Epilepsy Vocabulary


Frequently Used Terms in Intractable Childhood Epilepsy

absence seizure

(formerly called petit mal) generalized seizure most common in children; a lapse in consciousness with a blank stare that begins and ends within a few seconds. May be accompanied by rapid eye blinking or chewing movements.

acute repetitive seizure

more than one seizure in 24 hours for an adult; more than one seizure in 12 hours for a child

atypical absence seizure generalized seizure seen mostly in epilepsy syndromes or epileptic encephalopathies; a lapse in consciousness with eyelid fluttering, mouth movements or smacking (known as automatisms), that may end within a few seconds or be continuous, leading to non-convulsive status epilepticus

adjunct therapy

(aka add-on therapy) treatment administered in addition to another therapy, as when one medication is taken with another.

AED (anti-epileptic drug, also known as anti-convulsant)

a seizure-preventing drug. AEDs are carried to the brain through the bloodstream.

anticonvulsant (also known as anti-epileptic drug)

preventing or arresting convulsions; agent that prevents convulsions


preventing seizures; there is no agent that prevents epilepsy.


Defect in or loss of the ability to express oneself using speech, writing, or signs, or to comprehend spoken or written language as a result of injury to or disease of the brain’s speech centers.


Cessation of breathing.


inability to coordinate muscle movement

atonic seizure

(aka. drop attack) generalized seizure where sudden complete loss of muscle control and balance results in collapse; patient suddenly falls to the floor or onto a table; common in certain epilepsy syndromes such as Doose syndrome and Lennox-Gastaut syndrome



a sensation recognized by a patient that precedes or signals the beginning of a seizure. May include uneasiness, deja vu, sensory illusions (odors, visual illusions or misconceptions, sounds), stomach discomfort, dizziness.


Involuntary, undirected movements during complex partial seizures and atypical absence seizures.


the amount of a drug that is available to work in the body


when two drugs with the same active pharmaceutical ingredient have the same bioavailability blood level monitoring

monitoring of levels of drugs through a blood sample.

breakthrough seizures

seizures that occur despite drug therapy.

CAT scan (computerized axial tomography)

(syn.: CT scan) imaging technique that creates three-dimensional images of the brain and shows possible abnormalities.

catamenial epilepsy

Epilepsy in which there is a tendency for a woman’s seizures to occur primarily at the time of menstruation.


a brain structure involved in the control and coordination of voluntary muscle movements.


Referring to a mutation in an ion channel in the brain that leads to an epilepsy or an epilepsy syndrome, such as a sodium channel (SCN1A) mutation leading to Dravet syndrome




A seizure in which there are generalized clonic contractions with the entire body jerking, but without a preceding tonic phase.


involves repeated seizures that follow immediately upon one another or which happen within hours of each other following periods without seizure activity.


the process by which knowledge is acquired; awareness, thinking, learning and memory

complex partial seizure

a seizure occurring on one side of the brain in an unconscious patient


Refers to patient adherence to physician directions for taking antiepileptic drugs.

convulsion (also known as seizure or fit)

involuntary muscle contractions common in generalized tonic-clonic seizures.

corpus callostomy

severing of nerve fibers that connect the two hemispheres of the brain in order to interrupt the spread of seizures from one side of the brain to the other.


(cerebral cortex) the thin outer layer of the brain that controls movement and the senses.

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cortical displasia

abnormal development of the cortext, a condition that can cause seizures.


an opening made into the skull for brain mapping and epilepsy surgery.


Of unknown origin.

EEG (electroencephalograph)

M edical equiptment that records, in the form of brain waves, electrical discharge from neurons in the brain through electrodes attached to the scalp.


inflammation of the brain from an infection or as the result of other diseases; sometimes causes epilepsy.


disease of the brain.


chronic neurological disorder characterized by recurrent seizures; estimated to affect 2.7 million Americans.


a physician (neurologist) expert in the diagnosis and treatment of epilepsy.


study of the cause of a disease or medical condition.

febrile seizure

seizure related to high fever in babies and children, usually under age five. Most children who have a febrile seizure do not develop epilepsy.

focal seizure (partial seizure)

an seizure that involves one hemisphere of the brain.


Identified area of the brain from which partial (or focal) seizures arise.

gamma knife surgery (radio surgery)

a form of radiation therapy that uses gamma rays to destroy seizure-causing tissue in the brain.


