Clinical characteristics of inferior vestibular neuritis

Concurrent abnormalities in galvanic cervical and ocular vestibular-evoked myogenic potentials as a predictive marker for prolonged dizziness in vestibular neuritis

BACKGROUND

Despite the growing use of cervical (cVEMP) and ocular (oVEMP) VEMP tests, their effectiveness in predicting chronic dizziness in vestibular neuritis (VN) patients remains unclear. Our research examines the link between long-lasting dizziness and inner ear assessments, encompassing VEMPs induced by air-conducted sound (ACS), bone-conducted vibration (BCV), and galvanic vestibular stimulation (GVS).

OBJECTIVES

This study explores prognostic markers by examining the relationship between the persistence of dizziness symptoms and various inner ear test findings in VN patients.

MATERIAL AND METHODS

A retrospective cohort of 60 unilateral VN patients underwent comprehensive audiovestibular tests, including pure tone audiometry, cVEMP and oVEMP induced by ACS, BCV, GVS, and caloric tests. Patient subgroups were established based on dizziness duration: short-term (<3 months) and long-term (≥3 months).

RESULTS

No substantial correlation existed between the dizziness duration and the outcomes of any particular single inner ear test. However, patients exhibiting concurrent abnormal GVS-cVEMP and GVS-oVEMP were more likely to experience prolonged dizziness, indicating more extensive vestibular system involvement.

CONCLUSIONS

Concurrent abnormalities in GVS-cVEMP and GVS-oVEMP may indicate a higher chance of long-term dizziness in VN.

SIGNIFICANCE

This study identifies concurrent abnormalities in GVS-cVEMP and GVS-VEMP as a potential prognostic marker for prolonged dizziness in VN.

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.

Acute unilateral vestibulopathy/vestibular neuritis: Diagnostic criteria

This paper describes the diagnostic criteria for Acute Unilateral Vestibulopathy (AUVP), a synonym for vestibular neuritis, as defined by the Committee for the Classification of Vestibular Disorders of the Bárány Society. AUVP manifests as an acute vestibular syndrome due to an acute unilateral loss of peripheral vestibular function without evidence for acute central or acute audiological symptoms or signs. This implies that the diagnosis of AUVP is based on the patient history, bedside examination, and, if necessary, laboratory evaluation. The leading symptom is an acute or rarely subacute onset of spinning or non-spinning vertigo with unsteadiness, nausea/vomiting and/or oscillopsia. A leading clinical sign is a spontaneous peripheral vestibular nystagmus, which is direction-fixed and enhanced by removal of visual fixation with a trajectory appropriate to the semicircular canal afferents involved (generally horizontal-torsional). The diagnostic criteria were classified by the committee for four categories: 1. "Acute Unilateral Vestibulopathy", 2. "Acute Unilateral Vestibulopathy in Evolution", 3. "Probable Acute Unilateral Vestibulopathy" and 4. "History of Acute Unilateral Vestibulopathy". The specific diagnostic criteria for these are as follows:"Acute Unilateral Vestibulopathy": A) Acute or subacute onset of sustained spinning or non-spinning vertigo (i.e., an acute vestibular syndrome) of moderate to severe intensity with symptoms lasting for at least 24 hours. B) Spontaneous peripheral vestibular nystagmus with a trajectory appropriate to the semicircular canal afferents involved, generally horizontal-torsional, direction-fixed, and enhanced by removal of visual fixation. C) Unambiguous evidence of reduced VOR function on the side opposite the direction of the fast phase of the spontaneous nystagmus. D) No evidence for acute central neurological, otological or audiological symptoms. E) No acute central neurological signs, namely no central ocular motor or central vestibular signs, in particular no pronounced skew deviation, no gaze-evoked nystagmus, and no acute audiologic or otological signs. F) Not better accounted for by another disease or disorder."Acute Unilateral Vestibulopathy in Evolution": A) Acute or subacute onset of sustained spinning or non-spinning vertigo with continuous symptoms for more than 3 hours, but not yet lasting for at least 24 h hours, when patient is seen; B) - F) as above. This category is useful for diagnostic reasons to differentiate from acute central vestibular syndromes, to initiate specific treatments, and for research to include patients in clinical studies."Probable Acute Unilateral Vestibulopathy": Identical to AUVP except that the unilateral VOR deficit is not clearly observed or documented."History of acute unilateral vestibulopathy": A) History of acute or subacute onset of vertigo lasting at least 24 hours and slowly decreasing in intensity. B) No history of simultaneous acute audiological or central neurological symptoms. C) Unambiguous evidence of unilaterally reduced VOR function. D) No history of simultaneous acute central neurological signs, namely no central ocular motor or central vestibular signs and no acute audiological or otological signs. E) Not better accounted for by another disease or disorder. This category allows a diagnosis in patients presenting with a unilateral peripheral vestibular deficit and a history of an acute vestibular syndrome who are examined well after the acute phase.It is important to note that there is no definite test for AUVP. Therefore, its diagnosis requires the exclusion of central lesions as well as a variety of other peripheral vestibular disorders. Finally, this consensus paper will discuss other aspects of AUVP such as etiology, pathophysiology and laboratory examinations if they are directly relevant to the classification criteria.

