Myoclonic seizures are seen. These are mainly of the head (causing nodding), eyeballs (which roll upwards), upper extremities (causing the arms to fling up and out) and diaphragm (resulting in vocalization). Rarely the lower limbs are affected, causing falls. Jerks can be singular or occur in a series and may vary in severity. Responsiveness is preserved, however may be reduced if there are clusters of jerks in a series. Jerks may occur in all states (alert, drowsiness, slow sleep and on wakening).
Other seizure types.