The aim of this audit study was to establish the utility of follow-up and sleep-deprived electroencephalography testing to improve the detection of interictal abnormalities in a tertiary referral center in Oman. As part of our ongoing auditing process, a total of 3010 EEGs were included in this study. All EEGs were routinely performed for Omanis aged 13 years and above, who were referred for possible diagnosis of seizure disorders. Each EEG was performed over an average period of 20-30 minutes. Of the 3010 EEGs, there were 553 follow-up and sleep-deprived EEGs, including initial baseline EEG studies which were analyzed for this study. The total progressive yield of serial follow-up EEGs to detect overall EEG changes was 53.5%, distributed as 8.8%, 11.4%, 0%, and 33.3% for the second, third, fourth, and fifth serial EEG studies, respectively. For the sleep deprivation EEG group, the yield was 6.5% for detecting overall EEG changes compared to the initial EEG studies. A limitation in this study was the small sample size in the subsequent follow-up and sleep deprivation EEGs. In conclusion, we found a minimal contribution of serial follow-up and sleep deprivation methods in improving the EEG abnormality detection in our study. National guidelines and an increase in awareness among physicians are required to increase the benefit of these well-established, yet not optimally utilized EEG methods.
Keywords: EEG; Oman; serial follow-up; sleep-deprivation.