Include generalized seizures, such as grand mal and petit mal, and the focal seizures of jacksonian and psychomotor epilepsy. These brain disorders, with their characteristic electroencephalographic patterns, are to be differentiated from a variety of other pathophysiological conditions in which a convulsive seizure may occur. The latter may follow withdrawal from alcohol, barbiturates, and a wide variety of other drugs. Seizures also may occur in cerebral vascular disease, brain tumor, brain abscess, hypoglycemia, hyponatremia, and many other metabolic and intracranial disorders.