Dravet Syndrome (DS) is a complex pathology of the Central Nervous System, in which epilepsy - in the foreground - is associated with different comorbidities, among which sleep disorders are becoming increasingly important. Although their negative impact on the quality of life of patients and families is evident, they have not so far been well characterized.

The present study therefore set itself the objective of retrospectively evaluating the presence and main characteristics of sleep disorders in a cohort of 96 patients with Dravet Syndrome, followed at the Child Neuropsychiatry Unit of Verona, through the '' analysis of the transcripts of interviews with families; in a subgroup of patients it was possible to analyze nocturnal electroencephalographic (EEG) recordings to extract objective data on sleep. It was possible to obtain anamnestic data relating to the quality and quantity of sleep in 74% of cases (71/96). In 76.1% of cases (54/71) at least one of the disorders considered was reported, of which the most frequent was daytime sleepiness, present in 55.6% of cases, followed by insomnia (33.3% ), frequent awakenings (27.8%), irregular sleep-wake rhythm (25.9%), breathing disorders in sleep (13%) and parasomnia or other undefined disorders (13%). In 50% of patients (27/54) more than one disorder had been reported over time. A different age of onset of these disorders emerged. Only in 17 patients (17.7%) it was possible to carry out the retrospective EEG study by evaluating the quantitative parameters that contribute to determining the "sleep efficiency" (SE) and the independent parameter of sleep fragmentation, "arousal index" (TO THE). The impact of the presence of epileptic seizures in sleep on these parameters was also assessed. They were positively correlated with the number of episodes of infrahypnic wakefulness, although recorded in only three cases. The arousal index proved inversely proportional to age. In 11 cases the presence of sleep disturbances was reported in the same period as the EEG recording, and in these a positive relationship with AI emerged. The sleep efficiency was below the normal threshold (85%) only in two cases, however, in patients who did not report a sleep disorder in the same age group as the EEG recording and in which no sleep disturbance was reported. they were experiencing crises.

The study therefore confirmed the high prevalence and heterogeneity of sleep disorders in Dravet Syndrome, and highlighted the fact that their presence may not be strictly linked to the quantitative parameters normally used in hypnology, for which they will be necessary. further prospective studies to determine the nature and impact on the clinical evolution of patients, in order to improve their management and the treatment process.