Glycerol Test Research Articles

Correlations Between the Degree of Endolymphatic Hydrops and Symptoms and Audiological Test Results in Patients With Menière's Disease: A Reevaluation.

This study was performed to reevaluate the diagnostic significance of clinically well-accepted audiological tests in indicating endolymphatic hydrops (EH) in Menière's disease (MD). Retrospective case review. Hospital. Fifty patients (52 affected ears) diagnosed with MD were enrolled. Diagnostic. To analyze the correlations between endolymphatic hydrops and results of audiological test including the pure-tone audiometry threshold, suprathreshold function tests, electrocochleogram, and glycerol test. Three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging demonstrated EH in either the vestibule or cochlea to various degrees in all of the MD patients, 24 hours after intratympanic gadolinium chelate injection. Both vestibular and cochlear EH were significantly correlated with PTA threshold. However, EH was not associated with alternate binaural loudness balance or the tone decay test, although a correlation was observed with the short-increment sensitivity index. There was also a correlation between vestibular EH, but not cochlear EH, and the negative summating potential/action potential (-SP/AP) ratio. Neither vestibular EH nor cochlear EH was correlated with the glycerol test results. In addition, the frequency of vertigo attacks, the existence of tinnitus, and aural fullness did not correlate with EH. Disrupted ionic homeostasis in the inner ear, but not the EH, may contribute to changes in the -SP/AP ratio. The relevance of glycerol test in identifying EH through detection of hearing changes needs further investigation in the future.

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.

Purple corn silk: A potential anti-obesity agent with inhibition on adipogenesis and induction on lipolysis and apoptosis in adipocytes

Ethnopharmacological relevanceCorn silk or the stigma of Zea mays L. has traditionally been used in weight loss stimulation and treatment of cystitis, urinary infections and obesity. Purple corn silk, rich of polyphenolic substances, was reported on anti-diabetic and anti-obesity effect in animal studies. However, scientific evidence on mechanisms and targets of action of purple corn silk related to adipocyte life cycle has been limited. Aim of studyTo determine phytochemical compositions and investigate anti-obesity potential of the purple corn silk focusing on interruption of adipocyte life cycle; effect on pre-adipocyte proliferation, adipogenesis, adipocyte lipolysis, and apoptosis. Materials and methodsThe ethanolic purple corn silk extract (PCS) was prepared and investigated for phytochemical compositions by LC/MS/MS technique and anti-obesity potential using murine 3T3-L1 cell line. Using methyl thiazole tetrazolium (MTT) assay, the effects on pre-adipocytes and adipocyte viability and on pre-adipocytes proliferation at 24-, 48-, and 72-h incubation period were evaluated. In addition, anti-adipogenesis via inhibition on adipocyte differentiation and reduction of total lipid accumulation was evaluated using Oil Red O staining and spectrophotometric methods, respectively. The lipolysis effect was determined by measurement of glycerol released content using glycerol test kit after 48-h treatment of PCS to adipocytes. Apoptosis inductive effect was done by using 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride (DAPI) staining method. ResultsThe polyphenols including anthocyanins, quercetin and phenolic acids and derivatives were found as the major chemical compositions of the PCS. With multiple-stages interruption on the adipocyte life cycle, anti-obesity effect of PCS was interestingly demonstrated. When compared to the control, the PCS at concentration range between 250–1000 μg/mL showed anti-adipogenesis effect as expressing of significant inhibition on pre-adipocyte proliferation at all incubation period (43.52±5.28 – 75.51±9.09%) and significant decreasing of total lipid accumulation at concentration of 500μg/mL (80.22±6.58%) and 1000μg/mL (69.62±5.42%). Moreover, the PCS exhibited lipolysis and apoptosis inductive effect with dose dependent manner and significance at concentration of 1000μg/mL by increase of released glycerol content (173.88±6.13% of the control) and of nuclei condensing and apoptotic bodies (with relative apoptosis induction as 131.74±1.64% of the control). ConclusionOur data has evidenced the anti-obesity potential of PCS related interruption at multiple stages of adipocyte life cycle. Its potency was attributed to inhibition on adipocyte proliferation and adipogenesis as well as induction on lipolysis and apoptosis at high concentration. However, further in vivo investigation should be considered to insist the possibility in applications of PCS in prevention and treatment of obesity.

