Vestibular evoked myogenic potentials in idiopathic posterior canal benign paroxysmal positional vertigo

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.

Evaluation of cervical vestibular evoked myogenic potential measures using different stimulus types in patients with posterior canal benign paroxysmal positional vertigo

Background: Cervical Vestibular Evoked Myogenic Potential (cVEMP) measurements still do not have standard normative values in posterior canal benign paroxysmal positional vertigo (BPPV).Aim/Objectives: We aimed to compare cVEMP recordings obtained with different stimuli applied in two different intensities in posterior canal BPPV patients.Methods: Thirty-four patients with unilateral posterior canal BPPV were included in the patient group. In cVEMP recordings obtained with different stimulus intensity [95 dB HL and 105 dB HL] and different stimuli[tone-burst cVEMP (T-cVEMP) and click cVEMP (C-cVEMP)].Results: When the C-cVEMP and T-cVEMP findings were compared in the patient group, differences were observed only in peak-to-peak p1-n1 amplitude values in the measurements performed with 95 dB stimulus. However, T-cVEMP measurements performed with 105 dB stimulus showed that both p1 and n1 latency values ​were longer and peak-to-peak p1-n1 amplitude values ​were higher than C-cVEMP measurements.Conclusions and significance: We recommend using priorly tone-burst stimulus for measurements with 105 dB HL in cVEMP evaluations we will perform in posterior BPPV patients. Both stimulants can be used when 95 dB HL stimuli is used.

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

Objective: The objective of our study was to investigate the potential association between the occurrence of benign paroxysmal positional vertigo (BPPV) and saccular dysfunction using cervical vestibular evoked myogenic potentials (cVEMP) testing. Methods: The databases including Pubmed, Embase, and CENTRAL were systemically searched for case-control literatures investigating saccular dysfunction using cVEMP testing in BPPV patients compared with healthy controls. The literatures were published up to 16 April 2019 and were limited to the English language. All statistical processes were carried out using software Review Manager, version 5.3. Subgroup analysis and sensitive analysis were performed simultaneously. Results: Of the 12 case-control studies confirmed for meta-analysis, p13 latency of cVEMP was assessed in 8 studies, n23 latency in 6 studies, amplitude in 5 studies, asymmetry ratio (AR) in 3 studies, proportion of absent response in 9 studies, and abnormal cVEMP in 8 studies. Compared with healthy controls, the p13 mean latency of cVEMP was longer (MD = 0.88, 95% CI = 0.64-1.12, p < 0.00001), the mean amplitude was lower (SMD = -0.60, 95% CI = -0.80 to -0.41, p < 0.00001), and the proportions of absent response (OR = 8.76, 95% CI = 2.28-33.61, p = 0.002), and abnormal cVEMP (OR = 7.47, 95% CI = 4.65-12.01, p < 0.00001) were higher in BPPV patients. But there was no significant difference in the n23 mean latency (MD = 0.37, 95% CI = -0.23-0.98, p = 0.22) and the AR of cVEMP (MD = 3.95, 95% CI = -4.75-12.65, p = 0.37) between BPPV patients and healthy controls. In the sub-group analysis based on age, only the result of the proportion of absent response of cVEMP indicated a significant difference existed (p = 0.002) between the studies with age-matched controls (OR = 2.78, 95% CI = 1.09-7.10, p = 0.03) and the studies without age-matched controls (OR = 53.85, 95% CI = 10.09-287.13, p < 0.00001). In the sub-group analysis of the proportion of abnormal cVEMP according to the diagnostic criteria of abnormal cVEMP, the result indicated no significant difference existed between the four groups (p = 0.61, I ² = 0%). In the sensitivity analysis, we obtained the consistent results after removing each study sequentially. Conclusion: The meta-analysis reveals that saccular dysfunction may be associated with BPPV occurrence, and neural degeneration in the saccular macula may be a potential pathogenesis for BPPV.

Vestibular-evoked myogenic potentials and subjective visual vertical testing in patients with vitamin D deficiency/insufficiency

Otolith function in subjects with vitamin D deficiency/insufficiency is investigated through vestibular-evoked myogenic potentials (VEMP) and subjective visual vertical (SVV) testing. The study group included 62 patients with vitamin D deficiency/insufficiency (30 females, 32 males), with age range 24-56 years (40.6 ± 9.1). The control group included 44 healthy volunteers of similar age and gender distribution. The entire study group had: (1) serum level of 25-hydroxyvitamin D <30 ng/ml; (2) normal bone mineral density as indicated by dual-energy X-ray absorptiometry with T-score >-1; (3) normal middle ear function; (4) Age is ≤60 years. All subjects enrolled in the current study underwent audiovestibular evaluation consisting of pure-tone audiometry, immittancemetry, cervical VEMP (cVEMP), ocular VEMP (oVEMP), and SSV. The entire control group had normal cVEMP, two subjects had abnormal oVEMP. Thirty-three subjects (53%) in the study group had abnormal oVEMP and 31 subjects (50%) had abnormal cVEMP. Forty-one (66%) had abnormal VEMP when abnormal VEMP was considered as either abnormal oVEMP or cVEMP. The entire control and study groups had normal SSV test results. Vitamin D deficiency may be associated with development of otolith dysfunction affecting both the utricle and saccule. This was suggested by the high prevalence of abnormal ocular vestibular-evoked myogenic potentials (oVEMP) and cervical vestibular-evoked myogenic potentials (cVEMP) in the study group.