Effects of nonprescription therapies on vestibular migraine: a questionnaire-based observational study.

BACKGROUND: Vestibular migraine (VM) is a common cause of recurrent vertigo. Migraine headache preventative therapies are currently prescribed to control vertigo symptoms in VM. Clinical trials of nutraceuticals for migraine headache prevention have shown positive outcomes, but, to date, there have been no studies to assess their effectiveness in the management of VM. AIMS: To report the effects of nonprescription therapy management on VM symptoms. METHODS: We undertook a prospective, questionnaire-based assessment of patients diagnosed with VM between November 2019 and August 2021 at two Sydney tertiary referral clinics. Patients were advised on optimising sleep, hydration, exercise and nutrition and instructed to use an over-the-counter combination product containing riboflavin 200 mg, magnesium 150 mg, coenzyme Q10 75 mg and feverfew 200 mcg. Symptom severity and frequency were assessed using the Dizziness Handicap Inventory (DHI), the Vertigo Symptom Score short-form (VSS-sf) and two visual analogue scales for severity (VAS-s) and frequency (VAS-f) before and 3 months after commencing treatment. RESULT: In 82 participants (78% female; mean age, 44 ± 14 years) we recorded a decrease in DHI (mean, 16.8 [95% confidence interval (CI), 12.8-20.9], VSS-sf (9.3, 7.1-11.5), VAS-s (3.0, 2.2-3.8) and VAS-f (2.8, 2.1-3.4), equating to an improvement of 44.1%, 44.9%, 44.1% and 38.9% for each measure respectively. On the DHI and VSS-sf, 41 (50%) and 44 (53.7%) patients showed improvement in their symptoms; 39 (47.6%) and 36 (43.9%) patients noted no change and two patients reported worsening. The supplement was well-tolerated. CONCLUSIONS: The results provide preliminary evidence that VM symptom frequency and severity can be reduced by using nonprescription therapies.

The role of cochlear and vestibular afferents in long-latency cervical vestibular evoked myogenic potentials.

OBJECTIVE: To examine the origin of cervical vestibular evoked myogenic potential (cVEMP) late waves (n34-p44) elicited with air-conducted click stimuli. DESIGN: Using a retrospective design, cVEMPs from normal volunteers were compared to those obtained from patients with vestibular and auditory pathologies. STUDY SAMPLE: (1) Normal volunteers (n = 56); (2) severe-to-profound sensorineural hearing loss (SNHL) with normal vestibular function (n = 21); (3) peripheral vestibular impairment with preserved hearing (n = 16); (4) total vestibulocochlear deficit (n = 23). RESULTS: All normal volunteers had ipsilateral-dominant early p13-n23 peaks. Late peaks were present bilaterally in 78%. The p13-n23 response was present in all patients with SNHL but normal vestibular function, and 43% had late waves. Statistical comparison of these patients to a subset of age-matched controls showed no significant difference in the frequencies, amplitudes or latencies of their ipsilateral early and late peaks. cVEMPs were absent in all patients with vestibular impairment. CONCLUSION: The presence of long-latency cVEMP waves was not dependent on the integrity of sensorineural hearing pathways, but instead correlated with intact vestibular function. This finding conflicts with the view that these late waves are cochlear in origin, and suggests that vestibular afferents may assume a more prominent role in their generation.

Progressive loss of hearing and balance in superficial siderosis due to occult spinal dural defects.

PURPOSE: Superficial siderosis, a progressive, debilitating, neurological disease, often presents with bilateral impairment of auditory and vestibular function. We highlight that superficial siderosis is often due to a repairable spinal dural defect of the type that can also cause spontaneous intracranial hypotension. METHODS: Retrospective chart review of five patients presenting with moderate to severe, progressive bilateral sensorineural hearing loss as well as vestibular loss. All patients had developed superficial siderosis from spinal dural defects: three after trauma, one after spinal surgery and one from a thoracic discogenic microspur. RESULTS: The diagnosis was made late in all five patients; despite surgical repair in four, hearing and vestibular loss failed to improve. CONCLUSIONS: In patients presenting with progressive bilateral sensorineural hearing loss, superficial siderosis should be considered as a possible cause. If these patients also have bilateral vestibular loss, cerebellar impairment and anosmia, then the diagnosis is likely and the inevitable disease progress might be halted by finding and repairing the spinal dural defect.

