Clinical diagnoses of patients showing caloric inversion.

OBJECTIVES: When air irrigation is used for caloric stimulation in patients with a perforated ear, warm irrigation may elicit a nystagmus that initially beats in the opposite direction of what is expected for warm irrigations, which is referred to as "caloric inversion". This study aimed to investigate the disease group in which caloric inversion appeared in patients who underwent caloric testing and to classify the patterns of caloric inversion. METHODS: We conducted a retrospective review of bithermal caloric test results that were collected in our dizziness clinic between 2005 and 2022. Caloric inversion was defined when nystagmus induced by caloric stimulation appeared in the opposite direction to that expected. The incidence of caloric inversion among all patients who underwent bithermal caloric tests was calculated. To confirm the clinical diagnoses of the patients with caloric inversion, their clinical records were reviewed. RESULTS: Out of 9923 patients who underwent bithermal caloric tests, 29 patients (0.29%) showed a caloric inversion. The most common clinical diagnosis was chronic otitis media (21 of 29, 72%). Of the 21 patients with chronic otitis media, 20 patients showed a caloric inversion by warm air irrigation and one patient showed caloric inversion by cold air stimulation. Patients with clinical diagnoses other than chronic otitis media such as sudden sensorineural hearing loss, benign paroxysmal vertigo of childhood and recurrent vestibulopathy showed caloric inversion by warm air irrigation. Caloric inversion by warm water irrigation was observed in patients with lateral semicircular canal cupulopathy and recurrent vestibulopathy. Two patients (one with Meniere's disease and one with age-related dizziness) showed caloric inversion by cold water irrigation. CONCLUSION: Caloric inversion can be observed in various diseases other than chronic otitis media with tympanic membrane perforation. Special care should be taken in the interpretation of caloric test results. LEVEL OF EVIDENCE: Level 4.

Dissociation between video head impulse test and caloric test: a marker of menière's disease? - A systematic review and meta-analysis.

OBJECTIVE: To analyze, by means of a systematic review and meta-analysis, the proportion of patients with Meniere's disease who have altered caloric test and vHIT, as well as to determine the prevalence of altered caloric test and normal vHIT dissociation in the diagnosis of Meniere's disease. METHODS: The literature search had no restriction regarding the period of publication on the following indexed data platforms: PubMed, PubMed PMC, BVS-Bireme, Web of Science, Embase and Cochrane Library. Articles that evaluated patients with Meniere's disease who underwent caloric test and vHIT were included. Two researchers independently conducted the analysis of the articles, promoting the selection and capture of data, following the recommendations of the PRISMA method, and complying with the criteria for articles inclusion and exclusion defined in the research protocol. In case of disagreement during the selection process, a third researcher was included for analysis. RESULTS: From a total of 427 initial studies, the researchers selected 12 articles, published between 2014 and 2021, with a total of 708 patients evaluated, with a mean age of 52.72 years old. The prevalence of patients with Meniere's disease with altered caloric reflex test was 64% (95% CI 57%‒71%), while the prevalence of altered vHIT was only 28% (95% CI 16%-40%). The prevalence of the altered caloric test + normal vHIT dissociation was 47% (95% CI 37%-57%). CONCLUSION: The video head impulse test and the caloric test are valuable tools for vestibular assessment. The dissociation of findings between these two tests in patients with Meniere's disease was more prevalent in this meta-analysis and may be a result of the tonotopy of specialized hair cells in the ampullary crest. The prevalence of altered caloric test was 64% and anormal vHIT was 28%. The dissociation caloric asymmetry and normal vHIT was observed in 47% of the patients.

Comparison between caloric and video-head impulse tests in Ménière's disease and vestibular neuritis.

