Vestibular neuronitis: epidemiological survey by questionnaire in Japan

Assessments of Subjective Visual Gravity and Spontaneous Nystagmus in Patients With Vestibular Neuritis

OBJECTIVE

This study aimed to assess the correlation between the spontaneous nystagmus (SN) and the subjective visual vertical/horizontal (SVV/SVH) among patients with vestibular neuritis (VN) at the different head positions.

STUDY DESIGN

Case-control study.

SETTING

Affiliated Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine.

METHODS

This study evaluated the SVV/SVH in both healthy subjects and patients with VN. These evaluations were performed in 5 different head positions: upright, 45° tilt to the left, 90° tilt to the left, 45° tilt to the right, and 90° tilt to the right. Additionally, the intensity of SN, as measured by slow-phase velocity, was recorded.

RESULTS

In patients with VN, a significant correlation was observed between SN and SVV/SVH in an upright position. The intensity of SN was higher when the head was tilted 90° toward the affected side compared to other positions. The SVV/SVH displayed an ipsiversive shift, when the head was tilted toward both the lesion and unaffected sides, exhibiting a contraversive direction. Furthermore, the changes in position-induced SN were consistent with the displacements of SVV and SVH caused by head tilt.

CONCLUSION

The presence of SN in patients with VN was observed to vary across different head position. These variations could potentially be attributed to the diverse activation patterns of the mechanical properties of otolith organs that are induced by head tilts.

Estimated incidence and characteristics of vestibular neuritis in Japan: A nationwide survey

OBJECTIVE

To assess the annual incidence of vestibular neuritis (VN) in the Japanese population.

METHODS

We conducted a mail-based survey targeting otolaryngologic clinics and hospitals across Japan to estimate the annual number of patients who were newly-diagnosed with VN during the one-year period of 2021. Using a stratified sampling method, we selected 1,107 departments and asked them to report the number of new patients with VN and their demographics. The total number of VN patients was estimated by multiplying the reported numbers by the reciprocal of the sampling rate and response rate.

RESULTS

The overall survey response rate was 40.5 % (448 departments). The estimated number of newly-diagnosed VN patients in 2021 was 8,861 (95 % confidential interval [CI], 2,290-15,432) The annual incidence of VN was 7.05 per 100,000 population in Japan. The male-to-female ratio of VN patients was 0.96, and the mean age was 60.3 ± 16.1 years (range 11-94 years).

CONCLUSIONS

The annual incidence of VN in Japan in 2021 had almost doubled and the mean age had become older compared to the previous study in 1993 (annual incidence; 3.5 per 100,000 per year; mean age: 45 years).

Diagnostic and therapeutic strategies for vestibular neuritis of the Japan Society for Equilibrium Research

OBJECTIVE

To provide diagnostic and therapeutic strategies for vestibular neuritis in accordance with the Japanese Clinical Practice Guidelines for Vestibular Neuritis 2021.

METHODS

The Committee for Clinical Practice Guidelines for Vestibular Neuritis was entrusted with a review of the relevant scientific literature on the above topic. Clinical Questions (CQs) concerning the treatment of vestibular neuritis were produced, and a search of the literature was conducted to identify studies related to the CQs. The recommendations were based on the literature review and the expert opinion of a subcommittee.

RESULTS

We proposed the diagnostic criteria for vestibular neuritis, as well as answers to CQs, recommendations, and evidence levels for the treatment of vestibular neuritis.

CONCLUSION

The diagnostic criteria for vestibular neuritis were based on clinical history and examination findings after completing the differential diagnosis process. The treatment of vestibular neuritis was divided into acute, subacute, and chronic stages. The Japanese Clinical Practice Guidelines for Vestibular Neuritis 2021 should be used as a reference in the diagnosis and treatment of vestibular neuritis.

Vestibular disorders following BNT162b2 mRNA COVID-19 vaccination: A retrospective case series

BACKGROUND

There are few publications regarding manifestations of vestibular disorders (VDs) following BNT162b2 mRNA COVID-19 vaccination.

PURPOSE

We describe cases of VD potentially related to BNT162b2 vaccination and calculate its reporting rate, in order to enlarge knowledge about this adverse effect.

METHODS

A retrospective analysis of cases of VD following BNT162b2 vaccination reported to the pharmacovigilance centre of Georges-Pompidou European Hospital (France), in 2021 was performed. In order to identify these cases from the pharmacovigilance database containing all our registered cases, we used the Standardised MedDRA Query (SMQ) 'vestibular disorders'. Then we analysed cases with vestibular symptoms, based on the association of typical manifestations. The reporting rate was calculated based on the number of VD cases and the number of vaccinated patients.

RESULTS

Among 6608 cases reported to our centre related to COVID-19 vaccines during 2021, 34 VDs associated with BNT162b2 administration were included. They were mainly reported in females (79%), 62% occurred after the first dose and 32% were serious. Symptoms had completely resolved in 13 cases (38%). Vertigo was the most common symptom followed by balance disorders. Three patients received second dose without reappearance of VD. The final diagnosis was reported in 10 patients (six cases of vestibular neuritis, two cases of central VD, two cases of benign paroxysmal positional vertigo). The regional reporting rate was 26 [95% CI: 17-34] cases of VD per 1 million persons vaccinated.

CONCLUSION

Although the relationship between vaccination and VD cannot be established, clinicians should be aware of this rare adverse effect.

Pharmacological Treatment of Acute Unilateral Vestibulopathy: A Review

There have been few investigations on the epidemiology, etiology, and medical management of acute unilateral vestibulopathy (AUV). Short-term pharmaceutical resolutions include vestibular symptomatic suppressants, anti-emetics, and some cause-based therapies. Anticholinergics, phenothiazines, antihistamines, antidopaminergics, benzodiazepines, and calcium channel antagonists are examples of vestibular suppressants. Some of these medications may show their effects through multiple mechanisms. In contrast, N-acetyl-L-leucine, Ginkgo biloba, and betahistine improve central vestibular compensation. Currently, AUV pathophysiology is poorly understood. Diverse hypotheses have previously been identified which have brought about some causal treatments presently used. According to some publications, acute administration of anti-inflammatory medications may have a deleterious impact on both post-lesional functional recovery and endogenous adaptive plasticity processes. Thus, some authors do not recommend the use of corticosteroids in AUV. Antivirals are even more contentious in the context of AUV treatment. Although vascular theories have been presented, no verified investigations employing anti-clotting or vasodilator medications have been conducted. There are no standardized treatment protocols for AUV to date, and the pharmacological treatment of AUV is still questionable. This review addresses the most current developments and controversies in AUV medical treatment.

