Kleine-Levin syndrome: clues to aetiology.

Kleine-Levin syndrome (KLS) is the commonest recurrent sleep disorder, with a prevalence of 1-2 per million population. Clear diagnostic criteria are now defined, but effective treatment remains elusive. The significant body of published literature allows consideration of possible aetiological mechanisms, an understanding of which could guide the development of therapeutic strategies. Functional imaging studies have been inconclusive; although diencephalic abnormalities are a common finding, no consistent pattern has emerged, and these studies have not revealed the mechanism(s) underlying the development of the abnormalities detected. An autoimmune aetiology is consistent with the available data. In this review, we argue that, in order to further our understanding of KLS, there needs to be a co-ordinated international effort to standardise approaches to functional imaging studies, genetic analyses that specifically address the possibility of an autoimmune aetiology, and clinical trials of immunosuppressive therapies.

Medical comorbidities in Saudi patients with narcolepsy: a case-control study.

OBJECTIVE: This case-control study sought to assess comorbid medical disorders in patients with narcolepsy type-1 (NT-1) and type-2 (NT-2). MATERIAL AND METHODS: The study comprised 80 consecutive Arab (Saudi) patients with narcolepsy (NT-1=56 and NT-2=24) and a control group of 211 adults matched for age, sex, and body mass index (BMI). Data were collected from cases and controls based on a predesigned questionnaire that was formulated based on previous studies to evaluate the chosen medical comorbidities. RESULTS: Narcolepsy patients had a higher prevalence of hypothyroidism and hyperlipidemia and a higher prevalence of high-risk for OSA than controls. Hyperlipidemia was more common in cases than controls, 8 (10%) vs. 3 (1.4%), p=0.002. After adjusting for age, sex, and BMI, the odds-ratios for hypothyroidism and high risk for OSA in the NT-1 group was 5.49 (95% CI, [0.8 - 38.6]) and 69.99 ((95%CI [20.6 -237.4]), respectively, and in the NT-2 group, 12.5, 95%CI [1.6-97.7], and 33.3, 95%CI [8.2-135.7], respectively. CONCLUSION: Arab (Saudi) narcolepsy patients had a higher association with hypothyroidism, hyperlipidemia, and a higher risk of OSA than controls.

Exploding Head Syndrome: A Case Series of Underdiagnosed Hypnic Parasomnia.

Exploding head syndrome (EHS) is an under-recognized parasomnia characterized by a complaint of sudden loud noise or a sense of explosion in the head that usually occurs at sleep onset. This paper is a report of 6 patients diagnosed with EHS through a structured clinical interview and video-polysomnography (vPSG) recordings. We also reviewed the available literature that addressed the presentation and clinical and PSG characteristics of EHS. The case series included 4 men and 2 women of a mean age of 44.2 years (between 13 and 77 years). Their episodes were variable in expression, between a sudden firecracker-like explosion to a gun-shot sound, mostly as if happening inside the head. EHS is always associated with distress but never with pain. Five out of 6 patients had other sleep-related problems with a close relationship of EHS symptoms to comorbid sleep disorder manifestations and exacerbations. The vPSG recordings of 5 patients were unremarkable. An attack of EHS was documented in 1 patient, arising during stage N2 of sleep. Three patients responded well to reassurance and treatment for the comorbid sleep disorder. The other 3 patients responded well to amitriptyline (10-50 mg). EHS is a well-characterized, underrecognized hypnic parasomnia with a benign course. Amitriptyline seems to be effective in persistent cases.

Management of Aerosol during Noninvasive Ventilation for Patients with Sleep-Disordered Breathing: Important Messages during the COVID-19 Pandemic.

With the advent of COVID-19 infection and its rapid spread, preventive strategies are being developed worldwide, besides following the universal infection control guidelines. Prevention of spread through aerosol generation is one of the essential strategies in this regard, particularly for patients with sleep-disordered breathing at home and during hospital admission. Aerosols are produced, at home and in health care facilities, by natural processes and aerosol-generating procedures. To address this impinging problem, aerosol-generating procedures, like non-invasive ventilation (NIV), are to be handled meticulously, which might warrant isolation and sometimes device/interface modifications.

Basic chronobiology: what do sleep physicians need to know?

Sleep is an essential physiological process, which profoundly affects a wide range of biological activities. It is now known that sleep supports myriad vital functions in the central nervous system. This includes neural plasticity, learning, memory, cognition and emotional regulation. Additionally, it affects basic processes such as cardiovascular, immunological and metabolic activity. Evidence from multiple lines of research has thus shown that good quality of sleep is essential for both survival and optimal functioning of life. Considerable evidence also supports the conclusion that even minimal dysfunctions in circadian regulation can significantly disrupt sleep and broadly affect body physiology. As a consequence, it is now appreciated that the therapy of sleep disorders is more complex than was once thought. At present, several clinical disciplines have recognized the significance of the biological clock in health and illness, and are incorporating this knowledge into treatment programs. Recent decades have seen the emergence of chronotherapies, i.e., treatment strategies that are aimed at producing adjustments in the circadian clock. The final objective of these approaches is to affect basic cellular and physiological processes, which in turn may be at the root of disorders such as physiological aging, immune functioning, metabolic activity, and psychiatric disturbance. It is suggested that the integration of chronobiological perspectives into many mainstream medical disciplines would be of significant benefit, both for the reduction of the prevalence of diseases and their treatment. This review considers the physiology of sleep and the importance of timekeeping mechanisms in the regulation of overall health.

Prevalence and Predictors of Arrhythmia in Patients with Obstructive Sleep Apnea.

OBJECTIVES: To assess the prevalence and types of arrhythmias in Saudi OSA patients and to identify predictors of arrhythmia in this group of patients. METHODS: This case-control study included all patients who underwent level I attended overnight polysomnography between 2009 and 2012. Electrocardiographic data collected during sleep studies of patients with and without OSA were manually reviewed. RESULTS: The study comprised 498 patients (394 OSA patients and 104 non-OSA patients (controls). The prevalence of arrhythmia in OSA patients was higher than that in the controls (26.9% vs. 11.5%; p=0.001). Comparing OSA patients and controls showed: premature atrial contraction (10.2%vs.2.9%;p=0.019), premature ventricular contraction (PVC) (19.3%vs.9.6%;p=0.02), non-isolated PVC (bi/tri/qua) 10.8%vs.2.3%;p=0.04) and atrial fibrillation (1.6%vs.0%;p=0.001). Multiple logistic regression analysis revealed that, patients with OSA had twice the odds of having any cardiac arrhythmia (OR 1.91; CI 95% 1.27-3.11; p <0.05). CONCLUSIONS: Patients with OSA had a higher prevalence of arrhythmia compared to controls, and OSA is a predictor of arrhythmia during sleep.