Posterior semicircular canal ossification following acute vestibular loss mimicking inferior vestibular neuritis: A case report

Vestibular neuritis (VN) mostly involves the superior vestibular nerve. Isolated inferior vestibular neuritis (IVN) has been more rarely described. The diagnosis of IVN is based on an abnormal head impulse test (HIT) for the posterior semicircular canal (PSC), pathological cervical vestibular-evoked myogenic potentials (C-VEMPs), and spontaneous downbeat nystagmus consistent with acute functional loss of inner ear sensors lying within the inferior part of the labyrinth. HIT for both lateral and superior semicircular canals is normal, as are ocular VEMPs and bithermal caloric irrigations. The etiology of IVN is debated since peripheral acute vestibular loss with a similar lesion pattern can often be associated with ipsilesional sudden hearing loss (HL). Viral inflammation of vestibular nerves is considered the most likely cause, although reports suggest that VN usually spares the inferior division. On the other hand, an ischemic lesion involving the terminal branches of the common cochlear artery has been hypothesized in cases with concurrent HL. Debated is also the lesion site in the case of IVN without HL since different instrumental patterns have been documented. Either isolated posterior ampullary nerve involvement presenting with selective PSC functional loss on video-HIT, or only saccular lesion with isolated ipsilesional C-VEMPs impairment, or inferior vestibular nerve damage (including both saccular and posterior ampullary afferents) exhibiting an impairment of both C-VEMPs and PSC-HIT. We report an interesting case of a patient with an acute vestibular loss consistent with IVN without HL who developed a PSC ossification on follow-up, questioning the viral origin of the lesion and rather orienting toward an occlusion of the posterior vestibular artery. To the best of our knowledge, this is the first report of PSC ossification after a clinical picture consistent with IVN.

Different time course of compensation of subjective visual vertical and ocular torsion after acute unilateral vestibular lesion

PURPOSE

Time course of the recovery of otolithic dis-function caused by superior vestibular neuritis has been examined in fifteen patients.

METHODS

The subjective visual vertical (SVV) and the ocular cyclotorsion (OT) have been measured four times after the acute episode up to 1 year RESULTS: In most of the patients the SVV tilt returned to control values within few months (3-6 months) after the acute episode, while OT remained out of normal range in almost all patients a year later.

CONCLUSION

The abnormal OT observed after 1 year from the acute episode of vestibular neuritis, suggests that the otolithic receptors remained altered for several months and the OT may be a good indicator of the entity of the residual peripheral otolithic lesion. Moreover, the dissociation between the SVV tilt recovery and that of OT supports the issue that the two signs of the otolithic disfunction are only partially linked each other with centrally or peripherally distinct re-balancing circuits.

Association between vestibular dysfunction and findings of horizontal head-shaking and vibration-induced nystagmus

BACKGROUND

The association between vestibular function and findings of horizontal head-shaking nystagmus (HHSN) and vibration-induced nystagmus (VIN) tests is not well understood.