Higher Cardio-Ankle Vascular Index Values in Patients With Vestibular Neuritis May Indicate a Better Prognosis

BACKGROUND

The presumed etiology of vestibular neuritis (VN), a sudden onset of spontaneous vertigo without auditory or cranial nerve symptoms, includes viral infections and vascular disorders. However, no clinical test for estimating vascular disorders in VN has been reported. Moreover, estimating the etiology of VN is important to predict the prognosis and select appropriate treatment. This study aimed to evaluate the cardio-ankle vascular index (CAVI), which reflects arterial stiffness and elasticity, as an additional indicator for estimating the prognosis and etiology of VN.

MATERIALS AND METHODS

Among 207 consecutive patients with suspected VN, 88 patients diagnosed with definite VN were enrolled. Age, initial and final percent canal paresis (CP) in the caloric test, CAVI, presence or absence of vestibular-evoked myogenic potential asymmetry, and medical history were evaluated using univariate and multivariate analyses.

RESULTS

Patients with VN with high CAVI had a better prognosis than those with low CAVI. High CAVI was a factor for improvement in percent CP, in addition to younger age and less severe initial percent CP in the Cox proportional hazard model.

CONCLUSION

CAVI can be an additional indicator for estimating the prognosis and etiology of VN. This indicator can potentially be applied to other diseases, including vascular disorders with other etiologies.

Influence of Age and Cardiovascular Risk Factors in Vestibular Neuritis: Retrospective Cohort Study

To analyze the influence of age and cardiovascular risk factors (CVRFs) in the evolution of vestibular neuritis (VN).

METHODS

Retrospective cohort study. VN-diagnosed patients were included and divided into two groups: those with and without CVRFs. We analyzed the mean vestibular-ocular reflex (VOR) gain, measured through the video head impulse test (vHIT) at the diagnosis and one-year follow-up. We conducted a factorial analysis of variance (ANOVA) to evaluate the effect of age, sex, and CVRFs in the mean VOR gain.

RESULTS

Sixty-three VN-diagnosed patients were included. There were no statistically significant differences in the mean VOR gain between both groups. However, in the subgroup analysis, there were statistically significant differences when comparing the mean VOR gain at the one-year follow-up between the group over 55 years of age 0.77 ± 0.20 and the group under 55 years 0.87 ± 0.15 (p = 0.036). Additionally, the factorial ANOVA demonstrated a significant main effect of age group on the mean VOR gain at the one-year follow-up (p = 0.018), and it also found a significant interaction between the factors of gender, age group, HTN (p = 0.043).

CONCLUSIONS

CVRFs do not independently affect the mean VOR gain in VN patients' follow-ups. However, age significantly impacts VOR gain in VN and could be modulated by gender and hypertension.

[Demographic and epidemiological risk factors in patients with acute vestibular neuritis]

OBJECTIVE

Vestibular neuritis (VN) is one of the most common peripheral vestibular balance disorder. Demographic and other risk factors associated with VN are insufficiently published. Therefore, the aim of this study is to identify associated risk factors in patients with acute VN.

METHODS

This study evaluated all hospitalized VN cases between 2017-2019. Inclusion criteria was an otoneurologically confirmed diagnosis of acute VN. Patient data was compared with data of the German normal population (Robert Koch Institute, "Gesundheit in Deutschland aktuell").

RESULTS

168 patients (Ø 59.8 years) were included. Compared with the normal German population, the study population was significantly more likely to have preexisting cardiovascular diseases, and the male patients were significantly more likely to have arterial hypertension. No significant differences were measurable between the study population and the normal population for other secondary diseases. Leukocytosis was present in 23% on admission, and 9% of patients reported a history of VZV or HSV-1 disease.

DISCUSSION

Etiology and pathogenesis of VN are poorly understood. Inflammatory and vascular causes are discussed. In this study, patients had increased prevalence of cardiovascular disease compared with the normal population, but the study population had a higher average age. Currently, it is unclear what significance nonspecific elevated leukocyte values could have as a possible sign of VN triggered by an infection. Since the number of inpatient cases with VN is rising, prospective studies should be performed to get a better understanding of the pathogenesis of the disease.

The incidence of vestibular neuritis in Italy

Objective

This study aims to estimate the incidence of Vestibular neuritis (VN) in three different districts in Italy, its epidemiological features, and the prevalence of comorbidities associated with it.

Methods

An observational prospective study of 198 patients referred to ENT departments in Siena, Grosseto, and Cuneo was carried out over a 2-year period. Each patient underwent a complete otoneurologic examination in the first 48 h from the onset of symptoms and a brain MRI in the early stages of the disease. The follow-up lasted for 1 year.

Results

The total VN incidence rate of the three municipalities was 48.497 (95% CI: 48.395-48.598) and its standardized value was 53.564 (95% CI: 53.463-53.666). The total VN incidence rate for the whole sample (municipality and district of the three centers) was 18.218 (95% CI: 18.164-18.272), and its standardized value was 20.185 (95% CI: 20.129-20.241). A significant difference was highlighted between patients living in the city compared to those living in the surrounding area (p < 0.000), this may be due to the ease of reaching the otoneurological referral center.

Conclusion

The total incidence rate for the three municipalities was 48.497. This result is higher than previously reported studies.

Bechterew's Phenomenon in Bilateral Sequential Vestibular Neuritis: A Report of Two Cases

The brain can compensate for the vestibular imbalance. When the unilateral labyrinthine function is lost, the asymmetry between the peripheral vestibular inputs is compensated centrally by readjusting the signal difference from both ears and regaining vestibular balance. If the other healthy labyrinth is destroyed, the vestibular nuclei become imbalanced again, creating spontaneous nystagmus even though there is no input to the vestibular nuclei from either labyrinth. This is called Bechterew's phenomenon; a rare and not widely recognized phenomenon that occurs in cases of bilateral sequential vestibular neuritis. This is of clinical importance because spontaneous nystagmus with bilaterally absent or diminished caloric responses may give a misleading impression of a central lesion rather than a second peripheral lesion superimposed upon the effects of central compensation for the first. Although well-documented in experimental animals, this phenomenon rarely occurs in human beings. The objective of this study is to highlight the characteristics and the progression of test results from two patients from our own experience. Along with careful history taking and physical examination, a complex interpretation of various vestibular function tests, including induced nystagmus, head impulse test, caloric test, and fundus photography, is needed to make an accurate diagnosis of bilateral sequential vestibular neuritis (BSVN).

