Idiopathic Bilateral Vestibulopathy Research Articles

Patterns of Vestibular Impairment in Bilateral Vestibulopathy and Its Relation to Etiology.

ObjectiveThis study aimed to investigate (1) the patterns of vestibular impairment in bilateral vestibulopathy (BVP) and subsequently, the implications regarding patient eligibility for vestibular implantation, and (2) whether this pattern and severity of vestibular impairment is etiology dependent.MethodsA total of one hundred and seventy-three subjects from three tertiary referral centers in Europe were diagnosed with BVP according to the Bárány Society diagnostic criteria. The subjects underwent vestibular testing such as the caloric test, torsion swing test, video Head Impulse Test (vHIT) in horizontal and vertical planes, and cervical and/or ocular vestibular evoked myogenic potentials (c- and oVEMPs). The etiologies were split into idiopathic, genetic, ototoxicity, infectious, Menière's Disease, (head)trauma, auto-immune, neurodegenerative, congenital, and mixed etiology.ResultsThe caloric test and horizontal vHIT more often indicated horizontal semicircular canal impairment than the torsion swing test. The vHIT results showed significantly higher gains for both anterior canals compared with the horizontal and posterior canals (p < 0.001). The rates of bilaterally absent oVEMP responses were higher compared to the bilaterally absent cVEMP responses (p = 0.010). A total of fifty-four percent of the patients diagnosed with BVP without missing data met all three Bárány Society diagnostic test criteria, whereas 76% of the patients were eligible for implantation according to the vestibular implantation criteria. Regarding etiology, only horizontal vHIT results were significantly lower for trauma, neurodegenerative, and genetic disorders, whereas the horizontal vHIT results were significantly higher for Menière's Disease, infectious and idiopathic BVP. The exploration with hierarchical cluster analysis showed no significant association between etiology and patterns of vestibular impairment.ConclusionThis study showed that caloric testing and vHIT seem to be more sensitive for measuring vestibular impairment, whereas the torsion swing test is more suited for measuring residual vestibular function. In addition, no striking patterns of vestibular impairment in relation to etiology were found. Nevertheless, it was demonstrated that although the implantation criteria are stricter compared with the Bárány Society diagnostic criteria, still, 76% of patients with BVP were eligible for implantation based on the vestibular test criteria. It is advised to carefully examine every patient for their overall pattern of vestibular impairment in order to make well-informed and personalized therapeutic decisions.

Acute vestibulopathy with simultaneous bilateral involvement of the vestibulo-ocular reflex limited to the low-frequency range

We report a novel type of idiopathic bilateral vestibulopathy with acute simultaneous involvement of the vestibulo-ocular reflex limited to the low-frequency range. A 64-year-old female presented with dizziness, oscillopsia, and difficulty walking. She did not experience rotatory vertigo and did not show any nystagmus. Vestibular function tests showed absent caloric responses in both ears, while vestibulo-ocular reflex (VOR) gains in the video head impulse test (vHIT) were preserved in all six semicircular canals. Cervical and ocular vestibular evoked myogenic potentials in response to air-conducted sound were absent on both sides. Since the caloric test and vHIT measures low-frequency and high-frequency VOR, respectively, we diagnosed the patient as having a bilateral VOR deficit limited to the low-frequency range. During a 1-year follow-up with vestibular rehabilitation, the subjective symptom of dizziness gradually recovered while recovery of vestibular function was minimal.

Vestibular evoked myogenic potentials

Vestibular Evoked Myogenic Potentials (VEMP) are commonly recorded in patients experiencing vertigo or chronic instability. This test evaluates the patient's otolith function and is often combined with both Videonystagmography and Video Head Impulse Test. VEMP is a simple, reproducible test, in the absence of any pre-existing conductive hearing loss. Cervical VEMP explore both saccular function and the inferior vestibular nerve, whereas ocular VEMP assess utricular function and the superior vestibular nerve. In combination with previously described tests, VEMP allows characterization of vertigo and provides support for the diagnosis of superior semicircular canal dehiscence syndrome, Menière's disease, vestibular neuritis, vestibular schwannoma or idiopathic bilateral vestibulopathy. A good knowledge of these electrophysiological tests is essential in order to precisely assess the presence or absence of vestibular function impairment. We describe the test recording technique and the most common pitfalls in interpretation of the results. We then outline the results observed in various diseases impacting vestibular function.

