Flexibility within the middle ears of vertebrates

AbstractIntroduction and aims:Tympanic middle ears have evolved multiple times independently among vertebrates, and share common features. We review flexibility within tympanic middle ears and consider its physiological and clinical implications.Comparative anatomy:The chain of conducting elements is flexible: even the ‘single ossicle’ ears of most non-mammalian tetrapods are functionally ‘double ossicle’ ears due to mobile articulations between the stapes and extrastapes; there may also be bending within individual elements.Simple models:Simple models suggest that flexibility will generally reduce the transmission of sound energy through the middle ear, although in certain theoretical situations flexibility within or between conducting elements might improve transmission. The most obvious role of middle-ear flexibility is to protect the inner ear from high-amplitude displacements.Clinical implications:Inter-ossicular joint dysfunction is associated with a number of pathologies in humans. We examine attempts to improve prosthesis design by incorporating flexible components.

Download Full-text

Role of Middle Ear Endotoxin in Inner Ear Inflammatory Response and Hydrops: Long-Term Study

Annals of Otology Rhinology & Laryngology ◽

10.1177/00034894900990s609 ◽

1990 ◽

Vol 99 (6_suppl) ◽

pp. 33-34 ◽

Cited By ~ 11

Author(s):

David J. Lim ◽

Hideyuki Kawauchi ◽

Thomas F. DeMaria

Keyword(s):

Inflammatory Response ◽

Inner Ear ◽

Middle Ear ◽

Term Study ◽

Long Term Study

Download Full-text

Dexamethasone pharmacokinetics in the inner ear: Comparison of route of administration and use of facilitating agents

Otolaryngology ◽

10.1067/mhn.2000.102578 ◽

2000 ◽

Vol 122 (4) ◽

pp. 521-528 ◽

Cited By ~ 17

Author(s):

Sujana S. Chandrasekhar ◽

Ran Y. Rubinstein ◽

Jed A. Kwartler ◽

Michael Gatz ◽

Patricia E. Connelly ◽

...

Keyword(s):

Hearing Loss ◽

Inner Ear ◽

Sudden Sensorineural Hearing Loss ◽

Laboratory Research ◽

Systemic Absorption ◽

Clinical Implications ◽

Clinical Papers ◽

The Subject ◽

Intratympanic Dexamethasone

There is growing otologic interest in treating inner ear disorders, such as sudden sensorineural hearing loss and acute or unremitting Meniere's disease, with intratympanic dexamethasone (IT-DEX). Although anecdotally reported, there are no scientific clinical papers and few prior laboratory research publications on the subject. This study compares perilymph dexamethasone concentrations after systemic and intratympanic administration and assesses the role of 3 potential transport facilitators of IT-DEX into perilymph. Forty guinea pigs (79 ears) were randomly separated into 5 groups. Dexamethasone levels were measured by radioimmunoassay. IT-DEX resulted in higher perilymph steroid levels than intravenous dexamethasone ( P < 0.05). Histamine facilitator resulted in significantly higher perilymph steroid levels than IT-DEX alone ( P < 0.05). Neither hyaluronic acid nor dimethylsulfoxide was a potent facilitator. This study demonstrates that IT-DEX administration results in superior perilymph levels within 1 hour of administration and does not result in systemic absorption. Histamine is a potent facilitating agent. The clinical implications are considerable.

Download Full-text

The Role of Pseudoephedrine Tablets Versus Xylometazoline Spray in Otic Barotrauma Prevention During Flights

Revista de Chimie ◽

10.37358/rc.18.11.6711 ◽

2018 ◽

Vol 69 (11) ◽

pp. 3199-3202

Author(s):

Ruxandra Oana Iana ◽

Dragos Cristian Stefanescu ◽

Viorel Zainea ◽

Razvan Hainarosie

Keyword(s):

Hearing Loss ◽

Inner Ear ◽

Tympanic Membrane ◽

Eustachian Tube ◽

Middle Ear ◽

Severe Pain ◽

Air Pressure ◽

Membrane Rupture ◽

Common Complaint

Otalgia during airplane flights is a common complaint among patients. This occurs due to the changes in air pressure during take-off and landing that affect middle ear and inner ear. The eustachian tube is responsible with equalizing pressure but in many cases, it happens insufficiently leading to mild to severe pain, hearing loss, tympanic membrane rupture and even inner ear lesions. The aim of this paper is to asses the efficacy of two decongestants, oral pseudoephedrine versus topical xylometazoline in preventing otic barotrauma.

