Acute Unilateral Vestibulopathy

A Systematic Review of the Reported Proportions of Diagnoses for Dizziness and Vertigo

OBJECTIVES

To determine the typical proportions of diagnoses for patients presenting with dizziness or vertigo based on clinical speciality and to assess the change in proportions of diagnoses over time.

DATA SOURCES

Following PRISMA guidelines, systematic searches of PubMed and CINAHL databases and follow-up reference searches were performed for articles published in English up to October 2016.

STUDY SELECTION

Analysis of searches yielded 42 studies meeting the criteria of case series of adult patients with dizziness and/or vertigo presenting to general practice, emergency departments or specialist outpatient clinics.

DATA EXTRACTION

Data comprising demographics, diagnostic cases, and the total number of cases were recorded and independently tested, followed by a risk of bias analysis.

DATA SYNTHESIS

Sample size weighted proportions expressed as percentages with confidence intervals were calculated and compared using χ analysis and a reference proportion formed by the combination of Ear Nose and Throat and Neurotology case series published between 2010 and 2016. Analysis of diagnostic trends over time used Poisson regression with consideration for overdispersion.

CONCLUSIONS

This systematic review of case series demonstrated significant differences in the proportions of diagnoses for patients presenting with dizziness or vertigo, depending on the specialty making the diagnosis. ENT proportions were dominated by BPPV, Psychogenic and Menière's disease diagnostic categories, whereas emergency proportions were dominated by Other, Cardiac, and Neurological categories. Analysis of case series proportions over time revealed increases in diagnoses such as Benign Paroxysmal Positional Vertigo and Vestibular Migraine, and a corresponding decrease in the diagnoses of Menière's disease.

Positional Testing in Acute Vestibular Syndrome: a Transversal and Longitudinal Study

OBJECTIVE

To evaluate the utility of positional testing in peripheral and central acute vestibular syndrome (pAVS, cAVS, respectively).

STUDY DESIGN

Prospective; observational.

SETTING

Tertiary referral center.

PATIENTS

Consecutive AVS patients.

INTERVENTIONS

Video-oculography in upright, supine and head hanging positions at presentation, 3-month and 1-year follow-up.

MAIN OUTCOME MEASURES

Positional modulation of spontaneous nystagmus; co-occurrence of central paroxysmal positional nystagmus (CPPN).

RESULTS

Fifteen pAVS [mean age (SD), 53.3 (16.6) (11 males)] and 15 cAVS [mean age (SD), 56.5 (17.8) (11 males)] patients were included (p=0.49). Acutely, in supine, in patients whose nystagmus was present in both head rotation sides, 12 of 13 (93%) pAVS and only 4 of 12 (33%) cAVS patients showed direction-fixed positional nystagmus which was stronger when turning the head to the slow phase side. The remaining cAVS patients showed either direction-fixed positional nystagmus which was stronger when turning the head to the fast phase side (5), or direction-changing positional geotropic nystagmus (2). One patient in each group showed direction-changing positional apogeotropic nystagmus. During follow-up, direction-changing positional apogeotropic and geotropic nystagmus became common in both groups. Acutely, in head hanging, 5 (33%) cAVS patients showed vertical CPPN and 2 showed positional saccadic intrusions. Positional downbeat nystagmus and saccadic intrusions became chronic.

CONCLUSIONS

The presence of acute direction-changing positional geotropic nystagmus, stronger direction-fixed positional nystagmus when turning the head to the fast phase side, and acute or chronic head hanging vertical CPPN should raise the suspicion for central AVS. Chronic geotropic and apogeotropic nystagmus following AVS constitute an underrecognized manifestation of vestibular compensation.