Clinical analysis of idiopathic bilateral vestibulopathy

Objective:To improve the level of clinical diagnosis and treatment of idiopathic bilateral vestibulopathy（IBV） by investigating the clinical characteristics of this disease. Method:Retrospective analysis was performed on patients with IBV diagnosed, excluding patients with clear primary factors, and including IBV patients with unknown causes, to analyze their clinical symptoms and vestibular function examination results. Result:In this group of cases, three cases were in line with the diagnosis of IBV. The clinical manifestations included imbalance, oscillopsia, and normal hearing level, which cannot be explained by other diseases. The vestibular function testing of the patients with IBV showed bilateral reduced response in caloric tests, positive response in video head impulse test, and decreased score in sensory organization test. Vestibular rehabilitation therapy were carried for these patients, and could improve the patients' symptoms. Conclusion:IBV has typical clinical manifestations. Vestibular function testing indicates bilateral vestibular dysfunction. Other diseases with bilateral vestibulopathy should be excluded for diagnoses, and vestibular rehabilitation therapy is one of the appropriate treatments.

Electrophysiological and inner ear MRI findings in patients with bilateral vestibulopathy.

Bilateral vestibulopathy (BV) is an uncommon disorder and the etiology remained idiopathic in most cases. Delayed 3D-FLAIR sequences have provided new insights into various inner ear diseases, allowing the evaluation of the endolymphatic space and the permeability of the blood-labyrinthine barrier (BLB). The aim of this study was to assess both the morphology of the endolymphatic space and the permeability of the BLB in patients with BV as evaluated by delayed 3D-FLAIR sequences. In this retrospective study, we performed 3D-FLAIR sequences 4h after administering contrast media to 42 patients with BV. Two radiologists independently evaluated the morphology of the endolymphatic space (either vestibular atelectasis or endolymphatic hydrops) and the permeability of the BLB. Morphologic anomalies of the endolymphatic space and vestibular blood-labyrinthine barrier impairment were observed in 59.6% of patients with BV. Bilateral vestibular atelectasis (VA) was found in 21 patients (50%), involving only the utricle and all three ampullas while the saccule was always observed with no sign of collapse: idiopathic BV (n = 19), aminoglycoside administration (n = 1) and few days following abdominal surgery (n = 1). One patient had bilateral vestibular malformation. BLB impairment was observed in five patients (11.9%): paraneoplastic (n = 1), lymphoma (n = 1), autoimmune (n = 1), and vestibular "neuritis" (n = 2). Seventeen patients (40.4%) had normal MRI with no endolymphatic space anomaly or BLB impairment. Patients with BV presented with morphologic anomalies of the endolymphatic space or BLB impairment in 59.6% of patients.

Amiodarone-associated bilateral vestibulopathy.

Bilateral vestibulopathy (BVP) is a debilitating disorder characterized by the hypofunction of both vestibular end organs or nerves. The most frequent identifiable causes of BVP are ototoxic drug effects, infectious and autoimmune disorders. The majority of cases, however, remain idiopathic. Medical records of patients diagnosed with idiopathic BVP were examined in five dizziness clinics. We identified 126 patients with "idiopathic" BVP. Out of these, 15 patients had a history of Amiodarone treatment before the diagnosis of BVP, resulting in a 12% prevalence. The present report supports the hypothesis that Amiodarone can cause BVP. Vestibular examination in patients taking Amiodarone and suffering from balance-related symptoms are recommended, to recognize this adverse effect as early as possible and allow for an informed judgement on a potential dose reduction or withdrawal for recovery of the vestibular function.

両側前庭神経炎が疑われた特発性両側性前庭機能低下症の一例

両側前庭神経炎が疑われた特発性両側性前庭機能低下症の一例

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).

Motion Perception in Patients with Idiopathic Bilateral Vestibular Hypofunction

We measured vestibular perceptual thresholds in patients with idiopathic bilateral vestibulopathy to assess the distribution of peripheral vestibular damage in this disorder. Thresholds were measured with standard psychometric techniques in 4 patients and compared with thresholds in normal subjects and patients with completely absent peripheral vestibular function. Motion paradigms included yaw rotation (testing the lateral canals), interaural translation (testing the utricles), superior-inferior translation (testing the saccules), and roll tilt (testing the vertical semicircular canals and the otolith organs). We found that perceptual thresholds were abnormally elevated in the patients with idiopathic bilateral vestibulopathy for yaw rotation at all frequencies and for interaural translation at only the lower frequencies. Thresholds were normal for the other 2 motion paradigms. The results demonstrate that the distribution of vestibular dysfunction in this disorder is not uniform but, rather, can affect lateral canal and utricular thresholds while relatively sparing vertical canal and saccular function.

