Possible role of COVID-19 in the relapse of Klein-Levin Syndrome

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.

CITATION

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.

Post-COVID central hypersomnia, a treatable trait in long COVID: 4 case reports

Introduction

Fatigue is the most commonly reported post-COVID symptom. A minority of patients also report excessive daytime sleepiness, which could be a target for treatment.

Methods

Among 530 patients with a post-COVID condition, those with excessive daytime sleepiness were systematically assessed for objective central hypersomnia, with exclusion of all cases not clearly attributable to SARS-CoV-2 infection.

Results

Four cases of post-COVID central hypersomnia were identified, three fulfilling the criteria of the 3rd International Classification of Sleep Disorders for idiopathic hypersomnia, and one for type II narcolepsy. We report here their clinical history, sleep examination data and treatment, with a favorable response to methylphenidate in three cases and spontaneous resolution in one case.

Conclusion

We highlight the importance of identifying cases of post-COVID central hypersomnia, as it may be a treatable trait of a post-COVID condition.

[Kleine-Levin syndrome]

Kleine-Levin syndrome (KLS) is manifested by periodic hypersomnolence with an increased appetite and psychopathological symptoms (psychomotor agitation, hallucinations, hypersexuality). The duration of the attack ranges from several days to several weeks. A forced awakening can provoke severe aggressive behavior. The disease occurs for an unknown reason, mainly in adolescence and mostly affects males. Lack of awareness among doctors about the disease leads to an incorrect diagnosis, often of a psychopathological disorder. This article presents modern data on the causes, clinical symptoms, diagnostic methods of KLS and provides a case of a 18 year-old man, whose disease manifested at the age of 16 years.

Impact of Taiwan's 2021 COVID-19 lockdown on the symptom severity and quality of life of patients with narcolepsy

COVID-19 lockdowns can influence the sleep quality and daytime condition of patients with narcolepsy. Using data from our cohort study, we investigated changes in the quality of life and the symptom severity of patients with narcolepsy during Taiwan's 2021 lockdown and investigated differences by narcolepsy subtype, sex, and age. Patients with type 1 and type 2 narcolepsy (NT1 and NT2, respectively) aged 6-40 years were retrospectively recruited from our narcolepsy cohort study. These patients were regularly evaluated using the Short Form 36 Health Survey questionnaire (SF-36), the Epworth Sleepiness Scale (ESS), the visual analog scale (VAS) for hypersomnolence, the VAS for cataplexy and sleep diary. We compared the differences between the lockdown and the prelockdown periods by narcolepsy subtype, sex, and age. We used a paired t test analysis to compare differences in the SF-36, ESS, VAS scores and data of sleep diary between the prelockdown and lockdown periods (p1), and an independent t test analysis was used to compare the changes in different subgroups between the prelockdown and lockdown periods (p2). A total of 120 patients with narcolepsy were recruited (mean age 24.22 ± 6.87 years; 58% male); 80 of the patients had NT1 (mean age 25.25 ± 6.79 years; 60% male) and 40 had NT2 (mean age 22.16 ± 6.64, 53% male). During the lockdown period, the ESS score of total patients was decreased (p = 0.039) and body mass index was increased (p = 0.02). The NT1 group decreased significantly (p1 = 0.017), especially in men (p1 = 0.016) and adults (p1 = 0.04); scores for the VT domain of the SF-36 increased significantly in male and adult patients with NT2 (p1 = 0.048 and 0.012). Additionally, male patients with NT2 exhibited significantly decreased scores in the physical and emotional role functioning domains (p1 = 0.028, 0.024). The children and adolescents with NT1 had significantly decreased scores in the general health domain of the SF-36, but no significant change was noted in that of adults (p1 = 0.027, p2 = 0.012). We observed both negative and positive impacts of Taiwan's 2021 lockdown on patients with narcolepsy. A more flexible but structured daily routine with adequate sleep time should be considered for this population during lockdown and nonlockdown periods.

COVID-19 Vaccine Could Trigger the Relapse of Secondary Hypersomnia

The coronavirus disease (COVID-19) has brought significant social and economic disruptions and devastating impacts on public health, and vaccines are being developed to combat the disease. Timely vaccination may prevent complications and morbidity but may also potentially result in unforeseen outcomes in some special clinical populations. We report on a case of hypersomnia relapse after the COVID-19 vaccination, with the aim of informing the development of the guideline on vaccination in specific groups. A 19-year old female presented with persistent daytime sleepiness after receiving the COVID-19 vaccine. She had a known history of hypersomnia secondary to infectious mononucleosis but has fully recovered for 8 months. A series of examinations were performed on this patient. Neurologic and psychiatric examinations were unremarkable. Despite normal nocturnal subjective sleep quality (Pittsburgh Sleep Quality Index score = 5, Insomnia Severity Index score = 7), her Epworth sleepiness scale score (15) suggested an abnormal level of subjective sleepiness. Consistent with the subjective report, the objective assessment by Multiple Sleep Latency Test found mean sleep latency was 1.3 min with no sleep onset rapid-eye-movement (REM) period. We speculate that COVID-19 vaccine may potentially trigger the relapse of hypersomnia. The immune memory could be an explanation for the increased response to vaccine in patients with secondary hypersomnia. Caution should be warranted when administering COVID-19 vaccine in patients with hypersomnia secondary to infections.