Fluctuating Posterior Canal Function in Benign Paroxysmal Positional Vertigo Depending on How and Where Otoconia Are Disposed

Lindsay-Hemenway Syndrome Involving the Horizontal Semicircular Canal: Some Considerations Upon Residual Canal Afferents in BPPV Secondary to an Ipsilateral Acute Unilateral Vestibulopathy

OBJECTIVE

To describe benign paroxysmal positional vertigo (BPPV) involving the horizontal semicircular canal (HSC) after ipsilateral acute unilateral vestibulopathy (AUVP) and to advance some hypotheses on the underlying pathomechanism.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

A case series of four patients presenting with HSC-BPPV after ipsilateral AUVP with impaired function of the involved canal at the video-head impulse test (vHIT). Ipsilateral sudden sensorineural hearing loss was detected in one case.

INTERVENTION

All patients underwent bedside examination and an instrumental audio-vestibular assessment, including pure-tone audiometry, vHIT, and vestibular-evoked myogenic potentials. Three patients underwent bithermal caloric testing (BCT). Brain magnetic resonance imaging scan was performed in all cases. Successful canal repositioning was conducted.

MAIN OUTCOME MEASURE

Clinical presentation with video recording and audio-vestibular findings.

RESULTS

Secondary HSC-BPPV was observed from 3 weeks to 8 months after the onset of ipsilateral AUVP. Two cases exhibited an apogeotropic variant, whereas two cases presented with a geotropic form. All BPPV resolved after physical therapy. Instrumental audio-vestibular assessment revealed vestibulo-ocular reflex (VOR) impairment for the affected canal on vHIT in all cases, whereas BCT revealed a borderline normal canal paresis.

CONCLUSIONS

BPPV after an AUVP can involve the HSC. A reduced VOR gain in the high-frequency domain attributable to a damage of the type I (phasic) afferents does not exclude the occurrence of a BPPV if type II (tonic) afferents are preserved or slightly impaired. Clinicians should not neglect to evaluate for provoking nystagmus in patients with vestibular symptoms and vestibular hypofunction on vHIT.

Variants of posterior semicircular canal involvement in benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo is the most common cause of peripheral vertigo. It is characterized by short and recurrent episodes of vertigo, trigged by specific head movements that displace otoconia within the semicircular canals. The movement of dislodge otoconia from the utricle cause abnormal positional endolymphatic currents. Primary treatment involves reposition maneuvers aimed at moving the displaced otoconia out the affected canal, therefore correct identification of the affected canal is essential for the diagnosis. The posterior semicircular canal (PSC) is the most frequently affected due to its spatial orientation and the force of gravity. Recent technological advances have allowed for better assessment of positional nystagmus during diagnostic and therapeutic maneuvers, revealing various possible scenarios of PSC involvement. Regarding the PSC, otoconia may be found in different parts of the canal, and not just in the expected location, floating in the long arm of the canal. The understanding of these variants is crucial, as the prognosis and the disease progression differ in such cases. This review aims to describe the six possible variants of PSC involvement described so far.

Posterior Semicircular Canal Dehiscence with Vestibulo-Ocular Reflex Reduction for the Affected Canal at the Video-Head Impulse Test: Considerations to Pathomechanisms

Posterior semicircular canal dehiscence (PSCD) has been demonstrated to result in a third mobile window mechanism (TMWM) in the inner ear similar to superior semicircular canal dehiscence (SSCD). Typical clinical and instrumental features of TMWM, including low-frequency conductive hearing loss (CHL), autophony, pulsatile tinnitus, sound/pressure-induced vertigo and enhanced vestibular-evoked myogenic potentials, have been widely described in cases with PSCD. Nevertheless, video-head impulse test (vHIT) results have been poorly investigated. Here, we present six patients with PSCD presenting with a clinical scenario consistent with a TMWM and an impaired vestibulo-ocular reflex (VOR) for the affected canal on vHIT. In two cases, an additional dehiscence between the facial nerve and the horizontal semicircular canal (HSC) was detected, leading to a concurrent VOR impairment for the HSC. While in SSCD, a VOR gain reduction could be ascribed to a spontaneous "auto-plugging" process due to a dural prolapse into the canal, the same pathomechanism is difficult to conceive in PSCD due to a different anatomical position, making a dural herniation less likely. Alternative putative pathomechanisms are discussed, including an endolymphatic flow dissipation during head impulses as already hypothesized in SSCD. The association of symptoms/signs consistent with TMWM and a reduced VOR gain for the posterior canal might address the diagnosis toward PSCD.

Audiovestibular Findings in Patients with Concurrent Superior Canal Dehiscence and Vestibular Schwannoma

OBJECTIVE

To describe the clinical-instrumental findings in case of concurrent superior canal dehiscence (SCD) and ipsilateral vestibular schwannoma (VS), aiming to highlight the importance of an extensive instrumental assessment to achieve a correct diagnosis.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Five patients with concurrent SCD and VS.

INTERVENTION

Clinical-instrumental assessment and imaging.

