focal seizure [L, focus, hearth; OFr, seisir] , a transitory disturbance in motor, sensory, or autonomic function that results from abnormal neuronal discharges in a localized part of the brain, most frequently motor or sensory areas adjacent to the central sulcus. Focal motor seizures commonly begin as spasmodic movements in the hand, face, or foot. Abnormal neuronal discharges that arise in the motor area that controls mastication and salivation may be manifested by chewing, lip smacking, swallowing movements, and profuse salivation. Abnormal electrical activity in the sensory strip of the cortex may be evident initially as a numb, prickling, tingling, or crawling feeling, and the neuronal discharge may spread to motor areas. See also epilepsy, motor seizure.
