Biomarkers of Oxidative Stress and Endogenous Antioxidants for Patients with Chronic Subjective Dizziness

Multifunctional redox modulator prevents blast-induced loss of cochlear and vestibular hair cells and auditory spiral ganglion neurons

Blast wave exposure, a leading cause of hearing loss and balance dysfunction among military personnel, arises primarily from direct mechanical damage to the mechanosensory hair cells and supporting structures or indirectly through excessive oxidative stress. We previously reported that HK-2, an orally active, multifunctional redox modulator (MFRM), was highly effective in reducing both hearing loss and hair cells loss in rats exposed to a moderate intensity workday noise that likely damages the cochlea primarily from oxidative stress versus direct mechanical trauma. To determine if HK-2 could also protect cochlear and vestibular cells from damage caused primarily from direct blast-induced mechanical trauma versus oxidative stress, we exposed rats to six blasts of 186 dB peak SPL. The rats were divided into four groups: (B) blast alone, (BEP) blast plus earplugs, (BHK-2) blast plus HK-2 and (BEPHK-2) blast plus earplugs plus HK-2. HK-2 was orally administered at 50 mg/kg/d from 7-days before to 30-day after the blast exposure. Cochlear and vestibular tissues were harvested 60-d post-exposure and evaluated for loss of outer hair cells (OHC), inner hair cells (IHC), auditory nerve fibers (ANF), spiral ganglion neurons (SGN) and vestibular hair cells in the saccule, utricle and semicircular canals. In the untreated blast-exposed group (B), massive losses occurred to OHC, IHC, ANF, SGN and only the vestibular hair cells in the striola region of the saccule. In contrast, rats treated with HK-2 (BHK-2) sustained significantly less OHC (67%) and IHC (57%) loss compared to the B group. OHC and IHC losses were smallest in the BEPHK-2 group, but not significantly different from the BEP group indicating lack of protective synergy between EP and HK-2. There was no loss of ANF, SGN or saccular hair cells in the BHK-2, BEP and BEPHK-2 groups. Thus, HK-2 not only significantly reduced OHC and IHC damage, but completely prevented loss of ANF, SGN and saccule hair cells. The powerful protective effects of this oral MFRM make HK-2 an extremely promising candidate for human clinical trials.

Inflammatory cytokines associated with mild traumatic brain injury and clinical outcomes: a systematic review and meta-analysis

Mild traumatic brain injuries (mTBIs) trigger a neuroinflammatory response, which leads to perturbations in the levels of inflammatory cytokines, resulting in a distinctive profile. A systematic review and meta-analysis were conducted to synthesize data related to levels of inflammatory cytokines in patients with mTBI. The electronic databases EMBASE, MEDLINE, and PUBMED were searched from January 2014 to December 12, 2021. A total of 5,138 articles were screened using a systematic approach based on the PRISMA and R-AMSTAR guidelines. Of these articles, 174 were selected for full-text review and 26 were included in the final analysis. The results of this study demonstrate that within 24 hours, patients with mTBI have significantly higher levels of Interleukin-6 (IL-6), Interleukin-1 Receptor Antagonist (IL-1RA), and Interferon-γ (IFN-γ) in blood, compared to healthy controls in majority of the included studies. Similarly one week following the injury, patients with mTBI have higher circulatory levels of Monocyte Chemoattractant Protein-1/C-C Motif Chemokine Ligand 2 (MCP-1/CCL2), compared to healthy controls in majority of the included studies. The results of the meta-analysis also confirmed these findings by demonstrating significantly elevated blood levels of IL-6, MCP-1/CCL2, and Interleukin-1 beta (IL-1β) in the mTBI population compared to healthy controls (p < 0.0001), particularly in the acute stages (<7 days). Furthermore, it was found that IL-6, Tumor Necrosis Factor-alpha (TNF-α), IL-1RA, IL-10, and MCP-1/CCL2 were associated with poor clinical outcomes following the mTBI. Finally, this research highlights the lack of consensus in the methodology of mTBI studies that measure inflammatory cytokines in the blood, and also provides direction for future mTBI research.

