Long-term efficacy of triple semicircular canal plugging in the treatment of patients with ipsilateral delayed endolymphatic hydrops.

This study aims to explore the long-term efficacy of triple semicircular canal plugging (TSCP) in the treatment of intractable ipsilateral delayed endolymphatic hydrops (DEH), so as to provide an alternative therapy for this disease. Forty-eight patients diagnosed with ipsilateral DEH referred to vertigo clinic of our hospital between Dec. 2010 and Dec. 2017, were included in this study for retrospective analysis. All patients were followed up for 2 years. Vertigo control and auditory functions were measured and analyzed. Pure tone audiometry, caloric test, and vestibular evoked myogenic potential (VEMP) were performed in two-year follow-up. Forty-five patients who accepted intratympanic gentamicin (26.7 mg/mL) twice given one week apart were selected as a control group. The total control rate of vertigo in TSCP group was 97.9% (47/48) in the two-year follow-up, with complete control rate of 83.3% (40/48) and substantial control rate of 14.6% (7/48). The rate of hearing loss was 22.9% (11/48). The total control rate of vertigo in intratympanic gentamicin group was 80.0% (36/45), with complete control rate of 57.8% (26/45) and substantial control rate of 22.2% (10/45), and the rate of hearing loss was 20.0% (9/45). The vertigo control rate of TSCP was significantly higher than that of intratympanic gentamicin (χ2 = 6.01, p < 0.05). There was no significant difference of hearing loss rate between two groups. (χ2 = 0.12, p > 0.05). TSCP, which can reduce vertiginous symptoms in patients with intractable ipsilateral DEH, represents an effective therapy for this disorder.

MRI Inner Ear Imaging and Tone Burst Electrocochleography in the Diagnosis of Ménière's Disease.

OBJECTIVE: To compare the sensitivity of gadolinium MRI inner imaging with tone burst electrocochleography (EcochG) for diagnosing endolymphatic hydrops. STUDY DESIGN: A prospective study on patients who were to have an MRI scan to exclude retrocochlear pathology. SETTING: Tertiary care center. PATIENTS: One hundred and two patients: 57 patients with Possible, Probable, or Definite Ménière's Disease, 25 with asymmetrical hearing loss, 18 with sudden sensorineural hearing loss, and 2 with unilateral tinnitus had additional MRI inner ear imaging and click and tone burst stimulus EcochG testing. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURE: To compare the sensitivity of the two techniques. RESULTS: In 30 patients with symptom-based Definite Ménière's Disease, tone burst EcochG was positive in 25 (83%) and the click EcochG was positive in 9/30 (30%), and gadolinium MRI imaging diagnosed hydrops in 14 (47%). A positive result for either MRI imaging or tone burst EcochG was seen in 26 patients (87%). In 14 subjects with symptom-based Probable Ménière's Disease, 10 (71%) had either a positive EcochG or MRI. In 13 with Possible Ménière's Disease, four (31%) had a positive EcochG or MRI. CONCLUSION: This study confirms the greatly enhanced diagnostic sensitivity of tone burst EcochG over click response in diagnosing endolymphatic hydrops in Ménière's disease. Even though adequate MRI imaging was achieved in 90%, tone burst EcochG was a more sensitive test.

Evaluation of low-frequency biasing as a diagnostic tool in Menière patients.

Although it is generally accepted that endolymphatic hydrops is the cause of complaints in patients suffering from Menière's disease, it has not been possible up to now to prove the presence of an endolymphatic hydrops in living humans. This study evaluated the psychophysical method introduced by Mrowinski et al. [Mrowinski D., Gerull G., Nubel K., Scholz G., 1995. Masking and pitch shift of tone bursts and clicks by low-frequency tones. Hear. Res. 85, 95-102; Mrowinski D., Scholz G., Krompass S., Nubel K., 1996. Diagnosis of endolymphatic hydrops by low-frequency masking. Audiol. Neurootol. 1, 125-134] to diagnose endolymphatic hydrops. These authors used low frequency biasing to differentiate between individuals with and individuals without Menière's disease. In the present study no statistically significant differences in masking parameters could be found between a large number (n=91) of ears with Menière's disease and ears (n=52) with comparable sensorineural hearing losses, but without symptoms of Menière's disease. Our results support the idea that results deviating from normal in low frequency biasing measurements are not due to endolymphatic hydrops itself, but to other pathological changes of the inner ear. An explanation could be that with increasing hearing loss the gain of the cochlear amplifier decreases, leading to smaller modulation depths.

