Update on current diagnosis and treatment of vestibular neuritis

Prevalence of Scarpa's ganglion enhancement on high-resolution MRI imaging

BACKGROUND AND PURPOSE

The vestibular ganglion, or Scarpa's ganglion, is a cluster of afferent vestibular neurons within the internal auditory canal (IAC). There is minimal literature describing enhancement of this region on magnetic resonance imaging (MRI) and its correlation to clinical symptoms. Here, we sought to find the prevalence of enhancement at Scarpa's ganglion, and determine whether such enhancement correlates with demographics or clinical symptoms.

MATERIALS AND METHODS

A retrospective review was performed of consecutive patients with an MRI of the IAC between 3/1/2021 and 5/20/2021. Two neuroradiologists independently reviewed for T1 and FLAIR enhancement of the Scarpa's ganglion on post-contrast fat-saturated T1 and post-contrast FLAIR images. Discrepancies were agreed upon by consensus. Clinical variables (hearing loss, vestibular symptoms, tinnitus, and MRI indication) were gathered from a retrospective chart review.

RESULTS

Eighty-nine patients were included (51 female); the mean age was 58 (range 19-85). The most common MRI indication was hearing loss (n = 53). FLAIR enhancement was present on the right in 7 patients, on the left in 7 patients, and bilaterally in 6 patients. No enhancement was seen on post-contrast T1 images. There was no statistically significant correlation between consensus FLAIR on at least one side and age (p = .74), gender (p = .29), hearing loss (p = .32), hearing loss side (p = .39), type of hearing loss (p = .87), vestibular symptoms (p = .71), or tinnitus (p = .81).

CONCLUSIONS

Enhancement is present in the minority of patients on post-contrast FLAIR images. If seen, it should be considered an uncommon but not unexpected finding with no clinical significance.

Evolution of Hyperventilation-Induced Nystagmus in Acute Unilateral Vestibulopathy-Interpretative Model and Etiopathogenetic Hypotheses

Hyperventilation induces metabolic changes that can elicit nystagmus (hyperventilation-induced nystagmus, HVIN) in various vestibular disorders, revealing vestibular imbalance and bringing out central or peripheral asymmetries. In acute unilateral vestibulopathy (AUVP, namely vestibular neuritis), hyperventilation can induce different patterns of nystagmus (excitatory, inhibitory, or negative), disclosing or modifying existing static vestibular asymmetries through its ability to invalidate compensation or increase peripheral excitability. In this context, we followed the evolutionary stages of HVIN in AUVP across 35 consecutive patients, with the goal of assessing alterations in the oculomotor pattern caused by hyperventilation over time. In the acute phase, the incidence of the excitatory pattern (and the strongly excitatory one, consisting of a reversal nystagmus evoked by hyperventilation) was significantly higher compared to the inhibitory pattern; then, a progressive reduction in the incidence of the excitatory pattern and a concomitant gradual increase in the incidence of the inhibitory one were observed in the follow-up period. Assuming the role of the ephaptic effect and the transient loss of vestibular compensation as opposing mechanisms, i.e., excitatory and inhibitory, respectively, the oculomotor pattern evoked by hyperventilation is the result of the interaction of these two factors. The data obtained allowed us to hypothesize an interpretative model regarding the pathogenetic aspects of responses evoked by hyperventilation and the etiologies of the disease: according to our hypotheses, the excitatory pattern implies a neuritic (viral) form of AUVP; instead, the inhibitory (and negative) one can be an expression of both the neuritic (viral) and vascular forms of the disease.

Vestibular function is associated with immune inflammatory response

Association between vestibular function and immune inflammatory response has garnered increasing interest. Immune responses can lead to anatomical or functional alterations of the vestibular system, and inflammatory reactions may impair hearing and balance. Vestibular disorders comprise a variety of conditions, such as vestibular neuritis, benign paroxysmal positional vertigo, Meniere's disease, vestibular migraine, posterior circulation ischemia, and bilateral vestibular disease. Moreover, some patients with autoimmune diseases develop vestibulocochlear symptom. This paper offers an overview of prevalent vestibular diseases and discusses associations between vestibular dysfunction and immune diseases.

