3D Model to Understand the Diagnosis and Treatment of Horizontal Canal BPPV

Objective:Our primary objective was to develop a three-dimensional (3D) model of the vestibular labyrinth to understand the pathophysiological mechanisms of benign paroxysmal positional vertigo (BPPV) observed during common diagnostic positional tests. We secondarily aimed to monitor the effects of the repositioning maneuvers and use this tool in teaching.Methods:A 3D model of a human semicircular canals (SSCs) system was created by 3D printing the core and assembling it with silicone tubing filled with lubricant oil containing colored small stones in the lumen mimicking otoconia. We used the model in horizontal canal BPPV diagnostic tests and therapeutic maneuvers. The working mechanism of the model we designed was recorded with video.Results:The model allowed for a clear display of the anatomy and the respective orientations of the SSCs. Otolith movement in the horizontal canals could be imitated during diagnostic positional tests (Dix-Hallpike and Pagnini-McClure) and therapeutic maneuvers (Epley, Semont, Lempert and Gufoni).Conclusion:As well as helping to understand the anatomy and physiology of the SSCs, this simple 3D model also provides a teaching tool for the diagnosis and treatment of BPPV. The mechanism of horizontal canal canalithiasis and the effect of therapeutic repositioning maneuvers could be clearly observed by watching the markers in the lumen demonstrating the progress of otolith movements with changes in head position relative to gravity

Evaluation of the efferent system with contralateral suppression in auditory neuropathy spectrum disorder

Amaç: İşitsel nöropati spektrum bozukluğunun (ANSD) medial olivokoklear efferent sistem aktivitesi üzerine olan etkilerini anlık uyarılmış otoakustik emisyon (TEOAE) ve kontralateral supresyon (KLS) kullanarak değerlendirmek amaçlandı. Gereç ve Yöntemler: TEOAE yanıtları 2 gruba ayrılmış 48 kulakta kaydedildi. İşitsel nöropati grubundan 24 kulağı (ortalama 51,2 ay), kontrol grubu ise 24 kulağı (ortalama 55,9 ay) araştırmaya dahil edildi. Her iki grubun TEOAE ölçümleri karşı kulakta gürültülü (geniş band gürültü, 60 dB SPL şiddetinde) ve gürültüsüz olarak kaydedildi. Bulgular: ANSD ve kontrol grupları arasında kontralateral supresyon değerleri karşılaştırıldığında, istatistiksel olarak anlamlı fark gözlendi. KLS sonrası kontrol grubunun değerleri, öncekinden istatistiksel olarak anlamlı derecede düşüktü. ANSD grubunun KLS öncesi ve sonrası TEOAE sinyal-gürültü oranları (SNR) karşılaştırıldığında, ölçülen frekanslarda istatistiksel olarak anlamlı bir fark gözlenmedi. Sonuç: ANSD olgularında KLS uygulandığında anlamlı bir supresyon gözlenmemektedir. Kontrol grubunda KLS uygulandığında ise istatistiksel olarak da anlamlı supresyon görülmektedir. İşitsel nöropatili olgularda supresyon gözlenmemesi, efferent sistemin işlevsel olmamasından kaynaklanabileceği gibi hem afferent hem de efferent sistemin işlevselliğini yitirmesine bağlı olabilir. KLS, işitsel nöropatinin tanısında kullanılabilecek bir test bataryası olarak değerlendirilebilir. Ancak, işitsel nöropati tanısında kullanımına ilişkin daha fazla araştırmaya ihtiyaç vardır.Objective: It was aimed to examine the effects of Auditory Neurophaty Spectrum Disorder (ANSD) on medial olivocochlear efferent system activity by using Transient Evoked Otoacoustic Emission (TEOAE) and Contralateral Suppression (CLS). Material and Methods: TEOAEs were recorded in a total of 48 ears, divided into two groups. Twenty-four ears of the ANSD group (mean 51.2 months) and 24 ears of the control group (mean 55.9 months) were included in the study. TEOAE measuremens of both groups were recorded with (broadband noise, 60 dB SPL) and without noise in the contralateral ear. Results: When the contraateral supression values were compared between the ANSD and control groups, statistically significant difference was observed. The values of the control group after CLS were statistically significantly lower than before. When the TEOAE signal-to-noise ratios (SNR) of the ANSD group before and after KLS were compared, no statistically significant difference was observed in the measured frequencies. Conclusion: No significant suppression effect was found when CLS is performed to patients with ANSD. The absence of suppression in the ANSD grup may be due to the non-functionality of the efferent system as well as the loss of functionality of both afferent and efferent system. CLS can be considered as a test battery that may be used in the diagnosis of auditory neuropathy. However, there is need further research on its use in the diagnosis for auditory neuropathy

Effect of Korean Red Ginseng on Noise-Induced Hearing Loss

Objective:Noise-induced hearing loss (NIHL) is one of the most important problems affecting both social and professional life of patients. There is no treatment method considered to be successful on the hearing loss that has become a permanent nature. Aim of this study is to evaluate protective effect of Korean Red Ginseng (KRG) against NIHL in an animal model.Methods:Twenty-eight rats were separated into four groups [control saline (group I), control KRG (group II), saline + noise (group III), KRG + noise (group IV)]. Rats in the saline and KRG groups were fed via oral gavage with a dose of 200 mg/kg/day throughout for 10 days. Fourteen rats (group III and IV) were exposed to 4 kHz octave band noise at 120 dB SPL for 5 hours. Hearing levels of rats were evaluated by distortion product otoacoustic emissions (DPOAE) and auditory brainstem responses (ABR) at 4, 8, 12, 16 and 32 kHz frequencies prior to and on days 1, 7 and 10 after the noise exposure. Rats were sacrificed on 10th day, after the last audiological test. Cochlea and spiral ganglion tissues were evaluated by light microscopy.Results:Audiological and histological results demonstrated that after noise the group IV showed better results than group III. In the noise exposed groups, the most prominent damage was seen at the 8 kHz frequency region than other regions. After the noise exposure, DPOAE responses were lost in 1st, 7th and 10th measurements in both group III and IV. Thus, we were not able to perform any statistical analyses for DPOAE results.Conclusion:Our findings suggest that KRG seems to be an efficient agent against NIHL. There is need for additional research to find out about the mechanisms of KRG’s protective effect