atonic seizure

(redirected from Atonic Seizures)


1. the sudden attack or recurrence of a disease.
2. a convulsion or attack of epilepsy.
absence seizure the seizure seen in petit mal epilepsy, marked by a momentary break in the stream of thought and activity, accompanied by a symmetrical spike and wave at 3 cycles per second on the electroencephalogram. Called also petit malseizure. See epilepsy.
atonic seizure an absence seizure characterized by sudden loss of muscle tone.
complex partial seizure see partial seizure.
febrile seizure febrile convulsion.
focal seizure partial seizure.
focal motor seizure a simple partial seizure consisting of clonus or spasm of a muscle or muscle group, occurring either singly or in a continuous repetitive series.
generalized tonic-clonic seizure (grand mal seizure) the seizure seen in grand mal epilepsy, marked by loss of consciousness and generalized tonic convulsions followed by clonic convulsions. See epilepsy.
jackknife s's infantile spasms.
myoclonic seizure one characterized by a brief episode of myoclonus.
partial seizure any seizure due to a lesion in a specific, known area of the cerebral cortex; symptoms vary with different lesion locations. A simple partial seizure is the most localized type, with a discharge that is predominantly one-sided or presents localized features without loss of consciousness. A complex partial seizure is associated with disease of the temporal lobe and characterized by varying degrees of impairment of consciousness. See epilepsy.
petit mal seizure absence seizure.
reflex seizure (sensory seizure) an epileptic seizure in response to a sensory stimulus, which may be tactile, visual, auditory, or musical.
simple partial seizure see partial seizure.
tonic-clonic seizure see generalized tonic-clonic seizure.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

a·ton·ic sei·zure

a seizure characterized by sudden, brief (1-2 second) loss of muscle tone, involving postural muscles; the term usually applies to bilaterally synchronous events.
Synonym(s): akinetic seizure
Farlex Partner Medical Dictionary © Farlex 2012
References in periodicals archive ?
Meanwhile, he also experienced clonic and generalized tonicclonic (GTCS) and atonic seizures and had spasticity predominant in the lower extremities with no pathological reflexes.
In Japan, the agent is approved as an adjunctive therapy to other AEDs in the treatment of tonic and atonic seizures associated with LGS when therapy with other AEDs is considered inadequate.
At three years and four months of age, he was experiencing five atonic seizures per day and 2-3 seizures per week with apnea and tonic arm flexion.
Other semiologies (absence and atonic seizures) were not seen in the present study.
This status may be confused with atonic seizures or negative myoclonus (6).
atonic seizures (drop attacks) are ideal cases for corpus callosotomy, as this prevents generalisation to the contralateral cortex.
Atonic seizures are characterized by sudden loss of postural muscle tone lasting 1-2 seconds.
According to Devinksy, GLS patients also saw a very favorable response for atonic seizures, which is one of the most common types in that syndrome, with a median reduction of 71 percent.
One type, generalized seizures, includes generalized tonic-clonic seizures (formerly called "grand mal" seizures), tonic seizures, atonic seizures, or absence seizures (formerly called "petit mal" seizures).
A confirmed case was defined as a probable case with a documented nodding episode that was either observed and recorded by a trained health-care worker, videotaped, or documented with video electroencephalography or electromyography as atonic seizures (Table 1).
Simultaneous recording of 2 episodes by EEG, videography, electromyography, and electrocardiography documented that the nodding episodes are manifestations of atonic seizures. In these case-patients, head nodding was associated with generalized electrodecrement, followed by generalized sharply contoured rhythmic theta activity, dropping of the chin, and paraspinal electromyographic abnormalities (Figure 5) (7).