Role of Cervical Vestibular Evoked Myogenic Potentials (cVEMP) as Outcome-Measure of Glycerol Test

Effect of Glycerol Administration on ECochG and VEMP Findings in Individual with Meniere's Disease

The present study aimed to find the effect of glycerol administration on Electrocochleography (ECochG), cervical and ocular Vestibular Evoked Myogenic Potential (c-VEMP, o-VEMP) findings in individual with Meniere's disease. Sixteen participants (32 ears) diagnosed with Meniere's disease underwent ECochG, c-VEMP and o-VEMP for both pre and 1 h post-glycerol administration. Paired t-test indicated that the SP/AP ratio of ECochG measures was significantly improved with post-glycerol administration. There was no significant difference in the mean amplitude of o-VEMP and c-VEMP between pre and post-glycerol administration. However, while individual differences were compared, 75% of the participants reported either improvement in c-VEMP amplitude or newly emerging c-VEMP& o-VEMP. Based on the recommendation by Adams et al. (Otolaryngol Clin North Am 43(5):995-1009, 2010), the improvement on these tests results with post glycerol administration were considered as a significant indicator for the presence of Meniere's disease.With post glycerol administration, the present study found that 84%of participants were found to have an improvement in the amplitude for ECochG measures. There was an improvement in the amplitude measures of o-VEMP and c-VEMP, which were observed in 75% and 68%of participants respectively with post-glycerol administration. Improvement in the amplitude of test measures with post-glycerol administration were observed to be more for cochlear potentials of ECochG followed by vestibular potentials of c-VEMP and o-VEMP. Thus, improvement of ECochG amplitude with post-glycerol administration might serve as an additional indicator for the presence of Meniere's disease.

Differences in responsiveness of intratympanic steroid injection for intractable vertigo in Meniere's disease

OBJECTIVES

The efficacy of intratympanic steroid (ITS) injection for intractable Meniere's disease has been reported; however, its differences in responsiveness are not fully understood. This study investigated the clinical characteristics of patients who responded to ITS injection treatment.

METHODS

This retrospective study included 32 patients with Meniere's disease who were unable to control frequent vertigo attacks despite conservative treatment for at least 3 months. They received an intratympanic injection of dexamethasone (3.3 mg/mL) in the affected side at least three times. We measured hearing threshold, subjective symptom scores, cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP), and performed glycerol and bithermal caloric tests.

RESULTS

Satisfactory control of vertigo for 1 year after the first round of injection was found in 18 patients (56.3%; the response group). However, the injections failed to control vertigo in the other 14 patients (43.8%; the non-response group), and they were then treated with middle ear micropressure therapy. The response group showed improvement in low-frequency hearing, whereas hearing acuity did not change in the non-response group. Significantly reduced amplitude of cVEMP on the affected side was found in 62.5% of patients in the response group; however, no patients in the non-response group showed reduced amplitude of cVEMP.

CONCLUSIONS

ITS injection significantly improved the subjective symptoms for intractable Meniere's disease; however, the long-term effects were heterogeneous. Our results suggest that reduced amplitude in cVEMP is associated with the effectiveness of ITS injection treatment.