jacksonian epilepsy /jaksō′nē·ən/ [John H. Jackson, English neurologist, 1835–1911] , epilepsy characterized by focal motor seizures with unilateral clonic movements that start in one group of muscles and spread systematically to adjacent groups, reflecting the march of the epileptic activity through the motor cortex (jacksonian march). The seizures are due to a discharging focus in the contralateral motor cortex.
