Clinical implication of cervical vestibular evoked myogenic potentials in benign paroxysmal positional vertigo

The assessment of fukuda stepping test results in prognosis of benign paroxysmal postural vertigo

INTRODUCTION

Benign paroxysmal postural vertigo originating from the peripheral vestibular system is characterized by brief vertigo spells triggered by the sudden head motion. Usually, vestibular dysfunction in benign paroxysmal postural vertigo is unilateral. Fukuda stepping test which is helpful in the diagnosis of unilateral vestibular dysfunction, may also be valuable in the prediction of prognosis of benign paroxysmal postural vertigo.

OBJECTIVE

The purpose of this study is to evaluate the relevance of Fukuda stepping test results with resistant and/or recurrent benign paroxysmal postural vertigo cases.

METHODS

We evaluated 62 patients with unilateral, idiopathic benign paroxysmal postural vertigo of posterior and/or lateral canals. The Fukuda stepping test was performed prior to the Dix-Hallpike and head-roll tests. Two groups were created according to the Fukuda stepping test results. In Group 1 Fukuda stepping test results were positive with a deviation angle >45°, while in Group 2 the results were negative with no apparent deviation. Two groups were compared by the number of canalith repositioning manuevers performed and the frequency of recurrences.

RESULTS

We found Fukuda stepping test to be invaluable in the diagnosis of benign paroxysmal postural vertigo since the ratio of Fukuda stepping test positivity and negativity were similar in benign paroxysmal postural vertigo patients. However, the need for multiple canalith repositioning manuevers was significantly higher in Group 1 (p = 0.0103). In addition, the recurrence frequency was found significantly lower in the Group 2 (p = 0.0441).

CONCLUSION

Although the sensitivity of Fukuda stepping test in detecting mild/moderate unilateral vestibular dysfunction is poor, it may be valuable in prediction of the prognosis of benign paroxysmal postural vertigo. We suggest that positive Fukuda stepping test results in benign paroxysmal postural vertigo patients indicate poor prognosis, the need for multipl canalith repositioning manuevers and the higher possibility of recurrences.

Ocular vs. Cervical Vestibular Evoked Myogenic Potentials in Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-Analysis

Objective: To compare utricular dysfunction with saccular dysfunction in benign paroxysmal positional vertigo (BPPV), based on ocular vestibular evoked myogenic potentials (oVEMP) and cervical VEMP (cVEMP), respectively.

Materials and Methods: We performed a literature search exploring utricular and saccular dysfunction in BPPV patients through June 2020 using oVEMP and cVEMP, respectively. The databases included Pubmed, Embase, CENTRAL, CNKI, Wan Fang Data, and CBM. The literatures were limited to Chinese and English. Inclusion criteria and exclusion criteria were defined. We adopted abnormal rate as the outcome. All statistical processes were conducted through software Review Manager. Considering the air-conducted sound (ACS) and bone conducted vibration (BCV) may have different mechanisms, and three types of diagnostic criteria for abnormal VEMP were available, sub-group analysis was performed simultaneously according to the sound stimuli and the diagnostic criteria of abnormal VEMP.

Results: We retrieved 828 potentially relevant literatures, and finally 12 studies were included for meta-analysis of abnormal rate after duplication removal, titles and abstracts screening, and full-text reading. The abnormal rate of oVEMP was not significantly different from cVEMP (OR = 1.59, 95% CI = 0.99–2.57). But the abnormal rate was obviously different between the subgroups adopting ACS oVEMP and BCV oVEMP. In studies adopting ACS oVEMP, the abnormal rate of oVEMP was higher than cVEMP (OR = 1.85, 95% CI = 1.38–2.49). The abnormal rate of oVEMP was also higher than cVEMP when adopting asymmetry ratio (AR) and no response (NR) as diagnostic criteria (OR = 2.16, 95% CI = 1.61–2.89).

Conclusion: The meta-analysis reveals that utricular dysfunction may be more predominant in BPPV compared with saccular dysfunction.

