The intravenously administered glycerol test

Association of cervical vestibular-evoked myogenic potential tuning property test results with MRI findings of endolymphatic hydrops in Meniere's disease

PURPOSE

To examine the concordance between cervical vestibular-evoked myogenic potential (cVEMP) tuning property test results and MRI findings of endolymphatic hydrops (EH).

METHODS

Fourteen subjects (age 24-76 years) that had been diagnosed with unilateral definite Meniere's disease (MD) (N = 8) or unilateral probable MD (N = 6) were enrolled. All of the subjects underwent cVEMP tests (using 500 Hz and 1000 Hz tone bursts), pure-tone audiometry, and gadolinium-enhanced 3 T-MRI. To examine tuning properties of cVEMP, the 500-1000 Hz amplitude ratio was calculated as the SLOPE. The results of the cVEMP tuning property test results were compared with EH-related MRI findings.

RESULTS

EH positivity in both the cochlea and vestibule on MRI was observed in 7 of the 8 affected ears of definite MD and 3 of the 6 affected ears of probable MD, although it was only in one of the 14 unaffected ears. EH(+) or no response (NR) in cVEMP tuning property test was significantly associated with EH positivity on MRI, while EH(-) in the cVEMP tuning property test was significantly associated with EH-negativity on MRI (p = 0.0016 Fisher's exact test test).

CONCLUSION

EH(+) or NR in the cVEMP tuning property test correspond well to EH positivity in the MRI findings. The cVEMP tuning property test is useful for screening and following up EH.

Meta-Analysis Comparing Steroids and Diuretics in the Treatment of Acute Low-Tone Sensorineural Hearing Loss

OBJECTIVE

Our objective was to perform a meta-analysis to compare the effectiveness of steroids and diuretics in the treatment of acute low-tone sensorineural hearing loss (ALHL).

METHODS

PubMed, Google Scholar, and Sci databases were searched for randomized controlled trials (RCTs) examining the treatment of ALHL with steroids and diuretics. The Cochrane Reviewer's Handbook 5.0 evaluation criteria were used to evaluate the quality of the included RCTs. Meta-analysis was performed using Revman 5.3 software to compare the recovery rate of low-tone hearing levels between patients treated with steroids and diuretics.

RESULTS

A total of 3 RCTs were included. There was no heterogeneity between the 3 studies (χ² = 2.61, P = .27, I² = 23%); thus, a fixed-effects model of analysis was used. Meta-analysis showed there was no significant difference in the recovery rate of patients treated with steroids and those treated with diuretics (odds ratio = 1.48, 95% confidence interval: 0.64-3.40, P = .36).

CONCLUSION

Steroids and diuretics are equally effective for the treatment of ALHL.

Detection of Saccular Endolymphatic Hydrops in Ménière's Disease Using a Modified Glycerol cVEMP Test in Combination With the Tuning Property Test

OBJECTIVE

To determine the optimal method for detecting saccular endolymphatic hydrops (EH) in patients with Ménière's disease (MD) using a glycerol cervical vestibular evoked myogenic potential (cVEMP) test in combination with a tuning property test.

STUDY DESIGN

Prospective patients series.

SETTING

Tertiary referral center.

PATIENTS

Twenty-three subjects (age: 36-77 years) were enrolled in this study. Seventeen subjects were diagnosed with definite MD. Six subjects were diagnosed with possible MD.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURE

The corrected amplitudes of p13-n23 (cVEMP) were measured before and after the administration of 10% glycerol (500 ml, 2 h, intravenously). A tuning property index and the p13-n23 amplitude improvement ratio were calculated.

RESULTS

The positivity rate (PR) during the tuning property test was 55% (definite MD-affected ears), 35% (definite MD-unaffected ears), and 25% (possible MD ears). The PR during the glycerol cVEMP amplitude test was 60, 8, and 0%, respectively. The use of modified criteria for the glycerol cVEMP test in combination with the tuning property test resulted in the PR increasing to 75, 57, and 25%, respectively. The pre-glycerol stage results obtained using the tuning property test almost (except in two ears) completely agreed with the glycerol cVEMP test results by the modified criteria.

CONCLUSION

The tuning property test is an easy and useful way of detecting saccular EH. However, the glycerol cVEMP test is required in patients that do not respond to either 500 or 1000 Hz short tone bursts (STB).

Short-Term Outcomes of Acute Low-Tone Sensorineural Hearing Loss According to Treatment Modality

BACKGROUND AND OBJECTIVES

We compared improvements in hearing thresholds in acute low-tone sensorineural hearing loss (ALHL) patients after two different treatments: steroid alone and steroid and diuretic combined. We analyzed how the duration between the onset of symptoms and the initiation of treatment affected hearing loss improvement and investigated the relation between presence of vertigo in ALHL patients and ALHL progression to Ménière's disease (MD).

SUBJECTS AND METHODS

We retrospectively analyzed the medical records of 47 ALHL patients aged 21 to 76 years. Patients received either orally administered steroid alone (n=12) or steroid and diuretic combined (n=35). We compared improvements in the two groups' hearing thresholds at three lower frequencies (125, 250, and 500 Hz) after participants had received one month of each respective treatment.

RESULTS

Our two treatments did not show any statistical difference in hearing loss improvement after one month. Forty percent of ALHL patients with vertigo developed MD, which was a significantly higher rate than the 12.5% of ALHL patients without vertigo who developed MD. The shorter duration between the onset of symptoms and the initiation of treatment significantly increased improvement in the sum of lower frequency hearing threshold after one month.