Methodological aspects of testing vestibular evoked myogenic potentials in infants at universal hearing screening program

Motor development in infants is dependent upon the function of the inner ear balance organ (vestibular organ). Vestibular failure causes motor delays in early infancy and suboptimal motor skills later on. A vestibular test for newborns and infants that is applicable on a large scale, safe and cost effective is in demand in various contexts: in the differential diagnosis of early onset hearing loss to determine forms associated with vestibular failure; in early hearing habilitation with cochlear implant, indicating the vestibular predominant side; and in the habilitation of children affected by motor skill disorders, revealing the contribution of a vestibular failure. This work explored the feasibility of cervical vestibular evoked myogenic potentials (VEMP) in conjunction with newborn universal hearing screening program. VEMP was measured after the hearing tests and was evoked by bone-conducted stimuli. Moreover, stimulus delivery was regulated by neck muscle activity, with infants rested unconstrained in their parents´ arms and with the head supported by the operator´s hand. This VEMP protocol showed a high level of feasibility in terms of test viability and result reproducibility. VEMP integrated into the newborn hearing screening program may represent a practical method for large-scale assessment of balance function in infants.

Assessment of Vestibulo-ocular Reflex Gain and Catch-up Saccades During Vestibular Rehabilitation

OBJECTIVE

To assess, in patients referred to vestibular rehabilitation (VR) for persistence of disability after acute unilateral vestibulopathy (AUV), whether the video head impulse test (vHIT) can be a useful technique to define the efficacy of the treatment.

STUDY DESIGN

Prospective clinical study.

SETTING

Tertiary academic referral hospitals.

PATIENTS

Thirty patients with residual symptoms after AUV were included.

INTERVENTION

Patients underwent a 10-week VR program.

MAIN OUTCOME MEASURES

Evaluation of dizziness handicap inventory score, high-velocity vestibulo-ocular reflex gain, asymmetry index, and catch-up saccade parameters before and after VR.

RESULTS

All patients reported a clear clinical improvement after VR, also demonstrated by better dizziness handicap inventory scores (p < 0.001). A consistent increased gain and decreased asymmetry index were also observed (p < 0.001 for both). Patients did not show any change in covert catch-up saccades, while a statistically significant reduction of the number and amplitude of the overt catch-up saccades was interestingly detected (p = 0.009 and p = 0.030, respectively).

CONCLUSION

VR is a valid approach for patients with residual disability after AUV. A reduction in number and amplitude of overt catch-up saccades seems useful to evaluate the efficacy of VR and to be related to clinical improvement.

Rehabilitation of dynamic visual acuity in patients with unilateral vestibular hypofunction: earlier is better

PURPOSE

Patients with acute peripheral unilateral hypofunction (UVH) complain of vertigo and dizziness and show posture imbalance and gaze instability. Vestibular rehabilitation therapy (VR) enhances the functional recovery and it has been shown that gaze stabilization exercises improved the dynamic visual acuity (DVA). Whether the effects of VR depend or not on the moment when it is applied remains however unknown, and investigation on how the recovery mechanisms could depend or not on the timing of VR has not yet been tested.

METHODS

Our study investigated the recovery of DVA in 28 UVH patients whose unilateral deficit was attested by clinical history and video head impulse test (vHIT). Patients were tested under passive conditions before (pre-tests) and after (post-tests) being subjected to an active DVA rehabilitation protocol. The DVA protocol consisted in active gaze stabilization exercises with two training sessions per week, each lasting 30 min, during four weeks. Patients were sub-divided into three groups depending on the time delay between onset of acute UVH and beginning of VR. The early DVA group (N = 10) was composed of patients receiving the DVA protocol during the first 2 weeks after onset (mean = 8.9 days), the late group 1 (N = 9) between the 3rd and the 4th week (mean = 27.5 days after) and the late group 2 (N = 9) after the 1st month (mean: 82.5 days). We evaluated the DVA score, the angular aVOR gain, the directional preponderance and the percentage of compensatory saccades during the HIT, and the subjective perception of dizziness with the Dizziness Handicap Inventory (DHI). The pre- and post-VR tests were performed with passive head rotations done by the physiotherapist in the plane of the horizontal and vertical canals.

