The epileptic blip syndrome.

Abstract

We report on the case of an adolescent with juvenile myoclonic epilepsy exhibiting compulsory sporadic voluntary movement. These movements entailed the deliberate act of touching her forehead with her hand and were triggered by a short and indefinable cephalic sensation. Upon inquiry regarding the nature of this movement, the patient reported a sudden perception of a peculiar event localized "inside her head". In the course of a prolonged video-electroencephalographic recording, it appeared that the movements consistently followed the occurrence of diffuse Generalized Spike-and-Wave Bursts (GSWBs), lasting one to three seconds. This observation suggests that the impact of the GSWBs on the patient's stream of consciousness could be detected by the patient herself, who attributed it to an internal sensation, like a "blip on a screen". This clinical observation echoes the "blip syndrome", as described by the neurologist James W. Lance thirty years ago. These findings give some support that "blips" could be of an epileptic origin and lend weight to the notion that some patients could perceive their own EEG discharges. Moreover, this observation should be added to the perennial debate on the cognitive impact of intercritical discharges.