Vestibular Nucleus Involvement in Patients With Acute Vertigo Due to Herpes Zoster Oticus or Vestibular Neuritis.

OBJECTIVES: Herpes zoster oticus (HZO) typically provokes vestibular symptoms and is traditionally viewed as a cranial nerve equivalent of shingles, but in contrast to vestibular neuritis (VN), it is unclear whether the pathology of HZO is limited to the vestibular nerve (neuritis) or can also involve the brainstem (nucleitis). METHODS: We retrospectively compared brain MRIs of patients with HZO with those of patients with VN to study radiologic changes in the brainstem. RESULTS: Five of 10 patients with HZO showed signal abnormalities in the vestibular nuclei, which lie in multiple vascular territories, whereas no patients with VN exhibited such findings. DISCUSSION: HZO may at least in part reflect vestibular nucleitis, as opposed to a pure neuritis.

Universal Repositioning Maneuver: A New Treatment for Single Canal and Multi-Canal Benign Paroxysmal Positional Vertigo by 3-Dimensional Model Analysis.

BACKGROUND: Benign paroxysmal positional vertigo is the most common peripheral vestibular disorder and is currently treated by many types of repositioning maneuvers. A simplification of this procedure would be desirable. A new, anatomically realistic, 3-dimensional computational simulator of the human labyrinth provides a novel insight to evaluate the viability of any new maneuver. The purpose of this study is to propose a single maneuver with potential to treat canalolithiasis-type benign paroxysmal positional vertigo of any individual canal, or even multiple canals on the same side, based on a 3-dimensional model. METHODS: The benign paroxysmal positional vertigo Viewer, a 3-dimensional model of the human labyrinth, was used to analyze a "Universal Repositioning Maneuver." RESULT: Through the gravity vector, the expected position of the otoliths was demonstrated by moving the model through a single sequence of head positions, successfully promoting otolith migration from the three semicircular canals to the utricular cavity, either individually or together. CONCLUSION: The analysis with the 3-dimensional model predicts the effectiveness of the Universal Repositioning Maneuver for the resolution of each single canal or multiple-canal benign paroxysmal positional vertigo canalolithiasis, making treatment much more straightforward.

Social concepts and the cerebellum: behavioural and functional connectivity signatures in cerebellar ataxic patients.

Neurocognitive research on social concepts underscores their reliance on fronto-temporo-limbic regions mediating broad socio-cognitive skills. Yet, the field has neglected another structure increasingly implicated in social cognition: the cerebellum. The present exploratory study examines this link combining a novel naturalistic text paradigm, a relevant atrophy model and functional magnetic resonance imaging. Fifteen cerebellar ataxia (CA) patients with focal cerebellar atrophy and 29 matched controls listened to a social text (highlighting interpersonal events) as well as a non-social text (focused on a single person's actions), and answered comprehension questionnaires. We compared behavioural outcomes between groups and examined their association with cerebellar connectivity. CA patients showed deficits in social text comprehension and normal scores in the non-social text. Also, social text outcomes in controls selectively correlated with connectivity between the cerebellum and key regions subserving multi-modal semantics and social cognition, including the superior and medial temporal gyri, the temporal pole and the insula. Conversely, brain-behaviour associations involving the cerebellum were abolished in the patients. Thus, cerebellar structures and connections seem involved in processing social concepts evoked by naturalistic discourse. Such findings invite new theoretical and translational developments integrating social neuroscience with embodied semantics. This article is part of the theme issue 'Concepts in interaction: social engagement and inner experiences'.

The Role of the Smartphone in the Diagnosis of Vestibular Hypofunction: A Clinical Strategy for Teleconsultation during the COVID-19 Pandemic and Beyond.

Introduction Vestibular disorders (VDs) are highly prevalent in primary care. Although in general they comprise conditions that are not life-threatening, they are associated with significant functional and physical disability. However, the current coronavirus disease 2019 (COVID-19) pandemic has imposed limitations on the standard treatment of benign conditions, including VDs. In this context, other resources may aid in the diagnosis and management of patients with VDs. It is well known that teleconsultation and teletreatment are both safe and effective alternatives to manage a variety of conditions, and we maintain that VDs should be among these. Objective To develop a preliminary model of clinical guidelines for the evaluation by teleconsultation of patients with suspected diagnosis of vestibular hypofunction during the COVID-19 pandemic and beyond. Methods A bibliographic review of the diagnostic feasibility in VDs by teleconsultation was carried out in the LILACS, SciELO, MEDLINE, and PubMed databases; books and specialized websites were also consulted. The legal, regulatory, and technical issues involving digital consultations were reviewed. Results We found 6 field studies published between 1990 and 2020 in which the efficiency of teleconsultations was observed in the contexts of epidemics and environmental disorders and disadvantageous geographical conditions. After reviewing them, we proposed a strategy to examine and address vestibular complaints related to vestibular hypofunction. Conclusion The creation of a digital vestibular management algorithm for the identification, counseling, initial intervention, monitoring and targeting of people with possible vestibular hypofunction seems to be feasible, and it will provide a reasonable alternative to in-person evaluations during the COVID-19 pandemic and beyond.