MAIN OUTCOME MEASURE

Clinical presentation, audiovestibular findings, and imaging.

RESULTS

The chief complaints were hearing loss (HL) and unsteadiness (80%). Other main symptoms included tinnitus (60%) and pressure-induced vertigo (40%). Mixed-HL was identified in three patients and pure sensorineural-HL in 1, including a roll-over curve in speech-audiometry in two cases. Vibration-induced nystagmus was elicited in all cases, whereas vestibular-evoked myogenic potentials showed reduced thresholds and enhanced amplitudes on the affected side in three patients. Ipsilesional weakness on caloric testing was detected in three patients and a bilateral hyporeflexia in one. A global canal impairment was detected by the video-head impulse test in one case, whereas the rest of the cohort exhibited a reduced function for the affected superior canal, together with ipsilateral posterior canal impairment in two cases. All patients performed both temporal bones HRCT scan and brain-MRI showing unilateral SCD and ipsilateral VS, respectively. All patients were submitted to a wait-and-scan approach, requiring VS removal only in one case.

CONCLUSION

Simultaneous SCD and VS might result in subtle clinical presentation with puzzling lesion patterns. When unclear symptoms and signs occur, a complete audiovestibular assessment plays a key role to address imaging and diagnosis.

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.

Resolution of atypical posterior semicircular canal BPPV: evidence for putative short-arm location

This case demonstrates the successful identification and treatment of atypical posterior semicircular canal benign paroxysmal positional vertigo (BPPV) based on a unique presentation of positional nystagmus, the resultant nystagmus from repositioning manoeuvers, and restored function of the affected semicircular canal. This case illustrates the importance of completing a comprehensive clinical examination and the value for incorporating the video head impulse test as well as adjusting treatment based on testing and patient response when managing variant cases of BPPV.

Soccer and Benign Paroxysmal Positional Vertigo

Introduction. Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo among adults. The etiology of BPPV is unknown in approximately 50 percent of cases. This condition is also termed primary BPPV, if the etiology is unknown, and secondary BPPV if patients have identified predisposing factors. A few studies suggest that there is a correlation between the development of BPPV and specific sports. Case Report. A 19-year-old male presented with recurrent episodes of vertigo during soccer play. Eight months prior to referral, the patient was involved in a car accident with a mild head trauma. The patient was later diagnosed with BPPV several times. Discussion. Soccer might be a plausible BPPV trigger, especially if there is a prehistory of head trauma. This is most likely due to the demands of the game such as the change of directions, repetitive head impacts (headers or head collisions), accelerations/decelerations, jumps, foot landings, and rapid head movements.

Patients’ Experiences with Management of Benign Paroxysmal Positional Vertigo: Insights from the Vestibular Disorders Association Registry

Introduction

Benign paroxysmal positional vertigo (BPPV) is the most frequently occurring peripheral vestibular disorder. Clinical practice guidelines (CPG) for BPPV exist; however, little is known about how affected patients perceive their condition is being managed. We aimed to leverage registry data to evaluate how adults who report BPPV are managed.

Material and Methods

We retrospectively analyzed of data from 1,262 adults (58.4 ± 12.6 years old, 81.1% female, 91.1% White) who were enrolled in the Vestibular Disorders Association Registry from 2014 to 2020. The following patient-reported outcomes were analyzed by proportions for those who did and did not report BPPV: symptoms experienced, falls reported, diagnostics undertaken, interventions received (eg, canalith repositioning maneuvers [CRMs], medications), and responses to interventions.

Results

Of the 1,262 adults included, 26% reported being diagnosed with BPPV. Many adults who reported BPPV (83%) also endorsed receiving additional vestibular diagnoses or may have had atypical BPPV. Those with BPPV underwent magnetic resonance imaging and were prescribed medications more frequently than those without BPPV (76% vs 57% [χ²=36.51, p<0.001] and 85% vs 78% [χ²=5.60, p=0.018], respectively). Falls were experienced by similar proportions of adults with and without BPPV (55% vs 56% [χ²⁼=11.26, p=0.59]). Adults with BPPV received CRMs more often than those without BPPV (86% vs 48%, χ²=127.23, p<0.001). More registrants with BPPV also endorsed benefit from CRMs compared to those without BPPV (51% vs 12% [χ²=105.30, p<0.001]).

Discussion

In this registry, BPPV was often reported with other vestibular disorders. Healthcare utilization was higher than would be expected with care based on the CPG. The rates of falls in those with and without BPPV are higher than previously reported. Adults with BPPV reported significant differences in how their care is managed and their overall outcomes compared to those without BPPV.

Conclusion

Patient-reported outcomes provide useful information regarding the lived experience of adults with BPPV.

