A study of epileptic drop attacks (EDA) by simultaneous video-polygraphic 
recordings was carried out in one epileptic patient with myoclonic astatic 
seizures (Doose syndrome). EDA was shown to correspond to a burst of generalized 
bilaterally synchronous spike and wave complexes (GBSSW) at 3 Hz. Absence 
seizures were also observed with a burst of GBSSW with similar characteristics. 
The amplitudes of the corresponding slow wave component of GBSSW among the three 
intensities of atonia, i.e. complete atonia, minor atonia and no discernible 
atonia (control), was compared. A high amplitude was demonstrated to correspond 
with more pronounced atonia and a lower amplitude with reduced or absent atonia. 
These findings suggest that EDA corresponding to GBSSW have a neurophysiological 
mechanism in common with absence seizures, and that if the GBSSW is intense, it 
may be sufficient to cause immediate loss of global muscle tone.