Motorized head impulse rotator in patients with vestibular schwannoma

Conclusion. Motorized head impulse rotator is an effective technique to assess peripheral vestibular function. Approximately a quarter of patients with vestibular schwannoma (VS) had preserved preoperative responses. Vestibular disability could not be predicted based on vestibulo-ocular reflex (VOR) performance during motion stimuli, or in the caloric test. Objectives. To explore motorized head impulse rotator for evaluation of angular horizontal VOR in patients with VS, and to compare these responses to those of the caloric test and the symptoms. Patients and methods. We prospectively recorded head and eye position during unpredictable motorized head impulses in 38 patients with VS. We calculated gain and asymmetry of VOR (mean±95% CI), and the results were compared to those of the caloric test and a questionnaire regarding dizziness, hearing and quality of life. Results. The VOR during motorized impulses was abnormal in 71% of patients. Asymmetry in gain correlated significantly (p<0.001) with unilateral weakness in the caloric test. Preoperative gain was significantly lowered to 0.83±0.08 on the ipsilateral side compared to 0.98±0.06 on the contralateral side. Postoperative gain on the operated side of 0.53±0.05 was significantly different from preoperative gain (p<0.001). Findings in vestibular tests did not correlate with subjective sensation of dizziness.     

Value of pre-operative caloric test in predicting speech perception after cochlear implantation in adults with post-lingual hearing loss

Conclusion: This study shows that, in cochlear implantation (CI) surgery, pre-operative caloric test results are not correlated with post-operative outcomes of dizziness or speech perception.

Objectives: To determine the role of pre-operative caloric tests in CI.

Methods: The records of 95 patients who underwent unilateral CI were reviewed retrospectively. Patients were divided into four groups according to caloric response. Forty-six patients with normal caloric responses were classified as Group A, 19 patients who underwent CI in the ear with worse caloric responses as Group B, 18 patients with bilateral loss of caloric responses as Group C, and 12 patients who underwent CI in the ear with better caloric responses as Group D. Speech performance and post-operative dizziness were compared between the four groups. Speech perception was determined by evaluating consonant-vowel phoneme detection, closed-set word and open-set mono-syllabic and bi-syllabic word identification, and sentence comprehension test scores.

Results: The speech perception and aided pure-tone average (PTA) test results at 3 and 6 months and at 1, 2, and 3 years after implantation were not significantly different between Groups A, B, C, and D (p?>?0.05). Eight patients (8.4%) reported post-operative dizziness, but there was no significant difference between the four groups (p?=?0.627).     

Caloric test and video-head-impulse: a study of vertigo/dizziness patients in a community hospital

The head-impulse test (HIT) is an important test for examining unilateral vestibular hypofunction. The new video-head-impulse test (vHIT) is more sensitive and specific than the clinical bedside-head-impulse test (bHIT). Alternatively, one can test for vestibular hypofunction with the caloric irrigation test. Various studies showed that both tests may not always identify vestibular hypofunction; instead, the results of the tests might be contradictory. To evaluate the diagnostic value of these tests, we routinely measured patients exhibiting vertigo or dizziness at our community hospital with bithermal caloric irrigation, the bHIT and the vHIT. Only those patients (n = 172) with a pathological caloric irrigation test of more than 25 % unilateral weakness in the Jongkee’s formula were included. Out of these patients, 41 % had a pathologic vHIT. Among the subgroup with acute symptoms (symptom onset within 5 days), 63 % had a pathological video-head-impulse, whereas only 33 % of the non-acute group (symptom onset more than 5 days) tested pathological. A pathological HIT depended on the disease stage, the amount of unilateral weakness in caloric examination and on the test itself.     

Compared study of optokinetic and caloric nystagmus in children with unilateral hyporeflexia and other vestibular disorders

