Are cervical vestibular evoked myogenic potentials sensitive to changes in the vestibular system associated with benign paroxysmal positional vertigo?

Bilateral Dysfunction of Otolith Pathway in Patients With Unilateral Idiopathic BPPV Detected by ACS-VEMPs

Objective

To observe the functional status of the otolith pathway in patients with unilateral idiopathic benign paroxysmal positional vertigo (BPPV) by combining air-conducted sound elicited cervical vestibular-evoked myogenic potential (ACS-cVEMP) and ocular vestibular-evoked myogenic potential (ACS-oVEMP).

Methods

One hundred and eighty patients with BPPV were recruited for conventional cVEMP and oVEMP tests. The abnormal rates of VEMPs were compared between BPPV patients and control participants.

Results

The abnormal rates of cVEMP and oVEMP in BPPV patients were 46.7% (84/180) and 57.2% (103/180) in affected ears, respectively, and 45.0% (81/180) and 56.7% (102/180) in unaffected ears, respectively; both were significantly higher than the abnormal rates of cVEMP and oVEMP in normal control ears. Compared with normal subjects, the cVEMP response rate was lower in affected and unaffected ears in BPPV patients. The abnormal rates of cVEMP and oVEMP were 48.1% (76/158) and 57.6% (91/158) in patients with posterior semicircular canal BPPV, and 36.4% (8/22) and 54.5% (12/22) in lateral semicircular canal BPPV. There was no significant difference in VEMP abnormalities between posterior semicircular canal BPPV and lateral semicircular canal BPPV.

Conclusion

The prevalence of abnormal cVEMPs and oVEMPs in both affected and unaffected ears of patients with BPPV was significantly higher than that observed in the control group. The pathological mechanism of unilateral idiopathic BPPV may be associated with bilateral degeneration of otolith pathways.

Relative efficacy of veria and mastoidectomy techniques of cochlear implantation in preservation of sound-induced saccular responses

OBJECTIVE

Cochlear implantation (CI) is a safe technique to give hearing sensation to a person with hearing impairment. The present study aimed to compare the two surgical approaches of CI, mastoidectomy and veria, for their effects on saccular function assessed using cervical vestibular-evoked myogenic potential (cVEMP).

DESIGN

Multiple group time series design.

STUDY SAMPLE

The study included 63 children (3-8 years old) who underwent CI using veria technique (n = 20) and mastoidectomy approach (n = 43). The 500-Hz tone-burst evoked cVEMP were recorded on three occasions- a day before CI surgery, a day after the device switch-on and 4 months after the switch-on.

RESULTS

The post-implant results revealed the absence of cVEMP in nearly 40% of the participants. The amplitudes were significantly lower at the time of the switch-on and at the 4-months follow-up period (p < 0.05). Among the participants undergoing CI using mastoidectomy approach, amplitudes were significantly larger after surgery than those undergoing surgery using veria technique (p < 0.05).

CONCLUSIONS

The saccular responses are better preserved with the mastoidectomy technique than the veria technique for CI surgery.

Balance Assessment of Children with Sensorineural Hearing Loss

This study aimed to assess the balance function in children with sensorineural hearing loss (SNHL) using different tests to assess vestibulospinal pathway and tests to assess vestibular system and to compare the result obtained with those of children with normal hearing sensitivity. Detailed balance assessment was done for 15 children with severe to profound SNHL and 15 children with normal hearing sensitivity in the age range of 6-10 years. The audiological evaluation included pure-tone audiometry, speech audiometry, immittance evaluation, otoacoustic emission, vestibular evoked myogenic potential (cervical VEMP and ocular VEMP), and tests to assess vestibulospinal pathway and cerebellar function, such as Romberg test, Fukuda stepping test, Tandem gait test, and Finger-to-nose test. cVEMP and oVEMP were absent in 8 ears (27%) of a total of 30 ears with SNHL. Statistical analysis shows no significant difference between latency and amplitude of cVEMP peaks and latency of oVEMP peaks across groups. Significant reduction of oVEMP peaks amplitude was seen in children with SNHL compared to children with normal hearing. Fukuda stepping test showed an abnormal response in 2 children with SNHL (13%) and one child could not perform tandem gait test (7%). Children with SNHL showed an evident abnormality on the balance assessment test results. The abnormal function of the vestibular system and the vestibulospinal pathway can compromise the child's motor development and thus needs investigation early in life.

Clinical significance of cervical and ocular vestibular evoked myogenic potentials in benign paroxysmal positional vertigo: a meta-analysis

PURPOSE

As the pathological cause of benign paroxysmal positional vertigo (BPPV), the dislocation or degeneration of otoconia in the utricle and saccule is suggested. Vestibular evoked myogenic potential (VEMP) could reflect otolithic dysfunction due to these etiologies of BPPV. The aim of this study was to validate the clinical significance of cervical (c) and ocular (o) VEMP in BPPV by a meta-analysis of previous articles.

METHODS

Articles related to BPPV with data on cVEMP and oVEMP were collected. The following keywords were used to search PubMed and Scopus for English language articles: benign paroxysmal positional vertigo or BPPV and vestibular evoked myogenic potential or VEMP.

RESULTS

The p13 latency in cVEMP and n1 latency in oVEMP were slightly but significantly prolonged in BPPV patients compared to control patients. AR in oVEMP of BPPV patients also showed higher value than that of control patients. However, the n23 latency and AR in cVEMP and p1 latency in oVEMP showed no significant difference between BPPV and control patients. Furthermore, latencies in VEMPs also showed no significant difference between an affected and a non-affected ear in BPPV patients.

CONCLUSIONS

Our results indicated that otolith dysfunction of BPPVs was detected by latencies in VEMPs, and AR in oVEMP more sensitively reflects the difference between affected and non-affected ears in BPPV patients. The otolith dysfunction of BPPV might be induced by the systemic condition. However, the differences of latencies between BPPV patients and control patients were too small to use VEMPs as a prognostic predictor.

Behavioural and objective vestibular assessment in persons with osteoporosis and osteopenia: a preliminary investigation

INTRODUCTION

Calcium is vital for the functioning of the inner ear hair cells as well as for the neurotransmitter release that triggers the generation of a nerve impulse. A reduction in calcium level could therefore impair the peripheric vestibular functioning. However, the outcome of balance assessment has rarely been explored in cases with osteopenia and osteoporosis, the medical conditions associated with reduction in calcium levels.

OBJECTIVE

The present study aimed to investigate the impact of osteopenia and osteoporosis on the outcomes of behavioural and objective vestibular assessment tests.

METHODS

The study included 12 individuals each in the healthy control group and osteopenia group, and 11 individuals were included in the osteoporosis group. The groups were divided based on the findings of bone mineral density. All the participants underwent behavioural tests (Fukuda stepping, tandem gait and subjective visual vertical) and objective assessment using cervical and ocular vestibular evoked myogenic potentials.

RESULTS

A significantly higher proportion of the individuals in the two clinical groups' demonstrated abnormal results on the behavioural balance assessment tests (p<0.05) than the control group. However, there was no significant difference in latencies or amplitude of cervical vestibular evoked myogenic potential and oVEMP between the groups. The proportion of individuals with absence of ocular vestibular evoked myogenic potential was significantly higher in the osteoporosis group than the other two groups (p<0.05).

CONCLUSION

The findings of the present study confirm the presence of balance-related deficits in individuals with osteopenia and osteoporosis. Hence the clinical evaluations should include balance assessment as a mandatory aspect of the overall audiological assessment of individuals with osteopenia and osteoporosis.