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Pathophysiological Mechanisms and Functional Hearing Consequences of Auditory Neuropathy
doi:10.1093/brain/awv270 BRAIN 2015: 138; 3141–3158 | 3141 REVIEW ARTICLE Pathophysiological mechanisms and functional hearing consequences of auditory neuropathy Gary Rance1 and Arnold Starr2 The effects of inner ear abnormality on audibility have been explored since the early 20th century when sound detection measures were first used to define and quantify ‘hearing loss’. The development in the 1970s of objective measures of cochlear hair cell Downloaded from function (cochlear microphonics, otoacoustic emissions, summating potentials) and auditory nerve/brainstem activity (auditory brainstem responses) have made it possible to distinguish both synaptic and auditory nerve disorders from sensory receptor loss. This distinction is critically important when considering aetiology and management. In this review we address the clinical and pathophysiological features of auditory neuropathy that distinguish site(s) of dysfunction. We describe the diagnostic criteria for: (i) presynaptic disorders affecting inner hair cells and ribbon synapses; (ii) postsynaptic disorders affecting unmyelinated auditory http://brain.oxfordjournals.org/ nerve dendrites; (iii) postsynaptic disorders affecting auditory ganglion cells and their myelinated axons and dendrites; and (iv) central neural pathway disorders affecting the auditory brainstem. We review data and principles to identify treatment options for affected patients and explore their benefits as a function of site of lesion. 1 Department of Audiology and Speech Pathology, The University of Melbourne, -
Sound and the Ear Chapter 2
© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Chapter© Jones & Bartlett 2 Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Sound and the Ear © Jones Karen &J. Kushla,Bartlett ScD, Learning, CCC-A, FAAA LLC © Jones & Bartlett Learning, LLC Lecturer NOT School FOR of SALE Communication OR DISTRIBUTION Disorders and Deafness NOT FOR SALE OR DISTRIBUTION Kean University © Jones & Bartlett Key Learning, Terms LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR Acceleration DISTRIBUTION Incus NOT FOR SALE OR Saccule DISTRIBUTION Acoustics Inertia Scala media Auditory labyrinth Inner hair cells Scala tympani Basilar membrane Linear scale Scala vestibuli Bel Logarithmic scale Semicircular canals Boyle’s law Malleus Sensorineural hearing loss Broca’s area © Jones & Bartlett Mass Learning, LLC Simple harmonic© Jones motion (SHM) & Bartlett Learning, LLC Brownian motion Membranous labyrinth Sound Cochlea NOT FOR SALE OR Mixed DISTRIBUTION hearing loss Stapedius muscleNOT FOR SALE OR DISTRIBUTION Compression Organ of Corti Stapes Condensation Osseous labyrinth Tectorial membrane Conductive hearing loss Ossicular chain Tensor tympani muscle Decibel (dB) Ossicles Tonotopic organization © Jones Decibel & hearing Bartlett level (dB Learning, HL) LLC Outer ear © Jones Transducer & Bartlett Learning, LLC Decibel sensation level (dB SL) Outer hair cells Traveling wave theory NOT Decibel FOR sound SALE pressure OR level DISTRIBUTION -
The Standing Acoustic Wave Principle Within the Frequency Analysis Of
inee Eng ring al & ic d M e e d Misun, J Biomed Eng Med Devic 2016, 1:3 m i o c i a B l D f o e v DOI: 10.4172/2475-7586.1000116 l i a c n e r s u o Journal of Biomedical Engineering and Medical Devices J ISSN: 2475-7586 Review Article Open Access The Standing Acoustic Wave Principle within the Frequency Analysis of Acoustic Signals in the Cochlea Vojtech Misun* Department of Solid Mechanics, Mechatronics and Biomechanics, Brno University of Technology, Brno, Czech Republic Abstract The organ of hearing is responsible for the correct frequency analysis of auditory perceptions coming from the outer environment. The article deals with the principles of the analysis of auditory perceptions in the cochlea only, i.e., from the overall signal leaving the oval