A Set of Eight Key Questions Helps to Classify Common Vestibular Disorders-Results From the DizzyReg Patient Registry

Precise history taking is the key to develop a first assumption on the diagnosis of vestibular disorders. Particularly in the primary care setting, algorithms are needed, which are based on a small number of questions and variables only to guide appropriate diagnostic decisions. The aim of this study is to identify a set of such key variables that can be used for preliminary classification of the most common vestibular disorders. A four-step approach was implemented to achieve this aim: (1) we conducted an online expert survey to collect variables that are meaningful for medical history taking, (2) we used qualitative content analysis to structure these variables, (3) we identified matching variables of the patient registry of the German Center for Vertigo and Balance Disorders, and (4) we used classification trees to build a classification model based on these identified variables and to analyze if and how these variables contribute to the classification of common vestibular disorders. We included a total of 1,066 patients with seven common vestibular disorders (mean age of 51.1 years, SD = 15.3, 56% female). Functional dizziness was the most frequent diagnosis (32.5%), followed by vestibular migraine (20.2%) and Menière's disease (13.3%). Using classification trees, we identified eight key variables which can differentiate the seven vestibular disorders with an accuracy of almost 50%. The key questions comprised attack duration, rotational vertigo, hearing problems, turning in bed as a trigger, doing sport or heavy household chores as a trigger, age, having problems with walking in the dark, and vomiting. The presented algorithm showed a high-face validity and can be helpful for taking initial medical history in patients with vertigo and dizziness. Further research is required to evaluate if the identified algorithm can be applied in the primary care setting and to evaluate its external validity.

Sequential Vestibular Neuritis: Report of Four Cases and Literature Review

Background and Objectives

Bilateral sequential vestibular neuritis (BSVN) is a rare condition in which an inflammation or an ischemic damage of the vestibular nerve occurs bilaterally in a sequential pattern. We described four cases of BSVN.

Subjects and Methods

Every patient underwent video-head impulse test during the first and the second episode of vestibular neuritis (VN), furthermore they have been studied with radiological imaging.

Results

Contralateral VN occurred after a variable period from prior event. Vestibular function recovered from the first episode in one case. The other three patients developed contralateral VN. One case was due to a bilateral VN in association with a Ramsay-Hunt syndrome, in another patient clinical records strongly suggested an ischemic etiology, whereas in two cases aetiology remained uncertain. Two patients subsequently developed a benign paroxysmal positional vertigo involving the posterior canal on the side of the latest VN (Lindsay-Hemenway syndrome).

Conclusions

Instrumental vestibular assessment represents a pivotal tool to confirm the diagnosis of VN and BSVN.

Systematic Review and Meta-analysis: Effectiveness of Corticosteroids in Treating Adults With Acute Vestibular Neuritis

OBJECTIVES

To determine whether steroids are effective in treating adults with acute vestibular neuritis.

DATA SOURCES

PubMed, Embase, CINAHL, Cochrane CENTRAL, Web of Science, CAB Abstract, ICTRP, LILACS, PEDRO, ClinicalTrials.Gov, Google Scholar, NARIC, and OT Seeker.

REVIEW METHODS

A systematic review was undertaken for articles reporting subjective and/or objective outcomes of corticosteroids in adults with acute vestibular neuritis between December 2010 and October 2019. Reports of patient recovery from clinical vestibular outcomes at various time points and adverse effects from corticosteroids were of interest. Statistical analysis included qualitative and quantitative assessments. A limited meta-analysis of the data was performed through a random effects model.

RESULTS

Eight studies met the criteria, and 6 were included in the meta-analysis. No significant differences between the groups (corticosteroid vs placebo, corticosteroid vs vestibular exercise, or corticosteroid vs combination of vestibular exercise and corticosteroid) were reported in the proportion of patients with complete recovery at 1, 6, and 12 months. The corticosteroid group had significantly better caloric recover at 1 month (95% CI, -16.33 to -0.32); however, there was no significant difference to the overall effect between the groups across 12 months. Subjective recovery did not differ between the groups. Five of the 8 studies reported on adverse effects from corticosteroids.

CONCLUSION

There is insufficient evidence to support the use of corticosteroids in managing acute vestibular neuritis in adults. At present, corticosteroids appear to have short-term benefits in canal paresis but no long-term benefits in canal paresis and symptomatic recovery. Future studies should consider including a wider variety of clinical vestibular tests and frequent acute follow-ups to monitor the effects of corticosteroids.

The Clinical Key Features of Persistent Postural Perceptual Dizziness in the General Medicine Outpatient Setting: A Case Series Study of 33 Patients

Objective This case series aimed to investigate the clinical and pathological characteristics of persistent postural perceptual dizziness (PPPD). Methods We retrospectively examined the medical records of patients with chronic dizziness in our department, and tracked the percentage of PPPD, the age and sex, disorder duration, exacerbating factors for dizziness, and duration of momentary worsening dizziness. We also examined the duration of momentary worsening dizziness in cases of depression, anxiety disorder, and somatic symptom disorder. Results Among 229 patients with chronic dizziness, 14.4% (33/229) met the diagnostic criteria for PPPD. PPPD was the second most common disorder of patients with chronic dizziness after depression. The median age of patients with PPPD was 75 (75.8% female) and the median duration of the disorder was 60 months (range: 3-360 months). The exacerbating factors were motion without regard to direction or position (90.9%), upright posture (66.7%), and exposure to moving visual stimuli or complex visual patterns (30.3%). While the duration of momentary worsening dizziness was less than 10 minutes in 93.9% of patients with PPPD, the duration in patients with depression, anxiety disorder, and somatic symptom disorder were 3.6 % (2/55), 16.1% (5/31), and 0% (0/11), respectively. When the duration was less than 10 minutes, the odds ratios of PPPD for depression and anxiety disorder were 46.5 (95% CI: 6.1-362.0) and 40.3 (95% CI: 7.4-219.3), respectively. Conclusion Short episodes of momentary worsening dizziness constitute a distinctive feature of PPPD that may be useful for differentiating PPPD from other types of psychogenic dizziness.

[Vestibular neuritis - prevalence of inpatient cases in Germany]

INTRODUCTION

The vestibular neuropathy (VN) is a frequently diagnosed, acute peripheral vestibular form of vertigo. Typical symptoms are spinning vertigo, ipsilateral tendency to fall with standing and gait insecurity, and vegetative side effects. Epidemiological studies of VN in the general population are rare and the little existing literature varies in results.

MATERIAL AND METHODS

All inpatient VN cases in Germany from 2000 to 2017 were evaluated. The data used was provided by the German Federal Statistical Office. In addition to the annual number of cases, information about age at diagnosis, gender and length of stay were evaluated.

RESULTS

Between 2000-2017, 401 242 inpatient cases with VN were reported in Germany. This translates into a prevalence of 36.7 cases/100 000 individuals in 2017. During the examined 17 years the number of cases with VN in Germany increased by approximately 180 %. Across all years evaluated, VN was observed more often among women than among men. The length of stay decreased continuously by a total of 3.3 days during the observation period.

DISCUSSION

In 2017, the observed prevalence of VN cases in Germany was 36.7 hospital cases/100 000 individuals. Literature shows a prevalence of non-hospitalized VN cases of 162/100 000 individuals in 2015. Even when taking into account an inaccuracy due to a possible bias, these numbers add up to a much higher prevalence of VN cases than described previously in the literature. The continuous increase in cases with VN in Germany may be associated with demographic changes in age structure and a related higher morbidity.

