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).

Patients admitted to hospital for vestibular neuritis in 2011-2021. / Pasienter innlagt for vestibularisnevritt 2011­21.

BACKGROUND: The incidence of vestibular neuritis in Norway is unknown. The disorder causes acute dizziness, which is a common reason for hospital admission. The objective of this study was to analyse the number of patients admitted to Norwegian hospitals for vestibular neuritis over an eleven-year period. MATERIAL AND METHOD: The number of patients admitted to hospital for vestibular neuritis and reported to the Norwegian Patient Registry in the period 2011-2021 was recorded. The figures were compared with the number of patients admitted for other vertiginous disorders. RESULTS: The number of patients admitted to hospital for vestibular neuritis was 11.2 per 100,000 inhabitants per year (range 8.2-15.3). The number of patients admitted to hospital in the study period increased by an average of 7.9 % per year and was highest in the final year. Out of 63,884 patients admitted for vertiginous disorders in the study period, 6,450 (10.1 %) had vestibular neuritis. INTERPRETATION: The number of patients admitted to hospital for vestibular neuritis each year increased considerably in the study period. This is likely to be a reflection of the increased hospitalisation rate and improvements in diagnostic workup more than an actual increase in the incidence of the disorder. A minority of patients admitted for vertiginous disorders had vestibular neuritis.

[Demographic and epidemiological risk factors in patients with acute vestibular neuritis]. / Demografische und epidemiologische Risikofaktoren bei Patienten mit akuter unilateraler Vestibulopathie M. Menière (hydropische Innenohrerkrankung).

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.

Vestibular syndromes, diagnosis and diagnostic errors in patients with dizziness presenting to the emergency department: a cross-sectional study.

OBJECTIVES: We aimed to determine the frequency of vestibular syndromes, diagnoses, diagnostic errors and resources used in patients with dizziness in the emergency department (ED). DESIGN: Retrospective cross-sectional study. SETTING: Tertiary referral hospital. PARTICIPANTS: Adult patients presenting with dizziness. PRIMARY AND SECONDARY OUTCOME MEASURES: We collected clinical data from the initial ED report from July 2015 to August 2020 and compared them with the follow-up report if available. We calculated the prevalence of vestibular syndromes and stroke prevalence in patients with dizziness. Vestibular syndromes are differentiated in acute (AVS) (eg, stroke, vestibular neuritis), episodic (EVS) (eg, benign paroxysmal positional vertigo, transient ischaemic attack) and chronic (CVS) (eg, persistent postural-perceptual dizziness) vestibular syndrome. We reported the rate of diagnostic errors using the follow-up diagnosis as the reference standard. RESULTS: We included 1535 patients with dizziness. 19.7% (303) of the patients presented with AVS, 34.7% (533) with EVS, 4.6% (71) with CVS and 40.9% (628) with no or unclassifiable vestibular syndrome. The three most frequent diagnoses were stroke/minor stroke (10.1%, 155), benign paroxysmal positional vertigo (9.8%, 150) and vestibular neuritis (9.6%, 148). Among patients with AVS, 25.4% (77) had stroke. The cause of the dizziness remained unknown in 45.0% (692) and 18.0% received a false diagnosis. There was a follow-up in 662 cases (43.1%) and 58.2% with an initially unknown diagnoses received a final diagnosis. Overall, 69.9% of all 1535 patients with dizziness received neuroimaging (MRI 58.2%, CT 11.6%) in the ED. CONCLUSIONS: One-fourth of patients with dizziness in the ED presented with AVS with a high prevalence (10%) of vestibular strokes. EVS was more frequent; however, the rate of undiagnosed patients with dizziness and the number of patients receiving neuroimaging were high. Almost half of them still remained without diagnosis and among those diagnosed were often misclassified. Many unclear cases of vertigo could be diagnostically clarified after a follow-up visit.

Incidence of peripheral vestibular disorders based on population data of South Korea.

