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

Application of a Video Head Impulse Test in the Diagnosis of Vestibular Neuritis

In patients presenting in the emergency department with acute vertigo, a rapid and accurate differential diagnosis is crucial, as posterior circulation strokes can mimic acute vestibular losses, leading to inappropriate treatment. The diagnosis of vestibular neuritis is made based on the clinical manifestation and a bedside otoneurological assessment. In the clinical examination, an evaluation of the vestibulo-ocular reflex is the key element; however, the accuracy of the bedside head impulse test depends on the clinician's experience. Thus, new diagnostic methods are needed to objectify and facilitate such rapid vestibular evaluations. The aim of our paper is to provide a comprehensive review of the video head impulse test's application in the diagnosis of vestibular neuritis. Numerous studies have reported advantages that make this method helpful in detailed otoneurological evaluations; in contrast to the bedside head impulse test, it enables an analysis of all six semicircular canals function and records the covert corrective saccades, which are invisible to the naked eye. As a portable and easy diagnostic tool, it is known to improve the diagnostic accuracy in patients with acute vertigo presenting in the emergency department. Moreover, as it evaluates the vestibulo-ocular reflex across different frequencies, as compared to caloric tests, it can be used as an additional test that is complementary to videonystagmography. Recently, several papers have described the application of the video head impulse test in follow-up and recovery evaluations in patients with vestibular neuritis.

Effects of vestibular rehabilitation training combined with anti-vertigo drugs on vertigo and balance function in patients with vestibular neuronitis: a systematic review and meta-analysis

Objective

To investigate the effects of vestibular rehabilitation training (VRT) combined with anti-vertigo drugs on vertigo and balance function in patients with vestibular neuronitis (VN).

Data sources

PubMed, EMBASE, The Cochrane Library, Web of Science, CNKI, Wan Fang Data, VIP, and CBM were searched until July 13, 2023.

Participants

Patients with vestibular neuronitis participated in the study.

Results

Twenty one studies including 1,415 patients were included in this review for meta-analysis. According to the Physiotherapy Evidence Database (PEDro) quality assessment, four studies received high quality (≥seven scores) and 17 studies received moderate quality (six scores). The meta-analysis showed that VRT combined with anti-vertigo drugs significantly reduced the Dizziness Handicap Inventory (DHI) score, the Vestibular Disorders Activities of Daily Living Scale (VADL) score and the Canal Paresis (CP) score, and improved the overall efficiency and the Berg Balance Scale (BBS) score, promoting vestibular evoked myogenic potentials (VEMPs) returned to normal in VN compared to simple anti-vertigo drugs or VRT alone.

Conclusion

The results of this meta-analysis demonstrate the efficacy and safety of VRT combined with anti-vertigo drugs in patients with VN. Combined therapy can alleviate vestibular dysfunction such as vertigo and vomiting in patients, improve daily activity ability and balance ability, in addition to VRT has fewer adverse reactions, so it is extremely safe. However, there are shortcomings such as lack of long-term follow-up and different frequency and duration of treatment. Therefore, future randomized controlled trials (RCTs) with larger sample sizes and longer-term observations are needed to verify the effectiveness of VRT in combination with anti-vertigo drugs for VN.Systematic Review Registration: https://www.crd.york.ac.uk/prospero/.

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.

Benign Paroxysmal Positional Vertigo Secondary to Acute Unilateral Peripheral Vestibulopathy: Evaluation of Cardiovascular Risk Factors

BACKGROUND

Lindsay-Hemenway syndrome was first described as an acute unilateral peripheral vestibulopathy followed by positional vertigo. A vascular etiology was proposed. An association between cardiovascular risk factors and benign paroxysmal positional vertigo secondary to acute unilateral peripheral vestibulopathy has been described with contradictory evidence. The study aimed to evaluate the prevalence of cardiovascular risk factors in patients with benign paroxysmal positional vertigo secondary to acute unilateral peripheral vestibulopathy and analyze differences in prior history of benign paroxysmal positional vertigo, affected semicircular canals, and response to repositioning maneuvers between patients with idiopathic benign paroxysmal positional vertigo and secondary to acute unilateral peripheral vestibulopathy.