The authors compare the nystagmus evoked by the caloric test and by two slow and fast optokinetic 'look' stimulations performed in 78 subjects subdivided into two groups and recorded by ENG: group 1 composed of 22 subjects with 'significative' unilateral hyporeflexia and group 2 composed of 56 subjects with important anomalies at the vestibular caloric test. The results can be summarized as follows: 1. the presence of unilateral vestibular hyporeflexia is not exceptional in the child: 22 over 140 cases (15.7%); 2. the comparison between the caloric test and the OKN test in the 22 subjects with significant unilateral hyporeflexia shows: slow and fast TAP homolateral to the side with labyrinthine deficit prevails in ten subjects (45.4%); TAP is inconsistency with respect to the hyporeflexic side (i.e. homolateral in one test and contralateral in the other) in seven cases (31.8%); TAP is contralateral in five cases (22.7%). Within the same group, STAP varies according to cases. 3. In group II, TAP values at the OKN test overlap considerably with respect to the caloric test (18 cases with a total TAP prevailing on the right side, 32.2%; 19 cases with divergent TAP, 33.9%; 19 cases with total TAP prevailing on the left side, 33.9%). 4. The data shown in group 1 with significant vestibular hyporeflexia can be correlated to the time elapsed between the last electronystagmography and that performed soon after disease onset. Since for ENG performed some days after vertigo onset (even though clinical examination is negative) shows a concordance of OKN TAP and the hyporeflexic side (as the mechanisms of central compensation are still being developed) and then when these mechanisms improve with time, an inconsistency of OKN TAP and hyporeflexic side and finally a contralaterality. We might rely on the comparison between OKN TAP and caloric test as a finding of the time distance from the vertigo onset (when unknown) and a rough prognostic sign. The only case of vestibular neuritis by us followed in time seems to confirm our assumption.     

Video head impulse test relevance in the early postoperative period after cochlear implantation

Background: Cochlear implantation (CI) is the gold standard therapy for profound or severe sensorineural hearing loss. It is a safe surgical procedure but, because of the proximity of the cochlea and vestibule, postoperative vestibular disorder may occur. Our hypothesis is that the video head impulse test (vHIT) may be a good tool to achieve a topographic diagnosis of dizziness in the early postoperative period after CI.

Aims/Objectives: To evaluate patients with instability, imbalance and vertigo between 7 and 14 days after CI procedure.

Material and methods: A total of 31patients scheduled for unilateral CI were included in this study. vHIT for horizontal semicircular canal was performed before CI and between days 7 to 14 after the surgery.

Results: Six subjects had dizziness complaints after CI: instability (N?=?2), imbalance (N?=?2) and vertigo (N?=?2). The postoperative vHIT test turned abnormal only in subjects with vertigo as compared to the preoperative vHIT test results.

Conclusion and significance: vHIT is a good vestibular function test during the first 2 weeks after CI surgery when vertigo is the main complaint     

Vestibular function after cochlear implant surgery

Objective: The aim of this study was to analyze vestibular function in cochlear implant (CI) patients for iatrogenic damage to vestibular function.

Methods: Prospective clinical study. Tertiary care audiological center. Twenty-five subjects receiving surgery for cochlear implantation during 2012 and 2013 were analyzed. Both vestibulo-ocular and vestibulo-spinal responses before and 2 months after CI surgery were evaluated using several tests: analysis of spontaneous nystagmus, head shaking test (HST), and head impulse test recorded by videooculography; caloric stimulation at 44° and 30° in both ears; cervical evoked myogenic potentials and static stabilometry. Residual cochlear function was tested by air-conduction pure-tone audiometry.

Results: Our tests showed damage to vestibular receptors after CI surgery in 12% of the patients; in particular, horizontal semicircular canal function and saccular function had lower responses after surgery. Audiometric results showed poorer thresholds after CI surgery. The static stabilometry results indicate good vestibulo-spinal responses and patients did not report disequilibrium nor postural deficit.

Conclusion: All data suggest an efficient vestibular compensation mechanism in CI patients.     

Somatosensory shift of postural control in dizzy patients

Conclusions: Postural control is dependent on the visual system in normal conditions. Shift from visual to somatosensory dependence in dizzy patients suggests that utilizing the stable visual references is recommended for the rehabilitation of dizzy patients. Objectives: To investigate which of the visual or somatosensory system is mainly used for substitution of the impaired spatial orientation in dizzy patients. Methods: We recruited 189 consecutive patients with or without dizziness and vestibular dysfunction. Dizzy patients were divided into three groups: acute, episodic, and chronic dizziness. Vestibular function was assessed by caloric test, traditional head impulse test, and head shaking nystagmus. Visual or somatosensory dependence of spatial orientation was assessed by posturography on a solid surface or on foam in eyes open or closed condition. The foam ratio (posturography with/without foam) when eyes were closed was indicative of somatosensory dependence of postural control, whereas the Romberg ratio on foam showed visual dependence. (Romberg ratio on foam)/(foam ratio with eyes closed) was calculated and used as an index of the visual/somatosensory dependence of postural control. Results: The visual/somatosensory ratio of postural control was significantly lower in dizzy patients as well as patients with vestibular dysfunction, however, no differences were found between acute, episodic, and chronic dizziness.     