[Vestibular rehabilitation for peripheral vestibular hypofunction: an interdisciplinary consensus]

The literature review presents approaches to the management of patients with vestibular disorders. The principles of organization of vestibular rehabilitation in peripheral vestibular hypofunction, indications for appointment, factors influencing its implementation, technique, methods of evaluating effectiveness are considered in detail. Attention is drawn to the fact that the selection of exercises and the duration of vestibular rehabilitation is carried out individually and depends on many factors, including the nature of vestibular deficiency and the specific characteristics of the patient. The possibilities of using additional pharmacological therapy with histamine preparations, which can accelerate the onset of vestibular compensation, are shown. It is noted that vestibular rehabilitation is a safe and effective method of treating peripheral vestibular hypofunction and should be recommended to patients of all ages with vestibular disorders leading to limited social and physical activity.

Hospital Admission Profile Related to Inner Ear Diseases in England and Wales

BACKGROUND

Due to an expansion in the usage of medications (such as anticancer therapies), increased exposure to noise, and an increase in life expectancy, the prevalence of inner ear disease-related hearing loss is rising. Diseases of the inner ear are frequently accompanied by other conditions, such as chronic heart failure, systemic inflammation, arterial hypertension, and cerebrovascular disease. The aim of this study was to investigate the profile of hospital admissions linked to inner ear diseases in England and Wales.

METHOD

This was an ecological descriptive study using public medical databases in England and Wales. Diagnostic codes for diseases of the inner ear (H80-H83) were used to identify all hospital admissions. Between 1999 and 2020, the chi-squared test was used to assess the difference between the admission rates.

RESULTS

From 5704 in 1999 to 19,097 in 2020, the total annual number of hospital admissions increased by 234.8%, which corresponds to a 192.3% increase in the admission rate [from 10.94 (95% CI 10.66-11.22) in 1999 to 31.98 (95% CI 31.52-32.43) in 2020 per 100,000 people, p < 0.01]. "Disorders of vestibular function" and "other inner ear diseases" were the most frequent causes of hospital admissions due to inner ear diseases, accounting for 47.6% and 43.6%, respectively. The age range of 15 to 59 years accounted for 42.3% of all diseases of the inner ear hospital admissions. Around 59.6% of all admissions were made by females. The female admission rate increased by 210.1% (from 12.43 (95% CI 12.01-12.85) in 1999 to 38.54 (95% CI 37.84-39.24) in 2020 per 100,000 people). The male admission rate for diseases of the inner ear increased by 169.6% [from 9.37 (95% CI 9.00-9.75) in 1999 to 25.26 (95% CI 24.69-25.84) per 100,000 people] in 2020.

CONCLUSION

Inner ear disease admissions increased markedly in England and Wales during the past two decades. Females and the middle-aged population were at higher risk of being admitted for inner ear diseases. Further cohort studies are warranted to identify other risk factors and develop effective prevention strategies.

Vertigo in the Setting of COVID-19 Infection: A Case Report

Extensive research has been conducted on the pathophysiological sequelae of the SARS-CoV-2 virus. Newer symptoms pertaining to cardiovascular, gastrointestinal, and neurological systems, apart from the recognized respiratory system, are constantly being reported. We report a case of a 22-year-old female with a seven-day history of COVID-19 who presented to the emergency department with an acute vertigo attack associated with nausea and vomiting for three hours. Physical examination and audiometry showed no neurological and auditory deficits; she was diagnosed with vestibular neuritis. The patient was managed with betahistine hydrochloride and an antihistamine. There was a complete resolution of symptoms after seven days. There have been reports of new-onset vertigo associated with SARS-CoV-2 infection, but more well-designed studies are needed to establish an association between COVID-19 and vertigo.

Identification of hub genes and pathophysiological mechanism related to acute unilateral vestibulopathy by integrated bioinformatics analysis

Background

Although many pathological mechanisms and etiological hypotheses of acute unilateral vestibulopathy (AUVP) have been reported, but the actual etiology remains to be elucidated.

Objective

This study was based on comprehensive bioinformatics to identify the critical genes of AUVP and explore its pathological mechanism.

Methods

Gene expression profiles of AUVP and normal samples were collected from GSE146230 datasets of the Gene Expression Omnibus (GEO) database. Weighted gene co-expression network analysis (WGCNA) was constructed, and the WGCNA R-package extracted significant modules. The limma R-package was applied to identify differentially expressed genes (DEGs). The common genes of practical modules and DEGs were screened for GO and KEGG pathways analysis. The protein–protein interaction (PPI) layout and hub genes validation was created by Cytoscape software using the link from the STRING database. The functions of hub genes were predicted through the CTD (comparative genetics database).