OBJECTIVE: To compare the diagnostic accuracies of air caloric testing with electronystagmography and the vHIT (video-head impulse test). DESIGN: Prospective, controlled study. STUDY SAMPLE: MD (Ménière's disease), 26; vestibular neuritis, 27; control, 56. RESULTS: In MD, CP (canal paresis) was pathological in 88.5%, the GA (gain asymmetry) on vHIT was pathological in 65.3%, and the gain was abnormal in only one patient. The GA and CP, were significantly higher in the MD group than in the control group, indicating hypofunction of the horizontal canals in MD, whereas a hyperfunction may also occur. No correlation was observed between the results of the two tests for evaluating MD, suggesting that pathological outcomes of one test do not guarantee abnormalities on the other test. For vestibular neuritis, significantly higher CP (96.3%), GA (81.5%), and gain (51.9%) values were detected. A correlation was identified between the two tests for vestibular neuritis, indicating a similar diagnostic efficiency. The higher percentage of pathological GA versus pathological gain values indicates that the asymmetry may be more informative. CONCLUSIONS: The vHIT showed a higher specificity, whereas the caloric test a higher sensitivity. No correlation between the two methods was observed; therefore, the tests appear to provide complementary information.

Effects of endolymphatic space volume on discrepancy of results between caloric test and video head impulse test.

OBJECTIVE: The caloric test (C-test) and video head impulse test (vHIT) are known to occasionally show contradictory results in patients with Meniere's disease (MD). The reasons underlying this discrepancy between the two tests are currently unclear. We aimed to reveal the mechanisms responsible for this discrepancy by performing volumetric evaluation of the endolymphatic space (ELS) by using endoluminal contrast-enhanced inner ear MRI (ieMRI). METHODS: We enrolled 136 patients (174 ears) who visited the vertigo/dizziness center of our university and underwent the C-test and vHIT between February 2018 and February 2020. Inner ear MRI was also performed to determine the presence of endolymphatic hydrops (EH). The percentage of patients diagnosed with each vestibular disease was as follows: MD, 23.0%; benign paroxysmal positional vertigo (BPPV), 17.8%; bilateral vestibular disorder (BVD), 9.2%; sudden deafness with vertigo (SD), 8.0%; peripheral dizziness (PD), 7.5%; unilateral vestibular disorder (UVD), 6.9%; vestibular neuritis (VN), 6.3%; delayed endolymphatic hydrops (DEH), 3.4%; central dizziness (CD), 2.9%; Hunt syndrome (Hunt), 1.2%; and other disorders (OD), 13.8%. RESULTS: Among the ears in the present study, 46.0% (80/174) showed a discrepancy in the results of the C-test and vHIT, and the disease-related distribution of patients showing this discrepancy was as follows; MD, 38.8% (27/80; p = 0.0019); BVD, 13.8% (11/80); UVD, 12.5% (10/80); SD, 7.5% (6/80); BPPV, 6.3% (5/80); PD, 6.3% (5/80); VN, 3.8% (3/80); DEH, 3.8% (3/80); CD, 2.5% (2/80); Hunt, 0.0% (0/80); and OD, 10.0% (8/80). In all cases, the discrepancy presented as a positive C-test result and negative vHIT result. The ELS ratio was measured for the whole inner ear, cochlea, vestibule, and semicircular canal, and the relationships between the rates and the presence of discrepancy was examined. Inner ear ELS ratio was 17.9% ± 10.8% in patients with the discrepancy and 15.2% ± 8.8% in those without the discrepancy (p = 0.036). Cochlear ELS ratio was 14.9% ± 11.3% in patients with the discrepancy and 11.9% ± 10.3% in those without the discrepancy (p = 0.0012). Vestibular ELS ratio was 22.3% ± 16.2% in patients with the discrepancy and 17.2% ± 12.7% in those without the discrepancy (p = 0.032). Semicircular canal ELS ratio was 18.0% ± 11.0% in patients with the discrepancy and 16.5% ± 9.6% in those without the discrepancy (p = 0.442). CONCLUSION: The volume of the ELS may affect the discrepancy of results between the C-test and vHIT.

Concordance of vestibular test batteries in patients with vestibular neuritis.