Related to genes; Genetic does not always mean inherited.


Genes hold the information to build and maintain an organism’s cellsand pass genetic traits to offspring

Gene mutation

A gene mutation is a permanent change in the DNA sequence that makes up a gene.  Gene mutations occur in two ways: they can be inherited from a parent or acquired during a person’s lifetime.

generalized seizure

a seizure that involves the whole brain.

grand mal

former name for tonic-clonic seizure


surgical removal of one hemisphere of the brain; with epilepsy, performed almost exclusively in children for whom severely damaged tissue spanning one hemisphere produces uncontrollable seizures.

hippocampal sclerosis

cell loss and hardening of the hippocampus, the brain structure that lies in the temple areas.


with the amygdala, the septum, and parts of the cortex, comprises the brain?s limbic system; hippocampus is partly responsible for memory.


Rapid, deep breathing. Use in EEG testing may produce abnormalities or even a seizure.


the time around a seizure.  The time before a seizure is called pre-ictal.  The time during a seizure is called ictal.  The time following a seizure, when the patient is often sleeping or lethargic, is called post-ictal.


Of unknown origin or cause.


the frequency with which a disease occurs in one year

infantile spasms

myoclonus seizures; generalized seizures causing the clonic spasms of a muscle or muscle group in an infant.


the period of time between one seizure and another.

International Classification

developed by the International League Against Epilepsy, a periodically updated classification of seizure types, behaviors, and causes used to characterize seizure disorders and epileptic syndromes. ILAE classifies seizures according to the location in the brain where the seizure activity takes place: generalized or partial. Updated periodically, most recently in 2009.

International League Against Epilepsy (ILAE)

Founded 1909. Headquarters: Bethesda, MD. The international professional organization for physicians which encourages scientific research on epilepsy and the exchange of information.


Intractable (also known as refractory)

Not responding to treatment.

Ion channels

Proteins in the body that control the electro-chemical gradient.  The main ion channels in the brain are sodium, calcium, potassium, and chloride.

ketogenic diet

high fat, low carbohydrate and protein diet.  This therapeutic option has a high response rate in many children with intractable epilepsy and should be offered.

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wound or injury which results in pathological change in tissue (e.g. head injury which results in seizure-causing lesions in the brain). Lesions are sometimes surgically removed to reduce or prevent recurring seizures.


refers to an abnormal smooth brain without folds.


any rounded, projecting part of the anatomy; components of the brain.


surgical removal of a lobe; surgical removal of all or part of the lobe of the brain bearing abnormal seizure-causing tissue

magnetic resonance imaging (MRI)

An imaging method using magnets instead of X-rays. Produces detailed pictures of the internal structure of the brain.

march (sometimes called Jacksonian march)

progression of muscular convulsions from one muscle or muscle group to another.

MEG (magnetoencephalography)

records magnetic activity generated by the brain’s electrical activity; helps identify brain areas where seizures begin.


inflammation of the membranes of the brain and spinal cord


Treatment with a single drug.


death rate

multifocal epilepsy

epilepsy in which the seizures come from a number of locations in the brain.

multiple subpial transcetion (MST)

surgery in which shallow parallel cuts are made in the cortex; used to reduce or eliminate seizures that come from critical brain areas that cannot be removed.

myoclonic seizures (also known as myoclonic jerks, jumps, startles, myoclonus)

usually generalized seizures causing massive rapid contractions of  muscle or group of muscles.


a parasitic brain infection from eating bad pork; a common cause of seizures in some US immigrants.


a specialist in the diagnosis and treatment of nervous system diseases and disorders such as epilepsy.

nocturnal seizures

seizures which occur routinely in evening hours.

nonepileptic seizures

seizures with a psychological cause or which are due to a sudden drop in blood pressure, low blood sugar, or other temporary condition.

occipital lobe

brain lobe at the rear of the head identified with vision.

parietal lobe

brain lobe which interprets sensory input and the body?s relation to space.

partial seizure

seizure occurring in one side of the brain.  A complex partial seizure means the patient is unconscious.  A simple partial seizure means the patient is conscious.


in development of a fetus, the period from the 28th week of gestation to 7 days after delivery; the period during which complications such as prolonged lack of oxygen or other trauma may result in epilepsy for a newborn.

petit mal

former name for absence seizure


medication therapy.


a reflex epilepsy in which seizures are triggered by flashing lights or patterns (e.g., strobe lights, video games, or flipping and rolling of a television screen, or sunlight between trees while driving). An estimated 3 % of people with epilepsy are photosensitive.


