Positive Glycerol Test Research Articles

UNILATERAL PROFOUND DEAFNESS – A POSSIBLE MECHANISM

Purpose: To explain the clinical findings of patients with profound unilateral deafness who have recovered the hearing function after a combined treatment of hyperbaric oxygenation and dehydrant therapy. Material and method: 11 patients with profound sudden unilateral hearing loss above 90 dB SPL, intolerance to sounds similar to recruitment, at levels 10-20 dB above the hearing threshold (105-120 dB SPL), positive glycerol test and unexpected good recovery of hearing within 1-2 months are described. Results: All patients have perfect outcome results without the use of glucocorticoids. Conclusions: Based on articles about experiments with genetically modified animals and acquired deafness, we propose a possible mechanism of damage explaining the clinical findings and the favorable outcome of the disease – a disconnection between the tectorial membrane and stereocilia. Thus mechano-electrical transducer (MET) of hair cells cannot be activated. The combined use of hyperbaric oxygenation and dehydrant medications can lead to recovery of the hearing function.

Contrast-Enhanced MRI Combined With the Glycerol Test Reveals the Heterogeneous Dynamics of Endolymphatic Hydrops in Patients With Menière's Disease.

The sensitivity of endolymphatic hydrops (EH) to the glycerol test varies in patients with Menière's disease (MD). To explore the features of EH and its glycerol-induced dynamics in MD. Case-control study. Twenty patients with MD (24 affected ears) were included. 3.0T 3D-FLAIR (fluid-attenuated inversion recovery) MRI and late gadolinium enhancement. Intratympanic gadolinium-enhanced MRI was performed in the MD-affected ears before and after the glycerol test. The borders of the endolymphatic and total lymphatic space were contoured on the axial MRI slices to evaluate the volume of hydrops in both the cochlear and vestibular regions. Paired and unpaired t-tests, the Mann-Whitney U-test, linear discriminant analysis, Pearson's correlation, and linear regression. After glycerol ingestion, vestibular EH decreased in all patients, whereas cochlear EH significantly decreased only in patients with positive glycerol test results (all P < 0.01). At baseline, cochlear EH in the positive result group was greater than in the negative result group (P = 0.007). Unexpectedly, in the positive result group a drastic glycerol-induced dehydrating effect was observed in patients whose pretest cochlear EH ratio was >16% (P = 0.011). Moreover, the dehydrating role of glycerol was positively correlated with the baseline cochlear hydrops level (r = 0.7691, P < 0.001). MRI provides evidence that glycerol administration improves the hearing threshold via dehydrating the EH. In the cochlear region, the baseline level of cochlear EH is a closely related factor for the validity of the glycerol test, whereas EH is consistently dehydrated in the vestibular component. 2 TECHNICAL EFFICACY STAGE: 3 J. Magn. Reson. Imaging 2020;52:1066-1073.

The prognostic value of glycerol test of electrocochleography on the effects of endolymphatic sac decompression surgery in patients with unilateral Meniere's disease

Objective:To determine whether the preoperative results of glycerol test of electrocochleography and hearing stage have a prognostic value on the effects of endolymphatic sac decompression surgery in patients with unilateral Meniere's disease. Method:A retrospective study was conducted of 58 unilateral Meniere's disease patients who underwent endolymphatic sac decompression surgery. The correlation between the preoperative results of glycerol test of electrocochleography， hearing stage and vertigo control was analyzed by Kendall test. Result:Patients in the positive glycerol test of electrocochleography group had better vertigo control after the decompression of the lymphatic sac than the negative group(P=0.029). Preoperative hearing staging was significantly associated with vertigo control after endolymphatic sac decompression(P=0.028). The better the preoperative hearing, the higher the control rate of vertigo after endolymphatic sac decompression. The stage Ⅰ patients were 91.7%, the stage Ⅱ patients were 78.1%, and the third stage Ⅲ patients were 57.1%, respectively. Conclusion:Our findings suggested that the positive preoperative results of glycerol test of electrocochleography and better hearing stage may indicate a better effects of endolymphatic sac decompression surgery in patients with unilateral Meniere's disease.