Meniere's disease: A mystery! Our way to diagnose

Introduction: Meniere's disease (MD) has long posed a diagnostic challenge. Characterized by recurrent vertigo, tinnitus, and fluctuant sensorineural hearing loss (SNHL), its presentation may limit initially to merely one or two of the above symptoms. Inability to obtain a fresh inner ear tissue leaves us to rely on hypothetical choices. Materials and Methods: Two adjuvants, glycerol test, and intratympanic gentamycin, were analyzed in our study, for their efficacy in diagnosing MD. Patients with symptoms of vertigo, tinnitus, and SNHL were evaluated. Those with presbycusis, conductive hearing loss (on pure tone audiogram [PTA]), benign paroxysmal positional vertigo (diagnosed by Dix Hallpike), retrocochlear pathology (short increment sensitivity index score below 70%), and central cause (magnetic resonance imaging angiography and neurology opinion) were excluded. Rest were subjected to glycerol test and subsequently intratympanic gentamicin. After a 6 month follow up, evaluation was performed for tinnitus and vertigo through a visual analog scale. Repeat PTA was done to look for any hearing deterioration due to gentamicin. Results: It was found that not only did glycerol positive patients get completely relieved of vertigo but also those who tested negative got completely or partially relieved of it. This shows a higher efficacy of intratympanic gentamycin as well as its significant association with glycerol test. Conclusion: This study lead us to form a strong diagnostic criterion which has already proven to be therapeutic in the management of MD.

Aquaporins and Fetal Membranes From Diabetic Parturient Women: Expression Abnormalities and Regulation by Insulin.

During pregnancy, aquaporins (AQPs) expressed in fetal membranes are essential for controlling the homeostasis of the amniotic volume, but their regulation by insulin was never explored in diabetic women. The aim of our study was to investigate the involvement of AQPs 1, 3, 8, and 9 expressed in fetal membranes in diabetic parturient women and the control of their expression by insulin. From 129 fetal membranes in four populations (controls, type 1, type 2 [T2D], and gestational diabetes [GD]), we established an expression AQP profile. In a second step, the amnion was used to study the control of the expression and functions of AQPs 3 and 9 by insulin. The expression of transcripts and proteins of AQPs was studied by quantitative RT-PCR and ELISA. We analyzed the regulation by insulin of the expression of AQPs 3 and 9 in the amnion. A tritiated glycerol test enabled us to measure the impact of insulin on the functional characteristics. Using an inhibitor of phosphatidylinositol 3-kinase, we analyzed the insulin intracellular signaling pathway. The expression of AQP3 protein was significantly weaker in groups T2D and GD. In nondiabetic fetal membranes, we showed for the amnion (but not for the chorion) a significant repression by insulin of the transcriptional expression of AQPs 3 and 9, which was blocked by a phosphatidylinositol 3-kinase inhibitor. In fetal membranes, the repression of AQP3 protein expression and functions observed in vivo is allowed by the hyperinsulinism described in pregnant women with T2D or GD.

Reappraisal of the glycerol test in patients with suspected Menière's disease.