(also known as polypharmacy) the use of two or more antiepileptic medications for control of seizures.


Indicating the onset of a disease. In epilepsy, indicating the onset of a seizure.


(also known as non epileptic attack disorder [NEAD]) a sudden disruptive change in a person’s behavior which resembles epileptic seizures but has no electrophysiological changes in the brain. NEADs may be related to physical illness, psychiatric disorder or emotional attacks.

reflex epilepsy (also known as environmental epilepsy)

rare epilepsy which occurs in response to patient being acutely sensitive to the environment.  Seizures are triggered by specific sensory stimulus, including light, sounds, tastes, smells, movements or sensations of touch. Photosensitivity is the most common reflex epilepsy.  Children with certain syndromes or refractory epilepsy may have reflex epilepsy more commonly.


Difficult to treat, unresponsive or of limited response to medication.

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The SCN1A gene codes for the alpha subunit of a neuronal voltage-gated sodium channel and is located on chromosome 2q containing 26 exons. Mutations in SCN1A are the cause of generalized (genetic) epilepsy with febrile seizures plus (GEFS+), Dravet syndrome and the Dravet syndrome spectrum.


abnormal electrical discharge in the brain.

seizure prediction

complex automated brainwave analysis that can predict an oncoming seizure up to 30 minutes or more before it is clinically apparent.

seizure semiology

the clinical symptoms of a seizure.

seizure threshold

the point at which a person can no longer tolerate a seizure-provoking stimulus

simple partial seizure

seizure activity in one part of the in a patient that remains conscious

single-photon emission computerized tomography

(SPECT) An imaging technique to measure blood flow in the brain.

spikes and waves

the brainwave pattern on an EEG tracing during a seizure.

status epilepticus

severe, potentially life-threatening non-stop seizures, not always related to epilepsy; status epilepticus can result from acute brain injury. A seizure that lasts 5 minutes should be treated as if it will be continuous, as 5 minutes is the operational definition of status epilepticus.  The clinical definition of status epilepticus is seizures lasting 30 minutes or longer.

stereotactic surgery

brain surgery performed with the head held in an immoveable position by a special positioning device.


referring to the area beneath the tough membrane (dura) which forms the outer envelope of the brain; subdural strips or grids are small plastic devices containing electrodes which are placed directly on the brain surface to record brain wave activity.

SUDEP (sudden unexplained death in epilepsy)

a rare condition in which death occurs without an apparent cause but which is presumed to be related to the person’s epilepsy.


fainting due to a loss of blood flow to the brain; sometimes misdiagnosed as seizures.


a set of symptoms characterizing a disease, disorder, or condition.  The ILAE 2009 definition of syndrome is “syndrome”  a group of clinical entities that are reliably identified by a cluster of electro-clinical characteristicsAn epilepsy syndrome is the complete set of seizure types and symptoms experienced by a patient.

temporal lobe seizure

a partial seizure involving the temporal lobe.

temporal lobes

the areas of the brain that lie at the side of the head behind the temples and which are involved in hearing, memory, emotion, language, illusions, tastes, and smells.


a medication or treatment with the potential to cause birth defects.


Muscles in the body suddenly contract and the whole body stiffens. patients may sometimes become unconscious and fall down so high risk of injury is possible.


most common and recognized type of seizure; generalized seizures which usually begin with rigidity (tonic phase) followed by muscle jerks, shallow breathing or temporarily suspended breathing (clonic phase), possible loss of bladder or bowel control; seizure usually lasts a couple of minutes, followed by a confusion and fatigue (post-ictal period).

vagus nerve

a nerve which begins at the brain stem, passes through the cranial cavity past the jugular, to the throat, larynx, lungs, heart, esophagus, stomach and abdomen.

vagus nerve stimulator (VNS)

a device to reduce severity of seizures through electrical stimulation of the vagus nerve. Device is implanted in the upper left chest with electrodes encircling the vagus nerve. Electrical impulses are sent at set intervals to the brain.

video monitoring

simultaneous video (TV) monitoring and EEG recording of brain waves to help identify the type of seizure that is taking place.