Simultaneous idiopathic bilateral sudden hearing loss – characteristics and response to treatment

Introduction

The aetiology of sudden hearing loss is poorly defined; however, infectious, vascular and neoplastic aetiologies are presumed to be responsible. In addition, the aetiology of bilateral sudden hearing loss is also unknown.

Sodium enoxaparin treatment of sensorineural hearing loss: an immune-mediated response?

The authors propose the existence of a new entity of autoimmune sensorineural hearing loss on the basis of diagnostic study and treatment experience with a series of 30 patients. Immunological mechanisms play an important role in the pathogenesis and natural course of various inner-ear diseases. Patients may present clinically with symptoms resembling Ménière's disease or even with sudden deafness. Currently, no widely used standard protocol for treatment of this autoimmune sensorineural hearing loss exists. Prompted by such observations, we implemented a protocol using a particular kind of heparin--sodium enoxaparin--with a low molecular weight. Patients were randomly assigned to two groups; to those in the first group, enoxaparin was administered subcutaneously at a dose of 2,000 IU twice daily for 10 days; the patients in the second group were treated with placebo. At the beginning and at the end of the therapy period, the patients were evaluated by instrumental examinations. Specifically excluded were patients with abnormal known coagulation. On discharge, all patients treated with enoxaparin presented both a subjective and objective decrease in symptoms. No patient experienced side effects from this treatment. The results indicate that administration of sodium enoxaparin abates sensorineural hearing loss in patients with autoimmune diseases. The clinical response to therapy can confirm diagnosis.     

A panel of biomarkers for predicting response to postoperative RT for laryngeal cancer?

ObjectivesPostoperative radiotherapy (PORT) improves locoregional control and survival rates for patients with advanced laryngeal carcinoma (LSCC), but reported outcomes after PORT for LSCC vary considerably. Predictive markers (including biomarkers) are needed for LSCC to orient the choice of the most appropriate adjuvant therapy for individual patients. The aim of this study was to identify a panel of LSCC tissue markers (considering EGFR, mTOR, survivin, Bcl-2, angiogenin, endoglin [CD105], nm23-H1) capable of pinpointing patients at higher risk of recurrence among 33 LSCC cases treated with PORT.Methods/ResultsUnivariate analysis found 4 biomarkers (mTOR, nuclear survivin, CD105, non-nuclear nm23-H1) significantly associated with LSCC recurrence. A collinearity emerged between mTOR and CD105 expressions. The predictive role of two different panels (panel 1: mTOR, nuclear survivin, non-nuclear nm23-H1; panel 2: CD105, nuclear survivin, non-nuclear nm23-H1) was considered. According to the Hosmer and Lemeshow scale, panel 1 demonstrated an outstanding discriminatory power (AUC 0.903) in predicting LSCC recurrence after PORT. Panel 2 had an excellent discriminatory power too (AUC 0.899).ConclusionsBoth panels of biomarkers showed an important discriminatory power in pinpointing patients at higher risk of recurrence after PORT for LSCC who could reasonably benefit from adjuvant postoperative chemo-RT.     

Zur Abhängigkeit der “amplitude modulation following response” von der Vigilanz

BACKGROUND AND OBJECTIVE: Amplitude modulation following responses (AMFR) allows good estimation of the hearing threshold due to the very narrow band excitation of the cochlea. Audiological use of AMFR requires knowledge of the relationship of these responses to the state of vigilance. The few studies published compared only qualitatively the amplitude of AMFR recorded in awake subjects to that recorded in sleeping subjects. A quantitative determination of the level of vigilance on the basis of recorded physiological parameters has not yet been carried out. In the present study, the relationship between the amplitude of AMFR and the level of vigilance was investigated quantitatively. PATIENTS/METHODS: In eight adults with normal hearing, the relationship between the AMFR amplitude and EEG amplitude in the delta- and theta-band was determined. The amplitude in both frequency bands was used to indicate the state of vigilance. The subjects were studied during natural and drug-induced sleep. A 1-kHz carrier tone with a sinusoidally modulated amplitude of 40 Hz or 80 Hz was used as stimulus. RESULTS: At 40-Hz modulation frequency, the AMFR amplitude correlates with the EEG amplitude both in natural and drug-induced sleep. An increase in EEG activity is paralleled by a significant reduction of AMFR amplitude. At 80-Hz modulation frequency, no relationship between AMFR amplitude and EEG activity could be detected. Under all conditions, the amplitudes of AMFR evoked by a modulation frequency of 80 Hz were significantly lower than those evoked by 40 Hz. CONCLUSIONS: These results suggest that for an audiological use of the 40-Hz AMFR the state of vigilance should be stabilised at a constantly high level. In spite of the lower influence of vigilance on the 80-Hz AMFR, this response appears less ideal for threshold estimation in adults due to the significantly smaller amplitudes.     

Gender differences in binaural speech-evoked auditory brainstem response: are they clinically significant?

