关键词: Kleine-Levin综合征, 定量脑电图, 脑电微状态, 功率谱密度, Omega复杂度

Abstract: Objective To characterize longitudinal quantitative electroencephalography(qEEG) changes from the symptomatic to recovery phase of Kleine-Levin syndrome (KLS) and examine the temporal relationship between clinical and electrophysiological recovery. Methods Longitudinal changes in brain electrical dynamics during a KLS episode were investigated using quantitative EEG approaches. A 14-year-old boy underwent serial EEG recordings on illness Days 2, 3, 4, 5, 8 and 14. Twelve age-matched healthy participants provided reference distributions. Six-minute artifact-cleaned eyes-closed segments were analyzed by conventional EEG assessment, microstate analysis, power spectral density (PSD), and correlation-based Omega complexity. The six KLS sessions were treated as repeated observations from one individual, with healthy reference-based standardized scores and single-case methods used for exploratory comparison. Results Days 2-5 showed paroxysmal generalized theta-delta slowing, poor preservation of conventional NREM markers, and occasional posterior sharp-and-slow-wave activity. Low-frequency intermittent photic stimulation elicited a self-limited bilateral occipital photoparoxysmal response. Clinical hypersomnia resolved by Day 8, although mild residual slowing remained; the conventional EEG was overall normal by Day 14. Global microstate mean duration decreased from 122.44-139.07 ms on Days 2-5 to 89.47 ms on Day 8 and 80.28 ms on Day 14, while occurrence increased from 7.19-8.17/s to 11.18/s and 12.46/s, respectively. PSD showed marked symptomatic delta predominance with progressive alpha-beta recovery. Omega complexity showed frequency- and region-dependent spatial changes. Conclusions KLS is associated with reversible temporal, spectral and spatial EEG abnormalities. Clinical recovery is preceded complete electrophysiological normalization, supporting quantitative EEG as a candidate tool for tracking disease-state transitions.

Key words: Kleine-Levin syndrome, quantitative EEG, EEG microstate, power spectral density, Omega complexity