METHODS

We performed a retrospective, descriptive study of all cases of benign paroxysmal positional vertigo between January/2017 and June/2020, with or without a history of acute unilateral peripheral vestibulopathy within the previous year. Cases secondary to trauma or otoneurological causes and acute unilateral peripheral vestibulopathy without confirmatory tests and cases with auditory symptoms were excluded.

RESULTS

In total, 242 cases were obtained; 158 idiopathic benign paroxysmal positional vertigo and 84 secondary to acute unilateral peripheral vestibulopathy. No statistically significant differences were found in relation to age: 61.2 ± 14.6 versus 62.4 ± 16.2 years (P=.55), sex: female 78.5% versus 73.8% (P=.41), presence of cardiovascular risk factors: 52.5% versus 54.8% (P=.67), prior history of benign paroxysmal positional vertigo: 22.2% versus 27.7% (P=.43), affected semicircular canals (P=.16) or number of repositioning maneuvers (P=.57).

CONCLUSION

Associations between age, cardiovascular risk factors, and benign paroxysmal positional vertigo secondary to acute unilateral peripheral vestibulopathy have been described with conflicting evidence. This is the first study to evaluate cardiovascular risk factors specifically for Lindsay-Hemenway syndrome, and we did not observe any differences between idiopathic benign paroxysmal positional vertigo cases and those secondary to acute unilateral peripheral vestibulopathy.

Head and vestibular kinematics during vertical semicircular canal impulses

BACKGROUND

The video head impulse test (vHIT) is a common assessment of semicircular canal function during high-speed impulses. Reliability of the vHIT for assessing vertical semicircular canals is uncertain. Vertical head impulses require a complex head movement, making it difficult to isolate a single semicircular canal and interpret resulting eye rotations.

OBJECTIVE

The purpose of this study was to provide descriptive head kinematics and vestibular stimuli during vertical plane impulses to ultimately improve impulse delivery and interpretation of vHIT results for vertical semicircular canals.

METHODS

Six participants received right anterior (RA) and left posterior (LP) semicircular canal impulses. Linear displacements, rotational displacements, and rotational velocities of the head were measured. Peak velocities in semicircular canal planes and peak-to-peak gravitoinertial accelerations at the otolith organs were derived from head kinematics.

RESULTS

The largest rotational velocities occurred in the target semicircular canal plane, with non-negligible velocities occurring in non-target planes. Larger vertical displacements and accelerations occurred on the right side of the head compared to the left for RA and LP impulses.

CONCLUSIONS

These results provide a foundation for designing protocols to optimize stimulation applied to a singular vertical semicircular canal and for interpreting results from the vHIT for vertical semicircular canals.

Posterior semicircular canal ossification following acute vestibular loss mimicking inferior vestibular neuritis: A case report

Vestibular neuritis (VN) mostly involves the superior vestibular nerve. Isolated inferior vestibular neuritis (IVN) has been more rarely described. The diagnosis of IVN is based on an abnormal head impulse test (HIT) for the posterior semicircular canal (PSC), pathological cervical vestibular-evoked myogenic potentials (C-VEMPs), and spontaneous downbeat nystagmus consistent with acute functional loss of inner ear sensors lying within the inferior part of the labyrinth. HIT for both lateral and superior semicircular canals is normal, as are ocular VEMPs and bithermal caloric irrigations. The etiology of IVN is debated since peripheral acute vestibular loss with a similar lesion pattern can often be associated with ipsilesional sudden hearing loss (HL). Viral inflammation of vestibular nerves is considered the most likely cause, although reports suggest that VN usually spares the inferior division. On the other hand, an ischemic lesion involving the terminal branches of the common cochlear artery has been hypothesized in cases with concurrent HL. Debated is also the lesion site in the case of IVN without HL since different instrumental patterns have been documented. Either isolated posterior ampullary nerve involvement presenting with selective PSC functional loss on video-HIT, or only saccular lesion with isolated ipsilesional C-VEMPs impairment, or inferior vestibular nerve damage (including both saccular and posterior ampullary afferents) exhibiting an impairment of both C-VEMPs and PSC-HIT. We report an interesting case of a patient with an acute vestibular loss consistent with IVN without HL who developed a PSC ossification on follow-up, questioning the viral origin of the lesion and rather orienting toward an occlusion of the posterior vestibular artery. To the best of our knowledge, this is the first report of PSC ossification after a clinical picture consistent with IVN.