Vestibular dysfunction in cochlear implant candidates: Prevalence and outcomes

PurposeCochlear implantation (CI) has been shown to reduce vestibular function postoperatively in the implanted ear. The objective of this study was to identify the prevalence of preoperative vestibular weakness in CI candidates and identify any risk factors for postoperative dizziness.Study designRetrospective cohort study.Materials and methodsPatients who underwent CI and had preoperative videonystagmography (VNG) at the Silverstein Institute from January 1, 2017 to May 31, 2020 were evaluated. The primary endpoint was dizziness lasting more than one month postoperatively.ResultsOne hundred and forty nine patients were evaluated. Preoperative VNG revealed that 46 (30.9%) had reduced vestibular response (RVR) on one side and 32 (21.5%) had bilateral vestibular hypofunction (BVH). Postoperative dizziness occurred in 14 (9.4%) patients. Patients with postoperative dizziness were more likely to have abnormal preoperative VNG (RVR or BVH), compared to patients without postoperative dizziness (78.6% versus 49.6%, p = 0.0497). In cases of RVR, implantation of the weaker or stronger vestibular ear did not affect the postoperative dizziness (16.1% versus 6.7%, p = 0.38). Postoperative VNG in patients with dizziness showed decreased caloric responses in the implanted ear (28.4 to 6.4 degrees/s, p = 0.02).ConclusionPreoperative caloric weakness is prevalent in CI candidates and abnormal preoperative vestibular testing may be a predictor of postoperative dizziness. CI has the potential to cause vestibular injury and preoperative testing may aid in both counseling and decision-making.     

Prevalence of aphysiologic performance on dynamic posturography in work-related patients

Introduction and objectivesMedical-legal implications of dizziness and imbalance in work-related patients are important. In these cases, computerized dynamic posturography (CDP) adds information to standard vestibular tests and aphysiologic patterns have been described. The objective is to assess the prevalence of aphysiologic performance on CDP in work-related patients complaining of dizziness/imbalance.Material and MethodsRetrospective review of patients referred by the workers’ compensation board for assessment of dizziness, imbalance or both. Standard vestibular assessment including CDP was carried out in all patients. The sensory organization test (SOT) summaries were scored as normal, aphysiologic or vestibular using the scoring method published by Cevette et al. in 1995.ResultsAphysiologic performance in SOT, evaluated with the Cevette formula, was found in 31 out of 100 cases. Low composite score results and aphysiologic SOT results had a statistically-significant association (P=.01). Videonystagmography (VNG) was altered in 14 out of 31 cases with aphysiologic SOT.ConclusionThe 31% prevalence of aphysiologic results on CDP among work-related patients complaining of dizziness/imbalance is relatively high in comparison with the 25% published by Longridge and Mallinson in 2005. However, aphysiologic performance should not necessarily be related to malingering or exaggeration and altered vestibular tests are found in some of these cases.     

Does High‐Frequency Pseudo‐random Rotational Chair Testing Increase the Diagnostic Yield of the ENG Caloric Test in Detecting Bilateral Vestibular Loss in the Dizzy Patient?

OBJECTIVES: To assess the incremental diagnostic yield of testing vestibulo-ocular (VOR) gain with high-frequency pseudo-random rotational chair (PsRRC) over testing with bithermal electronystagmography caloric tests in the dizzy patient, particularly in detecting bilateral vestibular loss. PATIENTS AND METHODS: One hundred ninety-eight patients presenting with dizziness underwent PsRRC and caloric testing. The VOR gain on PsRRC was measured at 0.32 to 5.0 Hz, with gain categorized as normal or decreased. PsRRC results were compared with caloric responses, also categorized as normal, or into graded categories of unilateral or bilateral vestibular loss. RESULTS: Reduced PsRRC gain was found in 29 (15%) patients, and reduced caloric tests responses in 70 (35%), with 25 (13%) having bilateral loss. Of patients with reduced chair gain, 25 of 29 (86%) demonstrated bilateral caloric loss. PsRRC gain was normal in most patients with unilateral caloric weakness, but was decreased in all patients with bilateral caloric weakness. The probability of a patient with completely normal caloric responses having an abnormal rotation chair in this study group was under 1% (1 of 128). CONCLUSIONS: PsRRC testing does not offer much additional diagnostic benefit when caloric responses are normal. It is useful in specific conditions, such as unilateral caloric loss for which the patient is not compensating, borderline caloric loss when traditional water caloric tests cannot be used, or for monitoring progressive bilateral vestibular loss.     

