Video-EEG monitoring in respiratory chain disorders

Subclinical epileptiform activity in patients with respiratory chain disord ers (RCDs) has not been previously investigated by video-EEG monitoring. Th e purpose of this study was to look for the type and frequency of epileptif orm activity during a 24h-video-EEG recording in RCD patients. Eleven patie nts with RCD, 7 women and 4 men, aged 24-72 years, underwent a clinical neu rologic examination, blood tests, CT/MRI scans of the brain, routine scalp EEG and continuous video-EEG monitoring over 24 consecutive hours. Ten pati ents had normal 24h-video-EEG recordings. One of these patients had no CNS involvement; her resting EEGs showed diffuse background slowing. In one pat ient, automatic spike detection revealed 12 spikes during a 6 hour period. Resting scalp EEG in this patient showed extensive, bilaterally synchronous , pseudoperiodic polyspike-waves. In conclusion, subclinical epileptiform a ctivity could be recorded by 24h-video-EEG monitoring in only 1 of 11 RCD p atients. The single patient with subclinical epileptiform activity presente d with intermittent myoclonic jerks.