epilepsy

Medical disorder characterized by a tendency to develop fits, which are convulsions or abnormal feelings caused by abnormal electrical discharges in the cerebral hemispheres of the brain. Epilepsy can be controlled with a number of anticonvulsant drugs.

The term epilepsy covers a range of conditions from mild ‘absences’, involving momentary loss of awareness, to major convulsions. In some cases the abnormal electrical activity is focal (confined to one area of the brain); in others it is generalized throughout the cerebral cortex. Fits are classified according to their clinical type. They include: the grand mal seizure with convulsions and loss of consciousness; the fleeting absence of awareness petit mal, almost exclusively a disorder of childhood; Jacksonian seizures, originating in the motor cortex; and temporal-lobe fits, which may be associated with visual hallucinations and bizarre disturbances of the sense of smell.

Epilepsy affects 1–3% of the world's population. It may arise spontaneously or may be a consequence of brain surgery, organic brain disease, head injury, metabolic disease, alcoholism, or withdrawal from some drugs. Almost a third of patients have a family history of the condition.

Most epileptics have infrequent fits that have little impact on their daily lives. Epilepsy does not imply that the sufferer has any impairment of intellect, behaviour, or personality.