High-risk Allele for Herpes Labialis Severity at the IFNL3/4 Locus is Associated With Vestibular Neuritis

Objective: Vestibular neuritis (VN) is a peripheral vestibular disorder leading to a sudden loss of unilateral vestibular function. Although the underlying etiological mechanisms for disease development are not yet known, there is evidence that a latent infection with herpes simplex virus type 1 (HSV-1) might be involved. The polymorphism rs12979860 has been associated with the severity of recurrent herpes labialis and hepatitis C virus (HCV) clearance and treatment outcome and is located within the first intron of the IFNL4 gene on chromosome 19.q13.2. This case control study was conducted to evaluate the association of rs12979860 with VN occurrence.

Methods: DNA was extracted from EDTA blood of 151 VN patients and 1,775 healthy controls. Genotyping of rs12979860 was performed using iPLEX and MassARRAY Matrix Assisted Laser Desorption Ionization—Time of Flight (MALDI-TOF) mass spectrometry. For association analyses, an additive, dominant and recessive logistic regression model was calculated, using age and sex as covariates.

Results: A significant association of rs12979860 with VN was obtained for the additive [OR = 1.51 (1.18–1.92); p = 9.23 × 10⁻⁴] and dominant models [OR = 2.15 (1.48–3.13); p = 5.86 × 10⁻⁵], with the T allele being more frequent in the VN group.

Conclusion: By detecting a significant association of the rs12979860-T risk allele for herpes labialis severity with susceptibility to VN, this study gives further indirect evidence for an involvement of HSV-1 in VN pathology, thereby strengthening the virus hypothesis.

[Acute vestibular syndrome in emergency departments : Clinical differentiation of peripheral and central vestibulopathy]

INTRODUCTION

The differentiation between central and peripheral vestibular disorders is difficult in some cases, especially during the clinical routine of an emergency department (ED) without otoneurological diagnostic equipment. This study evaluated the frequency of vestibular pseudoneuritis as distinguished from acute peripheral vestibular disorders in patients who were admitted to hospital with the suspicion of vestibular neuropathy (VN).

METHODS

This retrospective study analyzed the results of anamnestic and clinical examinations of 315 patients admitted to the emergency department and the inpatient otoneurological examination results as well as the imaging of morphological alterations. In the ED, the clinical examination by a neurologist and an otorhinolaryngologist resulted in the characteristic signs of peripheral VN but no further evidence of a neurological disorder. Patients without signs of a peripheral vestibular disorder in the otoneurological diagnostics subsequently underwent cerebral magnetic resonance imaging scans (cMRI).

RESULTS

Suspected isolated VN could be confirmed in 69% of the patients; however, in a further 29% of the patients neither the suspected isolated VN nor an ischemic pathology of the central nervous system as a cause of the vertigo could be confirmed. Additional cMRI scans revealed that 2% of patients suffered from an infarction of the mesencephalon, the pons, the medulla oblongata and the cerebellum.

CONCLUSION

In rare cases central cerebral disorders mimic the pattern of a peripheral vestibular disorder. Despite thorough history taking, neurological and otolaryngological clinical examinations, it is not always possible to distinguish central and peripheral vestibular disorders of patients in emergency care suffering from acute vertigo. Video oculography-assisted caloric testing and the video head impulse test are recommended to confirm a peripheral VN. In cases without confirmation of suspected NV in otoneurological diagnostics, infarction of the mesencephalon, brain stem and cerebellum should be excluded by diffusion-weighted cMRI.

Peripheral Vestibular Disorders: Nationwide Evidence From Taiwan

OBJECTIVES/HYPOTHESIS

This study aimed to evaluate the prevalence of peripheral vestibular disorders in an Asian population of predominantly Han Chinese ethnicity.

STUDY DESIGN

Cross-sectional study.

METHODS

Patients with a peripheral vertigo disorder were identified from the Taiwan Health Insurance Research Database, a database of all medical claims of a randomly selected, population-representative sample of 2 million enrollees of Taiwan's National Health Insurance system covering over 99% of Taiwan's citizens. In 2016, 59,986 patients received a diagnosis of peripheral vestibular disorders in Taiwan. We calculated the population-wide prevalence rates of peripheral vestibular disorders in 2016 by sex and age group (20 to 24, 25 to 29, 30 to 34, 35 to 39, 40 to 44, 45 to 49, 50 to 54, 55 to 59, 60 to 64, 65 to 69, and ≥ 70 years) stratified into five urbanization levels.

RESULTS

The prevalence rate of peripheral vestibular disorders was 2,833.4 per 100,000 population during the year. Prevalence of Meniere's disease was 70.4 per 100,000, benign paroxysmal positional vertigo, 446.4, vestibular neuritis 307.2, and other or unspecified peripheral vestibular dizziness, 2,009.5 per 100,000. Prevalence rates steadily increased with age for every type of peripheral vestibular disorder, and were higher among females compared to males. The female-to-male gender ratios were 1.84, 1.89, and 1.93 for Meniere's disease, vestibular neuritis, and other peripheral vestibular dizziness, respectively. Counties with the lowest urbanization level had the highest prevalence rates of all types of peripheral vestibular disorders except vestibular neuritis.

CONCLUSIONS

Results showed that peripheral vestibular disorders are common in Taiwan, increase with age, are predominantly female, and show higher prevalence in rural areas.

LEVEL OF EVIDENCE

2b Laryngoscope, 131:639-643, 2021.

Demographic data and seasonal variation in peripheral vestibular disorders in ENT practices in Germany

AIM

The aim of this study was to analyze the demographic data pertaining to and seasonal variation in specific vestibular disorders in ear, nose, and throat (ENT) practices in Germany based on data from a representative nationwide practice database.

METHOD

The study sample included patients from 116 ENT practices in Germany who received an initial diagnosis (ICD-10 code) of Meniere's disease (MD, H81.0), benign paroxysmal positioning vertigo (BPPV, H81.1), or vestibular neuronitis (VN, H81.2) between January 2014 and December 2016. Collected parameters included age, sex, and month of diagnosis. Seasonal variation was analyzed for younger vs. older patients (≤50 vs. >50 years of age). Two univariate Poisson regression models were fitted to estimate the association between the month of diagnosis and the number of diagnosed patients per practice.

RESULTS

A total of 20,720 patients were available for analysis. The average case numbers for MD, BPPV, and VN were 0.8 patients, 2.7 patients, and 1.5 patients per practice per month, respectively. The mean ages of female vs. male patients were 55 and 56 years (MD), 59 and 60 years (BPPV), and 58 and 57 years (VN), respectively. The proportions of female patients with these diagnoses were 62%, 70%, and 61%, respectively. All diagnoses were evenly distributed throughout the years in all age groups. No seasonal variation was observed.

CONCLUSIONS

The demographic data of MD and BPPV patients are comparable to those found by previous large-scale epidemiologic studies. However, no seasonal variation was demonstrated for any vestibular disorder in this large sample.