OBJECTIVE

To investigate the association between function in the five distinct vestibular end organs and findings of these nystagmus tests.

METHODS

We retrospectively reviewed the medical records of 50 patients with vestibular diseases who underwent HHSN testing, VIN testing, video head impulse testing (vHIT), cervical vestibular evoked myogenic potential testing to air-conducted sound (ACS cVEMP) and ocular VEMP testing to ACS (ACS oVEMP). We performed mixed-effects logistic regression analyses to see whether age, sex or the presence of nystagmus in HHSN or VIN have an association with the presence of peripheral vestibular dysfunction on the opposite side to the direction of nystagmus.

RESULTS

The presence of HHSN had a significant association with abnormal vHIT in the lateral semicircular canal (LSCC) on the opposite side to the direction of nystagmus. The presence of VIN had a significant association with abnormal vHIT in all the SCCs and abnormal ACS oVEMP on the opposite side to the direction of nystagmus.

CONCLUSIONS

HHSN had an association with LSCC dysfunction alone. VIN had an association with dysfunction in all the SCCs and the utricle.

[A follow-Up Study with the Video Head Impulse Test for the patients with vestibular neuritis]

Objective:To detect the impairment degree and recovery process of the semicircular canals of patients with vestibular neuritis（VN） by video head impulse test（vHIT） over different periods. Method:The clinical data of patients with VN, who were diagnosed by Vertigo clinic'physicians in the Department of ENT, Dalian Municipal Central Hospital from Sept. 2018 to Sept. 2019, were analyzed and followed up at 1 and 3 month. The damage degree and recovery process of each semicircular canal function were evaluated by vHIT. Result:During the onset period, 89.7% horizontal semicircular canal HSC, 86.2% anterior semicircular canal ASC and 44.8% posterior semicircular canal PSC were abnormal in 29 patients. 23.8% HSC were back to normal, 75.0% ASC were back to normal, 15.4% PSC were back to normal at 1 month; 47.1% HSC were back to normal, 87.5%ASC were back to normal, 25.0% PSC were back to normal at 3 month. Conclusion:vHIT can effectively and dynamically detect the damage and recovery of the high-frequency region of the semicircular canal in patients with VN; the damaged function of the ASC is best recovered, followed by the HSC.

Comparison of Video Head Impulse Test in the Posterior Semicircular Canal Plane and Cervical Vestibular Evoked Myogenic Potential in Patients With Vestibular Neuritis

OBJECTIVE

The purpose of this study was to evaluate and compare the results of cervical vestibular evoked myogenic potential (cVEMP) and video head impulse test (p-vHIT) of posterior semicircular canal considered tools of inferior vestibular nerve function in vestibular neuritis.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary otology clinic.

PATIENTS AND INTERVENTIONS

Seventy-nine patients with vestibular neuritis participated in this study. We analyzed the interaural amplitude difference in cVEMP with a positive rate of p-vHIT according to gain and corrective saccade in the study population.

MAIN OUTCOME MEASURE

To evaluate the concordance rate of both tests, we analyzed Fleiss' Kappa value inter-test agreement of cVEMP with p-vHIT. Finally, we performed detailed analysis of the bilaterally absent response on cVEMP according to the p-vHIT results.

RESULTS

The inter-test agreement between cVEMP and p-vHIT was 69.8% as we also considered the lesion side. This result indicated a statistically fair to good agreement in both tests. In mostly elderly patients with a bilaterally absent response (11 patients) on cVEMP, as a result of vHIT, nine patients with a bilaterally negative response on p-vHIT showed only canal paresis. Two patients showed canal paresis and a unilaterally positive response on p-vHIT.

CONCLUSIONS

Inter-test agreement between cVEMP and p-vHIT assessed in vestibular neuritis was relatively lower than we had predicted. Probably, p-vHIT can provide additional information on the differential diagnosis of dysfunction of the inferior vestibular nerve which is composed of the saccular nerve and the posterior ampullary nerve.

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.