RESULTS

The results showed that patients submitted to an early DVA rehab improved significantly their DVA score by increasing their passive aVOR gain and decreasing the percentage of compensatory saccades, while the late 1 and late 2 DVA groups 1 and 2 showed less DVA improvement and an inverse pattern, with no change in the aVOR gain and an increase in the percentage of compensatory saccades. All groups of patients exhibited significant reductions of the DHI score, with higher improvement in subjective perception of dizziness handicap in the patients receiving the DVA rehab protocol in the first month.

CONCLUSION

Our data provide the first demonstration in UVH patients that earlier is better to improve DVA and passive aVOR gain. Gaze stabilization exercises would benefit from the plastic events occurring in brain structures during a sensitive period or opportunity time window to elaborate optimal functional reorganizations. This result is potentially very important for the VR programs to restore the aVOR gain instead of recruiting compensatory saccades assisting gaze stability.

Cervical myogenic potentials and controlled postural responses elicited by a prototype vestibular implant

Gaze stabilization and postural control are two key functions of the vestibular system. In consequence, oscillopsia and chronic imbalance are the two main complaints of patients presenting with a severe bilateral vestibular function loss. The vestibular implant is emerging as a promising treatment for this group of patients whose quality of life is significantly impaired. Although the final aim of the vestibular implant should be to restore vestibular function as a whole, until now the research has focused mainly on the restoration of the vestibulo-ocular reflex to improve gaze stabilization. In this study, we aimed to explore whether the vestibulo-collic and vestibulo-spinal pathways could be activated and controlled with the electrical stimuli provided by our vestibular implant prototype. This was first explored and demonstrated with recordings of electrically elicited cervical vestibular evoked myogenic potentials (ecVEMPs). ecVEMPs with characteristics similar to the classical acoustically elicited cervical vestibular evoked myogenic potentials (cVEMPs) were successfully evoked in five out of the eight tested patients. Amplitudes of the electrically elicited N–P complex varied, ranging from 44 to 120 µV. Mean latencies of the N and P waves were of 9.71(± 1.17) ms and 17.24 ms (± 1.74), respectively. We also evaluated the possibility of generating controlled postural responses using a stepping test. Here, we showed that controlled and consistent whole-body postural responses can be effectively obtained with rapid changes in the “baseline” (constant rate and amplitude) electrical activity delivered by the vestibular implant in two out of the three tested subjects. Furthermore, obtained amplitude of body rotations was significantly correlated with the intensity of stimulation and direction of body rotations correlated with the side of the delivered stimulus (implanted side). Altogether, these data suggest that the vestibular implant could also be used to improve postural control in patients with bilateral vestibulopathy.

Morphological and functional correlates of vestibular synaptic deafferentation and repair in a mouse model of acute-onset vertigo

Damage to cochlear primary afferent synapses has been shown to be a key factor in various auditory pathologies. Similarly, the selective lesioning of primary vestibular synapses might be an underlying cause of peripheral vestibulopathies that cause vertigo and dizziness, for which the pathophysiology is currently unknown. To thoroughly address this possibility, we selectively damaged the synaptic contacts between hair cells and primary vestibular neurons in mice through the transtympanic administration of a glutamate receptor agonist. Using a combination of histological and functional approaches, we demonstrated four key findings: (1) selective synaptic deafferentation is sufficient to generate acute vestibular syndrome with characteristics similar to those reported in patients; (2) the reduction of the vestibulo-ocular reflex and posturo-locomotor deficits mainly depends on spared synapses; (3) damaged primary vestibular synapses can be repaired over the days and weeks following deafferentation; and (4) the synaptic repair process occurs through the re-expression and re-pairing of synaptic proteins such as CtBP2 and SHANK-1. Primary synapse repair might contribute to re-establishing the initial sensory network. Deciphering the molecular mechanism that supports synaptic repair could offer a therapeutic opportunity to rescue full vestibular input and restore gait and balance in patients.

Summary: The molecular rearrangements of the synaptic proteins that accompany the deafferentation and subsequent reafferentation of the inner ear sensors following an excitotoxic insult are demonstrated for the first time.

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.

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.

