A video-polygraphic analysis of the cataplectic attack

Abstract

Objectives and methods: To perform a video-polygraphic analysis of 11 cataplectic attacks in a 39-year-old narcoleptic patient, correlating clinical manifestations with polygraphic findings. Polygraphic recordings monitored EEG, EMG activity from several cranial, trunk, upper and lower limbs muscles, eye movements, EKG, thoracic respiration. Results: Eleven attacks were recorded, all of them lasting less than 1 min and ending with the fall of the patient to the ground. We identified, based on the video-polygraphic analysis of the episodes, 3 phases: initial phase, characterized essentially by arrest of eye movements and phasic, massive, inhibitory muscular events; falling phase, characterized by a rhythmic pattern of suppressions and enhancements of muscular activity, leading to the fall; atonic phase, characterized by complete muscle atonia. Six episodes out of 11 were associated with bradycardia, that was maximal during the atonic phase. Conclusions: Analysis of the muscular phenomena that characterize cataplectic attacks in a standing patient suggests that the cataplectic fall occurs with a pattern that might result from the interaction between neuronal networks mediating muscular atonia of REM sleep and neural structures subserving postural control.