BACKGROUND: There have been no comprehensive studies on the incidence of peripheral vestibular disorders based on population-based data for a long-term period. OBJECTIVE: We investigated the incidence of peripheral vestibular disorders using population-based data representing the whole population of South Korea. METHODS: This study used the National Health Insurance Service data in Korea from 2008 to 2020. Peripheral vestibular disorders such as benign paroxysmal positional vertigo (BPPV), vestibular neuritis (VN), and Meniere's disease (MD) were defined with diagnostic, treatment, or audiovestibular test codes. The annual incidence in total and according to sex, age, and residence was analyzed. RESULTS: The annual incidence of BPPV, VN, and MD per 100,000 was 51.4, 22.7, and 12.4 in 2008 and 181.1, 62.9, and 50.5 in 2020, respectively. The incidence of each was significantly different by sex (p < 0.001), age (p < 0.001), and residence (p < 0.001), with the highest value in female, people aged 60 years or older, and people who resided in metropolitan cities. CONCLUSIONS: The annual incidence of BPPV, VN, and MD had increasing trends from 2008 through 2020 in South Korea, and all were significantly higher in female, people aged 60 years or older, and people who resided in metropolitan cities.

Monthly and seasonal variations in vestibular neuritis.

Seasonal variations in vestibular neuritis (VN) could support the etiology of viral infection. However, several recent studies revealed no significant seasonal variations in VN. Further studies are necessary to determine the etiology of VN. We analyzed patients with VN to evaluate monthly and seasonal variations. Patients with VN who visited our otorhinolaryngology department or were referred to our department from the emergency department between March 2014 and February 2019 were included retrospectively in this study. Differences among the months and seasons of VN visits were analyzed. Patients were divided into 2 groups according to sex and age (65 years or older and younger than 65 years). Differences among the months and seasons of VN visits were analyzed between groups. There were no significant differences in monthly and seasonal distributions in 248 patients with VN. There were also no significant differences in monthly and seasonal distributions in male and female patients or in older and younger patients. There were no significant differences in monthly or seasonal distributions of patients with VN. Factors other than viruses, such as vascular ischemia, should also be considered in the incidence of VN, especially in older patients.

The utilization and demographic characteristics of in-hospital rehabilitation for acute vestibular neuritis in Japan.

OBJECTIVE: To investigate the utilization and demographic characteristics of in-hospital rehabilitation for patients with acute vestibular neuritis using the Japan Medical Data Center (JMDC) database. METHODS: We gathered information on patients that were at least 20 years of age who were admitted with a diagnosis of VN (ICD-10 code: H81.2). We defined in-hospital rehabilitation service use as payment of insurance claims for at least one session of rehabilitation during admission. RESULTS: We identified 809 patients that were eligible for this study; among these, 59 patients (7.3%) received rehabilitation while 750 patients did not. The median total time spent and the median time per day in inpatient rehabilitation were 140 min and 11.7 min, respectively. Factors that significantly affected the rehabilitation service use, in order of greater odds, were primary care, internal medicine, and age in multivariate logistic regression analysis (odds ratio = 4.42, 2.17, 1.33, respectively). CONCLUSIONS: This study showed that (1) utilization of rehabilitation services by acute patients with VN was low; and (2) age, admission to internal medicine, and admission to primary care were associated with the use of rehabilitation services.

Prevalence of cardiovascular risk factors in superior vestibular neuritis: A cross-sectional study following STROBE guidelines.

OBJECTIVE: To compare the prevalence of cardiovascular risk factors (CVRF) in patients with superior vestibular neuritis (SVN) versus the general French population, and to examine the possibility of vascular etiology in acute superior vestibular deficit. MATERIAL AND METHODS: A single-center retrospective study compared the prevalence of hypercholesterolemia, hypertension, diabetes, smoking, cardiovascular disease and atrial fibrillation between patients with SVN and the French general population. Inclusion criteria comprised: rotatory vertigo lasting several days, without hearing impairment or neurological signs, with anterior and lateral semicircular canal involvement on video-Head-Impulse-Test (vHIT). A senior radiologist analyzed superior vestibular nerve and inner ear structure enhancement on cerebellopontine MRI. RESULTS: One hundred and eighteen cases of SVN were included from May 2016 to February 2020. Statistical analyses concerned 106 cases. The SVN population had significantly less hypercholesterolemia (RR=0.40) than the general French population. There was no significant difference concerning other CVRFs. Superior vestibular nerve enhancement was observed on 84% of MRIs. CONCLUSION: Prevalence of CVRF was not higher in patients with SVN than in the general population. The present study highlighted involvement of the superior vestibular nerve more than of the anterior vestibular artery in SVN.

[Vestibular neuritis - prevalence of inpatient cases in Germany]. / Neuropathia vestibularis ­ Prävalenz der stationären Fälle in Deutschland.