Advances in pharmacotherapy of vestibular and ocular motor disorders

INTRODUCTION

Vertigo and dizziness are common chief complaints of vestibular and ocular motor disorders (lifetime prevalence 30%). Treatment relies on physical, pharmacological, psychological and rarely surgical approaches. Eight groups of drugs are currently used in vestibular and ocular motor disorders, namely anti-vertiginous, anti-inflammatory, anti-menière's, anti-migrainous medications, anti-depressants, anti-convulsants, aminopyridines and agents that enhance vestibular plasticity.

AREAS COVERED

The purpose of this review is to summarize the pharmacological characteristics and clinical applications of medications that are used for peripheral, central and functional vestibular and ocular motor disorders. The level of evidence for the respective drugs is described alongside the pathophysiological premises supporting their use. The authors place particular focus on translation and back-translation in vestibular pharmacological research and the repurposing of known drugs for new indications and rare disorders.

EXPERT OPINION

The use of drugs in vestibular and ocular motor disorders is often based on open-label, non-controlled studies and expert opinion. In the future, strong evidence derived from RCTs is needed to support the effectiveness and tolerability of these therapies in well-defined vestibular and ocular motor disorders. Vestibular pharmacological research must be guided by a better understanding of the molecular targets relevant in the pathophysiology of vestibular and ocular motor disorders.

Safety, tolerability, pharmacokinetics and pharmacokinetic-pharmacodynamic modelling of the novel H4 receptor inhibitor SENS-111 using a modified caloric test in healthy subjects

AIM

A Phase 1 study was performed to evaluate safety, pharmacokinetics (PK) and pharmacodynamics (PD) of the selective histamine H₄ receptor antagonist SENS-111, an oral small molecule.

METHODS

One hundred healthy subjects were randomized in a placebo-controlled, double-blind study evaluating single-ascending doses (SAD; 100-500 mg) and multiple-ascending doses (MAD; 50-150 mg day^-1 , 4 days; 200-250 mg day^-1 , 7 days). Effects of SENS-111 on nystagmus and vertigo induced by modified caloric tests were measured in the MAD studies. Population PK and PK/PD models were developed using a nonlinear mixed-effects approach.

RESULTS

SENS-111 was well tolerated with mild to moderate events. No sedation was reported. A maximal tolerated dose was not reached. Dose-proportional increases in concentrations were seen up to 200 mg and more than dose-proportional thereafter, with mean half-life between 24 and 56 h. The caloric test induced mild but measurable vertigo and nystagmus with large intra/inter-individual variation for all parameters. SENS-111 did not significantly impact nystagmus but significantly improved latency of vertigo appearance/disappearance, duration and European Evaluation of Vertigo questionnaire parameters vs. baseline. A two-compartment model with first-order absorption, distribution and elimination best fit the data. PK/PD indirect modelling applied to vertigo duration and latency of appearance indicated maximum activity between 100 and 500 ng ml^-1 plasma concentrations, corresponding to 100 and 200 mg day^-1 , which are appropriate for clinical efficacy evaluations in vestibular diseases.

CONCLUSIONS

SENS-111 is a well-tolerated first-in-class H₄ receptor antagonist with acceptable PK for oral daily dosing. PK/PD modelling determined plasma concentrations and doses for efficacy studies in patients with vertigo symptoms.

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.

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 ± 98 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.

Hierarchical Cluster Analysis of Semicircular Canal and Otolith Deficits in Bilateral Vestibulopathy

Background

Gait imbalance and oscillopsia are frequent complaints of bilateral vestibular loss (BLV). Video-head-impulse testing (vHIT) of all six semicircular canals (SCCs) has demonstrated varying involvement of the different canals. Sparing of anterior-canal function has been linked to aminoglycoside-related vestibulopathy and Menière’s disease. We hypothesized that utricular and saccular impairment [assessed by vestibular-evoked myogenic potentials (VEMPs)] may be disease-specific also, possibly facilitating the differential diagnosis.