Persistent positional perceptual dizziness in clinical practice: a scoping review

INTRODUCTION

Dizziness is an important symptom presenting in routine practice and the life time prevalence ranges from 17 to 30%. Persistent positional perceptual dizziness (PPPD) is a common cause of chronic dizziness and has often been labeled as psychogenic dizziness in the past.

DISCUSSION

PPPD is diagnosed based on clinical criteria laid down by the Barany society. The vestibular function tests and imaging of the brain and the inner ear are often normal. Most of the patients have an underlying anxiety trait and most cases of PPPD arise following an attack of acute vertigo like Meniere's disease and vestibular neuritis. It is important to differentiate the condition from bilateral vestibulopathy. There is no role of vestibular sedative in the treatment of such condition. Vestibular rehabilitation therapy (VRT), cognitive behavioral therapy (CBT), and selective serotonin reuptake inhibitors (SSRI) like sertraline have shown benefits. However, long-term outcome is not known.

CONCLUSION

PPPD is a relatively new entity in the ever-expanding field of neurotology that requires a multimodality approach for effective management. The otologists and general physicians must identify the condition so that favorable outcome can be achieved. The long-term effects of treatment with CBT and VRT are not known. It is important to formulate standard guidelines for treatment. Further research is necessary to identify the role of endogenous biomarkers in the outcome of treatment.

Pharmacological Properties of Jaeumgeonbi-Tang on Redox System and Stress-Related Hormones in Chronic Subjective Dizziness: A Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Trial

Jaeumgeonbi-Tang (JGT), a traditional herbal medicine, has been used to treat dizziness and vertigo in Korea and China for hundreds of years. The purpose of this study was to evaluate the pharmacological properties of JGT in chronic subjective dizziness (CSD) patients. A randomized, double-blind, parallel-group and placebo-controlled trial was performed with a total of 50 CSD patients. The patients were randomly assigned to one of two groups: JGT or placebo (n = 25 for each). All participants received the treatment (placebo or JGT, 24 g/day) for 4 weeks. We analyzed the serum levels of oxidative stressors, antioxidants, and stress hormones. Serum levels of lipid peroxidation, but not nitric oxide, were significantly decreased in the JGT group. JGT not only prevented the decline of serum total glutathione contents and total antioxidant capacity, but it also increased superoxide dismutase and catalase activities. Serum levels of stress hormones including cortisol, adrenaline, and serotonin were notably normalized by JGT treatment, but noradrenaline levels were not affected. Regarding the safety and tolerability of JGT, we found no allergic, adverse, or side effects in any of the participants. JGT showed beneficial effects on CSD patients by improving redox status and balancing psycho-emotional stress hormones.

Prevalence of symptoms in 1512 COVID-19 patients: have dizziness and vertigo been underestimated thus far?

The relationship between SARS-CoV-2 infection and dizziness is still unclear. The aim of this study is to assess the prevalence and characteristics of dizziness and vertigo among patients with mild-to-moderate COVID-19. Patients discharged from the emergency rooms with a confirmed SARS-CoV-2 diagnosis were assisted by daily telephone calls until nasopharyngeal swab negativization, and specific symptoms concerning balance disorders were investigated through targeted questions posed by experienced physicians. The study included 1512 subjects (765 females, 747 males), with a median age of 51 ± 18.4 years. New-onset dizziness was reported by 251 (16.6%) patients, among whom 110 (43.8%) complained of lightheadedness, 70 (27.9%) of disequilibrium, 41 (16.3%) of presyncope, and 30 (12%) of vertigo. This study analyzed in detail the prevalence and pathophysiological mechanisms of the different types of balance disorders in a large sample, and the results suggest that dizziness should be included among the main symptoms of COVID-19 because one-sixth of patients reported this symptom, with females being significantly more affected than males (20.3 vs 12.9%, P < 0.001). Most cases of dizziness were attributable to lightheadedness, which was probably exacerbated by psychophysical stress following acute infection and mandatory quarantine. Vertigo should not be underestimated because it might underlie serious vestibular disorders, and disequilibrium in elderly individuals should be monitored due to the possible risk of falls.