BackgroundRecent advances in magnetic resonance imaging make it possible to visualize the presumed pathophysiologic correlate of Menière’s disease: endolymphatic hydrops. As traditional diagnostic tests can provide only indirect evidence, they are hardly competitive in this respect and need to be rethought. This is done here for the glycerol test.MethodsThe data of a previous retrospective analysis of the glycerol test in patients with suspected Menière’s disease are reinterpreted using a simple model. The mean threshold reduction (MTR) in the frequency range from 125 to 1500 Hz (calculated from audiograms obtained immediately before and four hours after the glycerol intake) is used as the test statistic. The proposed model explains the frequency distribution of the observed MTR by the convolution of a Gaussian probability density function (representing measurement errors) with a template representing the frequency distribution of the true MTR. The latter is defined in terms of two adjustable parameters. After fitting the model to the data, the performance of the test is evaluated using receiver operating characteristic (ROC) analysis.ResultsThe cumulative frequency distribution of the observed MTR can be explained almost perfectly by the model. According to the ROC analysis performed, the capability of the currently used audiometric procedure to detect a glycerol-induced threshold reduction corresponds to a diagnostic test of rather high accuracy (area under the ROC curve greater than 0.9). Simulations show that methodological improvements could further enhance the performance.ConclusionsOwing to their ability to reveal functional aspects without an obvious morphological correlate, traditional test for Menière’s disease could be decisive for defining the stage of the disease. A distinctive feature of the glycerol test is that it is capable of determining, with high accuracy, whether the pathophysiologic condition of the inner ear is partially reversible. Prospectively, this could help to estimate the chances of specific therapies.

Osmotic Dehydration of Yacon Using Glycerol and Sorbitol as Solutes: Water Effective Diffusivity Evaluation

Osmotic dehydration of yacon (Smallanthus sonchifolius) was carried out in varying temperatures (30 and 50 °C) and glycerol or sorbitol concentration (30, 50, and 70 %). The solution of Fick’s law for unsteady state mass transfer in a plane sheet configuration was used to calculate the effective diffusivities of water. Peleg’s model was used to predict the equilibrium condition, which was shown to be appropriate for water loss and solute uptake. It was found to have two rate periods of dehydration. For the above conditions of osmotic dehydration, the effective diffusivity of water was found to be in the range of 5.82 ± 0.68 × 10−10 to 2.15 ± 0.61 × 10−10 m2/s in first period and 1.60 ± 0.28 × 10−10 to 1.29 ± 0.24 × 10−10 m2/s in second period for glycerol tests and, for sorbitol, was 3.82 ± 0.17 × 10−10 to 1.54 ± 0.50 × 10−10 m2/s for the first period and 1.73 ± 0.04 × 10−10 to 1.33 ± 0.06 × 10−10 m2/s for the second. The greatest reduction in water activity was achieved when 70 % of glycerol was used at 50 °C (final a w 0.704 ± 0.010). The treatments with 70 % of solution concentration at 30 °C were repeated, and by adding 20 g/L of calcium lactate in the osmotic solution, it resulted in higher calcium content, strengthening the cell wall for both solutes. Microstructure of the yacon samples (fresh, blanched, and in different conditions of osmotic dehydration) was examined by scanning electron microscopy.

Does Endolymphatic Sac Decompression Surgery with Local Steroids Prevent Bilateral Development of Ménière's Disease?

Objectives: Elucidate whether endolymphatic sac decompression surgery (ESDS) has the potential to prevent unilateral Ménière’s disease (MD) from becoming bilateral. Methods: Prospective case-control study. Between 1996 and 2008, we performed a glycerol test (G-test) and electrocochleography (ECoG) on 237 patients with intractable MD at a tertiary referral center. We performed ESDS on 179 patients (144 without endolymphatic hydrops and 35 with silent endolymphatic hydrops in the contralateral ear). The other 58 patients (40 without endolymphatic hydrops and 18 with silent endolymphatic hydrops in the contralateral ear) were given available medical treatments. All underwent regular follow-up for at least 5 years. Results: Altogether, 22.4% (53/237) of patients with clinically diagnosed unilateral intractable MD had silent endolymphatic hydrops in the contralateral ear using G-test and ECoG. In the nonsurgical group, 6 of 40 patients with unilateral MD without endolymphatic hydops in the contralateral ear developed bilateral disease, whereas in the surgical group, 12 of 144 patients did so ( P > .05). In the nonsurgical group, 9 of 18 patients with unilateral MD and silent endolymphatic hydrops developed the disease in the contralateral ear, whereas in the surgical group, 6 of 35 patients developed bilateral disease ( P < .05). Conclusions: The present findings suggest that ESDS may decrease the incidence of developing MD in silent endolymphatic hydronic contra lateral ears diagnosed with G-test and ECoG within the first 5 postoperative years.