Vestibular impairment and cochlear implantation

Conclusion. Cochlear implantation (CI) may induce vestibular impairment soon after surgery as well as after implant activation. This impairment seems to be independent from the cause of deafness and can be considered a possible complication from the intra-operative trauma and, to minor degree, from the ongoing electric stimulation. It would also seem that vestibular damage occurs independently from the likelihood of post-operative hearing deterioration. In unilateral selected CI cases, vestibular examination can be proposed as additional pre-operative exam for selection of the ear to be implanted. Objectives. This study has been planned in order to get evidence of eventual impairment of the vestibular apparatus after cochlear implantation as well as to verify whether the impairment could be related to different variables, such as cause of deafness, concomitant hearing deterioration, surgical trauma and duration of electrical stimulation. Method. Charts from two different populations of implantees have been reviewed, 21 from a prospective, 72 from a retrospective study, respectively. All the patients were implanted with Clarion® devices of different generation. Vestibular testing was based on rotatory, caloric (when possible) and stabilometric measurements, which were carried out pre-operatively and at the following different times: 5 weeks after CI surgery, and 30, 60 and 90 days after CI activation. Hearing thresholds were also assessed in those patients who showed signs of vestibular impairment as well as in a group of patients without vestibular disorders (control). Patients belonging to the retrospective group were all asked to fill a questionnaire regarding their balance condition. Results. In 14.3% of the prospective study group, a grade I and II spontaneous nystagmus was evidenced pre-operatively and remained unchanged during the whole assessment period. A grade II spontaneous nystagmus was present in 3 patients (21.4%) of the same group after surgery. In the immediate post-operative period, vestibular impairment was displayed as true rotational vertigo in 21.4% and unsteadiness in 42.8% of the study group. Severe unsteadiness was present during the first 2 days after activation in 14.3% of the subjects. In 21.4% of the patients a VPPB episode occured. In the retrospective study group, 26.4% of the subjects referred pre-operative dizziness and 25 patients (34.7%) referred immediate post-operative vertigo episodes, which remained in a milder form after CI activation in 12% of them. The hearing threshold showed to deteriorate in both vestibular-impaired and control CI population without significant difference.     

Dynamic vestibular compensation in vestibular peripheral diseases

Vestibular compensation, or neuronal plasticity in the central vestibular system, is quite an important process in patients with acute unilateral peripheral vestibular disease, allowing them to lead a comfortable daily life when medical treatments fail to cure the peripheral vestibular function. Is the residual unilateral vestibular input from damaged vestibular endo-organs a positive or negative factor for the development of dynamic vestibular compensation in the central nervous system? To elucidate the true mechanism of vestibular compensation, we examined the ENG findings and dizziness handicap inventory questionnaire in patients with vestibular neuronitis (VN), sudden deafness with vertigo (SDV), Meniere's disease (MD) and acoustic tumor (AT) during remission of the vertigo attacks. We obtained neuro-otological findings from caloric tests and head shaking after nystagmus using ENG and information on motion-evoked dizziness in daily life using the questionnaire. There were no significant differences in the sex, age or canal paresis % (CP%) among the four groups. The results of the present study showed that dynamic vestibular compensation processes developed progressively in the order of patients with SDV, VN, MD and AT (Kruskal-Wallis : p < 0.05). This finding suggests that processes of dynamic vestibular compensation could be accelerated in patients with fixed vestibular lesions caused by SDV and VN more than in those with fluctuating vestibular functions caused by MD and AT. In patients with fixed vestibular lesions caused by SDV and VN, patients with lower CP% showed dynamic vestibular compensation (i.e. disappearance of head shaking after nystagmus (chi-square: p < 0.05) and motion-evoked dizziness (Mann-Whitney: p < 0.0005)) more rapidly than those with higher CP%. In patients with fluctuating vestibular functions caused by MD and AT, patients with lower CP% did not always develop dynamic vestibular compensation more smoothly than those with higher CP%.     

