Absence seizures are characterized by a brief loss and return of consciousness, generally not followed by a period of lethargy (i.e. without a notable postictal state).
[1] In the past, absence epilepsy was referred to as "pyknolepsy," a term derived from the Greek word "pyknos," signifying "extremely frequent" or "grouped".
On classic electroencephalograms (EEGs), distinct patterns emerge, featuring generalized spike-wave bursts occurring at a frequency of 3 Hz, accompanied by normal background brain activity.
Children affected by this condition often experience cognitive deficits and encounter enduring psychosocial challenges in the long term.
However, if an individual suffers an absence seizure while driving or operating dangerous machinery, a fatal accident may occur.
Furthermore, patients with childhood absence epilepsy have also been reported to exhibit certain copy number variations (CNVs), such as 15q11.2, 15q13.3, and 16p13.11 microdeletions.
[6] Some specific anticonvulsant drugs such as phenytoin, carbamazepine, and vigabatrin have been identified to raise the chances of experiencing absence seizures.
The hallmark of the absence seizures is abrupt and sudden-onset impairment of consciousness, interruption of ongoing activities, a blank stare, possibly a brief upward rotation of the eyes.
If the patient is speaking, speech is slowed or interrupted; if walking, they stand transfixed; if eating, the food will stop on its way to the mouth.
[16] Intermittent photic stimulation may precipitate or facilitate absence seizures; eyelid myoclonia is a common clinical feature.
[citation needed] A specific mechanism difference exists in absence seizures in that T-type Ca++ channels are believed to be involved.
Antiepileptic drugs such as Gabapentin, Tiagabine and Vigabatrin cause inhibition of GABA resulting in exacerbation of absence seizures.
The initial documentation of JME dates back to 1867 by Herpin, followed by Janz and Christian labeling it as 'Impulsive Petit Mal' in 1957, and Lund's 1975 designation of 'JME'.
While EM (Epileptic Myoclonus) is commonly acknowledged as a type of seizure, the formal recognition of JS as a separate medical entity by the International League Against Epilepsy (ILAE) has not yet occurred.
This summary has been recently confirmed by Glauser et al. (2010),[4] who studied the effects of ethosuximide, valproic acid, and lamotrigine in children with newly diagnosed childhood absence epilepsy.
Drug dosages were incrementally increased until the child was free of seizures, the maximal allowable dose was reached, or a criterion indicating treatment failure was met.
[28] Appropriate medication is the best way to manage absence seizures, but prevention can be considerably enhanced by life-style changes such as exercise, stress reduction, good sleep hygiene, and healthy diet.
[29] Carbamazepine, vigabatrin, and tiagabine are contraindicated in the treatment of absence seizures, irrespective of cause and severity.
[26] In the treatment of absence seizures there is often insufficient evidence for which of the available medications has the best combination of safety and efficacy for a particular patient.
[31] Nor is it easily known how long a medication must be continued before an off-medication trial should be conducted to determine whether the patient has outgrown the absence seizures, as is often the case in children.
To date there have been no published results of any large, double-blind, placebo-controlled studies comparing the efficacy and safety of these or any other medications for absence seizures.