When the Room Is Spinning: Experience of Vestibular Neuritis by a Neurotologist

Vestibular neuritis (VN) is the most common cause of acute prolonged spontaneous vertigo, and is characterized by acute unilateral vestibular hypofunction, probably due to inflammation of the vestibular nerve. VN is diagnosed at the bedside when there is spontaneous horizontal-torsional nystagmus beating away from the side of the lesion, abnormal head impulse tests for the semicircular canals involved on the lesion side, and when other neurological symptoms and signs are absent. Here, as a neuro-otologist, I describe my experience during an attack of VN and discuss how it may help physicians to better understand why and what a patient feels during attacks of vertigo.

Decreased 25-Hydroxyvitamin D Levels in Patients With Vestibular Neuritis

Objective: Vestibular neuritis (VN) is characterized by acute onset of vertigo, nausea, and vomiting, without auditory or other neurological symptoms. Although the pathogenesis of VN is not yet clear, many studies have shown that a pro-inflammatory environment can lead to the induction and progression of the disease. Considering the importance of vitamin D in modulating the activation, proliferation, and differentiation of inflammatory physiological processes, we hypothesized that decreased serum vitamin D may be associated with the development of VN. In this study, we evaluated serum levels of 25-hydroxyvitamin D [25(OH)D] in patients presenting acutely with VN and healthy controls and investigated the possible correlation of serum 25(OH)D levels with VN.

Methods: A total of 59 consecutive patients diagnosed with VN within 7 days of symptom onset and 112 age- and sex-matched healthy controls referred to Hwa Mei Hospital, University of Chinese Academy of Science, between March 2017 and March 2019 were recruited. Demographic and clinical data, such as age, sex, height, weight, living habits, ongoing health problems, and medication history, for all subjects were recorded, and levels of 25(OH)D were measured and compared.

Results: Serum levels of 25(OH)D were lower in patients with VN than in controls (19.01 ± 6.53 vs. 22.94 ± 6.74 ng/ml, p < 0.001). Patients with VN had a higher frequency of vitamin D deficiency (61.0 vs. 34.8%, P = 0.001) than did controls. Regression analyses demonstrated that vitamin D deficiency was associated with VN, with an odds ratio of 4.53 (95% CI = 1.342–15.279, P = 0.015).

Conclusion: This prospective study is the first to evaluate serum 25(OH)D levels in patients with VN and found that decreased serum 25(OH)D may be associated with VN occurrence.

Persistent static imbalance among acute unilateral vestibulopathy patients could be related to a damaged velocity storage system

Background: Acute unilateral vestibulopathy (AUV) is common but, the course of disease recovery is variable. Moreover, the final recovery status might vary between subjects. The remaining symptoms of these patients indicate the poor recovery of static imbalance, which could limit social activities and decrease their quality of life. Objective: To determine the possible predictive parameters of prolonged static imbalance (PSI) among acute AUV, we compared several vestibular function test (VFT) results between control vestibulopathy (CV) and PSI patients. Materials and methods: Subjects were divided into two groups: PSI and CV. PSI was determined by the observation of spontaneous nystagmus at 1 month after discharge from the hospital. VFT results taken during the initial symptoms were compared. Results: Increased phase lead was observed in low-frequency stimulations (p < .05), while the other test results failed to reveal a significant difference. These results indicate that a larger phase lead, which is related to a decrease in the time constant, could be responsible for the delayed recovery of static imbalance. Conclusion and significance: The phase lead was higher in the PSI group compared to the CV group, suggesting the possible role of phase as a parameter to predict the delayed compensation of static imbalance.

Sexual dimorphism in vestibular function and dysfunction

It has been recognized for some time that females appear to be overrepresented in the incidence of many vestibular disorders, and recent epidemiological studies further support this idea. While it is possible that this is due to a reporting bias, another possibility is that there are actual differences in the incidence of vestibular dysfunction between males and females. If this is true, it could be due to a sexual dimorphism in vestibular function and therefore dysfunction, possibly related to the hormonal differences between females and males, although the higher incidence of vestibular dysfunction in females appears to last long after menopause. Many other neurochemical differences exist between males and females, however, that could be implicated in sexual dimorphism. This review critically explores the possibility of sexual dimorphism in vestibular function and dysfunction, and the implications it may have for the treatment of vestibular disorders.

The Vestibular System and Ageing

The world's population is ageing due to increased hygiene and improved medical care. Dizziness and imbalance frequently affect the elderly and is most common among individuals over the age of 60. In this age group approximately 30% of the population experience these debilitating symptoms at some point. They contribute to falls and frailty, which often result in hospitalization causing tremendous cost for the health care systems, and increased mortality. To make the matters worse balance disorders are often complex. Physicians face the difficulty of diagnosing the patient with the exact disorder especially since each disorder may manifest differently in each patient. In addition, several treatment options exist, however, with a low level of evidence. This chapter summarizes the underlying degenerative processes of the peripheral as well as the central vestibular system, diagnostic tools, the most common balance disorders in the elderly, and possible treatment options of these disorders.

Detection of intralabyrinthine abnormalities using post-contrast delayed 3D-FLAIR MRI sequences in patients with acute vestibular syndrome

PURPOSE

3D-FLAIR sequences with delayed acquisition after contrast medium injection have demonstrated new insights into blood-labyrinthine barrier (BLB) abnormalities in various diseases. The aim of this study was to assess the BLB in patients referred with unilateral acute vestibular syndrome (UAVS).

MATERIALS AND METHODS

In this retrospective multicenter imaging study, we performed 3D-FLAIR and steady-state free precession (SSFP) sequences 4 h after contrast medium administration in 26 healthy volunteers and in 30 patients with UAVS. Two radiologists, blinded to the clinical data, independently assessed the asymmetrical enhancement of the labyrinthine structures and the vestibular nerve on 3D-FLAIR sequences, and the signal of the labyrinthine structures on SSFP sequences. Inter-reader agreement tests were performed.

RESULTS

An asymmetrical enhancement of the semicircular canals was observed in 26 out of 30 ears (86.6%, p < 0.001) and never observed in healthy subjects. An asymmetrical enhancement of the vestibular nerve was never observed in either patients or healthy subjects. An asymmetrical enhancement of the cochlea was observed on the 3D-FLAIR sequence in 6 out of 30 ears only in the patients' group (20%, p = 0.03) and always associated with an enhancement of at least one semicircular canal. A low signal on SSFP sequences was observed only in 11 out of 30 symptomatic ears (36.7%, p < 0.001), involving the utricle in 7 ears and the superior semicircular canal in 4 ears.

CONCLUSION

Patients with typical UAVS presented with semicircular canal enhancement on MRI, while an asymmetrical enhancement of the vestibular nerve was not displayed.

TRIAL REGISTRATION

NCT02529475 KEY POINTS: • Patients with typical vestibular neuronitis presented with semicircular canal enhancement on MRI in 87% of cases. • An enhancement of the vestibular nerve was never displayed.