Functional Integrity of the Inferior Vestibular Nerve and Posterior Canal BPPV

The functional integrity of the inferior vestibular nerve (IVN) may be evaluated by the cervical vestibular evoked myogenic potential (cVEMP) response, which requires signal transmission via the nerve. As functional integrity of the IVN innervating the posterior semicircular canal is required to produce the typical positioning vertigo and nystagmus characterizing posterior canal benign paroxysmal positional vertigo (PCBPPV), we hypothesized that normal cVEMPs would be found in most PCBPPV patients. Twenty-four PCBPPV patients participated in a prospective cohort study. All were treated by canal repositioning maneuver and had air-conduction cVEMP and videonystagmography (VNG). Follow-up evaluations including history and otoneurological bedside examination were carried out 1, 3, 6, and 12 months after the initial treatment. At the last follow-up, the patients filled the Dizziness Handicap Inventory (DHI) questionnaire. Normal cVEMPs were recorded in 19 (79%) and were absent in 5 (21%) of the subjects. The average DHI in the patients with normal cVEMP was 16.42 ± 17.99 vs. 0.4 ± 0.89 among those with pathological cVEMP (p < 0.04, Mann-Whitney test). Thirteen (54%) patients experienced recurrent PCBPPV (rPCBPPV). The average DHI score was significantly higher among patients having recurrence (22.15 ± 18.61) when compared to those with complete cure (2.36 ± 5.98; p < 0.003, Mann-Whitney test). Ten (77%) of the subjects with rPCBPPV had normal and 3 (23%) had pathological cVEMP as compared to 9 (82%) and 2 (18%) subjects in the non-recurrent (nrPCBPPV) group (Fisher's exact test-not significant). cVEMP p13 and n23 wave latencies and amplitudes, inter-aural differences in p13-n23 peak-to-peak amplitudes, and response thresholds did not differ between the groups. No differences were found between the rPCBBPV and nrPCBBPV groups in VNG caloric lateralization and directional preponderance values. We have found that in most cases, PCBPPV symptoms and signs are associated with normal cVEMP response supporting the role of IVN functional integrity. The absent cVEMPs in the minority of patients, although having similar clinical presentation, raise the possibility that the ipsilateral saccule is affected by the same pathology causing degeneration of the utricle macula. Alternatively, lacking inhibitory stimuli from the involved ipsilateral utricle or partial degeneration of the IVN and ganglion could explain the diminished cVEMP response. Clinical Trial Registration: The study was registered in ClinicalTrials.gov Internet site (study ID-NCT01004913; https://clinicaltrials.gov/ct2/show/NCT01004913?cond=BPPV&cntry=IL&draw=2&rank=3).

Clinical utility of cervical vestibular-evoked myogenic potentials in predicting residual dizziness after benign paroxysmal positional vertigo

OBJECTIVES

In the present study, the value of cervical vestibular-evoked myogenic potential (cVEMP) as a predictive factor for residual dizziness after recovery of benign paroxysmal positional vertigo (BPPV) was evaluated.

METHODS

The present study included 65 patients who had BPPV and underwent cVEMP testing. Patients were divided into two groups depending on the presence or absence of residual dizziness after recovery of BPPV. Univariate and multivariate analyses were performed to determine the factors associated with residual dizziness using age, gender, affected semicircular canal, affected side, BPPV duration, and cVEMP parameters.

RESULTS

In univariate analysis, cVEMP-modified interaural amplitude difference (IAD) ratio and p13 latency showed a relatively significant association (p < 0.20) with residual dizziness. Based on multivariate analysis, increased cVEMP-modified interaural amplitude difference (IAD) ratio at the affected side (≥25%; p = 0.018, OR 6.623) remained as an associated factor.

CONCLUSIONS

Increased cVEMP-modified IAD ratio at the affected side is associated with residual dizziness. BPPV patients with increased cVEMP-modified IAD ratio at the affected side are more likely to have residual dizziness after recovery of BPPV.

SIGNIFICANCE

cVEMP testing could be used for the prediction of residual dizziness. An increased cVEMP-modified IAD ratio at the affected side may be used as a predictor of residual dizziness.