BACKGROUND: A growing number of vestibular function tests are utilized to differentiate and verify the diagnosis of vestibular neuritis. The aim of this study is to retrospectively investigate the consistency of the results of the objective vestibular test batteries in patients with a preliminary diagnosis of vestibular neuritis. METHODS: We reviewed a total of 37 adult patients (mean age: 39.03 ± 11.67, 19 females, 18 males) who met the inclusion criteria with a prediagnosis of vestibular neuritis from 379 patients suffering vestibular symptoms. Caloric test (CVT), video head impulse test (vHIT), and ocular and cervical VEMP tests were compared with Cohen's kappa (Κ) analysis according to the likely affected part of the vestibular nerve. RESULTS: The highest statistically significant K value was found between horizontal vHIT and ocular VEMP (K = 0.707; good grade, p < 0.05). All the tests compared with CVT were poorly in agreement (K = 0.288; 0.262; 0.256 for HvHIT, oVEMP, AvHIT, respectively, p < 0.05). DISCUSSION: VEMP and vHIT tests have prominent diagnostic value and agree with each other for detecting and differentiating the types of vestibular neuritis. Further studies should aim to include cutting-edge technologies such as functional HIT and ocular counter roll test.

[Dissociation of the results of caloric and video head impulse tests as a marker of Meniere's disease]. / Dissotsiatsiya kaloricheskogo i videoimpul'snogo testov u patsientov s bolezn'yu Men'era.

The study of vestibular function in patients with Meniere's disease (MD) is an urgent task, since it influences the choice of treatment tactic. We evaluated the results of caloric and video head impulse (vHIT) tests in 76 patients who met the clinical criteria for significant Meniere's disease (AAO-HNS modified by the Barany Society, 2015). Dissociation of the results of caloric and vHIT tests is observed in the majority (74%) of patients with MD: at normal gain, according to vHIT data, hypofunction of peripheral vestibular structures is recorded according to the caloric test (KASL 47 ± 7.8%). In patients with MD, vestibular dysfunction is observed mainly at low frequencies (0.003 Hz), therefore vHIT, which allows assessing horizontal semicircular canal function at high frequencies (3-5 Hz), is not an optimal study for assessing the degree of vestibular dysfunction in patients with MD.

Discordant vestibulo-ocular reflex function according to the frequency and mode of stimulation.

This study aimed to determine the incidence, pattern, and etiology of dissociated vestibulo-ocular reflex (VOR) function according to the stimulus frequency in dizzy patients. We retrospectively evaluated the results of bithermal caloric tests and video-head impulse tests (vHITs) in 1022 patients with dizziness or vertigo between July 2016 and April 2021. Patients were classified into concordant group (normal or abnormal results on both tests) and discordant group (dissociated results between two tests). Of 1022 patients, discordant group had 159 (16%), comprising abnormal horizontal vHITs with normal caloric responses (n = 36, 23%) and abnormal caloric tests with normal horizontal vHITs (n = 123, 77%). The former group showed similar frequency of peripheral (44%) and central (42%) causes, and more common involvement of bilateral horizontal semicircular canals in central than peripheral causes (86.7 vs 37.5%, p = 0.005). The most common peripheral causes were Meniere's disease and chronic vestibular neuritis, while central causes were variable, but mainly affecting the cerebellum. In the latter group, peripheral causes were common (67%), with the main etiologies being Meniere's disease and vestibular neuritis, whereas central causes were found in only 5%. The degree of canal paresis did not differ significantly between patients with central and peripheral causes. Discordant VOR function according to the stimulus frequency was not uncommon in dizzy patients. Specific patterns of VOR dissociation according to the disease etiologies may offer insight into underlying pathophysiology.

Differences in responsiveness of intratympanic steroid injection for intractable vertigo in Meniere's disease.