Optimization of ribonucleic acid detection from archival Guinea pig temporal bone specimens.

HYPOTHESIS: The choice of ribonucleic acid (RNA) isolation protocol coupled with modifications to RNA extraction and detection procedures may result in a more reliable method to detect gene expression in archived temporal bones. BACKGROUND: A large number of archival temporal bones exist. Retrospective analysis of these specimens using techniques of RNA extraction will greatly enrich our understanding of the pathophysiology of specific otologic diseases. However, archival human temporal bones are aged and embedded in paraffin or celloidin, rendering isolation and manipulation of nucleic acid in preserved specimens difficult, especially as it pertains to RNA degradation. Despite some reports of moderate success in the recent past, RNA isolation and gene expression using polymerase chain reaction (PCR) analysis continues to be challenging and unreliable. Archival guinea pig temporal bone specimens were used to develop and optimize a protocol for RNA extraction and gene expression analysis using PCR and quantitative PCR methods. The genes amplified comprise housekeeping genes and genes associated with the glutamate pathway. METHODS: Archival celloidin-embedded guinea pig temporal bones were collected from the senior author's collection of experimental hydropic inner ear specimens. RNA from this tissue was extracted using the protocol described previously in 16animals and using a modified trizol extraction technique in 10 animals. Gene expression analysis was performed on the extracted RNA. Analysis included two housekeeping genes, GAPDH and 18S, as well as three mediators of the glutamate pathway, glutamate aspartate transporter, glutamate synthetase, and inducible nitric oxide synthase. RESULTS: Compared with the standard extraction protocol, the trizol-based extraction technique showed greater reliability and reproducibility of RNA detection. The housekeeping gene GAPDH or 18S was detected in 7 of 36 attempts with the standard protocol versus 9 of 9 using the modified extraction method (P < 0.001). The gene of interest, glutamate aspartate transporter, was detected in 3 of 26 attempts with the standard protocol versus 12 of 13 attempts using the modified extraction method (P < 0.001). Quantification of messenger RNA levels was then achieved using quantitative PCR methods. CONCLUSION: Improved reliability for detection of gene expression and demonstration of reproducibility were accomplished by modification of RNA extraction technique and standard reverse transcriptase PCR protocol. In addition, we also showed that gene expression from archival material can be quantified by real-time PCR.

Do musical hallucinations always arise from the inner ear?

It has been known for some time that musical hallucinations occur in deaf patients. This has been ignored, as it has been believed that neurological and psychiatric causes predominate. However, despite specific appeals, no one with musical hallucinations and a lesion in the brain but not in the ear has been produced. The postulated otological basis is a hyperactive state of the ear, a slight endolymphatic hydrops or pre-Meniere's disease. The hallucinations probably develop out of rhythmic tinnitus. A review of all the very disparate states and diseases supposedly causing musical hallucinations shows that peripheral ear symptoms are always present. It therefore seems that they always have the same simple otological trigger.

Time course of endolymph volume increase in experimental hydrops measured in vivo with an ionic volume marker.

A new method has been developed to measure the cross-sectional area (CSA) of scala media in the living cochlea. The method has some advantages over histological methods, in which tissues may shrink or move during processing. In the present study, scala media CSA was measured in the second turn of guinea-pig cochleas in which endolymphatic hydrops was induced surgically. The area measurement method used an iontophoretic injection of a volume marker into scala media, during which the concentration of marker in endolymph was monitored with an ion-selective microelectrode. The measured marker concentration was inversely proportional to the CSA of endolymph. The marker we used was the anion arsenic hexafluoride (AsF6-), which was almost ideal for the purpose as it was retained well in endolymph. Area was measured in normal animals and in hydropic animals at times from 4 days to 16 weeks after endolymphatic duct obstruction. The results showed that hydrops develops within days of ablation of the endolymphatic duct. The degree of hydrops was compared with electrophysiological measures of function, including the endocochlear potential, action potential thresholds and the amplitudes of the cochlear microphonic, summating potential and action potentials. In the initial stages of hydrops development, electrophysiological changes were small. In contrast, there were marked functional changes between 8 and 16 weeks, when endolymph volume was no longer increasing. If the same is true for dysfunction in the ears of patients with Ménière's Disease, then it may not be possible to restore normal function simply by alleviating the hydrops.(ABSTRACT TRUNCATED AT 250 WORDS)