Methods

We searched our vHIT database (n = 3,271) for patients with bilaterally impaired SCC function who also received ocular VEMPs (oVEMPs) and cervical VEMPs (cVEMPs) and identified 101 patients. oVEMP/cVEMP latencies above the 95th percentile and peak-to-peak amplitudes below the 5th percentile of normal were considered abnormal. Frequency of impairment of vestibular end organs (horizontal/anterior/posterior SCC, utriculus/sacculus) was analyzed with hierarchical cluster analysis and correlated with the underlying etiology.

Results

Rates of utricular and saccular loss of function were similar (87.1 vs. 78.2%, p = 0.136, Fisher’s exact test). oVEMP abnormalities were found more frequent in aminoglycoside-related bilateral vestibular loss (BVL) compared with Menière’s disease (91.7 vs. 54.6%, p = 0.039). Hierarchical cluster analysis indicated distinct patterns of vestibular end-organ impairment, showing that the results for the same end-organs on both sides are more similar than to other end-organs. Relative sparing of anterior-canal function was reflected in late merging with the other end-organs, emphasizing their distinct state. An anatomically corresponding pattern of SCC/otolith hypofunction was present in 60.4% (oVEMPs vs. horizontal SCCs), 34.7% (oVEMPs vs. anterior SCCs), and 48.5% (cVEMPs vs. posterior SCCs) of cases. Average (±1 SD) number of damaged sensors was 6.8 ± 2.2 out of 10. Significantly (p < 0.001) more sensors were impaired in patients with aminoglycoside-related BVL (8.1 ± 1.2) or inner-ear infections (8.7 ± 1.8) compared with Menière-related BVL (5.5 ± 1.5).

Discussion

Hierarchical cluster analysis may help differentiate characteristic patterns of BVL. With a prevalence of ≈80%, utricular and/or saccular impairment is frequent in BVL. The extent of SCC and otolith impairment was disease-dependent, showing most extensive damage in BVL related to inner-ear infection and aminoglycoside-exposure and more selective impairment in Menière’s disease. Specifically, assessing utricular function may help in the distinction between aminoglycoside-related BVL and bilateral Menière’s disease.

Vestibular Restoration and Adaptation in Vestibular Neuritis and Ramsay Hunt Syndrome With Vertigo

OBJECTIVE

To evaluate vestibular restoration and the evolution of the compensatory saccades in acute severe inflammatory vestibular nerve paralysis, including vestibular neuritis and Ramsay Hunt syndrome with vertigo.

STUDY DESIGN

Prospective.

SETTING

Tertiary referral center.

PATIENTS

Vestibular neuritis (n = 18) and Ramsay Hunt syndrome patients with vertigo (n = 13) were enrolled.

INTERVENTION

After treatment with oral corticosteroids, patients were followed up for 6 months.

MAIN OUTCOME MEASURES

Functional recovery of the facial nerve was scored according to the House-Brackman grading system. Caloric and video head impulse tests were performed in every patient at the time of enrolment. Subsequently, successive video head impulse test (vHIT) exploration was performed at the 1, 3, and 6-month follow-up.

RESULTS

Eighteen patients with vestibular neuritis and 13 with Ramsay Hunt syndrome and associated vertigo were included. Vestibular function was significantly worse in patients with Ramsay Hunt syndrome than in those with vestibular neuritis. Similar compensatory saccades velocity and latency values were observed in both groups, in both the caloric and initial vHIT tests. Successive vHIT results showed a significantly higher vestibulo-ocular reflex gain recovery in vestibular neuritis patients than in Ramsay Hunt syndrome patients. A significantly faster reduction in the latency, velocity, and organization of the compensatory saccades was observed in neuritis than in Ramsay Hunt syndrome patients.

CONCLUSIONS

In addition to the recovery of the vestibulo-ocular reflex, the reduction of latency, velocity and the organization of compensatory saccades play a role in vestibular compensation.

Clinical value of 4-hour delayed gadolinium-Enhanced 3D FLAIR MR Images in Acute Vestibular Neuritis

OBJECTIVE

To investigate the clinical significance of 4-hour delayed-enhanced 3.0 Tesla three-dimensional (3D) fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging in acute vestibular neuritis.