Vestibular function testing in the 21st century: video head impulse test, vestibular evoked myogenic potential, video nystagmography; which tests will provide answers?

PURPOSE OF REVIEW: To most neurologists, assessing the patient with vertigo is an unpleasant and worrisome task. A structured history and focused examination can be complemented by carefully selected laboratory tests, to reach an early and accurate diagnosis. We provide evidence-based recommendations for vestibular test selection. RECENT FINDINGS: The video head impulse test (vHIT), cervical and ocular vestibular evoked myogenic potential (VEMP) and home-video nystagmography are four modern, noninvasive methods of assessing vestibular function, which are equally applicable in the hospital and office-practice. Collectively, they enable assessment of all five vestibular end-organs. The prevalence and patterns of test abnormalities are distinct for each vestibular disorder. We summarize typical abnormalities encountered in four common vestibular syndromes. SUMMARY: In the context of acute vestibular syndrome, an abnormal vHIT with low gain and large amplitude refixation saccades and an asymmetric oVEMP separates innocuous vestibular neuritis from stroke. In episodic spontaneous vertigo, high-velocity ictal nystagmus and asymmetric cVEMP help separate Ménière's disease from vestibular migraine. In chronic imbalance, all three tests help detect unilateral or bilateral vestibular loss as the root cause. Recurrent positional vertigo requires no laboratory test and can be diagnosed and treated at the bedside, guided by video nystagmography.

Subjective Cognitive Dysfunction in Patients with Dizziness and Vertigo.

INTRODUCTION: Patients with vestibular disorders sometimes report cognitive difficulties, but there is no consensus about the type or degree of cognitive complaint. We therefore investigated subjective cognitive dysfunction in a well-defined sample of neuro-otology patients and used demographic factors and scores from a measure of depression, anxiety, and stress to control for potential confounding factors. METHODS: We asked 126 neuro-otology clinic outpatients whether they experienced difficulties with thinking, memory, or concentration as a result of dizziness or vertigo. They and 42 nonvertiginous control subjects also completed the Neuropsychological Vertigo Inventory (NVI, which measures cognitive, emotional, vision, and motor complaints), the Everyday Memory Questionnaire (EMQ), and Depression, Anxiety, and Stress Scales (DASS). RESULTS: In the initial interview questions, 60% of patients reported experiencing cognitive difficulties. Cognitive questionnaire scores were positively correlated with the overall DASS score and to a lesser extent with age and gender. Therefore, we compared patients and controls on the NVI and EMQ, using these mood and demographic variables as covariates. Linear regression analyses revealed that patients scored significantly worse on the total NVI, NVI cognitive composite, and 3 individual NVI cognition subscales (Attention, Space Perception, and Time Perception), but not the EMQ. Patients also scored significantly worse on the NVI Emotion and Motor subscales. CONCLUSIONS: Patients with dizziness and vertigo reported high levels of cognitive dysfunction, affecting attention, perceptions of space and time. Although perceptions of cognitive dysfunction were correlated with emotional distress, they were significantly elevated in patients over and above the impact of depression, anxiety, or stress.

Clinical, oculographic, and vestibular test characteristics of vestibular migraine.