Video Head Impulse Test Findings in Patients With Benign Paroxysmal Positional Vertigo Secondary to Idiopathic Sudden Sensorineural Hearing Loss

Benign paroxysmal positional vertigo (BPPV) is amongst the most common causes of episodic vestibular syndrome. It can be classified as idiopathic and secondary types according to the causative factors, and the underlying mechanism between idiopathic (i-BPPV) and secondary BPPV (s-BPPV) may differ. Idiopathic sudden sensorineural hearing loss (ISSNHL) has been considered as a common inner ear disease that precipitates s-BPPV. Yet, few studies have addressed the functional impairment of the semicircular canal (SCC) system in patients with s-BPPV associated with ISSNHL. Our purpose was to explore the pathophysiological mechanism and investigate the clinical implications of video head impulse test (vHIT) in these patients. Here, the clinical and laboratory data of patients with BPPV secondary to ISSNHL, including the results of vHIT, were retrospectively reviewed, and compared with those of patients with i-BPPV. Pathological vHIT findings (low vestibulo-ocular reflex gain and re-fixation saccade), which mainly affected the posterior SCC, were more common in the s-BPPV group than in the i-BPPV group (41.9 and 0%, respectively). The incidence of horizontal SCC involvement was also higher in the s-BPPV group (45.16 and 16.67%, respectively). Furthermore, patients with s-BPPV showed lower vHIT gains of the posterior and horizontal SCCs in affected ears than in unaffected ears. Compared to i-BPPV, posterior SCC paresis detected by vHIT is more prevalent in BPPV secondary to ISSNHL. This dysfunction may be associated mainly with vestibular impairments caused by ISSNHL, and not with BPPV per se.

Atypical Positional Vertigo: Definition, Causes, and Mechanisms

Paroxysmal positional vertigo is a frequent cause for consultation. When approaching these patients, we try to differentiate central from peripheral causes, but sometimes we find manifestations that generate diagnostic doubts. In this review, we address atypical paroxysmal positional vertigo, reviewing the literature on the subject and giving a provisional definition of atypical positional vertigo as well as outlining its causes and pathophysiological mechanisms.

Recovery of Regular Daily Physical Activities Prevents Residual Dizziness after Canalith Repositioning Procedures

OBJECTIVE

Residual dizziness is a disorder of unknown pathophysiology, which may occur after repositioning procedures for benign paroxysmal positional vertigo. This study evaluates the relationship between regular daily physical activity and the development of residual dizziness after treatment for benign paroxysmal positional vertigo.

STUDY DESIGN

Prospective observational cohort study.

SETTING

Academic university hospital.

METHODS

Seventy-one patients admitted with benign paroxysmal positional vertigo involving the posterior semicircular canal were managed with Epley's procedure. Three days after successful treatment, the patients underwent a telephone interview to investigate vertigo relapse. If the patients no longer complained of vertigo, they were asked about symptoms consistent with residual dizziness. Subsequently, they were asked about the recovery of physical activities they regularly performed prior to the onset of vertigo.

RESULTS

Sixty-nine patients (age: 57.79 ± 15.05) were enrolled: five (7.24%) reported vertigo relapse whereas twenty-one of sixty-four non-relapsed patients (32.81%) reported residual dizziness. A significant difference in the incidence of residual dizziness was observed considering the patients' age (p = 0.0003). Of the non-relapsed patients, 46 (71.88%) recovered their regular dynamic daily activities after treatment and 9 (19.57%) reported residual dizziness, while 12 of the 18 patients (66.67%) who did not resume daily activity reported residual symptoms (p = 0.0003). A logistic regression analysis showed a significant association between daily activity resumption and lack of residual dizziness (OR: 14.01, 95% CI limits 3.14-62.47; p = 0.001).

CONCLUSIONS

Regardless of age, the resumption of regular daily physical activities is associated with a lack of residual dizziness.

Spontaneous Upbeat Nystagmus and Selective Anterior Semicircular Canal Hypofunction on Video Head Impulse Test: A New Variant of Canalith Jam?

We describe a rare case of spontaneous upbeat nystagmus (UBN) attributable to a canalith jam involving the anterior semicircular canal (ASC) in a patient in whom comprehensive vestibular assessment was useful to identify the underlying pathomechanism. A 56-year-old woman with unsteadiness following repositioning procedures for left-sided benign paroxysmal positional vertigo (BPPV) presented with spontaneous UBN that showed slight right torsional components. A vestibular test battery detected isolated left ASC hypofunction on a video-head impulse test (Video-HIT). We postulated a persistent utriculopetal deflection of the left ASC cupula, which was attributable to entrapment of debris in a narrow canal tract, with consequent sustained inhibition of the ampullary afferents. Although spontaneous UBN receded after impulsive physical therapy, unsteadiness deteriorated into positional vertigo secondary to canalolithiasis involving the ipsilateral posterior canal. In our view, physical therapy possibly fragmented the canalith jam and released free-floating otoconia that eventually settled into the ipsilateral posterior canal. Video HIT revealed normalization of ASC hypofunction, and left-sided posterior canal canalolithiasis was successfully treated using appropriate repositioning procedures. We propose that a canalith jam involving the ASC should be considered in the differential diagnosis of spontaneous UBN, particularly in patients with a history of BPPV and isolated ASC hypofunction detected on video HIT.