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.

Stroke mimics: Clinical characteristics and outcome.

OBJECTIVE: To study the prevalence and nature of stroke mimics (SM) among Saudi patients who came to the emergency department with a sudden neurological deficit and suspected stroke. METHODS: The electronic health records from February 2016 to July 2018 of patients who were admitted to the Stroke Unit at King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia (KAMC-RD) with a suspected stroke were all reviewed. A comparison between SM and stroke was established. Our study identified the predictors of SM by using logistic regression analysis. This study was approved by the local institutional review board. RESULTS: Out of 1,063 patients, 131 (12.3%) had SM. The most common causes were a peripheral vestibular disorder (27.4%) followed by psychogenic causes (24.4%). Stroke mimics were more common among younger individuals and women. Arterial hypertension, diabetes, and smoking were less likely to be found in SMs. At discharge, individuals with SM were more likely to be independent, had milder deficits, and shorter hospital stays. Predictors of SM were young age, female gender, mild deficit at presentation, and good functional status before the stroke. CONCLUSION: The incidence of stroke mimics is common among suspected stroke patients. Practicing physicians should consider potential diagnostic errors, particularly in the hyperacute phase of the stroke.

[Prevalence of peripheral vestibular diseases in children in Germany]. / Prävalenz peripher-vestibulärer Erkrankungen bei Kindern in Deutschland.

INTRODUCTION: Dizziness is a common complaint among patients; however, a lack of valid data concerning age and gender distribution of dizziness disorders among children under the age of 15 years can preclude effective diagnosis and treatment. The goal of this study was to describe the prevalence and gender distribution of three classical peripheral vestibular disorders; benign paroxysmal positional vertigo (BPPV), vestibular neuritis (VN), and Menière's disease (MD) as well as unspecific dizziness (UV) in children between 0 and 15 years of age, using state sponsored health insurance data. METHODS: A population-based epidemiological survey based on confirmed International Classification of Diseases (ICD) 10 codes of all persons aged 0-15 years in a national population was performed. Outcome measures were age and gender distribution and prevalence of BPPV, VN, and MD in this population. RESULTS: Dizziness diagnosed as being of peripheral vestibular origin was found in 1414 patients. The prevalence of peripheral vestibular disorders was found to be 15.16 per 100,000 individuals. The BPPV was coded most frequently with a prevalence of 10.21 per 100,000 individuals, followed by VN with a prevalence of 3.5 per 100,000 and MD at 1.54 per 100,000. CONCLUSION: Peripheral vestibular disorders can occur in childhood and the prevalence increases with age. In childhood, girls and boys are similarly affected. Peripheral vestibular disorders should be taken into consideration when a young child presents with vertigo or dizziness and are even more important when a child presents with unclear symptoms, as very young children might not be able to adequately verbalize dizziness and vertigo. For that reason peripheral vestibular disorders in childhood are probably underdiagnosed.

Acute vestibular asymmetry disorder: a new disease entity in acute vestibular syndrome?

BACKGROUND: Acute vestibular syndrome (AVS) is characterized by the rapid onset of vertigo, nausea, vomiting and gait unsteadiness, which lasts for days. AIMS/OBJECTIVES: We report cases as acute vestibular asymmetry disorder (AVAD), with presentations that mimic vestibular neuritis (VN) but without central lesions. MATERIALS AND METHODS: We retrospectively reviewed records of patients presenting with acute spontaneous vertigo lasting more than 24 h from January 2011 to June 2016. Among 341 patients, five showed different findings that did not indicate either VN or stroke. We analyzed the clinical features and vestibular assessments of these patients. RESULTS: All five patients showed spontaneous nystagmus continuing for several days. However, head impulse tests (HITs) did not reveal a corrective saccade. Brain magnetic resonance imaging showed no abnormal lesions. The bithermal caloric test revealed directional preponderance without canal paresis. Finally, the slow harmonic test of the rotatory chair revealed unilateral high gain and phase within the normal range, but a significantly asymmetric response was observed. No patients showed recurrence during follow-up. CONCLUSIONS AND SIGNIFICANCE: Our study suggests that a normal HIT in AVS is not always a dangerous sign indicating an acute stroke. From our observations, we propose that AVAD would be a new disease entity within AVS.

White matter lesions in magnetic resonance imaging of the brain in 56 patients with visual vertigo.

