Acute encephalitis induced Kleine-Levin syndrome with episodic vertical gaze dysfunction during hypersomnia episodes

Kleine-Levin syndrome (KLS) is a rare, recurring sleep disorder that easily ignored. Episodic upward-gaze palsy is an uncommon manifestation observed in patients of KLS, which further complicates this disorder. Although peripheral microbial infection have been recognized as most common triggers for KLS, the underlying pathophysiology of this disorder remains unclear. We reported a unique case of KLS elicited by acute encephalitis, which was confirmed by pleocytosis of cerebrospinal fluid at the early stage. The cerebrospinal fluid returned to normal over time while the attacks continued to recur frequently. Episodic upward-gaze palsy was observed during attacks and clinical symptoms were exacerbated following a subsequent COVID-19 infection. This report presents a classic KLS case with distinctive characteristics, which should facilitate more accurate and earlier diagnosis for clinicians. Furthermore, it provides a new perspective for understanding the pathogenesis of this rare disease.

Lv H, Long X, Lv Y, Zhou J. Acute encephalitis induced Kleine-Levin syndrome with episodic vertical gaze dysfunction during hypersomnia episodes. J Clin Sleep Med. 2024;20(9):1555-1556.