Atypical presentation of sunflower epilepsy featuring an EEG pattern of continuous spike waves during slow-wave sleep

Abstract

Sunflower epilepsy is a rare photosensitive and commonly pharmacoresistant reflex epilepsy characterized by stereotyped seizures involving turning of the head towards light, similar to a sunflower turning towards the sun, and waving of the hands in front of the eyes, sometimes followed by absence seizures, myoclonic jerks, and tonic-clonic seizures. In the original description, seizures in sunflower epilepsy have been perceived as self-induced, but contemporary case series suggest that hand waving corresponds to an ictal phenomenon and not to a precipitating factor. We describe a nine-year-old girl featuring absence seizures with eye rolling or fluttering associated with hand waving movements. The chronological sequence of events based on a video-EEG-documented episode of our patient adds to the controversy surrounding the hypothesis of "self-induced" epileptic seizures in sunflower epilepsy. Shortly after epilepsy diagnosis, our patient presented with an EEG pattern of continuous spike waves in slow-wave sleep, an EEG feature that has not been described before and may relate to the cognitive deficit observed in some patients with sunflower epilepsy. Continuous spike waves in slow-wave sleep resolved, and lasting seizure freedom was achieved by a combination of ethosuximide and lamotrigine, which may be a possible alternative to valproic acid, particularly in girls and women of childbearing age. However, an attempt to taper anti-seizure drugs two years later led to seizure recurrence. We suggest performing sleep EEG recordings for sunflower epilepsy, particularly in patients with developmental stagnation or regression, to timely diagnose and treat continuous spike waves in slow-wave sleep syndrome.

Keywords: CSWS; photosensitivity; self-induced seizures; sunflower epilepsy.