhood, characterized by multiple seizure types, including drop attacks, absence and tonic-clonic seizures. Mental retardation is common and often progressive.

MRI Scan

A magnetic resonance imaging scan that creates images of the brain to help detect abnormalities; unlike CT or Cat scans, MRI scans use no x-rays.

Myoclonic Jerk

Brief muscle jerk; may be normal (as one falls asleep) or caused by a seizure or other disorders.

Myoclonic Seizure

Sudden brief, shocklike jerking of muscle groups in the hand, leg, shoulder, or entire body. May occur as a single seizure or a cluster of seizures. May occur in a variety of epilepsy syndromes.

Partial Seizure

A seizure that starts in one particular part of the brain. The abnormal electrical activity may remain confined to that area, or may spread to the entire brain. The function that part of the brain controls determines the type of behavior or sensation that will be manifested during the partial seizure.

PET Scan

Positron Emission Tomography; a diagnostic test that uses a very low and safe dose of a radioactive compound to measure metabolic activity in the brain; helpful in planning epilepsy surgery.

Petit Mal Seizure

An older term for a “small seizure”, now known as an absence seizure, which tends to involve short staring spells. May occur in clusters.


The minutes or hours of abnormal consciousness, confusion or sleepiness after a seizure. During the post-ictal period, the brain is recovering from the seizure & returning to normal function.

Progressive Myoclonic Epilepsy

A rare form of epilepsy, often hereditary, characterized by myoclonic and other types of seizures and progressive neurological impairment.

Psychogenic Seizure

A behavioral episode that resembles an epileptic seizure but does not result from abnormal brain electrical activity. Psychological in origin, but does not always come from conscious actions. Also known as pseudo seizures.

Psychomotor Seizure

An older term for a complex partial seizure with automatisms.

Rasmussen’s Syndrome

A rare disorder with frequent or continuous partial seizures and progressive neurological & intellectual impairment.

Reflex Epilepsy

Seizure triggered by something in the environment, such as flashing lights, certain types of music or particular odors.


A sudden, excessive discharge of electrical activity in the brain.

Simple Partial Seizure

A seizure that affects only part of the brain and does not impair consciousness.

Status Epilepticus

A prolonged seizure (usually defined as lasting longer than 30 minutes in a partial seizure, 5 minutes in a tonic-clonic seizure) or a series of repeated seizures; a continuous state of seizure activity. Most common with tonic-clonic, but may occur in almost any seizure type. Can be life-threatening and requires immediate emergency care.


A collection of signs and symptoms that together form a condition with a known outcome, and which requires special treatment.


The brain’s susceptibility to having a seizure. Antiepileptic drugs raise this threshold and make a person less likely to have a seizure. In contrast, lack of sleep, fever, and other factors can lower the threshold and make seizures more likely.

Tonic Seizure

A generalized seizure that involves stiffening or rigidity of the entire body.

Tonic-Clonic Seizure

Generalized seizure characterized by loss of consciousness, falling, stiffening of the body (tonic phase) , then rhythmic jerking movements or convulsions (clonic phase.) This is the type of seizure most commonly thought of as epilepsy. Formerly known as grand mal seizure.

Tuberous Sclerosis

A disease in which benign tumors affect the brain, eyes, skin and internal organs. It is associated with mental retardation and seizures.

Vagus Nerve Stimulation (VNS)

A surgically implanted battery that sends bursts of electrical energy every few minutes to the vagus nerve. In some cases it has been effective in decreasing seizure activity.

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