Absence seizure: is a type of seizure that causes a brief loss of consciousness (also known as “dialeptic seizure” or as “petit mal seizure”, which is the older term describing absence seizures). During an absence seizure, the patient typically interrupts his/her activity, and appears to stare blankly. Rarely, there may be some eye blinking or other minor movements of the mouth and hands.
Absence seizures are more common in children (who may have a condition known as “childhood absence epilepsy”). Unlike generalized tonic-clonic seizures (“grand mal seizures”) absence seizures are often very brief (5 to 20 seconds), and may occur multiple times each day. Children with absence seizures may be mistakenly thought to be “daydreamers” in school. A significant number of children with absence seizures (up to 50-70%) may “outgrow” their seizures by late adolescence.
Adverse effect: side effect; negative, unwanted effect from a medication or other therapeutic intervention
Ambulatory EEG monitoring: a system for recording the electroencephalogram outside the hospital for prolonged periods of time (24 hours or longer, up to 3 to 4 days). This system gives the patient the capability to walk around and carry on normally, while EEG recordings are being made. EEG electrodes are connected to a special recorder that is slightly larger than a portable cassette player. The recorder can be strapped onto the patient’s waist, with the wire running either under or outside of his/her shirt.
Americans with Disabilities Act: a comprehensive civil rights law that makes discrimination against people with disabilities illegal; the act applies to employment, access to public places, and places of accommodation.
Amygdala: an almond shaped deep structure of the brain located by the hippocampus on the underside of the temporal lobe. Its main function is to take in the information from the environment, assess its emotional importance, and arrange a proper response.
Anticonvulsant: an anti-seizure medication used to control both convulsive and nonconvulsive seizures (usually referred to as “antiepileptic drug”).
Aseptic meningitis: irritation of the covering of the brain and spinal cord caused by blood or blood byproducts, usually treated with steroids, not antibiotics.
Atonic seizure: a type of seizure, that causes a sudden loss of muscle tone, particularly in the arms and legs; this seizure type often causes the patient to fall (“epileptic fall”).
Aura: a warning, which is usually the first symptom, that occurs at the beginning of a seizure; the aura refers to a subjective experience by the patient, and is not visible to observers. The type of symptom experienced depends upon the part of the brain that is affected first. Some of the typical auras include, episodes of “déjà-vu” (a sense that one has been in a certain situation before), epigastric auras (an uncomfortable abdominal sensation of “rising” numbness or tingling), unexplained tastes or odors or sometimes even a “hard to describe feeling”. Auras usually occur in patients with focal epilepsy, although not all patients with focal epilepsy experience auras. (Auras may occur in isolation, or progress to become a stronger focal or a “full-blown” convulsive seizure).