Proglonged epileptic twilight states: continuous recordings with nasopharyngeal electrodes and videotape analysis.

Confusion, speech arrest, automatic behavior, and amnesia characterize the prolonged twilight states of both petit mal and psychomotor status. However, in psychomotor status two electroclinical phases were differentiated: (1) A continuous twilight state with partial responsiveness and reactive automatisms interrupted by (2) staring, total loss of responsiveness, and stereotyped automatisms. During the first phase, with reactive behavior, the EEG showed bilateral diffuse slowing. During the second phase, with stereotyped automatisms, there were spreading right temporal 4- to 12-Hz discharges. Petit mal status had one continuous twilight state, during which both stereotyped and reactive automatisms merged as 1.5- to 4-Hz spike-wave complexes, and bimedial temporal 4-Hz discharges' appeared in the EEG.