Quantitative EEG Differences Across Two Sedation Conditions in a Child with Epilepsy: A Case Report

Background: Sedation is frequently required to obtain electroencephalography (EEG) recordings in children with neurodevelopmental disorders and structural etiologies of epilepsy. However, the extent to which different sedative agents influence quantitative interictal epileptiform discharge (IED) burden remains insufficiently characterized. Methods: A child with congenital cytomegalovirus-associated structural brain injury underwent EEG recordings under two sedation conditions: continuous low-dose propofol infusion and oral chloral hydrate. Quantitative analyses were performed using a duration-matched, within-subject design. Artifact-minimized EEG segments of equal duration (15.52 min) were analyzed. IED burden was quantified using spike frequency (spikes/min) and spike index (percentage of 10 s epochs containing ≥1 spike). Spectral power distribution and spectral edge frequency (SEF95) were also evaluated. Results: The chloral hydrate recording showed a higher observed spike frequency than the propofol recording (14.11 vs. 4.12 spikes/min; descriptive rate ratio, 3.42) and a higher 10-s spike index (84.95% vs. 27.96%). Spectral analysis demonstrated lower SEF95 and greater delta predominance in the propofol recording, whereas the chloral hydrate recording showed relatively greater theta-alpha activity. Conclusions: The two recordings showed marked differences in apparent IED burden and background spectral characteristics. However, because they were obtained approximately one year apart and under different clinical circumstances, including intercurrent illness during the chloral hydrate recording, these differences cannot be attributed specifically to the sedative agents. This case illustrates the importance of considering sedation, clinical context, and vigilance state when longitudinally interpreting quantitative pediatric EEG findings.