OBJECTIVES: The efficacy of intratympanic steroid (ITS) injection for intractable Meniere's disease has been reported; however, its differences in responsiveness are not fully understood. This study investigated the clinical characteristics of patients who responded to ITS injection treatment. METHODS: This retrospective study included 32 patients with Meniere's disease who were unable to control frequent vertigo attacks despite conservative treatment for at least 3 months. They received an intratympanic injection of dexamethasone (3.3 mg/mL) in the affected side at least three times. We measured hearing threshold, subjective symptom scores, cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP), and performed glycerol and bithermal caloric tests. RESULTS: Satisfactory control of vertigo for 1 year after the first round of injection was found in 18 patients (56.3%; the response group). However, the injections failed to control vertigo in the other 14 patients (43.8%; the non-response group), and they were then treated with middle ear micropressure therapy. The response group showed improvement in low-frequency hearing, whereas hearing acuity did not change in the non-response group. Significantly reduced amplitude of cVEMP on the affected side was found in 62.5% of patients in the response group; however, no patients in the non-response group showed reduced amplitude of cVEMP. CONCLUSIONS: ITS injection significantly improved the subjective symptoms for intractable Meniere's disease; however, the long-term effects were heterogeneous. Our results suggest that reduced amplitude in cVEMP is associated with the effectiveness of ITS injection treatment.

Preoperative Differences in Intracranial Facial Versus Vestibular Schwannomas: A Four Nerve Assessment.

OBJECTIVES: Assesses whether preoperative functional testing can distinguish vestibular schwannomas from facial nerve schwannomas medial to the labyrinthine segment. STUDY DESIGN: Retrospective cohort. METHODS: Retrospectively review surgically managed intracranial facial and vestibular schwannomas between January 2015 and December 2019 at two tertiary care centers. Patients with neurofibromatosis 2 and surgery for recurrence were excluded. Preoperative functional testing to include House-Brackmann scores, electroneuronography (ENoG), cervical vestibular evoked myogenic potentials (cVEMP), caloric testing, acoustic brainstem responses (ABRs), acoustic reflexes, and audiograms was compared between the two groups of schwannomas. RESULTS: Twelve facial and 128 vestibular schwannomas met inclusion criteria. In only one case was a facial schwannoma diagnosed preoperatively from imaging. No statistically significant difference was found in preoperative House-Brackmann scores, ENoG, cVEMP, caloric testing, ABRs, or acoustic reflexes. Pure tone average was worse in the vestibular schwannoma group (63 dB [95% CI: 58-68 dB] vs. 46 dB [95% CI: 34-58 dB], P = .01), and the difference was more apparent in the lower frequencies. Word recognition score was better in the facial schwannoma group (66% [95% CI: 45-86%] vs. 41% [95% CI: 34-47%], P = .02). CONCLUSION: Specialized preoperative functional evaluation of the nerves of the internal auditory canal cannot reliably predict the presence of an intracranial facial schwannoma. Hearing is better in facial schwannomas, particularly in the lower frequencies. This should raise the index of suspicion for an intracranial facial schwannoma, especially in candidates for hearing preservation vestibular schwannoma surgery. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2098-2105, 2021.

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.

Influence of vestibular rehabilitation on the recovery of all vestibular receptor organs in patients with unilateral vestibular hypofunction.

BACKGROUND: Only a few studies in the literature demonstrate the effect of vestibular rehabilitation (VR) on all vestibular receptor organs. Furthermore, very little evidence of the effect of VR on isolated otolith dysfunction (IOD) is available. OBJECTIVE: The study aimed to investigate the effect of VR on all vestibular receptor organs in patients with different types of unilateral vestibular hypofunction (UVH). METHODS: We enrolled 80 patients with three different types of UVH; combined and isolated loss of semicircular canal and otolith organ function. All patients performed a 12-week customized program of VR and received a full battery of vestibular function tests, before and after the VR. The DHI and SF-36 were performed before, after 6 weeks, and 12 weeks of the VR. RESULTS: Parameters of the caloric test, video head impulse test, ocular and cervical vestibular evoked myogenic potentials were significantly improved after VR. A total of 59 (74%) patients fully recovered, with no significant difference in recovery regarding the type (p = 0.13) and stage of UVH (p = 0.13). All patients reported significantly lower disability and a better quality of life after the VR based on the DHI and SF-36 score. CONCLUSIONS: Vestibular rehabilitation has a positive effect on the recovery of all vestibular receptor organs and it should be used in patients with IOD.