BACKGROUND: We characterise the history, vestibular tests, ictal and interictal nystagmus in vestibular migraine. METHOD: We present our observations on 101 adult-patients presenting to an outpatient facility with recurrent spontaneous and/or positional vertigo whose final diagnosis was vestibular migraine (n = 27) or probable vestibular migraine (n = 74). Ictal and interictal video-oculography, caloric and video head impulse tests, vestibular-evoked myogenic potentials and audiometry were performed. RESULTS: Common presenting symptoms were headache (81.2%), spinning vertigo (72.3%), Mal de Débarquement (58.4%), and motion sensitivity (30.7%). With fixation denied, ictal and interictal spontaneous nystagmus was observed in 71.3 and 14.9%, and purely positional nystagmus in 25.8 and 55.4%. Spontaneous ictal nystagmus was horizontal in 49.5%, and vertical in 21.8%. Ictal spontaneous and positional nystagmus velocities were 5.3 ± 9.0°/s (range 0.0-57.4), and 10.4 ± 5.8°/s (0.0-99.9). Interictal spontaneous and positional nystagmus velocities were <3°/s in 91.8 and 23.3%. Nystagmus velocities were significantly higher when ictal (p < 0.001/confidence interval: 2.908‒6.733, p < 0.001/confidence interval: 5.308‒10.085). Normal lateral video head impulse test gains were found in 97.8% (mean gain 0.95 ± 0.12) and symmetric caloric results in 84.2% (mean canal paresis 7.0 ± 23.3%). Air- and bone-conducted cervical-vestibular-evoked myogenic potential amplitudes were symmetric in 88.4 and 93.4% (mean corrected amplitude 1.6 ± 0.7, 1.6 ± 0.8) with mean asymmetry ratios of 13.0 and 9.0%. Air- and bone-conducted ocular-vestibular-evoked myogenic potentials were symmetric in 67.7 and 97.2% (mean amplitude 9.2 ± 6.4 and 20.3 ± 12.8 µV) with mean asymmetry ratios of 15.7 and 9.9%. Audiometry was age consistent and symmetric in 85.5%. CONCLUSION: Vestibular migraine is characterised by low velocity ictal spontaneous nystagmus, which can be horizontal, vertical, or torsional, and normal audiovestibular test results.

Machine Learning Techniques for Differential Diagnosis of Vertigo and Dizziness: A Review.

Vertigo is a sensation of movement that results from disorders of the inner ear balance organs and their central connections, with aetiologies that are often benign and sometimes serious. An individual who develops vertigo can be effectively treated only after a correct diagnosis of the underlying vestibular disorder is reached. Recent advances in artificial intelligence promise novel strategies for the diagnosis and treatment of patients with this common symptom. Human analysts may experience difficulties manually extracting patterns from large clinical datasets. Machine learning techniques can be used to visualize, understand, and classify clinical data to create a computerized, faster, and more accurate evaluation of vertiginous disorders. Practitioners can also use them as a teaching tool to gain knowledge and valuable insights from medical data. This paper provides a review of the literatures from 1999 to 2021 using various feature extraction and machine learning techniques to diagnose vertigo disorders. This paper aims to provide a better understanding of the work done thus far and to provide future directions for research into the use of machine learning in vertigo diagnosis.

Vestibular-Evoked Myogenic Potential Testing in Vestibular Localization and Diagnosis.

Vestibular-evoked myogenic potentials (VEMPs) are short-latency, otolith-dependent reflexes recorded from the neck and eye muscles. They are widely used in neuro-otology clinics as tests of otolith function. Cervical VEMPs are recorded from the neck muscles and reflect predominantly saccular function, while ocular VEMPs are reflexes of the extraocular muscles and reflect utricular function. They have an important role in the diagnosis of superior canal dehiscence syndrome and provide complementary information about otolith function that is useful in the diagnosis of other vestibular disorders. Like other evoked potentials, they can provide important localizing information about lesions that may occur along the VEMP pathway. This review will describe the VEMP abnormalities seen in common disorders of the vestibular system and its pathways.

Bone-conducted vestibular and stretch reflexes in human neck muscles.

