Sleep architecture in drug-naive adult patients with epilepsy: Comparison between focal and generalized epilepsy

Objective: Sleep impairment is one of the most common comorbidities affecting people with epilepsy (PWE). The bidirectional relation between epilepsy and sleep has been widely established. Several studies investigated subjective sleep quality and daytime vigilance in PWE, highlighting frequent complaints of sleep fragmentation, difficulties in falling asleep, and daytime sleepiness. The present study aimed to evaluate sleep structure in drug-naive PWE, distributed on the basis of epilepsy type, and compared with controls. Methods: This observational study included adult patients newly diagnosed with epilepsy and drug-naive as well as a control group of healthy subjects. All PWE and controls underwent a dynamic 24-h EEG with signals for sleep recording to evaluate sleep architecture, structure, continuity, and fragmentation. Results: Twenty-four PWE were included and distributed in two groups based on epilepsy type. Eleven patients were included in the generalized epilepsy group (63.6% male; 34.91 +/- 9.80 years) and 13 patients in the focal epilepsy group (53.8% male; 38.69 +/- 12.74 years). The control group included 16 subjects (56.3% male; 32.75 +/- 12.19 years). Patients with generalized or focal epilepsy had a significantly lower sleep efficiency than controls. Moreover, both patient groups presented the alteration of markers of sleep fragmentation and loss of continuity, with higher indices of sleep stage transitions and arousal. Finally, the two patient groups presented less REM sleep than controls. Significance: This study highlighted the alteration of sleep quality, continuity, and stability in both patients with focal or generalized epilepsy compared with controls, also in the absence of ictal events. This sleep impairment resulted in the reduction of REM sleep. Therefore, these findings may be explained by the increase in awakenings and sleep stage shifts, which may be attributed to both sleep networks impairment and neurotransmission dysfunction in PWE, and also possibly triggered by paroxysmal interictal abnormalities.