The Video Head Impulse Test

In 1988, we introduced impulsive testing of semicircular canal (SCC) function measured with scleral search coils and showed that it could accurately and reliably detect impaired function even of a single lateral canal. Later we showed that it was also possible to test individual vertical canal function in peripheral and also in central vestibular disorders and proposed a physiological mechanism for why this might be so. For the next 20 years, between 1988 and 2008, impulsive testing of individual SCC function could only be accurately done by a few aficionados with the time and money to support scleral search-coil systems—an expensive, complicated and cumbersome, semi-invasive technique that never made the transition from the research lab to the dizzy clinic. Then, in 2009 and 2013, we introduced a video method of testing function of each of the six canals individually. Since 2009, the method has been taken up by most dizzy clinics around the world, with now close to 100 refereed articles in PubMed. In many dizzy clinics around the world, video Head Impulse Testing has supplanted caloric testing as the initial and in some cases the final test of choice in patients with suspected vestibular disorders. Here, we consider seven current, interesting, and controversial aspects of video Head Impulse Testing: (1) introduction to the test; (2) the progress from the head impulse protocol (HIMPs) to the new variant—suppression head impulse protocol (SHIMPs); (3) the physiological basis for head impulse testing; (4) practical aspects and potential pitfalls of video head impulse testing; (5) problems of vestibulo-ocular reflex gain calculations; (6) head impulse testing in central vestibular disorders; and (7) to stay right up-to-date—new clinical disease patterns emerging from video head impulse testing. With thanks and appreciation we dedicate this article to our friend, colleague, and mentor, Dr Bernard Cohen of Mount Sinai Medical School, New York, who since his first article 55 years ago on compensatory eye movements induced by vertical SCC stimulation has become one of the giants of the vestibular world.

Association of posterior semicircular canal hypofunction on video-head-impulse testing with other vestibulo-cochlear deficits

OBJECTIVES

The video-head-impulse test (vHIT) provides a functional assessment of all six semicircular canals (SCC). Occasionally isolated loss of the posterior canal(s) (ILPC) is diagnosed, though this finding is poorly characterized. Here we assessed how accurate that diagnosis is by measuring the co-occurrence of abnormalities on caloric irrigation, vestibular-evoked myogenic-potentials and audiometry.

METHODS

We identified 52 patients with ILPC (unilateral=40, bilateral=12). We determined vHIT-gains and saccade-amplitudes and correlated vHIT-findings with other vestibulo-cochlear tests.

RESULTS

The most frequent diagnoses were history of vestibular neuritis (13/52), Menière's disease (12/52) and vertigo/dizziness of unclear origin (13/52). Unilateral ILPC on vHIT was accompanied by a deficient horizontal canal on calorics, saccular and/or utricular deficits ipsilesionally in 33/40 (83%), while ipsilesional hearing-loss was noted in 24/40 (60%). Involvement of other sensors was highest for vestibular schwannoma (100%) and history of vestibular neuritis (92%). Bilateral deficits in ≥1 vestibulo-cochlear sensor(s) were noted in 2/12 cases with bilateral ILPC.

CONCLUSIONS

>80% of patients with unilateral ILPC had additional deficits of other parts of the vestibular organ, while this rate was ≤20% for patients with bilateral ILPC.

SIGNIFICANCE

Dizzy patients should receive testing of the posterior canals and if abnormalities are observed, additional vestibulo-cochlear testing should be obtained.

Aspects of cerebral plasticity related to clinical features in acute vestibular neuritis: a "starting point" review from neuroimaging studies

Vestibular neuritis (VN) is one of the most common causes of vertigo and is characterised by a sudden unilateral vestibular failure (UVF). Many neuroimaging studies in the last 10 years have focused on brain changes related to sudden vestibular deafferentation as in VN. However, most of these studies, also due to different possibilities across diverse centres, were based on different times of first acquisition from the onset of VN symptoms, neuroimaging techniques, statistical analysis and correlation with otoneurological and psychological findings. In the present review, the authors aim to merge together the similarities and discrepancies across various investigations that have employed neuroimaging techniques and group analysis with the purpose of better understanding about how the brain changes and what characteristic clinical features may relate to each other in the acute phase of VN. Six studies that strictly met inclusion criteria were analysed to assess cortical-subcortical correlates of acute clinical features related to VN. The present review clearly reveals that sudden UVF may induce a wide variety of cortical and subcortical responses - with changes in different sensory modules - as a result of acute plasticity in the central nervous system.