STUDY DESIGN

A prospective observational study.

METHODS

Twenty-nine vestibular neuritis patients were enrolled between January 2017 and June 2017. Vestibular function tests, comprising the caloric and video head impulse tests and vestibular-evoked myogenic potential measurements, were performed. Precontrast, 10-minute, and 4-hour delayed-enhanced 3D-FLAIR MR images using double-dose IV gadolinium were obtained. After laterality and extent of inner ear enhancement were defined, the patients were divided into groups based on the patterns of enhancement, and clinical parameters were analyzed according to the groups.

RESULTS

Twenty patients (20 of 29, 69.0%) had obviously asymmetric enhancement of the affected inner ear structures on 4-hour delayed images, whereas only three patients (10.3%) had marked enhancement on 10-minute delayed images. The duration of spontaneous nystagmus (DurSN) was significantly longer in the patients with enhancement, especially with enhancement of the whole inner ear, including the vestibule and semicircular canals (P < 0.033). Spontaneous nystagmus resolved within 12 days in patients without laterality of enhancement, and within 16 days in ipsilesional enhancement confined to the inner auditory canal and fundus. Other results of vestibular function tests did not reveal any significant associations with MR enhancement.

CONCLUSIONS

Contrast enhancement of the vestibular nerve and inner ear structures can be identified on 4-hour delayed-enhanced 3T 3D-FLAIR MR images in acute vestibular neuritis. The extent of inner ear enhancement may be associated with the DurSN.

LEVEL OF EVIDENCE

4. Laryngoscope, 1946-1951, 2018.

[Dizziness and vertigo associated with vestibular neuronitis: the approaches to the diagnostics and treatment]

This article is focused on the peculiar features of diagnostics and treatment of dizziness and vertigo in the patients presenting with vestibular neuronitis. The authors present the detailed overview of various theories concerning etiology and pathogenesis of this condition, describe the methods for its clinical and instrumental diagnostics (including its differential diagnostics from other diseases associated with acute dizziness and vertigo). Special attention is given to the methods of pharmacological and physical rehabilitation of the patients suffering from vestibular neuronitis.

Current diagnostic procedures for diagnosing vertigo and dizziness

Vertigo is a multisensory syndrome that otolaryngologists are confronted with every day. With regard to the complex functions of the sense of orientation, vertigo is considered today as a disorder of the sense of direction, a disturbed spatial perception of the body. Beside the frequent classical syndromes for which vertigo is the leading symptom (e.g. positional vertigo, vestibular neuritis, Menière’s disease), vertigo may occur as main or accompanying symptom of a multitude of ENT-related diseases involving the inner ear. It also concerns for example acute and chronic viral or bacterial infections of the ear with serous or bacterial labyrinthitis, disorders due to injury (e.g. barotrauma, fracture of the oto-base, contusion of the labyrinth), chronic-inflammatory bone processes as well as inner ear affections in the perioperative course. In the last years, diagnostics of vertigo have experienced a paradigm shift due to new diagnostic possibilities. In the diagnostics of emergency cases, peripheral and central disorders of vertigo (acute vestibular syndrome) may be differentiated with simple algorithms. The introduction of modern vestibular test procedures (video head impulse test, vestibular evoked myogenic potentials) in the clinical practice led to new diagnostic options that for the first time allow a complex objective assessment of all components of the vestibular organ with relatively low effort. Combined with established methods, a frequency-specific assessment of the function of vestibular reflexes is possible. New classifications allow a clinically better differentiation of vertigo syndromes. Modern radiological procedures such as for example intratympanic gadolinium application for Menière’s disease with visualization of an endolymphatic hydrops also influence current medical standards. Recent methodical developments significantly contributed to the possibilities that nowadays vertigo can be better and more quickly clarified in particular in otolaryngology.