Effect of glycerol test on audiovestibular tests in patients with Meniere’s disease

This stud to explore the effect of glycerol on audiovestibular tests in patients with Meniere’s disease (MD) and to reflect different pathologic states of endolymphatic hydrops (EH) in the inner ear and compare the results of glycerol on these results. SubjectsThirty patients and 15 normal volunteers. MethodsEach subject of this study underwent pure tone audiometry testing, evoked vestibular evoked myogenic potential (VEMP) and Vidionystagmography (VNG) before G1 and 2h after glycerol G2 administration (1.3g/kg). ResultsAffected ears were 32 and unaffected ears were 28. The affected ears had higher hearing and SRT thresholds when compared to the unaffected ears and control group. VEMPs of the affected ears were normal in six ears (18.75%), absent in four ears (12.5%) and augmented amplitude in 22 (68.75%), their VNG results showed peripheral vestibular disorder. After oral administration of glycerol, the previous test battery was repeated and it’s result on PTA showed that 53.13% (17/32) of affected ears had positive glycerol test mainly in stage II and III. Ten of the 32 affected ears (31.26%) showed improvement of VEMPs after glycerol administration. Also, two (7.8%) of the unaffected ears showed positive glycerol. Latency of the VEMP had no significant changes after glycerol administration and there was no statistical correlation between the results of G-PTA and G-VEMP. There was statistical significant improvement of the slow peak velocity of caloric test in patient’s affected ears and insignificant improvement in control group and in unaffected ears after glycerol administration.

Dynamics of pure tone audiometry and DPOAE changes induced by glycerol in Meniere’s disease

The purpose of this study is to follow up the dynamics of pure tone threshold and DPOAE amplitude changes induced by glycerol with reference to its activity in the inner ear. Selection was made among 38 patients with Meniere’s disease for those having positive glycerol test. Pure-tone audiometry and DP-gram were performed in four series: as an initial examination before glycerol intake, 1, 2 and 3 h after. Audiometric changes formed distinct biphasal pattern at all frequencies between 250 and 4,000 Hz. The most dynamic pure tone threshold decrease occurred during the first hour. Between the first and second hour after glycerol ingestion there was a phase of no significant hearing changes. Further pure tone threshold decrease went on within the third hour reaching its top. Observing DPOAE changes, the highest DP amplitude growth occurred after the second and the third hour at DP-gram frequencies 2, 3 and 4 kHz. The fastest DP-amplitude increase was registered as well during the first hour after glycerol ingestion. In 11 persons with both audiometry and DPOAE positive glycerol test, parallel dynamics in the course of the glycerol test was observed. Biphasal glycerol test dynamics suggests the possibility of two mechanisms of glycerol activity in the inner ear.

Vestibular Evoked Myogenic Potentials and Distortion-Product Otoacoustic Emissions Combined with Glycerol Testing in Endolymphatic Hydrops: Their Value in Early Diagnosis

The present investigation was specifically designed to evaluate the ability of the glycerol test combined with pure tone audiometry, distortion-product otoacoustic emissions (DPOAEs), and vestibular evoked myogenic potentials (VEMPs) to diagnose endolymphatic hydrops early and to identify cases that may evolve toward Meniere's disease. This investigation consisted of 29 consecutive patients with mild dizziness or vertigo who received no treatment. Each patient underwent glycerol testing measured with conventional pure tone audiometry and with both DPOAEs and VEMPs. It is interesting to note that in 7 and 8 of the 29 cases, the VEMPs and DPOAEs, respectively, showed an improvement after glycerol administration that had not been shown on traditional audiometry. A further element worthy of consideration emerges from an analysis of the VEMP results compared to the DPOAE results that divided the patients into 4 groups. The first group had a postglycerol improvement with both methods, which would seem to suggest hydrops in both the anterior and posterior parts of the labyrinth. In the second and third groups, there was an improvement only either with VEMPs or DPOAEs, and this finding seems to indicate that only one endolymphatic compartment might be involved. In the last group, all patients had a positive glycerol test with positive DPOAEs on one side and with positive VEMPs on the other. Although endolymphatic hydrops can only be proven after death, a combination of VEMPs and DPOAEs with the glycerol test may permit early diagnosis of endolymphatic hydrops. These results clearly imply that these methods should be permanently included in the diagnostic protocol of patients with vestibular and audiological symptoms.