BACKGROUND: Visual vertigo is defined as a condition in which there is worsening or triggering of vestibular symptoms in certain visual environments. Previous studies have associated visual vertigo with an increased prevalence of underlying white matter lesions on brain imaging. METHOD: This study evaluated the magnetic resonance imaging scans of the brain from a cohort of patients with visual vertigo, and compared the outcomes to an age- and gender-matched group of healthy volunteers.Results and conclusionWhite matter lesions were observed in 17.9 per cent of the patient group and in 16.3 per cent of the control group. The prevalence of white matter lesions in the patient group was not too different to that expected based on age.

Inpatient Treatment of Patients Admitted for Dizziness: A Population-Based Healthcare Research Study on Epidemiology, Diagnosis, Treatment, and Outcome.

OBJECTIVE: To determine inpatient treatment rates of patients with dizziness with focus on diagnostics, treatment and outcome. STUDY DESIGN: Retrospective population-based study. SETTING: Inpatients in the federal state Thuringia in 2014. PATIENTS: All 1,262 inpatients (62% females, median age: 61 yr) treated for inpatient dizziness were included. MAIN OUTCOME MEASURES: The association between analyzed parameters and probability of improvement and recovery was tested using univariable and multivariable statistics. RESULTS: Final diagnosis at demission was peripheral vestibular disorder (PVD), central vestibular disorder (CVD), cardiovascular syndrome, somatoform syndrome, and unclassified disease in 75, 9, 3, 0.6, and 13%, respectively. The most frequent diseases were acute vestibular neuritis (28%) and benign paroxysmal positional vertigo (22%). The follow-up time was 38 ±â€Š98 days. 88.5% of patients showed at least an improvement of complaints and 31.4% a complete recovery. The probability for no improvement from inpatient dizziness was higher if the patient had a history of ear/vestibular disease (hazard ratio [HR] = 1.506; 95% confidence interval [CI] = 1.301-1.742), and was taking more than two drugs for comorbidity (HR = 1.163; CI = 1.032-1.310). Compared with final diagnosis of cardiovascular syndrome, patients with PVD (HR = 1.715; CI = 1.219-2.415) and CVD (HR = 1.587; CI = 1.076-2.341) had a worse outcome. CONCLUSIONS: Inpatient treatment of dizziness was highly variable in daily practice. The population-based recovery rate was worse than reported in clinical trials. We need better ways to implement clinical trial findings for inpatients with dizziness.

Cardiovascular Risk Factors Among Patients With Vestibular Neuritis.

OBJECTIVE: To investigate the correlation between cardiovascular risk factors (CVRFs) and vestibular neuritis (VN) in hospitalized adult patients. METHODS: A cross-sectional retrospective study was conducted in a tertiary hospital setting. The medical records of patients (aged over 18 years old) who were hospitalized between the years 2005 and 2014 with the diagnosis of VN were retrieved. Inclusion criteria were: (1) acute vertigo lasting for at least 24 hours, (2) absence of auditory complaints, (3) horizontal unidirectional nystagmus present during physical examination, and (4) absence of neurological symptoms or signs. The ratio of CVRFs among VN patients was compared to the ratio of those among the general Israeli population. RESULTS: A significantly higher prevalence of CVRFs was found among VN hospitalized patients in comparison to the general population ( P < .05). Furthermore, a significant correlation ( P < .001) was found between the patients' age and the number of CVRFs (r = .387). A positive correlation (r = .643) was found between the number of CVRFs and VN in each age group ( P = .119). CONCLUSION: There may be a possible interrelation between CVRFs and VN. This correlation can be caused by occlusion of small blood vessels leading to labyrinthine ischemia and apparition of symptoms of VN.

Association between ambient particulate matter and disorders of vestibular function.