In Vivo Imaging of Glial Activation after Unilateral Labyrinthectomy in the Rat: A [18F]GE180-PET Study

The functional relevance of reactive gliosis for recovery from acute unilateral vestibulopathy is unknown. In the present study, glial activation was visualized in vivo by [¹⁸F]GE180-PET in a rat model of unilateral labyrinthectomy (UL) and compared to behavioral vestibular compensation (VC) overtime. 14 Sprague-Dawley rats underwent a UL by transtympanic injection of bupivacaine/arsenilate, 14 rats a SHAM UL (injection of normal saline). Glial activation was depicted with [¹⁸F]GE180-PET and ex vivo autoradiography at baseline and 7, 15, 30 days after UL/SHAM UL. Postural asymmetry and nystagmus were registered at 1, 2, 3, 7, 15, 30 days after UL/SHAM UL. Signs of vestibular imbalance were found only after UL, which significantly decreased until days 15 and 30. In parallel, [¹⁸F]GE180-PET and ex vivo autoradiography depicted glial activation in the ipsilesional vestibular nerve and nucleus on days 7 and 15 after UL. Correlation analysis revealed a strong negative association of [¹⁸F]GE180 uptake in the ipsilesional vestibular nucleus on day 7 with the rate of postural recovery (R = −0.90, p < 0.001), suggesting that glial activation accelerates VC. In conclusion, glial activation takes place in the ipsilesional vestibular nerve and nucleus within the first 30 days after UL in the rat and can be visualized in vivo by [¹⁸F]GE180-PET.

Predicting the Outcome after Acute Unilateral Vestibulopathy: Analysis of Vestibulo-ocular Reflex Gain and Catch-up Saccades

Objectives

(1) To describe the relationships among the main instrumental features characterizing an acute unilateral vestibulopathy and (2) to clarify the role of the video head impulse test in predicting the development of chronic vestibular insufficiency.

Study Design

Case series with chart review.

Setting

Tertiary referral center.

Subjects and Methods

Sixty patients suffering from acute unilateral vestibulopathy were retrospectively analyzed: 30 who recovered spontaneously (group 1) and 30 who needed a vestibular rehabilitation program (group 2). The main outcome measures included Dizziness Handicap Inventory score, canal paresis, high-velocity vestibulo-oculomotor reflex gain, and catch-up saccade parameters. The tests were all performed between 4 and 8 weeks from the onset of symptoms.

Results

The high-velocity vestibulo-oculomotor reflex gain correlated with the Dizziness Handicap Inventory score ( P = .004), with the amplitude of covert and overt saccades ( P < .001), and with the prevalence of overt saccades ( P < .001). Patients in need for vestibular rehabilitation programs had a significantly lower gain ( P < .001) and a higher prevalence and amplitude of overt saccades ( P = .002 and P = .008, respectively). Conversely, we found no differences in terms of response to the caloric test ( P = .359).

Conclusions

Lower values of high-velocity vestibulo-oculomotor reflex gain and a high prevalence of overt saccades are related to a worse prognosis after acute unilateral vestibulopathy. This is of great interest to clinicians in identifying which patients are less likely to recover and more likely to need a vestibular rehabilitation program.

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.

[Peripheral, central and functional vertigo syndromes]

Depending on the temporal course, three forms of vertigo syndrome can be differentiated: 1) vertigo attacks, e.g. benign paroxysmal positional vertigo (BPPV), Menière's disease and vestibular migraine, 2) acute spontaneous vertigo lasting for days, e.g. acute unilateral vestibulopathy, brainstem or cerebellar infarction and 3) symptoms lasting for months or years, e.g. bilateral vestibulopathy and functional vertigo. The specific therapy of the various syndromes is based on three principles: 1) physical treatment with liberatory maneuvers for BPPV and balance training for vestibular deficits, 2) pharmacotherapy, e.g. for acute unilateral vestibulopathy (corticosteroids) and Menière's disease (transtympanic administration of gentamicin or steroids and high-dose betahistine therapy); placebo-controlled pharmacotherapy studies are currently being carried out for acute unilateral vestibulopathy, vestibular paroxysmia, prophylaxis of BPPV, vestibular migraine, episodic ataxia type 2 and cerebellar ataxia; 3) psychotherapy for functional dizziness.