In normal humans, tapping the forehead produces a neck muscle reflex that is used clinically to test vestibular function, the cervical vestibular evoked myogenic potential (cVEMP). As stretch receptors can also be activated by skull taps, we investigated the origin of the early and late peaks of the bone-conducted cVEMP. In twelve normal participants, we differentially stimulated the vestibular and neck stretch receptors by applying vibration to the forehead (activating both vestibular and stretch receptors) and to the sternum (activating mainly stretch receptors). Patients with bilateral vestibulopathy (BVP; n = 26) and unilateral vestibular loss (uVL; n = 17) were also investigated for comparison. Comparison of peaks in normal subjects suggested that the early peaks were vestibular-dependent, while the later peaks had mixed vestibular and stretch input. The late peaks were present but small (1.1 amplitude ratio) in patients with BVP and absent VEMPs, confirming that they do not strictly depend on vestibular function, and largest in age-matched controls (1.5 amplitude ratio, p = 0.049), suggesting that there is an additional vestibular reflex at this latency (approx. 30 ms). Patients with uVL had larger late peaks on the affected than the normal side (1.4 vs 1.0 amplitude ratio, p = 0.034). The results suggest that the early responses in SCM to skull vibration in humans are vestibular-dependent, while there is a late stretch reflex bilaterally and a late vestibular reflex in the contralateral muscle.

Evidence of a Vestibular Origin for Crossed-Sternocleidomastoid Muscle Responses to Air-Conducted Sound.

OBJECTIVES: Small, excitatory surface potentials can sometimes be recorded from the contralateral sternocleidomastoid muscle (SCM) following monaural acoustic stimulation. Little is known about the physiological properties of these crossed reflexes. In this study, we sought the properties of crossed SCM responses and through comparison with other cochlear and vestibular myogenic potentials, their likely receptor origin. DESIGN: Surface potentials were recorded from the ipsilateral and contralateral SCM and postauricular (PAM) muscles of 11 healthy volunteers, 4 patients with superior canal dehiscence and 1 with profound hearing loss. Air-conducted clicks of 105 dB nHL and tone bursts (250 to 4000 Hz) of 100 dB nHL were presented monaurally through TDH 49 headphones during head elevation. Click-evoked responses were recorded under two conditions of gaze in random order: gaze straight ahead and rotated hard toward the contralateral recording electrodes. Amplitudes (corrected and uncorrected) and latencies for crossed SCM responses were compared with vestibular (ipsilateral SCM) and cochlear (PAM) responses between groups and across the different recording conditions. RESULTS: Surface waveforms were biphasic; positive-negative for the ipsilateral SCM, and negative-positive for the contralateral SCM and PAM. There were significant differences in the amplitudes and latencies (p = 0.004) for click responses of healthy controls across recording sites. PAM responses had the largest mean-corrected amplitudes (2.3 ± 2.8) and longest latencies (13.0 ± 1.2 msec), compared with ipsilateral (1.6 ± 0.5; 12.0 ± 0.7 msec) and contralateral (0.8 ± 0.3; 10.4 ± 1.0 msec) SCM responses. Uncorrected amplitudes and muscle activation for PAM increased by 104.4% and 46.8% with lateral gaze respectively, whereas SCM responses were not significantly affected. Click responses of patients with superior canal dehiscence followed a similar latency, amplitude, and gaze modulation trend as controls. SCM responses were preserved in the patient with profound hearing loss, yet all PAM were absent. There were significant differences in the frequency tuning of the three reflexes (p < 0.001). Tuning curves of healthy controls were flat for PAM and down sloping for ipsilateral and contralateral SCM responses. For superior canal dehiscence, they were rising for PAM and slightly down sloping for SCM responses. CONCLUSIONS: Properties of crossed SCM responses were similar, though not identical, to those of ipsilateral SCM responses and are likely to be predominantly vestibular in origin. They are unlikely to represent volume conduction from the PAM as they were unaffected by lateral gaze, were shorter in latency, and had different tuning properties. The influence of crossed vestibulo-collic pathways should be considered when interpreting cervical vestibular-evoked myogenic potentials recorded under conditions of binaural stimulation.