window to its decomposition realized by the basilar membrane. The paper presents two different methods with the function of the cochlea considered as a frequency analyzer of perceived acoustic signals. First, there is an analysis of the principle that cochlear function involves acoustic waves travelling along the basilar membrane; this concept is one that prevails in the contemporary specialist literature. Then, a new principle with the working name “the principle of standing acoustic waves in the common cavity of the scala vestibuli and scala tympani” is presented and defined in depth. According to this principle, individual structural modes of the basilar membrane are excited by continuous standing waves of acoustic pressure in the scale tympani. Keywords: Cochlea function; Acoustic signals; Frequency analysis; The following is a description of the theories in question: Travelling wave principle; Standing wave principle 1. -
Endolymphatic Sac Tumors: an Overview Michael B
Endolymphatic Sac Tumors: An Overview Michael B. Gluth, MD, FACS Associate Professor Director, Comprehensive Ear & Hearing Ctr. Section of Otolaryngology-Head & Neck Surgery VHL Alliance, Chicago, 2015 Disclosure • No relevant financial interests or other relevant relationships to disclose • Will discuss off-label use of cochlear implants for single-sided SNHL VHL | 2 Outline • What is an endolymphatic sac tumor? • What are the symptoms? • What is the work-up and treatment? VHL | 3 Endolymphatic Sac Anatomy VHL | 4 Endolymphatic Sac Function • Part of the “membranous labyrinth” • Filled with fluid called endolymph • Secretes locally acting chemical called “saccin” • Involved with inner ear fluid homeostasis, mechanisms not fully understood – ELS is involved with Meniere’s disease VHL | 5 ELS Tumors • Extremely rare tumor originating from the endolymphatic sac, only recognized as a unique entity since 1989 • Benign (not cancer) • Highly destructive, slowly progressive – Destroy bone of inner ear, around cranial vault/skull base, and around facial nerve – Can grow into nerves, pass through dura (sac around brain) and press on cerebellum • May be asymptomatic until inner ear is partially destroyed • Key: if hearing loss is present: high chance dura is invaded VHL | 6 Symptoms • Most common presenting symptoms: – Hearing loss (85%) – Visible mass in the ear (50%) – Ringing in the ear (48%) – Facial paralysis (44%) – Dizziness/imbalance (44%) – Headache (37%) – Other neurologic (cranial nerve) weakness (25%) • If present in both ears, outlook -
Anatomical Changes and Audiological Profile in Branchio-Oto-Renal
THIEME 68 Review Article Anatomical Changes and Audiological Profile in Branchio-oto-renal Syndrome: A Literature Review Tâmara Andrade Lindau1 Ana Cláudia Vieira Cardoso1 Natalia Freitas Rossi1 Célia Maria Giacheti1 1 Department of Speech Pathology, Universidade Estadual Paulista - Address for correspondence Célia Maria Giacheti, PhD, Department of UNESP, Marília, São Paulo, Brazil Speech Pathology, Universidade Estadual Paulista UNESP, Av. Hygino Muzzi Filho, 737, Marília, São Paulo 14525-900, Brazil Int Arch Otorhinolaryngol 2014;18:68–76. (e-mail: [email protected]). Abstract Introduction Branchio-oto-renal (BOR) syndrome is an autosomal-dominant genetic condition with high penetrance and variable expressivity, with an estimated prevalence of 1 in 40,000. Approximately 40% of the patients with the syndrome have mutations in the gene EYA1, located at chromosomal region 8q13.3, and 5% have mutations in the gene SIX5 in chromosome region 19q13. The phenotype of this syndrome is character- ized by preauricular fistulas; structural malformations of the external, middle, and inner ears; branchial fistulas; renal disorders; cleft palate; and variable type and degree of hearing loss. Aim Hearing loss is part of BOR syndrome phenotype. The aim of this study was to present a literature review on the anatomical aspects and audiological profile of BOR syndrome. Keywords Data Synthesis Thirty-four studies were selected for analysis. Some aspects when ► branchio-oto-renal specifying the phenotype of BOR syndrome are controversial, especially those issues syndrome related to the audiological profile in which there was variability on auditory standard, ► BOR syndrome hearing loss progression, and type and degree of the hearing loss. -