Vestibular neuritis in children and adolescents: Clinical features and recovery

OBJECTIVE

Describe the clinical presentation and recovery of vestibular neuritis in children and adolescents.

STUDY DESIGN

Retrospective case series.

SETTING

Pediatric tertiary care center.

SUBJECTS AND METHODS

Eleven patients diagnosed with vestibular neuritis were identified from a database of 301 patients evaluated at our pediatric vestibular clinic from January 2012 through January 2015. Medical records were reviewed to determine clinical presentation, vestibular testing results, treatment, and recovery. Incomplete recovery was defined as residual dizziness or imbalance at most recent follow-up >30 days from symptom onset.

RESULTS

Patients were 5-19 years old (mean 13.1±5.34) and included 6 boys and 5 girls. All presented with a sudden rotational vertigo, imbalance, and nausea for an average of 10 days without other associated symptoms. Testing included rotary chair (8 of 9 abnormal), caloric (2 of 2 abnormal), video head impulse (5 of 8 abnormal), subjective visual vertical (4 of 8 abnormal), and cervical vestibular evoked myogenic potential (0 of 6 abnormal) tests. All patients with incomplete recovery (n=4; 36%) were ≥15 years old at symptom onset. All patients with incomplete recovery that underwent vestibular rehabilitation (n=2) initiated it ≥90 days from symptom onset, while 3 out of 4 patients with complete recovery that underwent vestibular rehabilitation initiated it ≤14 days from symptom onset. Two patients received oral steroids, neither of whom had incomplete recovery.

CONCLUSION

Vestibular neuritis should be considered in pediatric patients with vertigo and may result in longstanding symptoms, particularly in adolescents. The treatment of pediatric vestibular neuritis with rehabilitation and steroids deserves further study.

Prediction of Short-Term Outcome in Acute Superior Vestibular Nerve Failure: Three-Dimensional Video-Head-Impulse Test and Caloric Irrigation

This retrospective study examines acute unilateral vestibular failure (up to seven days after onset) with modern vestibular testing (caloric irrigation and video-head-impulse test, vHIT) in 54 patients in order to test if the short-term outcome of the patients depends on the lesion pattern defined by the two tests. Patients were grouped according to a pathological unilateral caloric weakness without a pathological vHIT: group I; additional a pathological vHIT of the lateral semicircular canal (SCC): group II; and an additional pathological vHIT of the anterior SCC: group III. Patients with involvement of the posterior SCC were less frequent and not included in the analysis. Basic parameters, such as age of the subjects, days after symptom onset, gender, side of the lesion, treatment, and dizziness handicap inventory, were not different in groups I to III. The frequency of pathological clinical findings and pathological quantified measurements increased from groups I to III. The outcome parameter "days spent in the hospital" was significantly higher in group III compared to group I. The analysis shows that differential vestibular testing predicts short-term outcome of the patients and might be in future important to treat and coach patients with vestibular failure.

Characteristics of vertigo and the affected vestibular nerve systems in idiopathic bilateral vestibulopathy

CONCLUSION

Vertigo attacks in IBV patients involving both the superior and inferior vestibular nerve systems were significantly more severe than vertigo attacks in patients with selective involvement of the inferior vestibular nerve system alone.

OBJECTIVE

To investigate the relationship between the frequency and duration of vertigo and the affected vestibular nerve system in idiopathic bilateral vestibulopathy (IBV).

METHODS

This study categorized 44 IBV patients into the following three sub-groups according to the affected vestibular nerve system: superior, inferior, and mixed type. These patients were also categorized into the following three sub-groups according to their clinical time course: progressive type showing no episodes of vertigo, sequential type showing recurrent vertigo attacks and single-attack type showing a single episode of vertigo.