CONCLUSIONS

The current study suggests that steroid and diuretic administered together and steroid alone similarly improve the hearing threshold in ALHL patients after one month. We concluded that patients should initiate ALHL treatment as soon as they experience symptoms. ALHL patients should also be notified of their higher risk of developing MD.

Audiovestibular testing in patients with Meniere's disease

In this article, the present state of the art with respect to audiovestibular testing for Meniere's disease (MD) is reviewed. There is no gold standard for MD diagnosis, and the classic dictum is that even the "best" tests yield positive results in only two-thirds of patients with MD. Still, we advocate the use and further investigation of advanced audiovestibular testing in patients with MD in an attempt to answer the questions that confront any clinician who cares for patients with audiovestibular symptoms.

Oral versus i.v. administration of the glycerol test: side-effects and usefulness

OBJECTIVE

To compare two methods of performing the glycerol test.

MATERIAL AND METHODS

Glycerol was given orally and intravenously to 12 patients suspected of having Ménière's disease.

RESULTS

Glycerol given orally at a dose of 0.51 g/kg produced a change of > 10 mOsm/kg in all 12 patients while glycerol given intravenously at a dose of 0.30 g/kg produced the same change in osmolality in only 1/12 patients. The results of the tests were similar in 10 cases using the Klockhoff criteria and in 8 cases using the Snyder criteria. Positive test results after oral compared to i.v. administration occurred in four and two cases, respectively using the Klockhoff criteria and in six and eight cases, respectively using the Snyder criteria. The amount of discomfort was consistently higher, with one exception, when glycerol was given orally rather than intravenously.

CONCLUSION

The glycerol test using the Snyder criteria probably yields most additional diagnostic information when the patient fulfils the clinical criteria of possible or probable Ménière's disease.

Furosemide loading vestibular evoked myogenic potential for unilateral Ménière's disease

OBJECTIVE

To investigate whether endolymphatic hydrops in Ménière's Disease could be diagnosed by comparing vestibular evoked myogenic potential (VEMP) before and after furosemide administration (F-VEMP).

STUDY DESIGN

Retrospective study.

SETTING

University hospital.

INTERVENTION

Furosemide administration.

PATIENTS

Twenty-five affected ears of patients with unilateral Ménière's Disease were studied. The patients had received confirmed diagnoses Ménière's Disease; thus, the presence of endolymphatic hydrops was suggested. For the control, 22 ears of 11 normal healthy volunteers who had never had vertigo or hearing disturbance were used.

MAIN OUTCOME MEASURE

The amplitude of the p13-n23 biphasic wave before and after furosemide administration.

RESULTS

The amplitude of the p13-n23 biphasic wave was significantly enlarged in 7 of 18 cases in which it could be detected before diuretic loading. The biphasic waves appeared after diuretic loading in 3 of 7 cases in which it could not be recorded before loading. Thus, the positive ratio of F-VEMP for unilateral Ménière's Disease was considered to be 40% (10 of 25). The ratio was similar to that of the conventional examinations for endolymphatic hydrops such as the glycerol test, furosemide test, and electrocochleogram.

CONCLUSION

The F-VEMP test may be useful in the diagnosis of endolymphatic hydrops.

Osmotic drugs in the treatment of cochlear disorders: a clinical and experimental study

On the grounds of positive results obtained with Meniere's patients, agents such as glycerol and mannitol have been included in the therapeutical protocol of other cochlear disorders presenting with hearing loss either of sudden onset, but not observed at an early stage, or accompanied by tinnitus and aural pressure. Intravenous infusions of either 10% glycerol or 18% mannitol were given to selected patients 3 to 6 times with a time interval of 1 to 3 days. Hearing loss, tinnitus and aural pressure were evaluated as improved, unchanged or worsened. In 33% of the glycerol group and 23.8% of the mannitol group we observed hearing threshold improvement, while aural fullness improved in 45% of the glycerol and 56.2% of the mannitol groups, and tinnitus was only relieved in 13.1% of the glycerol and 5.8% of the mannitol group. A parallel experimental study was carried out on guinea-pigs in order to shed light on the effects of mannitol and glycerol on the inner ear. Cochlear blood flow was measured with a laser Doppler flowmeter at the level of the basal turn of the cochlear lateral wall, both in normal and hydropic guinea-pigs, before and after osmotic intraperitoneal infusion. Basal values in the normal cochlea were much higher than in the hydropic one, and both mannitol and glycerol markedly influenced the local blood flow in the normal cochlea, giving few or no changes in the hydropic one.

Electrocochleography in the diagnosis of delayed endolymphatic hydrops

It is known that delayed endolymphatic hydrops (DEH) occurs in patients with unilateral and/or bilateral profound hearing loss. In the ipsilateral and bilateral types of DEH, no audiological tests can be performed on the affected ear because of profound deafness, although these tests can be done in the contralateral type. Electrocochleography (ECochG) was recorded on better hearing ears in both types of DEH. The results showed an increased negative summating potential (SP) in 6 out of 10 contralateral DEH patients whereas it could be measured in only one of 10 ipsilateral DEH patients. The mean SP/AP ratio of the contralateral type was 0.42 which was significantly larger than that of the ipsilateral type. The results suggest that contralateral-type DEH has the same pathology in the cochlea as Meniere's disease, and that ECochG can distinguish between these two types of DEH.