Vestibular and oculomotor abnormalities among HIV-infected and HIV-uninfected men and women: A pilot study.

OBJECTIVE: To determine if middle-aged and aging men and women with HIV disease (HIV+) should be screened for vestibular and oculomotor dysfunction. METHODS: Age- and sociodemographically matched HIV+ and HIV- men and women were tested on vestibular evoked myogenic potential (VEMP), bi-thermic caloric testing, Dix-Hallpike maneuvers and saccades. RESULTS: HIV+ men had more caloric weakness than HIV- men. HIV+ subjects had more saccade abnormalities than HIV- subjects. A saccade abnormality was positively associated with being HIV+. Among the HIV+ sample, abnormalities were associated with increasing age, being male, ever taking monotherapy, and having an undetectable viral load. Only being male and having an undetectable viral load were statistically significant. Unilateral caloric weakness had a decreased prevalence with age per 10 years, and being HIV+ showed an increased prevalence. In HIV+ subjects only, these abnormalities decreased with age and being male but increased with undetectable viral load and ever taking antiretroviral monotherapy. No statistically significant differences were found. CONCLUSION: Women are at greater risk of vestibular and oculomotor abnormalities than men. HIV+ adults are at greater risk than HIV- adults. Physicians who care for HIV+ men and women should monitor the symptoms of vestibular and oculomotor impairment.

The vestibular implant: Opinion statement on implantation criteria for research.

This opinion statement proposes a set of candidacy criteria for vestibular implantation of adult patients with bilateral vestibulopathy (BVP) in a research setting. The criteria include disabling chronic symptoms like postural imbalance, unsteadiness of gait and/or head movement-induced oscillopsia, combined with objective signs of reduced or absent vestibular function in both ears. These signs include abnormal test results recorded during head impulses (video head impulse test or scleral coil technique), bithermal caloric testing and rotatory chair testing (sinusoidal stimulation of 0.1 Hz). Vestibular implant (VI) implantation criteria are not the same as diagnostic criteria for bilateral vestibulopathy. The major difference between VI-implantation criteria and the approved diagnostic criteria for BVP are that all included vestibular tests of semicircular canal function (head impulse test, caloric test, and rotatory chair test) need to show significant impairments of vestibular function in the implantation criteria. For this, a two-step paradigm was developed. First, at least one of the vestibular tests needs to fulfill stringent criteria, close to those for BVP. If this is applicable, then the other vestibular tests have to fulfill a second set of criteria which are less stringent than the original criteria for BVP. If the VI-implantation is intended to excite the utricle and/or saccule (otolith stimulation), responses to cervical and ocular vestibular evoked myogenic potentials must be absent in addition to the above mentioned abnormalities of semicircular canal function. Finally, requirements for safe and potentially effective stimulation should be met, including implanting patients with BVP of peripheral origin only, and assessing possible medical and psychiatric contraindications.

The feasibility, validity and reliability of a child friendly vestibular assessment in infants and children candidates to cochlear implant.