Does endolymphatic sac decompression surgery prevent bilateral development of unilateral Ménière disease?

The aim of the study was to elucidate whether endolymphatic sac decompression surgery (ESDS) has the potential to prevent unilateral Ménière disease (MD) from becoming bilateral. Prospective case-control study at tertiary referral center. Between 1996 and 2008, we performed a glycerol test (G-test) and electrocochleography (ECoG) on 237 patients with intractable unilateral MD. We performed ESDS on 179 patients (144 with no endolymphatic hydrops and 35 with silent endolymphatic hydrops in the contralateral ear). The other 58 patients (40 without endolymphatic hydrops and 18 with silent endolymphatic hydrops in the contralateral ear) were given available medical treatments. All underwent regular follow-up for at least 5 years. Altogether, 22.4% (53 of 237) of patients with clinically diagnosed unilateral intractable MD had silent endolymphatic hydrops in the contralateral ear using G-test and ECoG. In the nonsurgical group, six of 40 patients with unilateral MD with no endolymphatic hydrops in the contralateral ear developed bilateral disease, whereas in the surgical group 12 of 144 patients did so (P = .231, Fisher test). In the nonsurgical group, nine of 18 patients with unilateral MD and silent endolymphatic hydrops developed the disease in the contralateral ear, whereas in the surgical group six of 35 patients developed bilateral disease (P = .022, Fisher test). The present findings suggest that ESDS may decrease the incidence of developing MD in silent endolymphatic hydronic contralateral ears diagnosed with G-test and ECoG within the first 5 postoperative years.

Correction: Predictive Modeling for Diagnostic Tests with High Specificity, but Low Sensitivity: A Study of the Glycerol Test in Patients with Suspected Menière’s Disease

Correction: Predictive Modeling for Diagnostic Tests with High Specificity, but Low Sensitivity: A Study of the Glycerol Test in Patients with Suspected Menière’s Disease

Effects of endolymphatic sac decompression surgery on endolymphatic hydrops

Conclusions: The present findings suggest that complete control of vertigo after endolymphatic sac decompression surgery (ESDS) does not always depend on improved vestibular function or reduced endolymphatic hydrops. Vertigo control is, however, associated with hearing stability.Objective: Among surgical treatments for intractable Meniere’s disease, ESDS is performed to preserve and improve inner ear function. We examined the correlation between changes in vertigo frequency and neuro-otologic function to understand the condition of the inner ear in patients whose vertigo was completely controlled after undergoing ESDS.Methods: This was a retrospective cross-tabulation study. Between 1997 and 2001, we treated 52 patients with intractable vertigo using ESDS and followed the patients regularly for 2 years. Postoperatively we evaluated and recorded changes in vertigo attack frequency, maximum slow phase eye velocity, worst hearing level, and glycerol test results according to modified American Academy of Otolaryngology–Head and Neck Surgery 1995 criteria.Results: We found no correlation between vertigo control and vestibular function. There was also no correlation between vertigo control and negative conversion of the glycerol test. There was a significant correlation between vertigo control and hearing control .

Predictive Modeling for Diagnostic Tests with High Specificity, but Low Sensitivity: A Study of the Glycerol Test in Patients with Suspected Menière’s Disease

A high specificity does not ensure that the expected benefit of a diagnostic test outweighs its cost. Problems arise, in particular, when the investigation is expensive, the prevalence of a positive test result is relatively small for the candidate patients, and the sensitivity of the test is low so that the information provided by a negative result is virtually negligible. The consequence may be that a potentially useful test does not gain broader acceptance. Here we show how predictive modeling can help to identify patients for whom the ratio of expected benefit and cost reaches an acceptable level so that testing these patients is reasonable even though testing all patients might be considered wasteful. Our application example is based on a retrospective study of the glycerol test, which is used to corroborate a suspected diagnosis of Menière’s disease. Using the pretest hearing thresholds at up to 10 frequencies, predictions were made by K-nearest neighbor classification or logistic regression. Both methods estimate, based on results from previous patients, the posterior probability that performing the considered test in a new patient will have a positive outcome. The quality of the prediction was evaluated using leave-one-out cross-validation, making various assumptions about the costs and benefits of testing. With reference to all 356 cases, the probability of a positive test result was almost 0.4. For subpopulations selected by K-nearest neighbor classification, which was clearly superior to logistic regression, this probability could be increased up to about 0.6. Thus, the odds of a positive test result were more than doubled.

