Breathing abnormalities during sleep in Kleine-Levin Syndrome: fact or coincidence?

PURPOSE OF REVIEW: To highlight and critically discuss the possibility that breathing abnormalities during hypersomnolent episodes are an additional clinical feature of Kleine-Levin Syndrome (KLS).

RECENT FINDINGS: A computerized literature search of breathing abnormalities in patients with KLS disclosed two old and a single recent publication describing a total of six patients with sleep apnea during hypersomnolent episodes.

SUMMARY: Owing to scarce reports on complete polysomnography during and in-between hypersomnic episodes of KLS, the possibility that breathing abnormalities are an additional clinical feature of this unique episodic sleep syndrome should be further studied.