[The comorbid mechanism of vestibular migraine and persistent postural-perceptual dizziness]

Vestibular migraine and persistent postural-perceptual dizziness both involve the vestibular system and are similar in clinical manifestations. After acute attack of vestibular migraine, it can gradually evolve into persistent posture-perceptual dizziness; persistent posture-perceptual dizziness caused by various factors can be combined with symptoms similar to vestibular migraine. Studies have shown that abnormal multi-sensory signal integration, abnormal neurotransmitters and genetic factors may be the co-disease mechanism of the two.

Age-Related Changes in the Cochlea and Vestibule: Shared Patterns and Processes

Both age-related hearing loss (ARHL) and age-related loss in vestibular function (ARVL) are prevalent conditions with deleterious consequences on the health and quality of life. Age-related changes in the inner ear are key contributors to both conditions. The auditory and vestibular systems rely on a shared sensory organ - the inner ear - and, like other sensory organs, the inner ear is susceptible to the effects of aging. Despite involvement of the same sensory structure, ARHL and ARVL are often considered separately. Insight essential for the development of improved diagnostics and treatments for both ARHL and ARVL can be gained by careful examination of their shared and unique pathophysiology in the auditory and vestibular end organs of the inner ear. To this end, this review begins by comparing the prevalence patterns of ARHL and ARVL. Next, the normal and age-related changes in the structure and function of the auditory and vestibular end organs are compared. Then, the contributions of various molecular mechanisms, notably inflammaging, oxidative stress, and genetic factors, are evaluated as possible common culprits that interrelate pathophysiology in the cochlea and vestibular end organs as part of ARHL and ARVL. A careful comparison of these changes reveals that the patterns of pathophysiology show similarities but also differences both between the cochlea and vestibular end organs and among the vestibular end organs. Future progress will depend on the development and application of new research strategies and the integrated investigation of ARHL and ARVL using both clinical and animal models.

Deanxit can improve the dizziness, anxiety, and quality of life of patients with chronic subjective dizziness

OBJECTIVE

This study was designed to analyze the clinical effectiveness of Deanxit (DEA) for treating chronic subjective dizziness (CSD).

METHODS

A total of 110 CSD patients (all from a community survey) admitted to our hospital from August 2018 to August 2020 were recruited as the study cohort. Among them, 60 who underwent DEA treatment were placed in the research group (RG) and 50 who underwent basic treatment were placed in the control group (CG). The two groups' efficacy, their dizziness disability rating scale (DHI) scores, the improvement in their clinical symptoms (duration of dizziness, frequency of dizziness attacks), their anxiety and depression (i.e., their Hamilton Anxiety Scale (HAMA) scores) and their Hamilton Depression Scale (HAMD)) scores, their sleep quality and their quality of life (short form 36 (SF-36) health survey scores) were observed and compared.

RESULTS

Compared with the CG, the DHI scores, the dizziness durations, the number of dizziness attacks and the HAMA and HAMD scores in the RG were markedly lower than they were in the CG, and the sleep quality levels and SF-36 scores were higher than they were in the CG.

CONCLUSION

DEA treatment helps to improve the dizziness, anxiety, and quality of life of CSD patients.

Melatonin Exerts Anti-Inflammatory, Antioxidant, and Neuromodulatory Effects That Could Potentially Be Useful in the Treatment of Vertigo

The acute phase of vertigo involves multiple neurotransmitters, inflammatory mediators, and products of oxidative stress. The vestibular pathway has multiple melatonin receptors distributed along its path, both centrally and peripherally. In addition, melatonin has been shown to be a powerful antioxidant and anti-inflammatory agent against factors related to vertigo, such as Bax/caspases, interleukins, and chemokines. Likewise, it exerts central GABAergic, antidopaminergic, and anti-migraine functions and regulates sympathetic activity in a similar way to the drugs classically used in acute vestibular crisis. In this review, the role of melatonin as a potential treatment of the acute phase of vertigo is discussed.