UŻYTECZNOŚĆ MIOGENNYCH PRZEDSIONKOWYCH POTENCJAŁÓW WYWOŁANYCH W DIAGNOSTYCE CHOROBY MENIERE’A: PRZEGLĄD

Meniere’s disease is an inner ear disorder characterized by aural fullness, spontaneous attacks of vertigo, fluctuating low-frequency sensorineural hearing loss and tinnitus. There are various tests such as puretone audiometry, electrocochleography, glycerol test, Caloric test, Cochlear hydrops analysis masking which have been utilised in diagnosing the Meniere’s disease. Recently cervical vestibular evoked myogenic potentials and ocular vestibular myogenic potentials have been utilised to measure the functioning of the sacculocollic and otolith ocular pathway respectively. The objective of the present study is to provide an overview of the cervical and ocular vestibular evoked myogenic potentials tests findings in individuals with Meniere’s disease.

Auditory Threshold Shifts After Glycerol Administration to Patients With Suspected Menière’s Disease

Nearly half a century ago, administration of glycerol was shown to temporarily improve the threshold of hearing in patients with suspected Menière's disease (glycerol test). Although a positive test result provides strong evidence of Menière's disease, the test has not gained widespread acceptance. A probable reason is that there is no consensus as to the definition of positive. Moreover, a negative test result is of little diagnostic value because Menière's disease cannot be excluded. By reanalyzing archived data, the authors sought to understand the test in light of signal detection theory. Moreover, they explored the possibility of estimating the probability of a positive test result from the pretest audiogram. The study is based on audiograms from 347 patients (356 ears) who underwent a glycerol test to corroborate a suspected diagnosis of Menière's disease. Subsequent to an initial pure-tone audiogram, glycerol (1.2 mL/kg body weight) was orally administered; follow-up audiograms were obtained after 1, 2, 3, and 4 hr. Transcription of the audiograms into a computer-readable form made them available for automated reanalysis. Averaged difference audiograms provided detailed insight into the frequency dependence and the temporal dynamics of the glycerol-induced threshold reduction. The strongest threshold reduction was observed 4 hr after glycerol intake, although nearly the same effect was already found after 3 hr. Strong overall threshold reductions were associated with a pronounced maximum at approximately 1000 Hz; weaker effects were associated with a plateau between 125 and 1000 Hz and a rapid decrease toward higher frequencies. To date, criteria suggested for a positive test result vastly differ in both sensitivity (with regard to the detection of a threshold reduction) and specificity (1 minus false-positive rate). Here, a criterion based on the aggregate threshold reduction in adjacent audiometric frequencies is suggested. This approach does not only seem to be more robust but also permits to freely adjust the false-positive rate. A positive test result is particularly likely when the mean low-frequency hearing loss is approximately 60 dB and the mean high-frequency hearing loss does not exceed 50 dB. If the pretest audiogram does not render a positive test result unlikely, a state-of-the-art implementation of the glycerol test is a competitive method for corroborating a suspected diagnosis of Menière's disease.

