Background Drug-induced sleep endoscopy (DISE) is a useful method to evaluate multiobstructive sites simulating sleep with drugs; and propofol is the most widely used sedative for this purpose. Different adverse effects have been reported for propofol, including decrease in ventilatory drive and respiratory depression. Several clinical reports have also suggested a possible excitatory effect on the CNS. The supporting electroencephalographic (EEG) evidence is variable; in some cases, where the EEG has been monitored during the administration of propofol, epileptiform activity is not accompanied by motor manifestations, while in other cases, the EEG recordings after the events are reported as normal. Case presentation A 44-year-old male OSA patient, with negative neurological history, had three close episodes of generalized tonic-clonic seizures during DISE few minutes after sedation with increasing doses of propofol. Polygraphic intraoperative recording with EEG monitoring showed the evidence of epileptiform activity. Conclusion The complete polygraphic intraoperative recording during DISE, inclusive of brain electrical function monitoring, allowed us to record the proconvulsive effect of propofol – a rare but possible adverse event.

Keywords: DISE, OSAS, Sleep Endoscopy, propofol, convulsions, case report