OBJECTIVES: The pediatric vestibular assessment has developed significantly in the past two decades, especially in terms of assessment of cochlear implant (CI) candidates. Different methods and test protocols have been applied, however without a general consensus. We present here the feasibility, validity and reliability of a child friendly vestibular testing in use at our department for the assessment of pediatric CI candidates. METHODS: The test battery consisted of head impulse test (HIT), video head impulse test (vHIT), cervical evoked myogenic potentials (cVEMP) and mini ice water caloric test (mIWC), all adapted from previous methods, mentioned in literature. We defined specific criteria for test feasibility, for test validity and test positivity (i.e. indicating vestibular insufficiency). The reliability of the whole protocol was assessed with test agreement analysis. RESULTS: Complete data from 35 children, all CI candidates, age ranging 4-79 months (67% under 2 years) and recruited over two years, were obtained. All but one child could complete at least one test with valid responses bilaterally, with the best compliance for HIT (97,1%) and least for cVEMP (68,6%). Feasibility did not appear to be affected by age or hearing loss etiology. Among the valid responses there was a substantial test agreement between HIT and vHIT, moderate agreement between vHIT/HIT and mIWC and no apparent agreement between the canal tests and cVEMP. Simple clinical guidelines were introduced to solve the tests' disagreement and to improve the protocol reliability: a) a pathological response had to be confirmed in at least two different canal tests and in at least three cVEMP trials; b) a canal/otolith disagreement was interpreted as a partial vestibular loss to be opposed to a complete vestibular insufficiency. CONCLUSIONS: The search for vestibular insufficiency in infants and young children can be attained with an opportunely adapted vestibular assessment, such the test battery proposed here. That assessment resulted easy to conduct and to interpret in a representative sample of CI candidates in preschool age, the most of whom were younger than 2 years. This method appears to particularly suit the demands of a vestibular assessment in young children CI candidates.

Prospective cohort study on the predictors of fall risk in 119 patients with bilateral vestibulopathy.

OBJECTIVES: To identify predictive factors for falls in patients with bilateral vestibulopathy (BV). Specific variables contributing to the general work-up of a vestibular patient were compared between BV patients experiencing falls and those who did not. DESIGN: Prospective multi-centric cohort study. SETTING: Department of Otorhinolaryngology & Head and Neck Surgery at two tertiary referral centers: Antwerp University Hospital and Maastricht University Medical Center. PARTICIPANTS: In total, 119 BV patients were included. BV diagnosis was defined in accordance with the diagnostic BV criteria, established by the Bárány Society in 2017. MAIN OUTCOME MEASURES: Patients were divided into fallers and non-fallers, depending on the experience of one or more falls in the preceding 12 months. Residual vestibular function on caloric testing, rotatory chair testing, video head impulse test (vHIT) and cervical vestibular evoked myogenic potentials (cVEMP) was evaluated as a predictive factor for falls. Furthermore, hearing function (speech perception in noise (SPIN)), sound localization performance, etiology, disease duration, sport practice, scores on the Dizziness Handicap Inventory (DHI) and the Oscillopsia Severity Questionnaire (OSQ) were compared between fallers and non-fallers. RESULTS: Forty-five (39%) patients reported falls. In a sub-analysis in the patients recruited at UZA (n = 69), 20% experienced three or more falls and three patients (4%) suffered from severe fall-related injuries. The DHI score and the OSQ score were significantly higher in fallers. Residual vestibular function, SPIN, sound localization performance, etiology, disease duration, age and sport practice did not differ between fallers and non-fallers. CONCLUSIONS: Falls and (severe) fall-related injuries are frequent among BV patients. A DHI score > 47 and an OSQ score > 27.5 might be indicative for BV patients at risk for falls, with a sensitivity of 70% and specificity of 60%. Residual vestibular function captured by single vestibular tests (vHIT, calorics, rotatory chair, cVEMP) or by overall vestibular function defined as the number of impaired vestibular sensors are not suitable to distinguish fallers and non-fallers in a BV population.

The "broken escalator" phenomenon: Vestibular dizziness interferes with locomotor adaptation.