Results

A total of 332 common genes were screened from practical modules and DEGs. Functional enrichment analysis revealed that these genes were predominantly associated with inflammation and infection. After construction of PPI, expressions of hub genes, and drawing ROC curves, LILRB2, FPR1, AQP9, and LILRA1 are highly expressed in AUVP (p < 0.05) and have a certain diagnostic efficacy for AUVP (AUC > 0.7), so they were selected as hub genes. The functions of hub genes suggested that the occurrence of AUVP may be related to inflammation, necrosis, hepatomegaly, and other conditions in CTD.

Conclusion

LILRB2, FPR1, AQP9, and LILRA1 may play essential roles in developing AUVP, providing new ideas for diagnosing and treating AUVP.

A Holistic Approach to a Dizzy Patient: A Practical Update

Dizziness is one of the most common symptoms encountered by physicians daily. It is divided into four categories: vertigo, disequilibrium, presyncope, and psychogenic dizziness. It is essential to distinguish these four symptoms because the causes, prognosis, and treatment differ. Vertigo constitutes a disease of the central or peripheral nervous system. Central origin vertigo may be a life-threatening situation and must be detected as soon as possible because it includes diseases such as stroke, hemorrhage, tumors, and multiple sclerosis. Peripheral origin vertigo includes benign diseases, which may be fully treatable such as vestibular migraine, benign paroxysmal positional vertigo, vestibular neuritis, Ménière’s disease, and cervical vertigo. The HINTS (head impulse, nystagmus, test of skew) examination is essential to distinguish central from peripheral causes. A detailed history including the duration of vertigo (episodic or continuous), its trigger, and a clinical examination step by step following the appropriate protocol could help to make a definite and accurate diagnosis and treatment. Due to a lack of expertise in dizziness and inappropriate treatment, many patients are admitted to dizziness clinics with long-standing dizziness. A holistic treatment combining medications, vestibular rehabilitation, physiotherapy, and psychotherapy should be initiated to improve the quality of life of these patients. So, this review aims to recommend a clinical protocol for approaching a dizzy patient with vertigo and to present in detail the epidemiology, pathophysiology, symptoms, diagnosis, and contemporary treatments of all causes of vertigo.

Acute vestibular neuritis: A rare complication after the adenoviral vector-based COVID-19 vaccine

Vestibular neuritis was first reported in 1952 by Dix and Hallpike, and 30% of patients reporting a flu-like symptom before acquiring the disorder. The most common causes are viral infections, often resulting from systemic viral infections or bacterial labyrinthitis. Here we presented a rare case of acute vestibular neuritis after the adenoviral vector-based COVID-19 vaccination. A 51-year-old male pilot awoke early in the morning with severe vertigo, nausea, and vomiting after receiving the first dose of the ChAdOx1 nCoV-19 vaccine 11 days ago. Nasopharyngeal SARS-CoV-2 RT-PCR test and chest CT scan were inconclusive for COVID-19 pneumonia. Significant findings were a severe spontaneous and constant true-whirling vertigo which worsened with head movement, horizontal-torsional spontaneous nystagmus, abnormal caloric test, positive bedside head impulse tests, and inability to tolerate head-thrust test. PTA, MRI of the brain and internal auditory canal, and cerebral CT arteriography were normal. According to the clinical, imaging, and laboratory findings, he was admitted to the neurology ward and received treatment for vestibular neuritis. His vertigo increased gradually over 6-8 h, peaking on the first day, and gradually subsided over 7 days. Ten days later, the symptoms became tolerable; the patient was discharged with advice for home-based vestibular rehabilitation exercises. Despite the proper treatment and rehabilitation, signs of dynamic vestibular imbalances persisted after 1 year. Based on the Federal Aviation Administration (FAA) regulations, the Air Medical Council (AMC) suspended him from flight duties until receiving full recovery. Several cases of vestibular neuritis have been reported in the COVID-19 patients and after the COVID-19 vaccination. This is the first case report of acute vestibular neuritis after the ChAdOx1 nCoV-19 vaccination in a healthy pilot without past medical history. However, the authors believe that this is a primary clinical suspicion that must be considered and confirmed after complete investigations.