Clinical, Radiological and Pathological Features of a Large American Cohort of Spinocerebellar Ataxia (SCA27B).

Objectives: Spinocerebellar ataxia 27B due to GAA repeat expansions in the fibroblast growth factor 14 (FGF14) gene has recently been recognized as a common cause of late-onset hereditary cerebellar ataxia. Here we present the first report of this disease in the US population, characterizing its clinical manifestations, disease progression, pathological abnormalities, and response to 4-aminopyridine in a cohort of 102 patients bearing GAA repeat expansions.

Methods: We compiled a series of patients with SCA27B, recruited from 5 academic centers across the United States.

A Preliminary Data Visualization Approach to Vestibulocochlear Diseases Based on Multiple Scalar Dimensions.

For vestibulocochlear diseases, traditional clinical history-taking, and the terminology of widely taught nosologic taxonomy, have misleading implications that can lead to errors in diagnosis and therefore in treatment. In the interest of facilitating differential diagnosis while simultaneously recognizing that many of these diseases may not be as discrete as textbooks suggest, we propose a data visualization approach focusing on several continuous scalar dimensions in the domains of anatomy, physiology, and chronology. We illustrate the application of this approach to several categories of clinical presentation.

When, where, and why should we look for vestibular dysfunction in people with diabetes mellitus?

The biochemistry of diabetes mellitus results in multi-system tissue compromise that reduces functional mobility and interferes with disease management. Sensory system compromise, such as peripheral neuropathy and retinopathy, are specific examples of tissue compromise detrimental to functional mobility. There is lack of clarity regarding if, when, and where parallel changes in the peripheral vestibular system, an additional essential sensory system for functional mobility, occur as a result of diabetes.

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.

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

 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.

The Enduring Controversy of Cervicogenic Vertigo, and Its Place among Positional Vertigo Syndromes.

The idea of cervicogenic vertigo (CV) was proposed nearly a century ago, yet despite considerable scrutiny and research, little progress has been made in clarifying the underlying mechanism of the disease, developing a confirmatory diagnostic test, or devising an appropriately targeted treatment. Given the history of this idea, we offer a review geared towards understanding why so many attempts at clarifying it have failed, with specific comments regarding how CV fits into the broader landscape of positional vertigo syndromes, what a successful diagnostic test might require, and some practical advice on how to approach this in the absence of a diagnostic test.

Vestibular Testing.

Purpose Of Review: Vestibular testing, both at the bedside and in the laboratory, is often critical in diagnosing patients with symptoms of vertigo, dizziness, unsteadiness, and oscillopsia. This article introduces readers to core concepts, as well as recent advances, in bedside and instrumented vestibular assessments.

Recent Findings: Vestibular testing has improved immensely in the past 2 decades.

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.

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.

Migraine Associated Vertigo.

This chapter is a brief overview of migraine associated vertigo (MAV), focusing on the points most relevant to the practicing clinician. We review the definition of MAV, theories regarding its underlying pathophysiology, clinical presentation, epidemiology, findings on physical examination and oto vestibular testing, differential diagnosis, management and prognosis.

Utricular function in vestibular neuritis: a pilot study of concordance/discordance between ocular vestibular evoked myogenic potentials and ocular cycloposition.

Vestibular neuritis (VN) can affect utricular afferents. Utricular function can be assessed by ocular vestibular evoked myogenic potentials (oVEMPs) whose abnormalities include weak or absent responses, and ocular cycloposition whose abnormalities include ocular torsion (OT). When studied independently in vestibular neuritis, oVEMPs are abnormal in 61-82% of cases, and OT is present in 72-80% of cases.

The Gain-Time Constant Product Quantifies Total Vestibular Output in Bilateral Vestibular Loss.

Patients with inner ear damage associated with bilateral vestibular impairment often ask "how much damage do I have." Although there are presently three clinical methods of measuring semicircular canal vestibular function; electronystagmography (ENG or VENG), rotatory chair and video head-impulse (VHIT) testing; none of these methods provides a method of measuring total vestibular output. Theory suggests that the slow cumulative eye position can be derived from the rotatory chair test by multiplying the high frequency gain by the time constant, or the "Gain product.

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.

Bilateral vestibular loss.

Bilateral vestibular loss is a rare cause of visual disturbance (oscillopsia) and imbalance. When severe, the most common cause is iatrogenic-gentamicin ototoxicity. Bilateral loss is easily diagnosed at the bedside with the dynamic illegible E test.

Infrequent causes of disequilibrium in the adult.

This content focuses on some of the less common causes of dizziness in the adult. The diseases have been divided into the 2 broad categories of those causing chronic symptoms and those causing episodic symptoms. Presented here are the unusual causes of chronic disequilibrium in the adult, including bilateral vestibular loss, progressive supranuclear palsy, spinocerebellar ataxias, and mal de debarquement.

Migraine-associated vertigo.

This article presents a brief overview of migraine-associated vertigo for the practicing otolaryngologist. Discussion includes the definition of migraine-associated vertigo and its pathophysiology, clinical features, demographics, findings on physical examination, use of otologic and vestibular testing, differential diagnosis, treatment, and prognosis.

Sound evoked triceps myogenic potentials.

Objective: To determine if a sound evoked myogenic potential could be obtained from the triceps with the recording and stimulus parameters routinely used to obtain a vestibular evoked myogenic potential (VEMP) from the sternocleidomastoid.

Study Design: Prospective study of myogenic potentials recorded from the triceps in healthy subjects. We used a monaural acoustic stimulus and measured the unrectified myogenic potential using surface electromyography electrodes, using response-triggered averaging, on the triceps of 18 subjects.