(Licheni et al. 2017) 57 patients from Australia completed a sleep questionnaire, with 75% reporting problems. The most commonly reported problem was difficulty initiating and maintaining sleep, with sleep-wake transition disorders second most common. 53%  had nocturnal seizures.

16 patients were monitored by pulse oximetry overnight, and 14 of those had a higher than normal oxygen desaturation index, though this may be indicative of nocturnal seizures.

Licheni SH, Mcmahon JM, Schneider AL, Davey MJ, Scheffer IE. Sleep problems in Dravet syndrome: a modifiable comorbidity.Dev Med Child Neurol. 2018 Feb;60(2):192-198. doi: 10.1111/dmcn.13601. Epub 2017 Nov 7. PubMed PMID: 29110313.