selective estrogen-receptor modulator A designer estrogen that can have the ability to both block and stimulate the actions of estrogen, having different effects on different body tissues. For example, raloxifene (brand name: Evista) prevents bone loss and lowers serum cholesterol as estrogen does, but it has been used, like tamoxifen, to block the action of…
seizure disorder One of a great many medical conditions that are characterized by episodes of uncontrolled electrical activity in the brain (seizures). Some seizure disorders are hereditary, and others are caused by birth defects or environmental hazards, such as lead poisoning. Seizure disorders are more likely to develop in patients who have other neurological disorders,…
seizure, tonic-clonic The most obvious type of seizure, which has two parts: the tonic phase (in which the body becomes rigid) and the clonic phase (in which there is uncontrolled jerking). Tonicclonic seizures may or may not be preceded by auras, and they are often followed by headache, confusion, and sleep. They may last for…
seizure, petit mal See seizure, absence.
seizure, partial A seizure that affects only one part of the brain. Symptoms depend on which part of the brain is affected: One part of the body, or multiple body parts confined to one side of the body, may start to twitch uncontrollably. Partial seizures may involve head turning, eye movements, lip smacking, mouth movements,…
seizure, myoclonic A seizure that is characterized by jerking (myoclonic) movements of a muscle or muscle group, without loss of consciousness.
seizure, local See seizure, partial.
seizure, Jacksonian A form of seizure that involves brief alterations in movement, sensation, or nerve function that is caused by abnormal electrical activity in a localized area of the brain. Jacksonian seizures typically cause no change in awareness or alertness. They are transient, fleeting, and ephemeral.
seizure, grand mal See seizure, tonic-clonic.
seizure, focal See seizure, partial.
seizure, febrile A convulsion that occurs in association with a fever. Febrile seizures are common in infants and young children and are usually of no lasting importance.
seizure, drop See seizure, atonic.