RESULTS

Ten, 11 and 23 patients were classified as the superior, the inferior, and the mixed type, respectively. Seventeen, 23, and four patients were classified as the progressive, the sequential, and the single-attack type, respectively. For the patients having one or more vertigo attacks, the duration of the vertigo attack was longer than 24 h in 69% of the mixed type, and the duration of vertigo in the mixed type was significantly longer than that in the inferior type (p < 0.05).

Clinical Characteristics of Patients With Abnormal Ocular/Cervical Vestibular Evoked Myogenic Potentials in the Presence of Normal Caloric Responses

Objective:

To investigate the clinical features and vestibular symptoms of patients with abnormal ocular vestibular evoked myogenic potentials (oVEMPs) and/or cervical VEMPs (cVEMPs) in the presence of normal caloric responses.

Study Design:

Retrospective chart review.

Setting:

Tertiary referral center.

Methods:

One thousand five hundred twenty-one consecutive patients with balance problems who underwent the caloric, cVEMP, and oVEMP tests were included, and patients who showed abnormal oVEMPs and/or cVEMPs in the presence of normal caloric responses were selected. Clinical characteristics, diagnoses, and vestibular symptoms of the patients were analyzed.

Results:

Of the 1521 patients, 227 (15%) were found to have abnormal oVEMPs and/or cVEMP responses with normal caloric responses. Benign paroxysmal positional vertigo (BBPV), Meniere’s disease, and vestibular migraine were the common diagnoses of these patients. Eighty-one patients (36%) could not be diagnosed with a recognizable disease. Multiple episodes of spinning vertigo with a duration of seconds to hours were their most common vestibular symptoms.

Conclusion:

BPPV, Meniere’s disease, and vestibular migraine are the most frequent diagnoses showing abnormal oVEMP and/or cVEMPs without canal paresis. Apart from these clinical entities, a portion of undiagnosed patients with multiple episodes of vertigo might have a disease that involves the otolith organs only.

Vestibular evoked myogenic potential

Vestibular evoked myogenic potential (VEMP), is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. Nowadays, two kinds of VEMP, cervical VEMP (cVEMP) and ocular VEMP (oVEMP) are clinically used. cVEMP is a test of sacculo-collic reflex while oVEMP is a test of utriculo-ocular reflex. Absence of responses, large interaural asymmetry of amplitudes, prolonged peak latencies, and abnormal thresholds of responses are regarded as abnormal responses. Clinical application to various diseases of the vestibular system was performed. Using VEMP, a new type of vestibular neuritis, inferior vestibular neuritis was established. A prominent feature of VEMP in Meniere’s disease is a shift of a preferred frequency in cVEMP. The whole aspects of VEMP findings in patients with benign paroxysmal positional vertigo are not clarified yet. Sensitivity of cVEMP to vestibular schwannoma was 80.0%, while specificity was 52.7%. Concerning diagnosis of superior canal dehiscence syndrome (SCDS), oVEMP to air-conducted sound is the most helpful. Augmentation of oVEMP responses is a prominent feature in SCDS. I also presented “idiopathic otolithic vertigo”, which I proposed as a new clinical entity based on VEMP findings. Some patients complained of lateral tilting sensation in the roll plane, or tilting or translational sensation in the pitch plane without rotatory vertigo. Majority of patients with these symptoms had absent or decreased responses of oVEMP and/or cVEMP. I proposed that these patients could be diagnosed as having “idiopathic otolithic vertigo”.

The methodology of Dynamic Uncertain Causality Graph for intelligent diagnosis of vertigo