Morphological and Functional Changes in a New Animal Model Of
Laboratory Investigation (2013) 93, 1001–1011 & 2013 USCAP, Inc All rights reserved 0023-6837/13 Morphological and functional changes in a new animal model of Me´nie`re’s disease Naoya Egami1, Akinobu Kakigi1, Takashi Sakamoto1, Taizo Takeda2, Masamitsu Hyodo2 and Tatsuya Yamasoba1 The purpose of this study was to clarify the underlying mechanism of vertiginous attacks in Me´nie`re’s disease (MD) while obtaining insight into water homeostasis in the inner ear using a new animal model. We conducted both histopatho- logical and functional assessment of the vestibular system in the guinea-pig. In the first experiment, all animals were maintained 1 or 4 weeks after electrocauterization of the endolymphatic sac of the left ear and were given either saline or desmopressin (vasopressin type 2 receptor agonist). The temporal bones from both ears were harvested and the extent of endolymphatic hydrops was quantitatively assessed. In the second experiment, either 1 or 4 weeks after surgery, animals were assessed for balance disorders and nystagmus after the administration of saline or desmopressin. In the first experiment, the proportion of endolymphatic space in the cochlea and the saccule was significantly greater in ears that survived for 4 weeks after surgery and were given desmopressin compared with other groups. In the second experiment, all animals that underwent surgery and were given desmopressin showed spontaneous nystagmus and balance disorder, whereas all animals that had surgery but without desmopressin administration were asymptomatic. Our animal model induced severe endolymphatic hydrops in the cochlea and the saccule, and showed episodes of balance disorder along with spontaneous nystagmus. -
Ear, Page 1 Lecture Outline
Ear - Hearing perspective Dr. Darren Hoffmann Lecture Objectives: After this lecture, you should be able to: -Describe the surface anatomy of the external ear in anatomical language -Recognize key anatomy in an otoscopic view of the tympanic membrane -Describe the anatomy and function of the ossicles and their associated muscles -Relate the anatomical structures of the middle ear to the anterior, posterior, lateral or medial walls -Explain the anatomy of middle ear infection and which regions have potential to spread to ear -Describe the anatomical structures of the inner ear -Discriminate between endolymph and perilymph in terms of their origin, composition and reabsorption mechanisms -Identify the structures of the Cochlea and Vestibular system histologically -Explain how hair cells function to transform fluid movement into electrical activity -Discriminate the location of cochlear activation for different frequencies of sound -Relate the hair cells of the cochlea to the hair cells of the vestibular system -Contrast the vestibular structures of macula and crista terminalis Let’s look at the following regions: Hoffmann – Ear, Page 1 Lecture Outline: C1. External Ear Function: Amplification of Sound waves Parts Auricle Visible part of external ear (pinna) Helix – large outer rim Tragus – tab anterior to external auditory meatus External auditory meatus Auditory Canal/External Auditory Meatus Leads from Auricle to Tympanic membrane Starts cartilaginous, becomes bony as it enters petrous part of temporal bone Earwax (Cerumen) Complex mixture -
Mathematical Model of the Cupula-Endolymph System with Morphological Parameters for the Axolotl (Ambystoma Tigrinum) Semicircular Canals