Correlation between vestibular neuritis and cerebrovascular risk factors

PURPOSE

To investigate the relationship between cerebrovascular risk factors, including carotid plaques, and vestibular neuritis (VN).

MATERIALS AND METHODS

According to the inclusion and exclusion criteria, this retrospective study included 90 VN patients and 74 age- and sex-matched healthy controls from January 2016 to December 2017. All subjects' records of cerebrovascular risk factors, such as age, sex, height, weight, history of hypertension and diabetes mellitus, living habits, serum levels of glucose, lipids, glycosylated haemoglobin (HbA1c), creatinine (CR), albumin (ALB), haemoglobin (HGB); and results of carotid colour Doppler ultrasound, were obtained and compared.

RESULTS

No significant differences in age; sex ratio; body mass index; history of hypertension or diabetes mellitus; or mean serum lipids, glucose, creatinine, haemoglobin or HbA1c were found between patients with VN and healthy controls (all P > 0.05). The mean serum ALB level was significantly lower in VN patients than in healthy controls (40.65 ± 3.77 vs 42.84 ± 4.32, P = 0.001).The prevalence of carotid plaques was significantly higher in VN patients than in healthy controls (36.67% vs. 16.22%, P = 0.003). Regression analyses demonstrated that a high frequency of carotid plaques was associated with VN with an odds ratio of 2.252 (95% CI 1.165-5.458, P = 0.019).

CONCLUSION

A high frequency of carotid plaques may be a risk factor for VN.

Genome-Wide Association Study in Vestibular Neuritis: Involvement of the Host Factor for HSV-1 Replication

Objective: In order to identify genetic variants associated with vestibular neuritis, a common cause of peripheral vertigo with a potential causative link to the reactivation of herpes simplex type 1 (HSV-1), we conducted a genome-wide association study.

Methods: Association was assessed using approximately 8 million variants. 131 patients with vestibular neuritis and 2,609 controls of European ancestry were included.

Results: Genome-wide associations with vestibular neuritis were detected in 4 regions containing protein coding genes assignable to two functional groups: virus hypothesis and insulin metabolism. Genes of set 1 are related to viral processes: nuclear receptor subfamily 3 group C member 2 (NR3C2) is a receptor for mineralocorticoids and glucocorticoids and was shown to be a host factor for HSV-1 replication. Ankyrin repeat domain 30A (ANKRD30A) encodes a host factor for human immunodeficiency virus-1 (HIV-1) infection. It shows rapid evolution and is induced by interferon stimulation. Mediator complex 30 (MED30), an important member of the mediator complex, has been shown to be involved in replication of HIV-1, a knockdown leading to impaired viral replication. The second set of genes LIM homeobox transcription factor 1 alpha (LMX1A), solute carrier family 30 member 8 (SLC30A8) is associated with insulin metabolism and resistance, a feature of some patients in whom type 2 diabetes is an accompanying comorbidity of vestibular neuritis.

Conclusions: Using a GWAS approach to evaluate the etiology of vestibular neuritis these findings provide another piece of evidence that it may be caused by a viral inflammation.

Disorders of the inner-ear balance organs and their pathways

Disorders of the inner-ear balance organs can be grouped by their manner of presentation into acute, episodic, or chronic vestibular syndromes. A sudden unilateral vestibular injury produces severe vertigo, nausea, and imbalance lasting days, known as the acute vestibular syndrome (AVS). A bedside head impulse and oculomotor examination helps separate vestibular neuritis, the more common and innocuous cause of AVS, from stroke. Benign positional vertigo, a common cause of episodic positional vertigo, occurs when otoconia overlying the otolith membrane falls into the semicircular canals, producing brief spells of spinning vertigo triggered by head movement. Benign positional vertigo is diagnosed by a positional test, which triggers paroxysmal positional nystagmus in the plane of the affected semicircular canal. Episodic spontaneous vertigo caused by vestibular migraine and Ménière's disease can sometimes prove hard to separate. Typically, Ménière's disease is associated with spinning vertigo lasting hours, aural fullness, tinnitus, and fluctuating hearing loss while VM can produce spinning, rocking, or tilting sensations and light-headedness lasting minutes to days, sometimes but not always associated with migraine headaches or photophobia. Injury to both vestibular end-organs results in ataxia and oscillopsia rather than vertigo. Head impulse testing, dynamic visual acuity, and matted Romberg tests are abnormal while conventional neurologic assessments are normal. A defect in the bony roof overlying the superior semicircular canal produces vertigo and oscillopsia provoked by loud sound and pressure (when coughing or sneezing). Three-dimensional temporal bone computed tomography scan and vestibular evoked myogenic potential testing help confirm the diagnosis of superior canal dehiscence. Collectively, these clinical syndromes account for a large proportion of dizzy and unbalanced patients.

Differential Involvement during Latent Herpes Simplex Virus 1 Infection of the Superior and Inferior Divisions of the Vestibular Ganglia: Implications for Vestibular Neuritis

Controversy still surrounds both the etiology and pathophysiology of vestibular neuritis (VN). Especially uncertain is why the superior vestibular nerve (SVN) is more frequently affected than the inferior vestibular nerve (IVN), which is partially or totally spared. To address this question, we developed an improved method for preparing human vestibular ganglia (VG) and nerve. Subsequently, macro- and microanatomical as well as PCR studies were performed on 38 human ganglia from 38 individuals. The SVN was 2.4 mm longer than the IVN, and in 65% of the cases, the IVN ran in two separate bony canals, which was not the case for the SVN. Anastomoses between the facial and cochlear nerves were more common for the SVN (14/38 and 9/38, respectively) than for the IVN (7/38 and 2/38, respectively). Using reverse transcription-quantitative PCR (RT-qPCR), we found only a few latently herpes simplex virus 1 (HSV-1)-infected VG (18.4%). In cases of two separate neuronal fields, infected neurons were located in the superior part only. In summary, these PCR and micro- and macroanatomical studies provide possible explanations for the high frequency of SVN infection in vestibular neuritis.IMPORTANCE Vestibular neuritis is known to affect the superior part of the vestibular nerve more frequently than the inferior part. The reason for this clinical phenomenon remains unclear. Anatomical differences may play a role, or if latent HSV-1 infection is assumed, the etiology may be due to the different distribution of the infection. To shed further light on this subject, we conducted different macro- and microanatomical studies. We also assessed the presence of HSV-1 in VG and in different sections of the VG. Our findings add new information on the macro- and microanatomy of the VG as well as the pathophysiology of vestibular neuritis. We also show that latent HSV-1 infection of VG neurons is less frequent than previously reported.