BACKGROUND: Although vestibular lesions degrade postural control we do not know the relative contributions of the magnitude of the vestibular loss and subjective vestibular symptoms to locomotor adaptation. OBJECTIVE: To study how dizzy symptoms interfere with adaptive locomotor learning. METHODS: We examined patients with contrasting peripheral vestibular deficits, vestibular neuritis in the chronic stable phase (n = 20) and strongly symptomatic unilateral Meniere's disease (n = 15), compared to age-matched healthy controls (n = 15). We measured locomotor adaptive learning using the "broken escalator" aftereffect, simulated on a motorised moving sled. RESULTS: Patients with Meniere's disease had an enhanced "broken escalator" postural aftereffect. More generally, the size of the locomotor aftereffect was related to how symptomatic patients were across both groups. Contrastingly, the degree of peripheral vestibular loss was not correlated with symptom load or locomotor aftereffect size. During the MOVING trials, both patient groups had larger levels of instability (trunk sway) and reduced adaptation than normal controls. CONCLUSION: Dizziness symptoms influence locomotor adaptation and its subsequent expression through motor aftereffects. Given that the unsteadiness experienced during the "broken escalator" paradigm is internally driven, the enhanced aftereffect found represents a new type of self-generated postural challenge for vestibular/unsteady patients.

Recognizing Decompensated Meniere's Disease Using High Frequency Rotational Test.

OBJECTIVES: The purpose of this study is to investigate the effectiveness of the high-frequency rotational test for discrimination of patients with decompensated from those with compensated Meniere's disease. MATERIALS AND METHODS: Patients with unilateral Meniere's disease were divided into two groups (compensated and decompensated), based on the presence of clinically significant positional nystagmus as a determinant of the compensation status. All patients and subjects underwent pure tone audiometry, video nystagmography, and the vestibular autorotation test (VAT). The gain, phase, and asymmetry values of VAT were evaluated to range between 2 and 6 Hz. RESULTS: Phase values of horizontal vestibulo-ocular reflex (VOR) at 2.0, 2.3, and 2.7 Hz were significantly higher in the decompensated group (p<0.05). There was no significant difference in gain values, phase values, of vertical VOR and horizontal asymmetry values. CONCLUSION: Our study confirmed that horizontal phase values were determined as sensitive markers in VAT to discriminate decompensated from compensated Meniere's disease.

Eye movements and imaging in vestibular migraine / Movimientos oculares y pruebas de imagen en migraña vestibular

BACKGROUND AND OBJECTIVE: Migrainous dizziness is one of the most frequent complaints. Dizziness associated with migraine may be the result of abnormal eye movements. Brain imaging and changes in eye movements may explain the dizziness and highlight possible pathophysiological substrates in migraine dizziness. Our aim is to evaluate eye movement using videonystagmography (VNG) and video head impulse test (vHIT) and to study the occipital lobe metabolic profile in vestibular migraine patients (VM). MATERIALS AND METHODS: There were 2 groups enrolled in the study; the first group consisted of 25 vestibular migraine patients (VM) according to the recent criteria of Barany society. The second group consisted of 20 age matched healthy subjects. Both groups underwent the following: (1) A detailed history, VNG test protocol, vHIT in three planes. (2) Magnetic resonance imaging (MRI) for the brain and inner ear using 1.5 T magnet and proton magnetic resonance spectroscopy (H1-MRS). RESULTS: Sixty eight percent of the patients complained of spontaneous vertigo and 28% complained of positional vertigo. Non-paroxysmal positional nystagmus was recorded in 92% during their dizzy spell. The brain MRI was unremarkable in 72% of the cases. Chemical shift in the occipital lobe was found in 92% of VM. Lactate peaks were statistically significant related with the presence of non-paroxysmal positional nystagmus. CONCLUSIONS: A statistically significant relationship exists between non-paroxysmal positional nystagmus and presence of lactate peaks in the occipital lobe in VM patients