The human vestibulo-ocular reflex and saccades: normal subjects and the effect of age.

Here we characterize in 80 normal subjects (16-84 yr (means ± SD, 47 ± 19 yr) the vestibulo-ocular reflex (VOR) and saccades in response to three-dimensional head impulses with a monocular video head impulse test (vHIT) of the right eye. Impulses toward the right lateral, right anterior, and left posterior canals (means: 0.98, 0.91, 0.79) had slightly higher mean gains compared with their counterparts (0.95, 0.86, 0.76). In the older age group (>60 yr), gains of the left posterior canal dropped 0.09 and left anterior canals rose 0.09 resulting in symmetry. All canal gains reduced with increasing head velocity (0.02-0.13 per 100°/s). Comparison of lateral canal gains calculated using five published algorithms yielded lower values (~0.80) when a narrow detection window was used. Low-amplitude refixation saccades (amplitude: 1.11 ± 0.98°, peak velocity: 63.9 ± 34.0°/s at 262.0 ± 93.9 ms) were observed among all age groups (frequency: 40.2 ± 23.4%), increasing in amplitude, peak velocity, and frequency in older subjects. Impulses toward anterior canals showed the least frequent saccades and lateral and posterior canals were similar, but lateral canal impulses showed the smallest saccades and the posterior canal showed the largest saccades. Saccade peak-velocity approximate amplitude "main sequence" slope was steeper for the horizontal canals compared with the vertical planes (60 vs. <40°/s per 1°). In summary, we found small but significant asymmetries in monocular vHIT gain that changed with age. Healthy subjects commonly have minuscule refixation saccades that are moderately to strongly correlated with vHIT gain. NEW & NOTEWORTHY Gaze fixation is normally stabilized during rapid "head-impulse" movements by the bisynaptic vestibulo-ocular reflex (VOR), but earlier studies of normal subjects also report small amplitude saccades. We found that with increased age of the subject the vertical VOR became more variable, while in all semicircular canal directions the saccade frequency, amplitude, and peak velocity increased. We also found that the VOR gain algorithm significantly influences values.

Immune-mediated conditions affecting the brain, eye and ear (BEE syndromes).

The triad of central nervous system symptoms, visual disturbance and hearing impairment is an oft-encountered clinical scenario. A number of immune-mediated diseases should be considered among the differential diagnoses including: Susac syndrome, Cogan syndrome or Vogt-Koyanagi-Harada disease; demyelinating conditions such as multiple sclerosis or neuromyelitis optica spectrum disorder; systemic diseases such as systemic lupus erythematosus, Sjögren syndrome or Behcet disease and granulomatous diseases such as sarcoidosis. In this article, we coin the term 'BEE syndromes' to draw attention to the various immune-mediated diseases that affect the brain, eye and ear. We present common disease manifestations and identify key clinical and investigation features.

Dizziness demystified.

Four vestibular presentations caused by six different disorders constitute most of the neuro-otology cases seen in clinical practice. 'Acute vestibular syndrome' refers to a first-ever attack of acute, spontaneous, isolated vertigo and there are two common causes: vestibular neuritis / labyrinthitis and cerebellar infarction. Recurrent positional vertigo is most often caused by benign paroxysmal positional vertigo and less commonly is central in origin. Recurrent spontaneous vertigo has two common causes: Ménière's disease and vestibular migraine. Lastly, chronic vestibular insufficiency (imbalance) results from bilateral, or severe unilateral, peripheral vestibular impairment. These six disorders can often be diagnosed on the basis of history, examination, audiometry, and in some cases, basic vestibular function testing. Here we show that most common neuro-otological problems can be readily managed by general neurologists.

