• Glossary of Epilepsy & Seizure Terms

    This glossary has been developed by the Comprehensive Epilepsy Center team. It provides you with some words you may hear during your child’s evaluation and treatment.

  • Absence seizures
    Seizures (previously called petit mal seizures) that are frequent, brief events (five to 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  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  recognize that a seizure occurred.

    Atonic seizures
    Seizures that involve a loss of tone in the head, upper torso or whole body. In the most severe cases, children with atonic seizures will collapse to the ground face first.

    Complex partial seizures
    Seizures that involve an alteration in a child’s level of consciousness coupled with changes in motor activity (e.g., jerking of one extremity or side of the body) and automatisms (e.g., repetitive chewing, swallowing, picking at clothes).

    Cryptogenic
    The cause is hidden or occult.

    Drop attacks
    A term used by some clinicians that lumps atonic and tonic seizures together.

    EEG
    An EEG, or electroencephalogram, is a recording of the electrical activity of the brain.

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

    Epilepsy
    A disease characterized by recurrent, unprovoked seizures. Epilepsy currently afflicts an estimated 40 million people worldwide and approximately 2.3 million in the United States.

    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.”

    Generalized onset seizures
    Discharges that begin in one part of the brain then travel throughout the brain.

    Grand mal seizures
    See tonic-clonic seizures.

    Idiopathic
    No underlying cause other than a possible inherited predisposition.
    Myoclonic seizures
    Myoclonic seizures are 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 waking 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.

    Partial onset seizures
    Discharges in small parts of the brain.

    Petit mal seizures
    See absence seizures.

    Postictal period
    The time following a seizure, where the child will be very tired and usually sleeps. Recovery back to baseline following a seizure can range from a few minutes to a few days.

    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 a child’s level of consciousness.

    Symptomatic
    Arising from a suspected or known cause

    Tonic seizures
    Tonic seizures involve stiffening of all extremities and can also lead to falling. At times, it is hard to tell visually whether the child fell due to loss of tone (atonic seizure) or stiffening (tonic seizure). Because of this difficulty separating atonic and tonic seizures, clinicians often lump atonic and tonic seizures together and label them as “drop attacks.”

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

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