内リンパ水腫診断における内耳造影MRIの有用性

Gadolinium (Gd) contrast-enhanced MRI has recently been introduced to clinical practice to detect endolymphatic hydrops. However, since the image depends on the hardware, pulse sequence or the way of Gd administration, the protocol and the evaluating criteria for hydrops on MRI have not yet been standardized. In this study, we assessed the usefulness of the hydrops detection by MRI following the intratympanic or intravenous Gd administration methods, and compared these findings with the electrocochleography and glycerol test. MRI was taken in 27 patients with Meniere's disease or delayed endolymphatic hydrops. All patients had frequent episodes of vertigo attacks which were clinically considered as of unilateral ear origin. Two types of Gd administration were used; injection into the tympanic cavity in 17 patients or intravenous injection in 10 patients. Axial 2D-FLAIR images were obtained with a 3.0T MRI unit, 24 and 4 h after intratympanic or intravenous administration, respectively. The endolymphatic space was detected as a low signal intensity area, while the surrounding perilymphatic space showed high intensity with Gd contrast. Those cases in which low signal areas corresponding to the cochlear duct could be clearly noticed, were classified as cochlear hydrops. When the greater part of the vestibule was occupied by a low signal area in more than half of the images, it was classified as vestibular hydrops. Endolymphatic hydrops was detected in 88% (15/17 cases) by the intratympanic Gd administration method, and 90% (9/10) by the intravenous method. In the contralateral ears, 20% (2/10) showed hydrops, detected by the intravenous method. ECochG and the glycerol test were difficult when the hearing of the patient was severely impaired. Positive results of EcochG and the glycerol test were obtained only in 15 and 6 cases, respectively. However, as far as the waves could be obtained, ECochG showed a high detection rate of 88% (15/17) in the affected ear. In those cases in which both MRI and EcochG could be obtained, including both ears, the results were matched in 78% (21/27ears). For the qualitative detection of hydrops, intratympanic and intravenous Gd administration methods were equivalent. Inner ear Gd contrast-enhanced MRI had higher efficacy in the detection of hydrops than the conventional tests.

Efficacy of the glycerol test in patients with endolymph hydrops

Efficacy of the glycerol test in patients with endolymph hydrops

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.

An analysis of the clinical features of patients who underwent the glycerol test

An analysis of the clinical features of patients who underwent the glycerol test

Comparison of the diagnostic value of 3 T MRI after intratympanic injection of GBCA, electrocochleography, and the glycerol test in patients with Meniere's disease

Conclusion. 3 T MRI after intratympanic injection of gadolinium-based contrast agent (GBCA) is more useful for the diagnosis of endolymphatic hydrops compared with the glycerol test and electrocochleography (ECoG). Objective: To investigate the relationship between 3 T MRI after intratympanic injection of GBCA, the glycerol test, and ECoG in patients with Meniere's disease (MD). Methods: A total of 20 patients with MD were evaluated. Diluted gadodiamide (a gadolinium-based contrast agent) was administered to the bilateral tympanic cavity by injection through the tympanic membrane. After 24 h, the endolymphatic hydrops was evaluated by a 3.0 T MR scanner. To investigate cochlear hydrops, the glycerol test and ECoG were carried out in all patients. Results: A positive result was observed in 11 patients (55%) in the glycerol test and in 12 patients (60%) by ECoG. The incidence of positive findings when evaluating the same patients with both the glycerol test and ECoG increased to 75%. Nineteen of 20 (95%) patients showed positive results for 3 T MRI.

Diagnostic value and clinical application of inner ear imaging after an intratympanic injection of gadolinium for Meniere's disease

To explore the positive visualization rate of endolymph space in Meniere's disease (MD) by three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI) and assess its diagnostic value of MD. 3D-FLAIR MRI was performed at 24 h after an intratympanic injection of gadolinium diethylenetriamine penta-acetic acid in 51 MD patients. Then the examination results were summarized, analyzed and compared with those of vestibular evoked myogenic potential (VEMP) and glycerol tests. Gadolinium was found in perilymph inside inner ear. Furthermore the border between perilymph and endolymph was visible so that endolymphatic space was distinctly visualized on 3D-FLAIR MRI. Forty-nine (96.1%) patients demonstrated the signs of endolymphatic hydrops. Statistically significant differences existed between the results of 3D-FLAIR MRI and those of VEMP and glycerol tests (P < 0.05). No complication of tympanic membrane perforation or infection was observed. After an intratympanic injection of gadolinium, 3D-FLAIR MRI has a higher positive rate in MD patients. Though as an invasive procedure, it has fewer side effects and will become an important diagnostic tool for MD.