The spectrum of acute vestibular neuropathy through modern vestibular testing: A descriptive analysis.

OBJECTIVE: Acute vestibular neuropathy (AVN), often referred to as vestibular neuritis, is a cranial neuropathy responsible for a significant proportion of cases of acute vertigo. This study describes the spectrum of lesion patterns in AVN as identified by video head impulse testing (vHIT) which assesses the high frequency vestibulo-ocular reflex function of the semicircular canals, and cervical and ocular vestibular evoked myogenic potentials (VEMPs) which assess otolith function. METHODS: We used vHIT and VEMPs to assess 35 patients with vestibular neuropathy in the acute stage. RESULTS: Unilateral superior division vestibular nerve involvement was the most common variant (57.1%), followed by unilateral superior and inferior division (28.5%), bilateral superior division (8.5%) and unilateral inferior division (5.7%). We observed a partial inverse correlation between the proportion of afferent fibers from an organelle, and the likelihood that the test of that organelle's function will be abnormal. CONCLUSION: vHIT and VEMPs provide more detailed characterization of lesion pattern in AVN than caloric testing. SIGNIFICANCE: Comparison of lesion patterns from neuro-physiological testing with what is known about the proportional distribution of afferent fibers from the vestibular end-organelles suggests a new, neuro-anatomically based insight regarding susceptibility of these pathways to AVN.

Histology and neuroanatomy suggest a unified mechanism to explain the distribution of lesion patterns in acute vestibular neuropathy.

Human temporal bone studies have described the distribution of afferent fibers from each of the five organelles in the labyrinth. Data from vestibular tests in patients with vestibular neuritis can be abnormal in almost any pattern. We propose a unified explanation for these patterns, based on histological and neuroanatomical factors.

Teleconsultation and Teletreatment Protocol to Diagnose and Manage Patients with Benign Paroxysmal Positional Vertigo (BPPV) during the COVID-19 Pandemic.

Introduction Telehealth consists in the application of technology to provide remote health service. This resource is considered safe and effective and has attracted an exponential interest in the context of the COVID pandemic. Expanded to dizzy patients, it would be able to provide diagnosis and treatment, minimizing the risk of disease transmission. Benign paroxysmal positional vertigo (BPPV) is the most common vestibular disorder. The diagnosis typically rests on the description of the symptoms along with the nystagmus observed at a well-established positional testing. Objectives The aim of the present study was to propose a teleconsultation and teletreatment protocol to manage patients with BPPV during the COVID-19 pandemic. Methods Specialists in the vestibular field met through remote access technologies to discuss the best strategy to manage BPPV patients by teleconsultation and teletreatment system. Additionally, several scientific sources were consulted. Technical issues, patient safety, and clinical assessment were independently analyzed. All relevant information was considered in order to design a clinical protocol to manage BPPV patients in the pandemic context. Results Teleconsultation for BPPV patients requires a double way (video and audio) digital system. An adapted informed consent to follow good clinical practice statements must be considered. The time, trigger and target eye bedside examination (TiTRaTe) protocol has proven to be a valuable first approach. The bow and lean test is the most rational screening maneuver for patients with suspected positional vertigo, followed by most specific maneuvers to diagnostic the sub-variants of BPPV. Conclusion Although with limited evidence, teleconsultation and teletreatment are both reasonable and feasible strategies for the management of patients with BPPV in adverse situations for face-to-face consultation.

Teleconsultation and Teletreatment Protocol to Diagnose and Manage Patients with Benign Paroxysmal Positional Vertigo (BPPV) during the COVID-19 Pandemic

Abstract Introduction Telehealth consists in the application of technology to provide remote health service. This resource is considered safe and effective and has attracted an exponential interest in the context of the COVID pandemic. Expanded to dizzy patients, it would be able to provide diagnosis and treatment, minimizing the risk of disease transmission. Benign paroxysmal positional vertigo (BPPV) is the most common vestibular disorder. The diagnosis typically rests on the description of the symptoms along with the nystagmus observed at a well-established positional testing. Objectives The aim of the present study was to propose a teleconsultation and teletreatment protocol to manage patients with BPPV during the COVID-19 pandemic. Methods Specialists in the vestibular field met through remote access technologies to discuss the best strategy to manage BPPV patients by teleconsultation and teletreatment system. Additionally, several scientific sources were consulted. Technical issues, patient safety, and clinical assessment were independently analyzed. All relevant information was considered in order to design a clinical protocol to manage BPPV patients in the pandemic context. Results Teleconsultation for BPPV patients requires a double way (video and audio) digital system. An adapted informed consent to follow good clinical practice statements must be considered. The time, trigger and target eye bedside examination (TiTRaTe) protocol has proven to be a valuable first approach. The bow and lean test is the most rational screening maneuver for patients with suspected positional vertigo, followed by most specific maneuvers to diagnostic the sub-variants of BPPV. Conclusion Although with limited evidence, teleconsultation and teletreatment are both reasonable and feasible strategies for the management of patients with BPPV in adverse situations for face-to-face consultation.

Benign Paroxysmal Positional Vertigo: Canal Switching Affecting All Canals During a Single Session.