138 The Open Medical Informatics Journal, 2008, 2, 138-148 Open Access Mathematical Model of the Cupula-Endolymph System with Morphological Parameters for the Axolotl (Ambystoma tigrinum) Semicircular Canals Rosario Vega1, Vladimir V. Alexandrov2,3, Tamara B. Alexandrova1,3 and Enrique Soto*,1 1Instituto de Fisiología, Universidad Autónoma de Puebla, 2Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Puebla, 3 Lomonosov Moscow State University, Mexico Abstract: By combining mathematical methods with the morphological analysis of the semicircular canals of the axolotl (Ambystoma tigrinum), a system of differential equations describing the mechanical coupling in the semicircular canals was obtained. The coefficients of this system have an explicit physiological meaning that allows for the introduction of morphological and dynamical parameters directly into the differential equations. The cupula of the semicircular canals was modeled both as a piston and as a membrane (diaphragm like), and the duct canals as toroids with two main regions: i) the semicircular canal duct and, ii) a larger diameter region corresponding to the ampulla and the utricle. The endolymph motion was described by the Navier-Stokes equations. The analysis of the model demonstrated that cupular behavior dynamics under periodic stimulation is equivalent in both the piston and the membrane cupular models, thus a general model in which the detailed cupular structure is not relevant was derived. Keywords: Inner ear, vestibular, hair cell, transduction, sensory coding, physiology. 1. INTRODUCTION linear acceleration detectors, and the SCs as angular accel- eration detectors, notwithstanding that both sensory organs The processing of sensory information in the semicircular are based on a very similar sensory cell type. -
Fallen in a Dead Ear: Intralabyrinthine Preservation of Stapes in Fossil Artiodactyls Maeva Orliac, Guillaume Billet
Fallen in a dead ear: intralabyrinthine preservation of stapes in fossil artiodactyls Maeva Orliac, Guillaume Billet To cite this version: Maeva Orliac, Guillaume Billet. Fallen in a dead ear: intralabyrinthine preservation of stapes in fossil artiodactyls. Palaeovertebrata, 2016, 40 (1), 10.18563/pv.40.1.e3. hal-01897786 HAL Id: hal-01897786 https://hal.archives-ouvertes.fr/hal-01897786 Submitted on 17 Oct 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/297725060 Fallen in a dead ear: intralabyrinthine preservation of stapes in fossil artiodactyls Article · March 2016 DOI: 10.18563/pv.40.1.e3 CITATIONS READS 2 254 2 authors: Maeva Orliac Guillaume Billet Université de Montpellier Muséum National d'Histoire Naturelle 76 PUBLICATIONS 745 CITATIONS 103 PUBLICATIONS 862 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: The ear region of Artiodactyla View project Origin, evolution, and dynamics of Amazonian-Andean ecosystems View project All content following this page was uploaded by Maeva Orliac on 14 March 2016. -
CONGENITAL MALFORMATIONS of the INNER EAR Malformaciones Congénitas Del Oído Interno
topic review CONGENITAL MALFORMATIONS OF THE INNER EAR Malformaciones congénitas del oído interno. Revisión de tema Laura Vanessa Ramírez Pedroza1 Hernán Darío Cano Riaño2 Federico Guillermo Lubinus Badillo2 Summary Key words (MeSH) There are a great variety of congenital malformations that can affect the inner ear, Ear with a diversity of physiopathologies, involved altered structures and age of symptom Ear, inner onset. Therefore, it is important to know and identify these alterations opportunely Hearing loss Vestibule, labyrinth to lower the risks of all the complications, being of great importance, among others, Cochlea the alterations in language development and social interactions. Magnetic resonance imaging Resumen Existe una gran variedad de malformaciones congénitas que pueden afectar al Palabras clave (DeCS) oído interno, con distintas fisiopatologías, diferentes estructuras alteradas y edad Oído de aparición de los síntomas. Por lo anterior, es necesario conocer e identificar Oído interno dichas alteraciones, con el fin de actuar oportunamente y reducir el riesgo de las Pérdida auditiva Vestíbulo del laberinto