BACKGROUND: Exposure to environmental chemicals has been suggested to alter the physiologic state of the inner and middle ear. However, it is unknown if particulate matter exposure is associated with acute vestibular dysfunction. OBJECTIVES: To estimate the effects of particulate matter exposure on the number of hospital visits related to three major diseases of vestibular dysfunction, Meniere's disease (MD), benign paroxysmal positional vertigo (BPPV), and vestibular neuronitis (VN). METHODS: Our study subject is from Korean National Health Insurance Service-National Sample Cohort, which is dynamic cohort consist of 1 million participants representing the Korean population. Among total cohort participants, we used the hospital visit data of 210,000 individuals who resided in Seoul from 2007 to 2010. Time series analysis using the Poisson generalized additive model and case-crossover analysis using conditional logistic regression were used to investigate the association between daily particulate matter levels (PM2.5, particulate matter <2.5µg/m3; PM10, particulate matter <10µg/m3; PM10-2.5, PM10- PM2.5) and number of MD, BPPV, and VN hospital visits. RESULTS: Time series analysis showed that an interquartile range (IQR) increase in PM10 and PM10-2.5 on lag day 1 was associated with an increased risk of MD hospital visits [relative risk (RR), 95% confidence interval (CI), PM10: 1.09 (1.02-1.15); PM10-2.5: 1.06 (1.02-1.10)]. In addition, elderly individuals (≥60 years old) showed an increased risk of MD hospital visits after particulate matter exposure when compared to younger individuals. An IQR increase in particulate matter on lag day 1 was associated with a marginally significant increase in VN hospital visits [RR (95%CI), PM2.5: 1.11 (0.98-1.25); PM10: 1.07 (0.99-1.15); PM10-2.5: 1.04 (0.99-1.09)]. However, no association between particulate matter exposure and BPPV hospital visits was noted. Case-crossover analyses showed similar results to the time-series analysis across all three diseases. CONCLUSION: MD hospital visits were associated with ambient particulate matter exposure. Elderly individuals, in particular, were more susceptible to particulate matter exposure than younger individuals.

Dorsal Medullary Infarction: Distinct Syndrome of Isolated Central Vestibulopathy.

BACKGROUND AND PURPOSE: The characteristics of infarctions restricted to the dorsal medulla have received little attention. This study aimed to define the distinct clinical features of dorsal medullary infarction. METHODS: Of the 172 patients with a diagnosis of medullary infarction at Seoul National University Bundang Hospital from 2003 to 2014, 18 patients with isolated dorsal medullary infarction were subjected to analyses of clinical and laboratory findings. RESULTS: All patients presented acute isolated vestibular syndrome with dizziness/vertigo and imbalance. Almost all patients (17/18, 94%) showed the signs from involvements of the vestibular nuclei, nucleus prepositus hypoglossi, or inferior cerebellar peduncle, which included direction-changing gaze-evoked nystagmus (n=12), negative head-impulse tests (n=8), skew deviation (n=7), central patterns of head-shaking nystagmus (n=6), and spontaneous nystagmus (n=2). Initial magnetic resonance imagings including diffusion-weighted images were negative in 7 patients (39%). Twelve patients (67%) showed a progression and developed additional neurological abnormalities, but the neurological outcomes were favorable. CONCLUSIONS: The presence of central vestibular signs allows bedside differentiation of isolated vestibular syndrome because of dorsal medullary infarction from acute peripheral vestibular disorders. Because initially false-negative magnetic resonance imagings and subsequent progression are frequent in dorsal medullary infarction, early recognition through scrutinized evaluation is important for proper managements.

Anxiety and depression among patients with different types of vestibular peripheral vertigo.

Numerous studies have been published on comorbid anxiety and depression in patients with vertigo. However, very few studies have separately described and analyzed anxiety or depression in patients with different types of vestibular peripheral vertigo. The present study investigated anxiety and depression among patients with 4 different types of peripheral vertigo. A total of 129 patients with 4 types of peripheral vertigo, namely, benign paroxysmal positional vertigo (BPPV, n = 49), migrainous vertigo (MV, n = 37), Menière disease (MD, n = 28), and vestibular neuritis (VN, n = 15), were included in the present study. Otological and neurootological examinations were carefully performed, and self-rating anxiety scale and self-rating depression scale were used to evaluate anxiety and depression. Patients were divided into 2 groups, according to the vestibular function: normal and abnormal vestibular function. There was no significant difference in the risk of anxiety/depression between these 2 groups. However, for patients with the 4 different vertigo types, the prevalence of anxiety (MV = 45.9%, MD = 50%) and depression (MV = 27%, MD = 28.6%) was significantly higher in the patients with MV or MD than those with BPPV or VN (P < 0.05). Vestibular function is not significantly associated with the risk of anxiety/depression. Anxiety/depression is more common in patients with MV or MD than those with BPPV or VN. This may be due to the different mechanisms involved in these 4 types of vertigo, as well as differences in the prevention and self-control of the patients against the vertigo.

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.