Acute Unilateral Vestibulopathy

Normal vestibular end organs generate an equal resting-firing frequency of the axons, which is the same on both sides under static conditions. An acute unilateral vestibulopathy leads to a vestibular tone imbalance. Acute unilateral vestibulopathy is defined by the patient history and the clinical examination and, in unclear cases, laboratory examinations. Key signs and symptoms are an acute onset of spinning vertigo, postural imbalance and nausea as well as a horizontal rotatory nystagmus beating towards the non-affected side, a pathological head-impulse test and no evidence for central vestibular or ocular motor dysfunction. The so-called big five allow a differentiation between a peripheral and central lesion by the bedside examination. The differential diagnosis of peripheral labyrinthine and vestibular nerve disorders mimicking acute unilateral vestibulopathy includes central vestibular disorders, in particular "vestibular pseudoneuritis" and other peripheral vestibular disorders, such as beginning Menière's disease. The management of acute unilateral vestibulopathy involves (1) symptomatic treatment with antivertiginous drugs, (2) causal treatment with corticosteroids, and (3) physical therapy.

Superior Versus Inferior Vestibular Neuritis: Are There Intrinsic Differences in Infection, Reactivation, or Production of Infectious Particles Between the Vestibular Ganglia?

HYPOTHESIS

Intrinsic differences in neurons of the vestibular ganglia result in the increased likelihood of superior vestibular ganglion involvement in vestibular neuritis.

BACKGROUND

Vestibular neuritis is hypothesized to result from herpes simplex type I (HSV1) infection or reactivation in vestibular ganglia. Involvement of the inferior vestibular ganglion is extremely rare in patients with vestibular neuritis.

METHODS

Primary cultures of rat superior and inferior vestibular ganglion neurons (VGNs) were cultivated separately. Neurons were lytically and latently infected with HSV1 with a US11-green fluorescent protein (GFP) chimera. Percentage lytic infection and baseline reactivation was assessed by microscopy for GFP fluorescence. Trichostatin-A (TSA) was used to stimulate HSV1 reactivation. Virion production was assessed by viral titers. Relative numbers of latency-associated (LAT) transcripts were determined by real-time reverse-transcription polymerase chain reaction (real-time RT-PCR).

RESULTS

Lytic infection rates were equivalent between the two ganglia (p > 0.05). Lytic infections yielded similar amounts of plaque-forming units (p > 0.05). Relative amounts of LAT transcripts did not differ between latently infected superior and inferior VGNs. Latently infected cultures showed no differences in rates of baseline and TSA-induced HSV1 reactivation (p > 0.05). Production of virions was not significantly different between reactivated, latently infected superior versus inferior VGNs (p = 0.45).

CONCLUSION

Differences in prevalence of superior and inferior vestibular neuritis do not result from intrinsic differences in HSV1 infection or virion production of these neurons. Other factors, such as the length and width of the bony canal containing the ganglia and nerves, account for the greater involvement of the superior vestibular ganglion in vestibular neuritis.

The epidemiology of dizziness and vertigo

This chapter gives an overview of the epidemiology of dizziness, vertigo, and imbalance, and of specific vestibular disorders. In the last decade, population-based epidemiologic studies have complemented previous publications from specialized settings and provided evidence for the high burden of dizziness and vertigo in the community. Dizziness (including vertigo) affects about 15% to over 20% of adults yearly in large population-based studies. Vestibular vertigo accounts for about a quarter of dizziness complaints and has a 12-month prevalence of 5% and an annual incidence of 1.4%. Its prevalence rises with age and is about two to three times higher in women than in men. Imbalance has been increasingly studied as a highly prevalent complaint particularly affecting healthy aging. Studies have documented the high prevalence of benign paroxysmal positional vertigo (BPPV) and vestibular migraine (VM), as well as of comorbid anxiety at the population level. BPPV and VM are largely underdiagnosed, while Menière's disease, which is about 10 times less frequent than BPPV, appears to be overdiagnosed. Risk factor research is only at its beginning, but has provided some interesting observations, such as the consistent association of vertigo and migraine, which has greatly contributed to the recognition of VM as a distinct vestibular syndrome.

The Pediatric Vestibular Symptom Questionnaire: A Validation Study

OBJECTIVE

To develop and validate the Pediatric Vestibular Symptom Questionnaire (PVSQ) and quantify subjective vestibular symptom (ie, dizziness, unsteadiness) severity in children.

STUDY DESIGN

One hundred sixty-eight healthy children (female, n = 91) and 56 children with postconcussion dizziness or a vestibular disorder (female, n = 32), between ages 6 and 17 years, were included. The PVSQ contains questions regarding vestibular symptom frequency during the previous month. The Strengths and Difficulties Questionnaire (SDQ), a brief behavioral screening instrument, was also completed.

RESULTS

The PVSQ showed high internal consistency (10 items; Cronbach α = 0.88). A significant between-group difference was noted with higher (ie, worse) PVSQ scores for children with vestibular symptoms (P < .001); no significant differences were noted between patient groups. The optimal cut-off score for discriminating between individuals with and without abnormal levels of vestibular symptoms was 0.68 out of 3 (sensitivity 95%, specificity 85%). Emotional and hyperactivity SDQ subscale scores were significantly worse for patients compared with healthy participants (P ≤ .01). A significant relationship was noted between mean PVSQ and SDQ (parent-rated version) hyperactivity and total scores for patients (P ≤ .01) and the SDQ (self-rated) emotional, hyperactivity, and total score (P ≤ .01) in healthy controls. However, mean SDQ subscale and total scores were within normal ranges for both groups.

CONCLUSIONS

Self-reported vestibular symptoms, measured by the PVSQ, discriminated between children presenting with vestibular symptoms and healthy controls and should be used to identify and quantify vestibular symptoms that require additional assessment and management.

Vestibular migraine

Vestibular migraine is now considered a distinct diagnostic entity by both the Barany Society and the International Headache Society. The recognition of vestibular migraine as a diagnostic entity required decades and was presaged by several reports indicating that a large proportion of patients with migraine headaches have vestibular symptoms and that a large proportion of patients with undiagnosed episodic vestibular symptoms have migraine headache. Despite the availability of diagnostic criteria for vestibular migraine, challenges to diagnosis include variability in terms of the character of dizziness, the presence or absence of clearly defined attacks, the duration of attacks, and the temporal association between headache or other migrainous features and vestibular symptoms. Also, symptoms of vestibular migraine often overlap with symptoms of other causes of dizziness, especially Ménière's disease and benign paroxysmal positional vertigo (BPPV). This article will discuss the demographics, epidemiology, clinical manifestations, physical examination findings, laboratory testing, comorbidities, treatment options, and pathophysiology of vestibular migraine. Future research in the field of vestibular migraine should include both clinical and basic science efforts to better understand the pathophysiology of this condition. Controlled treatment trials for vestibular migraine are desperately needed.

[Characteristics of dizziness in elderly]

Clinical features of the main diseases that may cause dizziness in elderly and approaches to its treatment are reviewed. The treatment plan and increase of its effectiveness as well as prevention of the complications and improvement of quality of life of patients should be based on these features.