Ocular vestibular-evoked myogenic potentials (oVEMP) to skull taps in normal and dehiscent ears: mechanisms and markers of superior canal dehiscence.

The site of stimulus delivery modulates the waveforms of cervical- and ocular vestibular-evoked myogenic potentials (cVEMP and oVEMP) to skull taps in healthy controls. We examine the influence of stimulus location on the oVEMP waveforms of 18 patients (24 ears) with superior canal dehiscence (SCD) and compare these with the results of 16 healthy control subjects (32 ears). oVEMPs were recorded in response to taps delivered with a triggered tendon-hammer and a hand-held minishaker at three midline locations; the hairline (Fz), vertex (Cz) and occiput (Oz). In controls, Fz stimulation evoked a consistent oVEMP waveform with a negative peak (n1) at 9.5 ± 0.5 ms. In SCD, stimulation at Fz produced large oVEMP waveforms with delayed n1 peaks (tendon-hammer = 13.2 ± 1.0 ms and minitap = 11.5 ± 1.1 ms). Vertex taps produced diverse low-amplitude waveforms in controls with n1 peaks at 15.5 ± 1.2 and 13.2 ± 1.3 ms for tendon-hammer taps and minitaps, respectively; in SCD, they produced large amplitude oVEMP waveforms with n1 peaks at 12.9 ± 0.8 ms (tendon-hammer) and 12.1 ± 0.5 ms (minitap). Occiput stimulation evoked oVEMPs with similar n1 latencies in both groups (tendon-hammer = 11.3 ± 1.3 and 10.7 ± 0.8; minitap = 10.3 ± 0.9 and 11.1 ± 0.4 for control and SCD ears, respectively). Compared to reflex amplitudes, n1 peak latencies to Fz taps provided clearer separation between SCD and control ears. The distinctly different effects of Fz and vertex taps on the oVEMP waveforms may represent an additional non-osseous mechanism of stimulus transmission in SCD. For skull taps at Fz, a prolonged n1 latency is an indicator of SCD.

Vestibular migraine as a mimic of benign paroxysmal positioning vertigo and Meniere's disease.

BACKGROUND: Vestibular migraine (VM) is a common cause of recurrent spontaneous and positional dizziness of varying durations. Short episodes of VM lasting seconds to minutes, triggered by changes in head position can resemble those of benign paroxysmal positioning vertigo (BPPV), while episodes lasting minutes to hours can mimic those of Meniere's disease (MD). OBJECTIVE: We aimed to compare symptoms and vestibular test results in patients with VM, BPPV and MD, where VM was categorized by episode duration. METHODS: We compared vestibular, aural and migraine symptoms, as well as cervical and ocular vestibular evoked myogenic potentials and 3D video head impulse tests, in 108 patients: 24 with BPPV, 33 with VM episodes of short duration (<10 min), 29 with VM of medium duration (≥10 min) and 22 with MD. RESULTS: We found significant overlap in the symptoms of all patient groups, and no significant differences between patients with short and medium VM. Abnormal test results occurred infrequently in all groups. CONCLUSIONS: Our results confirm significant symptom overlap between BPPV or MD and VM, and suggest that VM mimics other conditions when the episode duration matches the differential diagnosis, rather than because patients with different durations of vertigo have different symptoms.

Machine learning models help differentiate between causes of recurrent spontaneous vertigo.