Hearing loss and vertigo in superficial siderosis of the central nervous system

PURPOSE: Otoneurologic findings in patients with superficial siderosis (SS) of the central nervous system are described. A 20-year-old man with acute vertigo, dizziness, with a history of head trauma in childhood; an 87-year-old woman with severe disequilibrium appearing after peridural anesthesia; and a 55-year-old woman with recurrent episodes of positional vertigo and progressive ataxia, suffering from a lumbar ependymoma are described; all patients complained of progressive bilateral hearing loss and tinnitus.Methods and results Otoneurologic examination showed bilateral sensorineural hearing loss, disturbed ocular pursuit and optokinetic nystagmus, incomplete visual suppression of the vestibulo-ocular reflex during rotatory pendular testing, right hyporeflexia, and bilateral caloric areflexia. Cerebral magnetic resonance imaging (MRI) revealed rims of hypointensity surrounding the brainstem and linear hypointensities following the surface of the cerebellar folia. CONCLUSIONS: The etiology stems from subarachnoid hemorrhage, but the source of bleeding may remain obscure. Bilateral hearing loss is described in 95% and disequilibrium in 90% because of peripheral vestibular deficit and cerebellar ataxia. In patients with progressive bilateral cochleo-vestibular deficit of unknown etiology, MRI is the examination of choice to confirm SS.     

Caloric and Search-Coil Head-Impulse Testing in Patients after Vestibular Neuritis

The objective of this study was to compare results of quantitative head-impulse testing using search coils with eye-movement responses to caloric irrigation in patients with unilateral vestibular hypofunction after vestibular neuritis. The study population consisted of an acute group (<3 days; N = 10; 5 male, 5 female; 26-89 years old) and a chronic group (>2 months; N = 14; 8 male, 6 female; 26-78 years old) of patients with unilateral vestibular hypofunction after vestibular neuritis. The testing battery included: (1) simultaneous measurement of eye and head rotations with search coils in a magnetic coil frame during passive Halmagyi-Curthoys head-impulse testing and (2) electronystagmography during bilateral monaural 44 degrees C-warm and 30 degrees C-cold caloric irrigation. The main outcome measures were (1) the gain of the horizontal vestibulo-ocular reflex during search-coil head-impulse testing and (2) the amount of canal paresis during caloric irrigation. All acute and chronic patients had a unilateral gain reduction during search-coil head-impulse testing. A pathological canal paresis factor was present in 100% of the acute patients but in only 64% of the chronic patients. The clinically suspected unilateral vestibular hypofunction resulting from vestibular neuritis was validated in all acute patients by both search-coil head-impulse and caloric testing. Hence, either of these tests is sufficient for diagnosis in the acute phase of vestibular neuritis. Chronic patients, however, were reliably identified only by search-coil head-impulse testing, which suggests that the low-frequency function of the labyrinths often becomes symmetrical, leading to a normal canal paresis factor.     

Insights on different analysis techniques in the monothermal and bithermal caloric test – which parameter should we use to quantify vestibular function?

Objective: To investigate the use of maximum slow component velocity (MSCV) and time-constant duration (TC_d) of elicited nystagmus in quantifying the caloric response and to assess the efficacy of these parameters in the monothermal screening test. Design: Retrospective analysis of caloric results obtained from 150 patients. Bithermal unilateral weakness (UW), directional preponderance (DP), monothermal caloric asymmetry (MCA) based on warm or cool irrigations only, were calculated using both MSCV and TC_d. Study sample: 66 males and 84 females, aged 16–88 years (μ?=?50, σ?=?17), who underwent vestibular assessment. Results: The correlation-coefficient between bithermal caloric unilateral weaknesses calculated using either MSCV or TC_d is 0.155 (p?d and setting significant MCA at 5%, the sensitivity and specificity were respectively 90% and 77% for monothermal warm and 100% and 74% for monothermal cool tests. Conclusions: In the monothermal warm caloric test, MSCV can be used more reliably than monothermal cool to predict normal bithermal caloric response. The reverse is true if using TC_d. Unilateral-weakness calculated using TC_d and MSCV were poorly correlated and therefore likely to be demonstrating different aspects of vestibular function.     