長期経過を追えたレルモワイエ症候群の１例

We report a patient with Lermoyez's syndrome who was followed up for 9 years and whose hearing activity was well maintained. The main pathological factor in this case was considered to be endolymphatic hydrops, judging from such findings as positive glycerol test, repeated vertigo attacks like Meniere disease and well-maintained hearing activity under Isosorbide therapy. Since Dilazep dihydrochloride was also effective in preserving good hearing function, disturbance of vascular circulation might have played a role in the pathology of this case.

Acute low-tone sensorineural hearing loss without vertigo.

To study the pathophysiological features of acute low-tone sensorineural hearing loss without vertigo (ALHL) and its correlation with Meniere's disease. Retrospective review of medical charts of patients with ALHL. University hospital clinic. Eighty consecutive patients with ALHL, including 45 patients whose conditions were followed up for more than 3 years (average, 5 years 2 months; range, 3 years 3 months to 8 years). Age and sex distributions and results of audiological and neuro-otological tests, initial outcome, recurrence rates, and differences between patients with and without recurrence. About 75% (62/80) of the patients were between the ages of 30 and 60 years and the female-male ratio was 2:6. Positive glycerol test results were found in 74% (26/35) of patients and abnormally increased negative summating potential/action potential ratio in 63% (50/80). No abnormalities were found on neuro-otological tests. Hearing loss improved within 3 months in 84% (67/80) of the patients. Of 45 patients followed up for more than 3 years, 28 (62%) showed no evidence of recurrence, 12 (27%) developed cochlear Meniere's disease, and five (11%) developed classic Meniere's disease. No significant differences were found at the first examination between patients with and without recurrence. These results suggest that ALHL may be caused by endolymphatic hydrops confined to the cochlea and that ALHL does not always lead to cochlear or classic Meniere's disease.

Antidiuretic Hormone (ADH) in Patients with Meniere's Disease

Correlations were investigated between plasma levels of antidiuretic hormone (ADH) and the frequency of vertigo attacks, and between hearing and serum Na levels in patients with Meniere's disease. Plasma ADH levels were measured every 3 months for 1 year in 48 patients. Those with persistently high plasma ADH levels tended to have frequent vertigo attacks (Fischer's exact probability test; P<.05). However, serum Na levels and pure tone average (PTA) levels showed no correlation with plasma ADH levels. These results, together with those of the previous study by the present authors, which showed a close correlation between plasma ADH levels and a positive glycerol test and ECoG, suggest that high plasma ADH levels in patients with Meniere's disease have a pathologic mechanism different from that of SIADH.

Clinical Factors Relating to the Positive Glycerol Test for Ménière’s Disease

In order to investigate the clinical factors relating to positive glycerol tests, 51 patients with Ménière's disease were subjected to a complete battery of audiometric examinations, including the short increment sensitivity index, Bekesy, alternate binaural loudness balance, speech discrimination and pure-tone audiometry tests, both before and after glycerol ingestion. The correlation between positive glycerol tests and vestibular response, cochlear symptoms, age at onset and disease duration was investigated. High ratios of positive tests were obtained in the following categories of patients with Ménière's disease: elderly patients with vertiginous attacks; patients with high-level hearing loss; nystagmus patients, and patients with fluctuating hearing loss.

Tinnitus Associated with Meniere's Disease

A study was performed to clarify the clinical characteristics of tinnitus associated with Meniere's disease, as influenced by such factors as unilaterality or bilaterality, glycerol test and ECoG results, types of onset, and time since last attack of vertigo. The criteria used were tinnitus test results and tinnitus scores based on loudness, discomfort level, and interference with life activities.Of the 92 patients studied, 53 (58%) had noise tinnitus and 39 (42%) had tonal tinnitus. The frequencies of tinnitus ranged from low (around 250 Hz) to high.Higher tinnitus scores were observed in Meniere's disease of cochlear or cochlear-vestibular onset, and in patients with bilateral fluctuant hearing loss and positive glycerol tests. Great care must be taken in the treatment of these patients.Noise tinnitus was more apt to occur sooner after the last attack of vertigo than tonal tinnitus, but tinnitus scores were higher when the last attack of vertigo was more than 1 year earlier. This may be due to a decreased psychological tolerance for tinnitus as the vertigo-free period lengthens.