Vertigo is a common complaint with many potential causes involving otology, neurology and general medicine, and it is fairly difficult to distinguish the vertiginous disorders from each other accurately even for experienced physicians. Based on comprehensive investigations to relevant characteristics of vertigo, we propose a diagnostic modeling and reasoning methodology using Dynamic Uncertain Causality Graph. The symptoms, signs, findings of examinations, medical histories, etiology and pathogenesis, and so on, are incorporated in the diagnostic model. A modularized modeling scheme is presented to reduce the difficulty in model construction, providing multiple perspectives and arbitrary granularity for disease causality representations. We resort to the "chaining" inference algorithm and weighted logic operation mechanism, which guarantee the exactness and efficiency of diagnostic reasoning under situations of incomplete and uncertain information. Moreover, the causal insights into underlying interactions among diseases and symptoms intuitively demonstrate the reasoning process in a graphical manner. These solutions make the conclusions and advices more explicable and convincing, further increasing the objectivity of clinical decision-making. Verification experiments and empirical evaluations are performed with clinical vertigo cases. The results reveal that, even with incomplete observations, this methodology achieves encouraging diagnostic accuracy and effectiveness. This study provides a promising assistance tool for physicians in diagnosis of vertigo.

Do patients who experience episodic tilting or translational sensations in the pitch plane have abnormal sacculo-collic reflexes?

The otolith-collic and otolith-ocular reflexes of patients who experienced episodic tilting or translational sensations in the pitch plane without any other vestibular symptoms were assessed using cervical vestibular evoked myogenic potentials (cVEMP) and ocular vestibular evoked myogenic potentials (oVEMP). Eleven patients (4 men and 7 women, mean age=40.4) were enrolled. All of the patients complained of episodic tilting or translational sensations in the pitch plane. Patients with a medical history of rotatory vertigo, loss of consciousness, head trauma, or symptoms of central nervous dysfunction or proprioceptive dysfunction and those who had been definitely diagnosed with a disease that causes disequilibrium were excluded. All 11 patients underwent cVEMP and caloric tests. Ten patients participated in the oVEMP tests. Seven of the 11 patients exhibited unilateral cVEMP absences, two displayed bilateral cVEMP absences, one demonstrated unilaterally decreased cVEMP, and one displayed normal cVEMP. Concerning oVEMP, 2 of the 10 patients showed unilateral oVEMP absences, 2 displayed bilateral oVEMP absences, 2 exhibited unilaterally decreased oVEMP, and 4 displayed normal oVEMP. All patients exhibited normal bilateral caloric responses. These findings were distinct from the results obtained for patients who experienced episodic lateral tilting sensations in previous studies. While most of the latter patients exhibited abnormal oVEMP, the patients in the present study tended to display abnormal cVEMP. These results suggest that patients with episodic tilting or translational sensations in the pitch plane suffer from saccular dysfunction. We propose "idiopathic otolithic vertigo" as a clinical entity and suggest that it is caused by idiopathic saccular dysfunction and/or utricular dysfunction.

Peripheral vestibular disorders

PURPOSE OF REVIEW

First, to update the diagnosis, pathophysiology, and treatment of the most frequent peripheral vestibular disorders. Second, to identify those disorders for which the diagnostic criteria are still deficient and treatment trials are still lacking.

RECENT FINDINGS

Bilateral vestibulopathy can be reliably diagnosed by the head-impulse test, caloric irrigation, and vestibular-evoked myogenic potentials. A new frequent subtype has been described: cerebellar ataxia, neuropathy, and vestibular areflexia syndrome. Benign paroxysmal positioning vertigo can be easily diagnosed and effectively treated. Vestibular neuritis is most likely caused by the reactivation of a herpes simplex type 1 infection; the inferior vestibular nerve subtype is now well established. More evidence is needed that the recovery can be improved by corticosteroids. Endolymphatic hydrops in Menière's disease can be depicted by high-resolution MRI after transtympanic gadolinium injection; a high-dosage and long-term prophylactic treatment with betahistine is evidently effective. Its mechanism of action is most likely an increase in the inner-ear blood flow. Vestibular paroxysmia is now a well established entity; carbamazepine is the treatment of first choice. Superior canal dehiscence syndrome can be reliably diagnosed; the best current treatment option is canal plugging.

SUMMARY

Although progress has been made in the diagnosis and treatment of most peripheral vestibular disorders, more state-of-the-art trials are needed on the treatment of bilateral vestibulopathy to prove the efficacy of balance training, of vestibular neuritis (in terms of recovery of peripheral vestibular function and central compensation), of vestibular paroxysmia to prove the effects of carbamazepine, and of Menière's disease to find the optimal dosage of betahistine.