Sleeping with Elevated Upper Body Does Not Attenuate Acute Mountain Sickness: Pragmatic Randomized Clinical Trial

Medically Unexplained Symptoms Are Linked to Chronic Inflammatory Diseases: Is There a Role for Frontal Cerebral Blood Oxygen Content?

INTRODUCTION

Patients often go to the physician with medically unexplained symptoms (MUS). MUS can be autonomic nervous system-related "unspecific" symptoms, such as palpitations, heart rhythm alterations, temperature dysregulation (hand, feet), anxiety, or depressive manifestations, fatigue, somnolence, nausea, hyperalgesia with varying pains and aches, dizziness, etc. Methods: In this real-world study, we investigated MUS in a cohort of unselected outpatients from general practitioners in Italy. It was our aim to increase the understanding of MUS by using principal component analyses to identify any subcategories of MUS and to check a role of chronic inflammatory diseases. Additionally, we studied cerebral blood oxygen (rCBO2) and associations with MUS and chronic inflammatory disease.

RESULTS

Participants included 1,597 subjects (50.6 ± 0.4 years, 65%/35% women/men). According to ICD-10 codes, 137 subjects had chronic inflammatory diseases. MUS were checked by a questionnaire with a numeric rating scale and cerebral blood flow with optical techniques. The analyses of men and women were stratified. Psychological symptom severity was higher in the inflamed compared to the non-inflamed group (fatigue, insomnia in women and men; recent mood changes, daytime sleepiness, anxiety, apathy, cold hands only in women; abnormal appetite and heart rhythm problems only in men). Principal component analysis with MUS provided new subcategories: brain symptoms, gut symptoms, and unspecific symptoms. Brain and gut symptoms were higher in inflamed women and men. Chronic inflammatory diseases and pain were tightly interrelated in men and women (p < 0.0001). In women, not in men, average frontal rCBO2 content was higher in inflamed compared to non-inflamed subjects. In men, not in women, individuals with pain demonstrated a lower average frontal rCBO2 content compared to pain-free men. MUS did not relate to rCBO2 parameters.

CONCLUSION

This study shows close relationships between MUS and chronic inflammatory diseases but not between MUS and rCBO2 parameters.

High Altitude Cerebral Edema: Improving Treatment Options

High altitude illness in its most severe form can lead to high altitude cerebral edema (HACE). Current strategies have focused on prevention with graduated ascents, pharmacologic prophylaxis, and descent at first signs of symptoms. Little is understood regarding treatment with steroids and oxygenation being commonly utilized. Pre-clinical studies with turmeric derivatives have offered promise due to its anti-inflammatory and antioxidant properties, but they warrant validation clinically. Ongoing work is focused on better understanding the disease pathophysiology with an emphasis on the glymphatic system and venous outflow obstruction. This review highlights what is known regarding diagnosis, treatment, and prevention, while also introducing novel pathophysiology mechanisms warranting further investigation.

Highland mate: Edible and functional foods in traditional medicine for the prevention and treatment of hypoxia-related symptoms

The highlands evoke both fascination and awe. Regardless of the reason to live in the highlands, symptoms related to altitude sickness are unbearable because of low atmospheric pressure, low oxygen concentration, strong ultraviolet radiation, cold, and psychological factors. Food and herbal medicines and/or health-care foods have protected highland dwellers owing to their multisystem regulation. These versatile products combine health-care properties with medical values by enhancing immunity, relieving physical fatigue, improving sleep, and augmenting hypoxia tolerance, with rare side effects. We therefore aimed to provide a more comprehensive analysis of these nutraceuticals, which can be used to prevent and treat symptoms of altitude hypoxia in the Chinese market. Finally, we dissect a new perspective for their promotion and development from molecular aspects.

High-altitude cerebral edema: its own entity or end-stage acute mountain sickness?

High-altitude cerebral edema (HACE) and acute mountain sickness (AMS) are neuropathologies associated with rapid exposure to hypoxia. However, speculation remains regarding the exact etiology of both HACE and AMS and whether they share a common mechanistic pathology. This review outlines the basic principles of HACE development, highlighting how edema could develop from 1) a progression from cytotoxic swelling to ionic edema or 2) permeation of the blood brain barrier (BBB) with or without ionic edema. Thereafter, discussion turns to the available neuroimaging literature in the context of cytotoxic, ionic, or vasogenic edema in both HACE and AMS. Although HACE is clearly caused by an increase in brain water of ionic and/or vasogenic origin, there is very little evidence that this type of edema is present when AMS develops. However, cerebral vasodilation, increased intracranial blood volume, and concomitant intracranial fluid shifts from the extracellular to the intracellular space, as interpreted from changes in diffusion indices within white matter, are observed consistently in persons acutely exposed to hypoxia and with AMS. Therefore, herein we explore the idea that intracellular swelling occurs alongside AMS, and is a critical precursor to extracellular ionic edema formation. We propose that this process produces a subtle modulation of the BBB, which either together with or independent of vasogenic edema provides a transvascular segue from the end-stage of AMS to HACE. Ultimately, this review seeks to shed light on the possible processes underlying HACE pathophysiology, and thus highlights potential avenues for future prevention and treatment.