メニエール病の臨床的研究 特に一側，両側り患について

The course of Meniere's disease was followed in 195 patients (137 with unilateral disease and 58 with bilateral fluctuating hearing loss).(1) In unilateral cases, hearing levels fell in 3 years to an average of 30 dB, followed by annual increases of 10 dB for the next 10 years. Deterioration then usually ceased. In the first involved ear in bilateral cases, hearing levels increased during the first year to an average of 50 dB, followed by a total 20 dB increase over the next 10 years. After this time another rapid deterioration occurred. Second involved ears showed hearing level increases averaging a total of 20 dB over the first 4 years, after which hearing rapidly deteriorated to the level of the first involved ear by the 10th year.(2) Vertigo attacks were most frequent during the first year, then decreased rapidly the second year, followed by more gradual decreases. Unilateral and bilateral cases showed an almost equal incidence of attacks.(3) In unilateral cases, caloric responses of the affected ears decreased steadily to approximately 60% of those of unaffected ears by the end of the second decade. Caloric responses in bilateral cases fell to approximately 50% of normal levels. The rate of reduction in both 1st and 2nd ears was almost the same.(4) The general course of bilateral cases differed from that of unilateral cases, suggesting the possibility of different etiologies and/or pathophysiologies. Accurate early diagnosis is thus of great importance. During our long term study it was found that : (5) Most suspected cases receiving definitive diagnoses showed recurrent vertigo attacks and cochlear symptoms such as hearing difficulty and/or tinnitus at the time of the first examination, though fluctuation was not evident.(6) Positive glycerol tests were generally predictive of later definite Meniere's disease.(7) Repetitive audiometry was useful for the confirmation of definite disease.

Diagnosis of Meniere's disease by electrocochleography

The negative summating potential (-SP) and action potential (AP) were recorded by extratympanic electrocochleography in patients with Meniere's disease. The -SP amplitude and the ratio of -SP amplitude to AP amplitude (-SP/AP ratio) were significantly larger in Meniere ears than in normal ears or ears with hair cells damaged by streptomycin or kanamycin or by noise. An increased -SP/AP ratio was observed more often in ears with endolymphatic hydrops, as in Meniere's disease (58 of 94 ears, 62%) or sensorineural hearing loss due to syphilis (4 of 7 ears, 57%) than in ears with hearing loss of other origins. The results demonstrate the usefulness of electrocochleography [in the diagnosis of Meniere's disease.An increased -SP/AP ratio and a positive glycerol test was recorded in 32 of 51 ears (63%) and 26 of 51 ears (51%), respectively. In 15 of 51 ears (29%) both tests were positive, and in 43 of 51 ears (84%) one of tests was positive. The incidence of an increased -SP/AP ratio was higher in ears with a moderate to severe hearing loss at high frequencies, whereas the glycerol test was more often positive in ears with a moderate to severe hearing loss at low frequencies. The difference in selectivity by the method makes the combination of both tests useful in the diagnosis of Meniere's disease.

Endolymphatic Hydrops and Otitis Media

In this investigation of the relationship between endolymphatic hydrops and otitis media, 25 patients with chronic otitis media received the glycerol test for endolymphatic hydrops before middle ear surgery.1) The incidence of positive reactions to the glycerol test was higher in the following patients with otitis media:a) those with a long duration of diseaseb) those with vertigo and tinnitusc) those with severe otorrhea.2) Patients with positive glycerol test before surgery were retested after the operation, and all had negative test after the elimination of middle ear inflammation.3) Some of the patients with chronic otitis media also seemed to have endolymphatic hydrops due to the spread of inflammation from the middle ear to the inner ear.

The effect of glycerol on cochlear blood flow.

Cochlear and cerebral blood flows were measured in albino rabbits by the microsphere method before and 15 min after intravenous administration of glycerol. Both cochlear and cerebral blood flow were significantly increased. The increase in cochlear blood circulation is interpreted as a contributory factor in producing the improvements in hearing threshold seen in the positive glycerol test in Ménière's disease.