Dissociation between Caloric and Video Head Impulse Tests in Dizziness Clinics

Vestibular assessment tests such as the video head impulse test (vHIT) for the horizontal semicircular canal, and caloric test (Cal), both evaluate horizontal canal function. One would assume that the outcomes for these tests should lead to concordant results, yet several studies have suggested that dissociation can occur in certain pathological conditions. As this topic remains inconclusive, this review aims to analyze the scientific evidence regarding the patterns of hypofunction observed in vHIT and Cal in different otoneurological diseases. A comprehensive review of the literature regarding dissociation between these tests in common neurotological diseases was carried out. Articles were analyzed when data for vHIT and Cal were described in a way that it was possible to calculate discordance rates; both retrospective and prospective studies were analyzed. In this review, the discordance rates were as follows: 56% in Ménière’s disease, 51.5% in vestibular migraine, 37.2% in vestibular schwannoma, and 20.8% in vestibular neuritis. These results highlight the benefit of using both Cal and vHIT, and that they are complementary tests.

Differential Involvement of Lateral Semicircular Canal and Otolith Organs in Common Vestibular Disorders

Semicircular canal and otolith functions came to be evaluated recently, but comprehensive and comparative analysis of canal and otolith dysfunction in common vestibular disorders is lacking. We aimed to analyze the abnormal rates of canal and otolith function in common vestibular disorders. We enrolled 302 patients who were managed for 2 months in a dizziness clinic. Results of caloric, video head impulse test (vHIT), and cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) tests were analyzed and compared among various diagnoses. Vestibular disorders diagnosed included recurrent vestibulopathy (RV, 27%), vestibular migraine (VM, 21%), benign paroxysmal positional vertigo (BPPV, 17%), Meniere's disease (MD, 11%), vestibular neuritis (VN, 10%), orthostatic dizziness (7%), and central lesions (3%). Lateral canal dysfunction was found most in VN (100%) and less commonly in definite MD (75%), RV (46%) and definite VM (29%). Abnormal caloric results were more common than abnormal vHIT in all disorders. Otolith dysfunction was found more frequently than lateral canal dysfunction in most vestibular disorders except VN. An abnormal cVEMP was more frequent in definite MD than the other disorders. Isolated otolith dysfunction without lateral canal dysfunction was the most found in BPPV, followed by definite VM, RV, and definite MD in decreasing order. Various patterns of involvement in canal and otoliths were revealed in vestibular disorders, suggesting different pathogenesis.

Recovery Nystagmus in Vestibular Neuritis with Minimal Canal Paresis. Clinical Observation and Interpretation

Recovery nystagmus in vestibular neuritis patients is a reversal of spontaneous nystagmus direction, beating towards the affected ear, observed along the time course of central compensation. It is rarely registered due either to its rarity as a phenomenon per se, or to the fact that it is missed between follow-up appointments. The aim of the manuscript is to describe in detail a case of recovery nystagmus found in an atypical case of vestibular neuritis and discuss pathophysiology and clinical considerations regarding this rare finding. A 26-year-old man was referred to our Otorhinolaryngology practice reporting “dizziness” sensation and nausea in the last 48 h. Clinical examination revealed left beating spontaneous nystagmus (average slow phase velocity aSPV 8.1°/s) with absence of fixation. The head impulse test (H.I.T.) was negative. Cervical vestibular evoked myogenic potentials (cVEMP) and Playtone audiometry (PTA) were normal. Romberg and Unterberger tests were not severely affected. A strong directional preponderance to the left was found in caloric vestibular test with minimal canal paresis (CP 13%) on the right. The first follow-up consultation took place on the 9th day after the onset of symptoms. Right beating weak (aSPV 2.4°/s) spontaneous nystagmus was observed with absence of fixation, whereas a strong right directional preponderance (DP) was found in caloric vestibular test. A brain MRI scan was ordered to exclude central causes of vertigo, which was normal. The patient was seen again completely free of symptoms 45 days later. He reported feeling dizzy during dynamic movements of the head and trunk for another 15 days after his second consultation. The unexpected observation of nystagmus direction reversal seven days after the first consultation is a typical sign of recovery nystagmus. Recovery nystagmus (RN) is centrally mediated and when found, it should always be carefully assessed in combination with the particularities of vestibular neuritis.