Incidence, seasonality and comorbidity in vestibular neuritis

Aims of the present study were: (1) to assess the incidence of vestibular neuritis (VN) in the adult population in two cities in Croatia, (2) to identify distribution of new VN cases in the different months and seasons by years, and (3) to identify comorbidities associated with VN. This is a prospective, population-based study conducted in the cities of Zagreb and Velika Gorica, Croatia in the 2011-2012 period. All diagnoses were confirmed either with caloric test or vestibular evoked myogenic potentials within 7 days of symptom onset. Following clinical parameters were collected from all patients: age, gender, side of the lesion, month and season of symptoms onset and comorbidities. We identified 79 new cases of VN (34 in 2011, 45 in 2012). The male to female ratio was 1.1:1. The mean age at the onset of the disease was 52.3 (range 20-86) years. The average annual incidence was 11.7 per 100,000 (95 % CI 7.8-15.6) in the 2011 period and 15.5 per 100,000 (95 % CI 11.0-20.0) in the 2012 period. For both years there was no statistically significant uneven distribution in the different months or seasons by years. The most frequent comorbidities present in VN patients were hypertension (30.4 %), diabetes mellitus (8.9 %), hyperlipidemia (7.5 %) and hypothyreosis (6.3 %). Our study has shown higher incidence of VN than previously reported. We have found no evidence of seasonality of VN and significant proportion of VN patients older than 50 years who had vascular risk factors present.

Dizziness and Imbalance in the Elderly: Age-related Decline in the Vestibular System

Dizziness and imbalance are amongst the most common complaints in older people, and are a growing public health concern since they put older people at a significantly higher risk of falling. Although the causes of dizziness in older people are multifactorial, peripheral vestibular dysfunction is one of the most frequent causes. Benign paroxysmal positional vertigo is the most frequent form of vestibular dysfunction in the elderly, followed by Meniere's disease. Every factor associated with the maintenance of postural stability deteriorates during aging. Age-related deterioration of peripheral vestibular function has been demonstrated through quantitative measurements of the vestibulo-ocular reflex with rotational testing and of the vestibulo-collic reflex with testing of vestibular evoked myogenic potentials. Age-related decline of vestibular function has been shown to correlate with the age-related decrease in the number of vestibular hair cells and neurons. The mechanism of age-related cellular loss in the vestibular endorgan is unclear, but it is thought that genetic predisposition and cumulative effect of oxidative stress may both play an important role. Since the causes of dizziness in older people are multi-factorial, management of this disease should be customized according to the etiologies of each individual. Vestibular rehabilitation is found to be effective in treating both unilateral and bilateral vestibular dysfunction. Various prosthetic devices have also been developed to improve postural balance in older people. Although there have been no medical treatments improving age-related vestibular dysfunction, new medical treatments such as mitochondrial antioxidants or caloric restriction, which have been effective in preventing age-related hearing loss, should be ienvestigated in the future.

Is vestibular neuritis an immune related vestibular neuropathy inducing vertigo?

OBJECTIVES

To review the current knowledge of the aetiology of vestibular neuritis including viral infections, vascular occlusion, and immunomediated mechanisms and to discuss the pathogenesis with relevance to pharmacotherapy.

SYSTEMATIC REVIEW METHODOLOGY

Relevant publications on the aetiology and treatment of vestibular neuritis from 1909 to 2013 were analysed.

RESULTS AND CONCLUSIONS

Vestibular neuritis is the second most common cause of peripheral vestibular vertigo and is due to a sudden unilateral loss of vestibular function. Vestibular neuronitis is a disorder thought to represent the vestibular-nerve equivalent of sudden sensorineural hearing loss. Histopathological studies of patients who died from unrelated clinical problems have demonstrated degeneration of the superior vestibular nerve. The characteristic signs and symptoms include sudden and prolonged vertigo, the absence of auditory symptoms, and the absence of other neurological symptoms. The aetiology and pathogenesis of the condition remain unknown. Proposed theories of causation include viral infections, vascular occlusion, and immunomediated mechanisms. The management of vestibular neuritis involves symptomatic treatment with antivertiginous drugs, causal treatment with corticosteroids, and physical therapy. Antiviral agents did not improve the outcomes.

Investigation of seasonal variability of vestibular neuronitis

Objective:

To determine if the incidence of vestibular neuronitis displays seasonal variation.

Methods:

A retrospective case review was performed to determine the monthly and quarterly incidence of vestibular neuronitis over a 36-month period. Incidence values were compiled, and the chi-square test and Rayleigh test for circular means were used to assess for uneven distribution and seasonality, respectively.

Results:

Fifty-two patients were diagnosed with vestibular neuronitis during the study period. The 2009–2010 study year showed uneven distribution and evidence of seasonality (R = 7.211, p < 0.001). However, the other two study years did not show statistical significance using either the chi-square test or Rayleigh test. In addition, when incidence values were aggregated across all three years of the study, neither the chi-square test nor Rayleigh test showed statistical significance.

Conclusion:

The present study found minimal evidence of seasonality in the incidence of vestibular neuronitis. These findings are consistent with studies of seasonality observed for other inner-ear disorders thought to be virally mediated.

Cultured vestibular ganglion neurons demonstrate latent HSV1 reactivation

OBJECTIVES/HYPOTHESIS

Vestibular neuritis is a common cause of both acute and chronic vestibular dysfunction. Multiple pathologies have been hypothesized to be the causative agent of vestibular neuritis; however, whether herpes simplex type I (HSV1) reactivation occurs within the vestibular ganglion has not been demonstrated previously by experimental evidence. We developed an in vitro system to study HSV1 infection of vestibular ganglion neurons (VGNs) using a cell culture model system.

STUDY DESIGN

basic science study.

RESULTS

Lytic infection of cultured rat VGNs was observed following low viral multiplicity of infection (MOI). Inclusion of acyclovir suppressed lytic replication and allowed latency to be established. Upon removal of acyclovir, latent infection was confirmed with reverse-transcription polymerase chain reaction and by RNA fluorescent in situ hybridization for the latency-associated transcript (LAT). A total of 29% cells in latently infected cultures were LAT positive. The lytic ICP27 transcript was not detected by reverse-transcription polymerase chain reaction (RT-PCR). Reactivation of HSV1 occurred at a high frequency in latently infected cultures following treatment with trichostatin A (TSA), a histone deactylase inhibitor.

CONCLUSIONS

VGNs can be both lytically and latently infected with HSV1. Furthermore, latently infected VGNs can be induced to reactivate using TSA. This demonstrates that reactivation of latent HSV1 infection in the vestibular ganglion can occur in a cell culture model, and suggests that reactivation of HSV1 infection a plausible etiologic mechanism of vestibular neuritis.

Vestibular neuritis

The epidemiology, diagnostic features, differential diagnosis, and treatment of vestibular neuritis are reviewed. The authors present considerations for physical examination, imaging, and management in both the acute and chronic phases of this disease. The authors also present a dizziness questionnaire in the Appendix of this publication.