Falls in patients with vestibular deficits

OBJECTIVE: To determine to what extent patients with vestibular hypofunction experience falls. STUDY DESIGN: Prospective clinical study. SETTING: Outpatient tertiary care facility in a university. PATIENTS: Patients with unilateral (n = 70) and bilateral (n = 45) vestibular hypofunction, confirmed on vestibular function testing, aged 24 to 89 years. INTERVENTION: None. MAIN OUTCOME MEASURE: Incidence of falls. RESULTS: There was a significant difference in the incidence of falls reported since the onset of the vestibular deficit by patients with unilateral (UVL) and bilateral (BVL) vestibular hypofunction. The incidence of falls for BVL was significantly greater than that for UVL. The incidence of falls for UVL was not different from that expected in a community-based population when age was considered. The incidence of falls for BVL was significantly greater than that reported for the general population aged 65 through 74 years (51.1% for BVL, 25% for community-dwelling individuals) but was significantly less than expected for persons aged > or =75 years (18.2% for BVL, 49% for community-dwelling individuals). The lower incidence of falls in patients with BVL aged > or =75 years may be related to the use of assistive devices and to a decrease in risky behavior. All patients with serious injury were from the UVL group, and all were >65 years old. The incidence of fall-related injuries requiring medical attention among patients with UVL was similar to that in community-dwelling individuals. CONCLUSIONS: Falls are an important consequence of bilateral vestibular hypofunction, and patients should be counseled about the increased risk of falling. Assistive devices should be considered, especially for persons aged >65 years with BVL.     

Typical sensory organization test findings and clinical implication in acute vestibular neuritis

Objective

Sensory organization test (SOT) is used to evaluate postural instability. We wanted to characterize the SOT findings in patients with acute vestibular neuritis (VN).

Caloric tests in clinical practice in benign paroxysmal positional vertigo

Background: The value of caloric tests in benign paroxysmal positional vertigo (BPPV) patients is unclear.

Objectives: To analyze the features and clinical significance of caloric tests in BPPV patients.

Materials and methods: About 2192 patients (256 BPPV and 1936 non-BPPV) who complained of dizziness triggered by movement, accompanied by the symptom of hearing loss or a history of vertigo, participated in this prospective clinical study. All subjects received a caloric test, 213 BPPV patients underwent follow-up for at least 6 months after canalith repositioning procedures (CRPs).

Results: (1) The abnormal canal paresis (CP) prevalence of BPPV was 57%. (2) The curative rate of single CRP decreased during follow-up from 90.1% after 7 days to 61% after 6 months and was significantly lower in patients with (54.1%) than in those without (70.1%) an abnormal CP at 6 months post-treatment (p?=?.01). (3) The recurrent rate was significantly higher in BPPV patients with abnormal CP (25.2%) than with normal CP (12.5%; p?=?.017).

Conclusions and significance: Patients with abnormal CP needed more CRPs and were more prone to relapse. The value of the caloric test in treatment planning and predicting recurrence in BPPV patients should be emphasized.     

Unilateral Vestibulotoxicity Due to Systemic Gentamicin Therapy

Systemic gentamicin can cause acute bilateral, simultaneous, symmetrical loss of vestibular function manifested by symptoms and signs of chronic vestibular insufficiency (ataxia and oscillopsia). We report 6 patients presenting with ataxia and oscillopsia, but without a history of vertigo, who had severe unilateral loss of vestibular function on caloric testing. The absence of vertigo in these patients could be explained by two possible mechanisms: either, the unilateral loss of vestibular function was subacute, occurring over several days so that compensation could occur, or bilateral vestibular loss occurred which was then followed by asymmetrical recovery of vestibular function. The second hypothesis is supported by the observation that vestibular hair cells can regenerate after aminoglycoside damage.     

The video ocular counter-roll (vOCR): a clinical test to detect loss of otolith-ocular function

Conclusion: vOCR can detect loss of otolith-ocular function without specifying the side of vestibular loss. Since vOCR is measured with a simple head tilt maneuver, it can be potentially used as a bedside clinical test in combination with video head impulse test.

Objective: Video-oculography (VOG) goggles are being integrated into the bedside assessment of patients with vestibular disorders. Lacking, however, is a method to evaluate otolith function. This study validated a VOG test for loss of otolith function.

Methods: VOG was used to measure ocular counter-roll (vOCR) in 12 healthy controls, 14 patients with unilateral vestibular loss (UVL), and six patients with bilateral vestibular loss (BVL) with a static lateral head tilt of 30°. The results were compared with vestibular evoked myogenic potentials (VEMP), a widely-used laboratory test of otolith function.

Results: The average vOCR for healthy controls (4.6°) was significantly different from UVL (2.7°) and BVL (1.6°) patients (p?R?=?0.45, tap oVEMP R?=?0.51; p?p?=?0.59).