A motor feature involves motor activity and may consist of an increase (positive) or decrease (negative) in muscle contraction. Motor features may be elementary or complex.
An elementary motor feature involves a stereotyped contraction of a muscle or group of muscles. Such motor features may be predominantly convulsive Convulsive: rhythmic jerking (clonic activity), may occur alone or in combination with tonic activity. (e.g. hemiclonic Hemiclonic: rhythmic jerking (clonic activity) involving only one side of the body), myoclonicMyoclonic: a single or short cluster of brief muscle contractions (jerks). Each jerk is typically milliseconds in duration., tonicTonic: increased muscle tone, usually lasting for seconds to minutes., epileptic spasmEpileptic spasm: sudden flexion, extension or mixed flexion-extension of proximal and truncal muscles, lasting 1-2 seconds, typically occurs in a series, versiveVersive: sustained, forced conjugate ocular, cephalic, and/or truncal rotation or lateral deviation from the midline. or dystonicDystonic: sustained contractions of both agonist and antagonist muscles producing athetoid or twisting movements, may produce abnormal postures..
A complex motor feature involves complex movement patterns. Three types are recognized:
A focal seizure may spread to involve both hemispheres, resulting in bilateral convulsive features. This was previously known as a 'secondary generalized seizure'. Motor components in such a situation may include tonic or clonic features.
Epilepsia partialis continua refers to recurrent focal motor seizures (typically affecting hand and face, although other body parts may be affected), that occur every few seconds or minutes for extended periods (days or years). The focal motor features may exhibit a Jacksonian march. A Todd's paresis may be seen in the affected body part.