ANTECEDENTES Y OBJETIVO: El mareo migrañoso es una de las quejas más frecuentes. Las pruebas de imagen del cerebro y los cambios en los movimientos oculares pueden explicar los mareos y destacar los posibles sustratos fisiopatológicos en la migraña vestibular. Nuestro objetivo fue evaluar el movimiento ocular utilizando videonistagmografía (VNG) y la prueba de impulso cefálico por vídeo (vHIT), y estudiar el perfil metabólico del lóbulo occipital en pacientes con migraña vestibular (VM). MATERIALES Y MÉTODOS: Se incluyeron dos grupos en el estudio; el primer grupo consistió en 25 pacientes con VM según los criterios recientes de la sociedad Bárány. El segundo grupo consistió en 20 sujetos sanos emparejados por edad. Ambos grupos se sometieron a lo siguiente: 1) Una historia detallada, protocolo de prueba de VNG y vHIT en 3 planos, y 2) Imágenes de resonancia magnética (IRM) para el cerebro y el oído interno con el imán de 1,5 tesla y la espectroscopía de resonancia magnética de protones (H1-MRS). RESULTADOS: El 68% de los pacientes se quejó de vértigo espontáneo, y el 28% de vértigo posicional. El nistagmo posicional no paroxístico se registró en el 60% de los pacientes durante su mareo. La resonancia magnética cerebral no mostró alteraciones en el 72% de los casos. El cambio químico en el lóbulo occipital se encontró en el 92% de los casos de VM. Los picos de lactato fueron estadísticamente significativos con relación a la presencia de nistagmo posicional no paroxístico. CONCLUSIONES: Existe una relación estadísticamente significativa entre el nistagmo posicional no paroxístico y la presencia de picos de lactato en el lóbulo occipital en pacientes con VM

Nystagmus duration after caloric irrigations.

Objective: To measure nystagmus duration after warm and cool caloric water irrigations, with the aim of providing preliminary evidence for the optimum interval between irrigation onsets; and to compare nystagmus durations between warm and cool irrigations, in addition to maximum slow phase velocity (SPV).Design: Participants underwent up to four caloric irrigations during routine appointments. Nystagmus was recorded to minimal levels (within 2°/s of subject's baseline). The nystagmus duration and maximum SPV were measured.Study Sample: 52 vestibular assessment patients (99 ears).Results: The mean nystagmus duration was 183.9 s (seconds) (3:04 min) from irrigation onset, and nystagmus became minimal after 264.8 s (4:25 min) in 97.5% of this sample. The population mean is within ±6.7 s of the sample mean (p = <0.001). There was no significant difference between warm and cool irrigation durations, and correlation and linear regression analysis showed duration cannot reliably be predicted by maximum SPV.Conclusions: Mean nystagmus duration (3 min after irrigation onset) and nystagmus duration for 97.5% of patients (<4.5 min) were substantially less than the BSA recommended 7 min between irrigations. These findings provide preliminary evidence for shortening of intervals between stimulus onsets, regardless of irrigation temperature or maximum SPV, to reduce caloric testing time and improve clinical efficiency.

Video head impulse test and caloric test in definite Ménière's disease.

PURPOSE: The objective of the study was to compare the results of caloric reflex tests and video head impulse tests (vHITs) of lateral semicircular canals (SCCs). METHODS: Patients aged over 18 years diagnosed with definite Ménière's disease (MD) according to the AAO-HNS 1995 criteria were recruited. Audiological tests, caloric tests and vHITs were conducted on all participants. A caloric weakness (canal paresis) of > 25% was considered significant. A VOR gain of < 0.8 in lateral or 0.7 in vertical SCCs was defined as significant. Patients were classified into active (having symptoms during the preceding 3 months) and inactive groups (free of symptoms for over 3 months). RESULTS: 51 patients (13 males and 38 females) participated. Caloric weakness was found in 39 patients (76.5%), while abnormal VOR gain was found in 24 (47.1%). The active group had 40 patients, and the inactive group had 11. There was statistical significance (p, 0.002) for disease duration but not for the caloric weakness and vHIT results of the two groups. Moreover, caloric weakness with an abnormal vHIT was not statistically significant, and there was no correlation between the two tests (r, 0.207) in lateral SCCs. The most common abnormal VOR gain in patients with caloric weakness was found in anterior SCCs. CONCLUSIONS: The caloric test can detect abnormalities of the vestibular function better than vHIT in all stages of MD. However, the vHIT showed more specificity for the detection of abnormal SCC function. The vHIT test can be used as a screening tool and the caloric test should be considered if a vHIT result is normal.