Effect of severity of vestibular dysfunction on postural instability in idiopathic bilateral vestibulopathy

Conclusions: Foam posturography reveals that idiopathic bilateral vestibulopathy (IBV) significantly affects postural stability. Instability was more severe in patients with damage to both of the vestibular nerve systems. Residual function in the spared vestibular nerve system might contribute to postural stability in IBV. Objective: Postural stability was assessed using foam posturography in patients with IBV according to whether the inferior, superior or both of the vestibular nerve systems were affected. Methods: Two-legged stance tasks were performed by patients with IBV (n = 29) in four conditions: eyes open with and without foam rubber, and eyes closed with and without foam rubber. We examined six variables: the velocity of movement of the center of pressure (COP), the envelopment area traced by the movement of the COP, Romberg's ratio of velocity and area, and the foam ratios of velocity and area. Results: The presence of IBV was significantly positively related to all the variables in adjusting for the subjects' gender and age (p < 0.001). Five of the 29 patients (17%) with IBV required assistance to prevent falling with eyes closed/foam rubber. Four of these five patients showed bilateral canal paresis in caloric testing and bilaterally no responses in cervical vestibular evoked myogenic potential testing.

Mitochondrial 12S rRNA susceptibility mutations in aminoglycoside-associated and idiopathic bilateral vestibulopathy

The mitochondrial 12S rRNA is considered a hotspot for mutations associated with nonsyndromic (NSHL) and aminoglycoside-induced hearing loss (AIHL). Although aminoglycoside ototoxicity is the most common cause of bilateral vestibular dysfunction, the conceivable role of 12S rRNA mutations has never been systematically investigated. We sequenced the 12S rRNA of 66 patients with bilateral vestibulopathy (BV) with (n=15) or without (n=51) prior exposure to aminoglycosides, as well as 155 healthy controls with intact vestibular function (sport pilots), and compared these to 2704 published sequences (Human Mitochondrial Genome Database). No mutations with a confirmed pathogenicity were found (A1555G, C1494T), but four mutations with a hitherto tentative status were detected (T669C, C960del, C960ins, T961G). Due to their predominant occurrence in patients without aminoglycoside exposure, their detection in controls and a weak evolutionary conservation, their pathogenic role in vestibulocochlear dysfunction remains provisional.

Why Neurologists Frequently Miss Bilateral Vestibular Loss: Two Views

Bilateral vestibulopathy (BV) is a rare, frequently idiopathic, disorder. This retrospective chart review involved 255 individuals with BV (mean age, 62; age range at onset, 12–98). Participants had undergone standardized evaluations in 1988–2005 at the authors’ dizziness clinic and had decreased vestibulo-ocular reflex during a head-thrust test or low caloric response on electronystagmography. The mean delay between first symptoms and diagnosis was 65 months. Nearly all patients had gait unsteadiness, and 44% had oscillopsia (illusion that the world moves during head movements). Episodic vertigo with a stuttering course occurred in 35%; other patients had a slowly progressive course without vertigo, and 65% of these patients had idiopathic BV. BV had definite or probable causes in …

Lesion site in idiopathic bilateral vestibulopathy: A galvanic vestibular-evoked myogenic potential study

ConclusionThe result suggests that patients with idiopathic bilateral vestibulopathy may have nerve lesions when the inferior nerve system is affected, while the inferior vestibular nerve system may be spared.ObjectiveTo clarify the lesion site in idiopathic bilateral vestibulopathy, an acquired bilateral vestibulopathy of unknown cause.Material and methodsTwo 75-year-old males diagnosed with idiopathic bilateral vestibulopathy were enrolled. Both showed absent or highly decreased responses on the caloric test on both sides. They underwent vestibular-evoked myogenic potential (VEMP) testing by means of acoustical and electrical stimulation. As acoustic stimulation, 95 dB nHL clicks and short tone bursts (500 Hz) were presented, while 3 mA (1 ms) short-duration galvanic stimuli were presented as electrical stimulation. Responses were recorded on the sternocleidomastoid muscles.ResultsBoth patients showed unilateral absence of VEMPs with both acoustic and short-duration galvanic stimuli.

Two Types of Oscillopsia in a Patient with Idiopathic Vestibulopathy

A patient with an idiopathic bilateral vestibulopathy described two types of oscillopsia, one induced by head movement, the other induced by changing pressure in the right external auditory canal. This is the first report of both types of oscillopsia occurring in the same individual and illustrates their different mechanisms and symptomatology.