Comparison of awake Electroencephalography, Electroencephalography after Sleep Deprivation, and Melatonin-Induced Sleep Electroencephalography Sensitivity in the Diagnosis of Epilepsy in Adults

Introduction: The aim of this study was to compare routine awake electroencephalography (r-EEG), melatonin-induced sleep EEG (m-EEG) and EEG (d-EEG) after sleep deprivation studies in terms of epileptiform anomalies (EA), and to compare d-EEG and m-EEG studies in terms of sleep induction in patients requiring differential diagnosis of epileptic seizure/nonepileptic seizure. Methods: The study included 45 patients aged 18-45 years who had at least one seizure suspected to be epileptic but could not be diagnosed with epilepsy with clinical and laboratory findings. Each patient underwent r-EEG on the 1st day, d-EEG on the 2nd day after 24 h of sleeplessness, and m-EEG on the 3rd day after the administration of 6 mg melatonin following 7 h night sleep. Three separate EEG tracings of the patients were compared for EA. The d-EEG and m-EEG methods were examined for their ability to achieve sleep, total sleep time (ST), and sleep latency (SL). Results: When the detection rate of EA in d-EEG and m-EEG was compared with that of r-EEG, it was found to be significantly higher (P < 0.001) (73.3% with d-EEG, 75.6% with m-EEG, and 35.6% with r-EEG). Sleep was achieved at a rate of 100% after receiving melatonin and at a rate of 97.8% with sleep deprivation. There was no significant difference between d-EEG and m-EEG in terms of mean ST and SL (ST = 58.6 +/- 12.6 min and 59.7 +/- 8.3 min, respectively; SL = 287.6 +/- 484.3 s and 152.2 +/- 178.7 s after the start of the EEG, respectively). Conclusions: Sleep EEG is superior to awake EEG in terms of detecting EA. In an EEG study, where melatonin was used to induce sleep, the sleep rate and SL were similar to those of d-EEG, and melatonin did not have an EA increasing or suppressing effect on EEG. Given the ease of application and low side effect profile, it is thought that m-EEG may be an applicable method in the diagnosis of epilepsy.