complicaciones, entre otras —de gran importancia— las alteraciones en el área del Cóclea lenguaje y en el ámbito social. Imagen por resonancia magnética 1. Epidemiology • Hyperbilirubinemia Ear malformations occur in 1 in 10,000 or 20,000 • Respiratory distress from meconium aspiration cases (1). One in every 1,000 children has some degree • Craniofacial alterations (3) of sensorineural hearing impairment, with an average • Mechanical ventilation for more than five days age at diagnosis of 4.9 years. The prevalence of hearing • TORCH Syndrome (4) impairment in newborns with risk factors has been determined to be 9.52% (2). -
Mediated Cochlear Gene Transfer
Gene Therapy (2000) 7, 377–383 2000 Macmillan Publishers Ltd All rights reserved 0969-7128/00 $15.00 www.nature.com/gt VIRAL TRANSFER TECHNOLOGY RESEARCH ARTICLE Transduction of the contralateral ear after adenovirus- mediated cochlear gene transfer T Sto¨ver1,2, M Yagi1,3 and Y Raphael1 1Kresge Hearing Research Institute, Department of Otolaryngology, The University of Michigan Medical School, Ann Arbor, MI, USA; 2Department of Otolaryngology, Medizinische Hochschule Hannover, Hannover, Germany; and 3Department of Otolaryngology, Kansai Medical University, Osaka, Japan Cochlear gene transfer is a promising new approach for cochleae, whereas virus inoculation into the bloodstream did inner ear therapy. Previous studies have demonstrated hair not. The cochlear aqueduct was identified as the most likely cell protection with cochlear gene transfer not only in the route of virus spread to the contralateral cochlea. These data inoculated, but also in the uninoculated ear. To characterize enhance our understanding of the kinetics of virus-mediated the kinetics of viral spread, we investigated the extent of transgene expression in the inner ear, and assist in the transgene expression in the contralateral (uninoculated) development of clinical applications for inner ear gene ther- cochlea after unilateral adenoviral cochlear gene transfer. apy. Our results showed a functional communication We used a lacZ reporter gene vector, and demonstrated between the CSF and the perilymphatic space of the inner spread of the adenovirus into the cerebrospinal fluid (CSF) ear, that is not only of importance for otological gene trans- after cochlear inoculation of 25 l viral vector. Direct virus fer, but also for CNS gene transfer. -
ANATOMY of EAR Basic Ear Anatomy
ANATOMY OF EAR Basic Ear Anatomy • Expected outcomes • To understand the hearing mechanism • To be able to identify the structures of the ear Development of Ear 1. Pinna develops from 1st & 2nd Branchial arch (Hillocks of His). Starts at 6 Weeks & is complete by 20 weeks. 2. E.A.M. develops from dorsal end of 1st branchial arch starting at 6-8 weeks and is complete by 28 weeks. 3. Middle Ear development —Malleus & Incus develop between 6-8 weeks from 1st & 2nd branchial arch. Branchial arches & Development of Ear Dev. contd---- • T.M at 28 weeks from all 3 germinal layers . • Foot plate of stapes develops from otic capsule b/w 6- 8 weeks. • Inner ear develops from otic capsule starting at 5 weeks & is complete by 25 weeks. • Development of external/middle/inner ear is independent of each other. Development of ear External Ear • It consists of - Pinna and External auditory meatus. Pinna • It is made up of fibro elastic cartilage covered by skin and connected to the surrounding parts by ligaments and muscles. • Various landmarks on the pinna are helix, antihelix, lobule, tragus, concha, scaphoid fossa and triangular fossa • Pinna has two surfaces i.e. medial or cranial surface and a lateral surface . • Cymba concha lies between crus helix and crus antihelix. It is an important landmark for mastoid antrum. Anatomy of external ear • Landmarks of pinna Anatomy of external ear • Bat-Ear is the most common congenital anomaly of pinna in which antihelix has not developed and excessive conchal cartilage is present. • Corrections of Pinna defects are done at 6 years of age.