: SDC Video Link:http://links.lww.com/MAO/B86.

Is Cerebellar Ataxia, Neuropathy, and Vestibular Areflexia Syndrome (CANVAS) a Vestibular Ganglionopathy?

OBJECTIVES: CANVAS is an acronym for cerebellar ataxia, neuropathy and vestibular areflexia syndrome. Limited autopsy data has suggested that CANVAS is caused by a focal dorsal root ganglionopathy that damages Scarpa's (vestibular) ganglion, but spares the Spiral (hearing) ganglion. If the vestibular areflexia of CANVAS is in fact due to ganglionopathy, then there should be global reduction of all vestibular responses. MATERIALS AND METHODS: With this hypothesis in mind, a retrospective review of 5 subjects who met the clinical criteria for CANVAS was performed. Recent advances in vestibular testing have made it possible to quantify responses from all 5 vestibular end organs in the inner ear. Results of the Video head impulse test (VHIT), video oculography, caloric test and vestibular evoked myogenic potential (VEMP) were examined to determine if all 5 end organs are nonfunctional in CANVAS. RESULTS: Severe reduction of function of the six semicircular canals and ocular VEMPs were observed. Only the cervical VEMPs were present and reproducible, consistent with either partial sparing of the inferior vestibular ganglia, specific embryologic resistance of the saccule to the degeneration or a mechanism for cervical VEMPs that does not require an intact vestibular ganglion. CONCLUSION: Our results suggest that Scarpa´s ganglia dysfunction could be the mechanism for loss of semicircular canal and utricular function in CANVAS patients, but the preservation of the cervical VEMP response is unexplained.

Bilateral Vestibular Weakness.

Bilateral vestibular weakness (BVW) is a rare cause of imbalance. Patients with BVW complain of oscillopsia. In approximately half of the patients with BVW, the cause remains undetermined; in the remainder, the most common etiology by far is gentamicin ototoxicity, followed by much rarer entities such as autoimmune inner ear disease, meningitis, bilateral Ménière's disease, bilateral vestibular neuritis, and bilateral vestibular schwannomas. While a number of bedside tests may raise the suspicion of BVW, the diagnosis should be confirmed by rotatory chair testing. Treatment of BVW is largely supportive. Medications with the unintended effect of vestibular suppression should be avoided.

Characteristics of vestibular corrective saccades in patients with slow visual saccades, vestibular disorders and controls: A descriptive analysis.

OBJECTIVE: Our aim was to determine whether overt catch up saccades (OS) provoked by vestibular stimuli, as observed in the video head impulse test (vHIT), have comparable metrics as visually triggered horizontal saccades (VS), indicating a common saccadic brainstem generator. METHODS: Three groups of patients were studied: patients with neurological disorders causing slow saccades (group 1, n = 12), patients with peripheral vestibular lesions (group 2, n = 43), and normal controls (group 3, = 24). All patients underwent vHIT and Videooculographic testing. OS velocity, acceleration, amplitude and duration and VS velocity in this group was compared between the groups. RESULTS: There was significant reduction in the velocity of visually guided saccades in group 1, as expected from the patient selection constraints of this study. Group 1 also exhibited saccades which were longer in duration and of reduced acceleration when compared to subjects without saccadic slowing to visual targets (Group 2 and 3). There were significant positive correlations between OS acceleration and amplitude in both normal saccade groups (2 and 3) which was not observed in the slow saccade group (1). CONCLUSIONS: The metrics of overt saccades measured by the vHIT in patients with slow saccades and normal controls are similar to visually guided saccades. This supports the hypothesis that overt saccades associated with vestibular stimuli and visually triggered saccades share common circuitry that controls metrics.

The Floccular Syndrome: Dynamic Changes in Eye Movements and Vestibulo-ocular Reflex in Isolated Infarction of the Cerebellar Flocculus.

The cerebellar flocculus is a critical structure involved in the control of eye movements. Both static and dynamic abnormalities of the vestibulo-ocular reflex (VOR) have been described in animals with experimental lesions of the flocculus/paraflocculus complex. In humans, lesions restricted to the flocculus are rare so they can become an exceptional model to contrast with the clinical features in experimental animals or in patients with more generalized cerebellar diseases. Here, we examined a 67-year-old patient with an acute vestibular syndrome due to an isolated infarct of the right flocculus. We evaluated him multiple times over 6 months-to follow the changes in eye movements and vestibular function-with caloric testing, video-oculography and head-impulse testing, and the anatomical changes on imaging. Acutely, he had an ipsilateral-beating spontaneous nystagmus, bilateral gaze-evoked nystagmus, borderline impaired smooth pursuit, and a complete contraversive ocular tilt reaction. The VOR gain was reduced for head impulses directed contralateral to the lesion, and there was also an ipsilesional caloric weakness. All abnormalities progressively improved at follow-up visits but with a considerable reduction in volume of the affected flocculus on imaging. The vestibular and ocular motor findings, qualitatively similar to a previously reported patient, further clarify the "acute floccular syndrome" in humans. We also add new information about the pattern of recovery from such a lesion with corresponding changes in the size of the affected flocculus on imaging.