メニエール病の反復性めまいに対する免疫アレルギー的考察

The reality of allergic endolymphatic hydrops as a cause of recurrent episodes of Meniere's disease was suggested from the results of the following studies: 1) Clinical studiesa) The skin test using 34 sorts of food antigen extracts and the glycerol test were performed on 23 patients with Meniere's disease. The rate of positive glycerol test was higher in the group with the positive skin reaction than in the negative group (p=0.05).b) In some patients, whose episodes were provoked by the challenge-feeding test, improvement in hearing was produced after Portmann's endolymphatic operation. 2) Experimental studiesa) Labyrinthine reactions were produced when challenged with the antigen through the left foramen stylomastoideum in 4 groups of rabbits as follows: (A) rabbits sensitized by hen's serum, (B) control rabbits, (C) rabbits inoculated with BCG vaccine and (D) control rabbits. Among these 4 groups, the positional nystagmus observed in group A bore a striking resemblance to that of Meniere's attack. The electrocochleograph of group A showed a pattern of cochlear impairment and a histological study revealed endolymphatic hydrops in the ear on the challenged side. This endolymphatic hydrops was not found in the other groups. From these findings, endolymphatic hydrops does not appear to be induced by cell-mediated immunity, but by humoral immunity.b) To determine the place of antigen-antibody reaction, the labyrinths of guinea pigs sensitized by horseradish peroxidase (HRP) were investigated by electronmicroscopy after challenge with this antigen through the perilymphatic space. Particles of HRP could pass through the Reissner's membrane by intracellular transportation and clung to the surface of dark cells in the stria vascularis. These findings were not observed in the control study and suggest that hyper-permeability of the Reissner's membrane and hypersecretion of the stria vascularis induced by the antigen-antibody reaction are probable causes of endolymphatic hydrops.

Ménière's disease and the summating potential. III. Effect of glycerol administration.

We investigated the effect of administering hypertonic glycerol on cochlear and auditory nerve responses to rectangular-pulse clicks and on pure-tone behavioral thresholds. Eleven ears with Ménière's disease, and 20 ears without the disease were studied. Among the ears with Ménière's disease summating potential (SP) amplitudes decreased and 250 to 1,000-Hz thresholds improved after glycerol administration. Action potential amplitudes from the ears with Ménière's disease also decreased after glycerol ingestion, but to a lesser degree. In contrast, among the ears without Ménieère's disease, 250- to 1,000-Hz behavioral thresholds did not change significantly after glycerol nor did any of the electrophysiologic responses. Analogous group differences were found when the ears were regrouped according to the presence of absence of pathologic SP enlargement. These results demonstrate a tendency for three variables-(1) clinical diagnosis of Ménière's disease, (2) enlarged SP, and (3) positive glycerol test result-to cluster together in the same population of ears.

The Prognostic Value of the Glycerol Test: A Review of 60 Ears with Unidirectional Inner Ear Valve Implants

The following are our conclusions in regard to glycerol test interpretation based on 60 valve implants: Negative Tests 1. A negative glycerol test result and no audiometric evidence of significant hearing fluctuations indicate that a patient is unlikely to have postoperative hearing that is better than his best preoperative hearing. 2. The patient with a negative test can still have an excellent chance (greater than 80 per cent) to be relieved of vertigo. 3. A negative test and no audiometric evidence of significant hearing fluctuations in a patient with cochlear Meniere's disease would contraindicate valve surgery. Positive Tests 1. A positive glycerol test, done under appropriate conditions with adequate audiometric controls, clinically confirms the histopathologic diagnosis of endolymphatic hydrops. 2. The patient will have a 30 to 40 per cent chance of having better postoperative hearing than his best preoperative hearing. 3. The patient will have an 80 to 90 per cent chance to be free of vertigo. 3. The patient will have an 80 to 90 per cent chance to be free of vertigo. 4. A positive glycerol test would be a contraindication for labyrinthectomy, since the patient has the potential for some hearing improvement as well as absence of vertigo.

Endolymphatic Sac Surgery for Hearing Conservation in Meniere Disease

Thirty-five patients with Meniere disease underwent endolymphatic sac decompression and drainage with a Silastic sac-mastoid shunt. On the basis of patients' responses to a questionnaire and on analysis of preoperative and postoperative audiometric studies, we found the method to be an effective means for conservation or improvement of hearing and for relief of vertigo in patients with positive glycerol tests. Of the 35 patients, eight had negative glycerol tests and did not benefit from surgery (P less than .001). Of the 27 patients with positive glycerol tests, 70.4% (19) had no further vertigo, and 18,5% (5) had decreased frequency or severity of attacks (an overall relief of vertigo in 88.9%). Hearing was improved in 16 (59.2%) and stabilized in five (18.5%). Subjectively, 85.2% (23/35) of the patients were satisfied with the hearing results of their operation.