IntroductionBinaurally evoked auditory evoked potentials have good diagnostic values when testing subjects with central auditory deficits. The literature on speech-evoked auditory brainstem response evoked by binaural stimulation is in fact limited. Gender disparities in speech-evoked auditory brainstem response results have been consistently noted but the magnitude of gender difference has not been reported.ObjectiveThe present study aimed to compare the magnitude of gender difference in speech-evoked auditory brainstem response results between monaural and binaural stimulations.MethodsA total of 34 healthy Asian adults aged 19–30 years participated in this comparative study. Eighteen of them were females (mean age = 23.6 ± 2.3 years) and the remaining sixteen were males (mean age = 22.0 ± 2.3 years). For each subject, speech-evoked auditory brainstem response was recorded with the synthesized syllable /da/ presented monaurally and binaurally.ResultsWhile latencies were not affected (p > 0.05), the binaural stimulation produced statistically higher speech-evoked auditory brainstem response amplitudes than the monaural stimulation (p < 0.05). As revealed by large effect sizes (d > 0.80), substantive gender differences were noted in most of speech-evoked auditory brainstem response peaks for both stimulation modes.ConclusionThe magnitude of gender difference between the two stimulation modes revealed some distinct patterns. Based on these clinically significant results, gender-specific normative data are highly recommended when using speech-evoked auditory brainstem response for clinical and future applications. The preliminary normative data provided in the present study can serve as the reference for future studies on this test among Asian adults.     

Auditory brainstem response – a valid and cost-effective screening tool for vestibular schwannoma?

Conclusion: Contemporary auditory brainstem response (ABR) is not valid as a screening tool for VS, when considering the sensitivity of 80%, the specificity of 77%, and the positive predictive value of 3.4%, MRI screening is superior to ABR in Denmark when considering cost-effectiveness.

Objectives: The aim of this study is to assess the sensitivity, specificity, and cost-effectiveness of ABR vs MRI, when screening for VS in a clinical setting. Method: Data was collected on all patients subjected to an ABR during a 3-year period (2005–2008) at a tertiary referral center. The data were compared to results of MRI and with data from The Danish National VS Database. In total, 1447 adults underwent ABR, of whom 349 were referred for a subsequent MRI. Sensitivity and specificity were calculated. To assess the cost-effectiveness of ABR vs MRI, procedure costs for ABR and MRI were retrieved from the National Board of Health. Results: Twelve (3.4%) of 349 patients were diagnosed with a VS. Of the 1098 patients not referred for MRI, three (0.3%) were later diagnosed with a VS. The sensitivity and specificity of ABR in diagnosing a VS were 80% and 77%, respectively. Procedure costs were 326?EURO for the ABR and 319?EURO for the MRI.     

Cell proliferation in the endolymphatic sac in situ during the immune response of inner ear

Background Normally, few immunocompetent cell are present in the endolymphatic sac (ES). During an active immune response in the inner ear, large amount of inflammatory cells, including immunocompetent cells, are seen in the ES. The current study aimed at assessing cellular proliferation within the ES during induced immune response in the inner ear. Methods Fifteen healthy, female SD rats were sensitized systemically with keyhole limpet hemocyanin (KLH), followed by local inoculation in the cochlea through basal turn fenestration with the same antigen. On Days 3, 7 and 14 following inoculation, the animal was sacrificed after intraperitoneal administration of 5-bromo-2'-deoxyuridine (BrdUrd), and the temporal bone harvested. Following decalcification, infiltration by BrdUrd- and IgG-positive cells in the ES was studied on frozen sections with H & E and immunohistochemical staining. Results During the secondary immune response in the inner ear against T-dependent antigens, there is increased cellular proliferation in the ES. The proliferated cells may differentiate into immunocompetent cells at the same location. Conclusions These findings indicate that the ES plays an important role in immune response of inner ear.     

Does the method of sternocleidomastoid muscle activation affect the vestibular evoked myogenic potential response?

The objective of this study was to assess the effects of different methods of sternocleidomastoid muscle (SCM) activation on vestibular evoked myogenic potentials (VEMP). Forty normal volunteers were tested using three different methods of SCM activation: sitting with the head turned away from the test ear (SIT), supine with the head held straight up (SHU), and supine with the head held up and turned away from the test ear (SHT). Dependent measures were latency, and amplitude. Head and body position significantly affected the amplitude of the VEMP, but had no significant effect on latency. Testing subjects in the supine position with the head up and turned toward the non-test ear yielded the most robust amplitude response and sternocleidomastoid EMG activity. When amplitude measures where corrected according to tonic electromyographic (EMG) activity no significant difference was noted between the three different test positions. The increased amplitude in the supine with head turned position can be directly attributed to increased tonic SCM EMG activity.     

Is glutathione-S-transferase-pi expression a reliable predictor of chemoradiation response in cancer of the head and neck?

PURPOSE: Concurrent radiation and chemotherapy is being evaluated as an alternative treatment to surgery for patients with advanced squamous cell carcinoma of the head and neck, because organ preservation maybe possible without compromising survival. However, the response to concurrent chemoradiation treatment varies from patient to patient, and there is currently no available molecular predictor of response for this particular treatment modality. There is some evidence to indicate that glutathione S-transferase-pi (GST-pi), which is one of the drug detoxifying enzymes, may decrease the effectiveness of platinum-based chemotherapy in the treatment of a variety of tumor types. This study was performed to investigate whether GST-pi expression was correlated with response to concurrent chemotherapy and radiotherapy in patients with advanced squamous cell carcinoma of the head and neck. MATERIALS AND METHODS: Diagnostic biopsy specimens of 36 patients who underwent concurrent chemoradiotherapy for the treatment of advanced squamous cell carcinoma of the head and neck were examined for GST-pi expression by using immunohistochemistry with polyclonal antihuman GST-pi antibodies. GST-pi expression scores were compared among responders and nonresponders. RESULTS: Although the staining rate with antiGST-pi was slightly lower in the responder group in comparison with the nonresponders (82% vs 100%), the difference was not statistically significant. CONCLUSION: GST-pi expression is unlikely to be a valuable predictor of response to concurrent chemotherapy and radiation treatment in patients with advanced squamous cell carcinoma of the head and neck.