epilepsy

epilepsy (ep-i-lep-si) n. a disorder of brain function characterized by recurrent seizures that have a sudden onset and may be generalized or partial. Generalized seizures, which involve the entire brain, may take the form of tonic-clonic or absence seizures. In tonic-clonic seizures (formerly called grand mal) the patient falls to the ground unconscious with his muscles in a state of spasm (the tonic phase). This is replaced by the convulsive movements of the clonic phase, when the tongue may be bitten and urinary incontinence may occur. Absence seizures (formerly called petit mal) are brief spells of unconsciousness, lasting for a few seconds, during which posture and balance are maintained and the eyes stare blankly. They seldom appear before the age of three or after adolescence and often subside spontaneously in adult life, although they may be followed by the onset of tonic-clonic or partial seizures. Partial (or focal) seizures affect localized areas of the brain, causing motor, sensory, or autonomic effects. In a simple partial motor seizure convulsive movements may spread from the thumb to the hand, arm, and face (this spread of symptoms is called the Jacksonian march). The symptoms of complex partial seizures include hallucinations of smell, taste, sight, and hearing, paroxysmal disorders of memory, and automatism. Commonly caused by damage to the cortex of the temporal lobe or the adjacent parietal lobe of the brain, such seizures are often called temporal lobe (or psychomotor) e.
—epileptic (epi-lep-tik) adj., n.www.epilepsy.org.uk Website of Epilepsy Action