Download Full-text

Immune Response of the Endolymphatic Sac to Horseradish Peroxidase: Immunologic Route from the Middle Ear to the Inner Ear

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348948909801211 ◽

1989 ◽

Vol 98 (12) ◽

pp. 975-979 ◽

Cited By ~ 5

Author(s):

Minoru Ikeda ◽

Claus Morgenstern

Keyword(s):

Immune Response ◽

Horseradish Peroxidase ◽

Inner Ear ◽

Middle Ear ◽

Plasma Cells ◽

Endolymphatic Sac ◽

Local Immune Response ◽

Frozen Sections ◽

Response Region

Twenty guinea pigs were immunized with horseradish peroxidase (HRP) intradermally and challenged with 5 mg of the same antigen in the tympanic bulla. The appearance of immunoglobulin-producing cells (plasma cells) in the inner ear structure was examined immunohistochemically in frozen sections. Four to 10 days following antigen challenge, 5 of the 20 animals showed significantly increased plasma cells in the subepithelial connective tissue of the endolymphatic sac (ES). Those cells showed positive reactions, mainly with IgG followed by IgM. The cells that reacted positively with IgA were few. Some of these plasma cells were considered to contain the specific antibody against HRP. The results indicate the role of the ES as a local immune response region for the inner ear complex, as well as the existence of an immunologic route from the middle ear cavity to the inner ear, particularly to the ES.

Download Full-text

Test–Retest Reliability of Multicomponent Tympanometry at 226-, 678-, and 1000-Hz Probe Tones Over 10 Sessions

American Journal of Audiology ◽

10.1044/2019_aja-ind50-18-0097 ◽

2019 ◽

Vol 28 (2S) ◽

pp. 516-523

Author(s):

Niraj Kumar Singh ◽

Trupti Lata Baral

Keyword(s):

Differential Diagnosis ◽

Inner Ear ◽

Treatment Outcomes ◽

Middle Ear ◽

Repeated Measurements ◽

Probe Tone ◽

Retest Reliability ◽

Test Retest Reliability ◽

Age Range

Purpose Numerous studies are testimony to the pivotal role of multicomponent tympanometry in diagnosis and differential diagnosis of auditory pathologies, not only of the middle ear but also the inner ear. Repeated measurements using multicomponent tympanometry have been used as a measure for stapedial tendon preservation during middle ear surgeries. However, such applications would produce reliable results only when multicomponent tympanometry produces replicable results across sessions. Nonetheless, there is dearth of studies exploring the test–retest repeatability of multicomponent tympanometry across multiple sessions using various probe tones. Therefore, this study aimed at examining the test–retest reliability of multicomponent tympanometry across 10 different sessions for 226-, 678-, and 1000-Hz probe-tone frequencies. Method The study included 28 healthy adults in the age range of 18 to 25 years. All participants underwent multicomponent (susceptance and conductance) tympanometry using 226-, 678-, and 1000-Hz probe tones. Results Multicomponent tympanometry showed excellent test–retest reliability for all parameters of 226- and 678-Hz probe tones. The probe tone of 1000 Hz produced excellent test–retest reliability for most of the parameters. Conclusions The clinical recording of multicomponent tympanometry over multiple sessions is more reliable when using 226- and 678-Hz probe tones. Hence, these probe tones lend themselves to possible applications requiring multiple recordings, such as evaluation of treatment outcomes or preservation of middle ear structures during surgery.

Download Full-text

The Effect of Stapedectomy on the Loudness of One’s Own Voice

Journal of Speech and Hearing Research ◽

10.1044/jshr.0803.223 ◽

1965 ◽

Vol 8 (3) ◽

pp. 223-234 ◽

Cited By ~ 1

Author(s):

William Melnick

Keyword(s):

Middle Ear ◽

Normal Subjects ◽

Sound Energy ◽

Loudness Function ◽

Before And After ◽

Increased Sensitivity

Five subjects with normal middle ear mechanisms, and otosclerotic patients, before and after stapedectomy, matched the loudness of their voices to the loudness of a 125-cps-sawtooth noise. The results showed loudness matching functions with gradual slopes, less than 1.00, for the normal subjects and the patients prior to stapedectomy. Post-surgically, the loudness function for the patients increased in steepness to considerably more than 1.00. These results are explained, most logically, in terms of increased sensitivity of the altered middle ear to sound energy generated by the listener’s own voice.

Download Full-text

Congenital perilymphatic fistula: Computed tomography appearance of middle ear and inner ear anomalies

Otolaryngology ◽

10.1016/s0194-5998(94)70598-4 ◽

1994 ◽

Vol 111 (3) ◽

pp. 243-249 ◽

Cited By ~ 13

Author(s):

J WEISSMAN ◽

P WEBER ◽

C BLUESTONE

Keyword(s):

Computed Tomography ◽

Inner Ear ◽

Middle Ear ◽

Perilymphatic Fistula ◽

Ear Anomalies ◽

Tomography Appearance

Download Full-text

Fibrinolytic Activity of Cerebro-Spinal Fluid and the Development of Artificial Cerebral Haematomas in Dogs

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653538 ◽

1969 ◽

Vol 21 (02) ◽

pp. 294-303 ◽

Cited By ~ 3

Author(s):

H Mihara ◽

T Fujii ◽

S Okamoto

Keyword(s):

Cerebrospinal Fluid ◽

Carboxylic Acid ◽

Fibrinolytic Activity ◽

Clinical Implications ◽

Trans Form ◽

Plate Method ◽

Blood Samples ◽

Fibrin Plate ◽

The Brain

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.

Download Full-text