Main Entry: jack·so·ni·an

Pronunciation: \jak-ˈsō-nē-ən\

Function: adjective

Usage: often capitalized

: of, relating to, associated with, or resembling Jacksonian epilepsy

Jack·son \ˈjak-sən\ , John Hughlings (1835–1911), British neurologist. Jackson was a pioneer in the study of epilepsy, speech defects, and nervous system disorders that arise from injury to the brain and spinal cord. In 1864 he confirmed Broca's discovery concerning the location of the speech center in the brain. In 1863 Jackson discovered epileptic convulsions, now known as Jacksonian epilepsy, that progress through the body in a series of spasms. In 1875 he was able to trace the convulsions to lesions of the motor region of the cerebral cortex.