BACKGROUND: Vestibular migraine (VM) and Menière's disease (MD) are two common causes of recurrent spontaneous vertigo. Using history, video-nystagmography and audiovestibular tests, we developed machine learning models to separate these two disorders. METHODS: We recruited patients with VM or MD from a neurology outpatient facility. One hundred features from six "feature subsets": history, acute video-nystagmography and four laboratory tests (video head impulse test, vestibular-evoked myogenic potentials, caloric testing and audiogram) were used. We applied ten machine learning algorithms to develop classification models. Modelling was performed using three "tiers" of data availability to simulate three clinical settings. "Tier 1" used all available data to simulate the neuro-otology clinic, "Tier 2" used only history, audiogram and caloric test data, representing the general neurology clinic, and "Tier 3" used history alone as occurs in primary care. Model performance was evaluated using tenfold cross-validation. RESULTS: Data from 160 patients with VM and 114 with MD were used for model development. All models effectively separated the two disorders for all three tiers, with accuracies of 85.77-97.81%. The best performing algorithms (AdaBoost and Random Forest) yielded accuracies of 97.81% (95% CI 95.24-99.60), 94.53% (91.09-99.52%) and 92.34% (92.28-96.76%) for tiers 1, 2 and 3. The best feature subset combination was history, acute video-nystagmography, video head impulse test and caloric testing, and the best single feature subset was history. CONCLUSIONS: Machine learning models can accurately differentiate between VM and MD and are promising tools to assist diagnosis by medical practitioners with diverse levels of expertise and resources.

Post Cochlear Implantation Vertigo: Ictal Nystagmus and Audiovestibular Test Characteristics.

OBJECTIVE: To investigate ictal nystagmus and audiovestibular characteristics in episodic spontaneous vertigo after cochlear implantation (CI). STUDY DESIGN: Retrospective and prospective case series. PATIENTS: Twenty-one CI patients with episodic spontaneous vertigo after implantation were recruited. INTERVENTIONS: Patient-initiated home video-oculography recordings were performed during one or more attacks of vertigo, using miniature portable home video-glasses. To assess canal and otolith function, video head-impulse tests (vHITs) and vestibular-evoked myogenic potential tests were conducted. MAIN OUTCOME MEASURES: Nystagmus slow-phase velocities (SPVs), the presence of horizontal direction-changing nystagmus, and post-CI audiovestibular tests. RESULTS: Main final diagnoses were post-CI secondary endolymphatic hydrops (48%) and exacerbation of existing Ménière's disease (29%). Symptomatic patients demonstrated high-velocity horizontal ictal-nystagmus (SPV, 44.2°/s and 68.2°/s in post-CI secondary endolymphatic hydrop and Ménière's disease). Direction-changing nystagmus was observed in 80 and 75%. Two were diagnosed with presumed autoimmune inner ear disease (SPV, 6.6°/s and 172.9°/s). One patient was diagnosed with probable vestibular migraine (15.1°/s).VHIT gains were 0.80 ± 0.20 (lateral), 0.70 ± 0.17 (anterior), and 0.62 ± 0.27 (posterior) in the implanted ear, with abnormal values in 33, 35, and 35% of each canal. Bone-conducted cervical and ocular vestibular-evoked myogenic potentials were asymmetric in 52 and 29% of patients (all lateralized to the implanted ear) with mean asymmetry ratios of 51.2 and 35.7%. Reversible reduction in vHIT gain was recorded in three acutely symptomatic patients. CONCLUSION: High-velocity, direction-changing nystagmus time-locked with vertigo attacks may be observed in post-CI implant vertigo and may indicate endolymphatic hydrops. Fluctuating vHIT gain may be an additional marker of a recurrent peripheral vestibulopathy.

Neurological update: neuro-otology 2023.

Much has changed since our last review of recent advances in neuro-otology 7 years ago. Unfortunately there are still not many practising neuro-otologists, so that most patients with vestibular problems need, in the first instance, to be evaluated and treated by neurologists whose special expertise is not neuro-otology. The areas we consider here are mostly those that almost any neurologist should be able to start managing: acute spontaneous vertigo in the Emergency Room-is it vestibular neuritis or posterior circulation stroke; recurrent spontaneous vertigo in the office-is it vestibular migraine or Meniere's disease and the most common vestibular problem of all-benign positional vertigo. Finally we consider the future: long-term vestibular monitoring and the impact of machine learning on vestibular diagnosis.