Atonic epileptic drop attacks associated with generalized spike-and-slow wave complexes: video-polygraphic study in two patients

We studied falling manifestations of atonic epileptic drop attacks (AEDA) in 2 patients with cryptogenic epilepsy with myoclonic-astatic seizures.

Using video-polygraphic examinations. For analysis, we recorded 51 seizures in 1 patient and 18 seizures in the other. The extent of AEDA ranged from collapsing and landing on the buttocks to head nodding only without falling.

Detailed video analysis of the drop attacks, with the patient in standing position, demonstrated the first manifestations to be flexion at the waist and knees, followed by further knee flexion, leading to falling straight down and landing on the buttocks. Ictal polygraphs demonstrated diffuse interruptions of ongoing EMG discharges corresponding to the falls, indicating that these attacks are true atonic seizures.

The falling manifestations of AEDA appeared to be characteristic and different from those of tonic drop seizures, which have been described as falling forward with tonic flexion of the hips, upper trunk, and head, as well as abduction or elevation of the arms.