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At least 775 records · Page 43Linked to original sources
PubMed2006

Otosyphilis mimics immune disorders of the inner ear.

Syphilis is a well established cause of hearing loss. Sensorineural hearing loss may develop in the congenital or acquired form. The clinical course of the early acquired and late congenital forms are similar: sudden or rapidly progressive bilateral sensorineural hearing loss with mild vestibular symptoms. Cochleovestibular involvement in early acquired syphilis has been related to a basilar meningitis with lymphocytic infiltration of the labyrinth and VIIIth nerve. However, neurosyphilis and inner ear syphilis are not the same disease. Prompt diagnosis and treatment with corticosteroids and penicillin are mandatory to reduce the immune response and fibrosis of the labyrinth and the endolymphatic sac. Unfortunately, early acquired syphilis is frequently overlooked in the differential diagnosis of other forms of sensorineural hearing loss, particularly autoimmune inner ear disease. Given the increasing number of luetic infection cases, especially in immunocompromised patients, this condition should be considered in any sexually active patients affected by sudden hearing loss. Cases of inner ear syphilis are presented. Immunopathology of luetic inner ear infection is discussed and compared with immune disorders of the inner ear.

Adolescent↗
PubMed1989

Does ciprofloxacin affect the inner ear? A preliminary report.

Ciprofloxacin, a 4-quinolone antibiotic was tested regarding its possible influence on the inner ear sensory epithelia. Adult guinea pigs were injected intraperitoneally with ciprofloxacin in a dosage of 25, 50, 100 and 150 mg/kg body weight per day. The animals in the high dosage ranges stopped eating and consequently lost weight quite rapidly. After sacrifice, the inner ear sensory epithelia were removed for ultrastructural analysis. The general outline of the vestibular sensory epithelia as well as the cochleae were normal. Mild changes in the sensory hairs of the third row of cochlear outer hair cells were noted in the specimens obtained from the high dose animals. These changes were discrete and did not resemble any previously known pattern of ototoxic damage. At present no data indicate that ciprofloxacin has a toxic effect on the inner ear.

Animals↗
PubMed2001

Antonio Scarpa and the discovery of the membranous inner ear.

OBJECTIVE: To give a historical perspective of Antonio Scarpa's contributions to otology, specifically the discovery of the inner ear organs as the foundation for the experimental work that followed. BACKGROUND/METHOD: Scarpa's original descriptions of the human inner ear were translated from the Latin text, and his illustrations were analyzed and compared with current knowledge. CONCLUSIONS: Antonio Scarpa's anatomic and clinical studies place him among the great scientists of the eighteenth century. His discoveries about the inner ear established the limit of what could be learned without advanced histologic techniques and provided the foundation for the work that eventually led to the modern understanding of ear physiology.

Anatomy↗
PubMed1989

[Mechanism of inner ear damage due to hyperlipidemia].

Some clinical data concerning the relationship between hyperlipidemia and sensorineural hearing loss have been reported, however, definite mechanism causing pathological changes in the cochlea and hearing loss has not yet been clarified. We studied the mechanism of hearing loss due to hyperlipidemia in rabbits by ABR hearing examination, biochemical study of the sera, observation of the inner ear morphology by Sem and Tem. We suggest that the decreased blood supply in the inner ear during hyperlipidemia because of increased platelet aggregation and blood viscosity may be responsible for the inner ear damage. At the same time, a high lipid peroxide level in the serum and the inner ear, as well as the metabolic disorder of lipids in the inner ear may also contribute to the development of hearing loss.

Animals↗
PubMed1990

Inner ear decompression sickness following a shallow scuba dive.

Inner Ear Decompression Sickness (IEDCS)--manifested by tinnitus, vertigo, nausea, vomiting, and hearing loss--is usually associated with deep air or mixed gas dives, and accompanied by other CNS symptoms of decompression sickness (DCS). Early recompression treatment is required in order to avoid permanent inner ear damage. We present an unusual case of a scuba diver suffering from IEDCS as the only manifestation of DCS following a short shallow scuba dive, successfully treated by U.S. Navy treatment table 6 and tranquilizers. This case suggests that diving medical personnel should be more aware of the possible occurrence of IEDCS among the wide population of sport scuba divers.

Adult↗
PubMed2004

Form and function in the unique inner ear of a teleost: the silver perch (Bairdiella chrysoura).

Members of the teleost family Sciaenidae show significant variation in inner ear and swim bladder morphology as well as in the relationship between the swim bladder and the inner ear. In the silver perch (Bairdiella chrysoura), a Stellifer-group sciaenid, both the saccular and utricular otoliths are enlarged relative to those in other teleosts. Additionally, its swim bladder is two-chambered, and the anterior chamber surrounds the otic capsule and terminates lateral to the saccules. Structure and function of the auditory system of the silver perch were explored by using gross dissections, scanning electron microscopy, CT scan reconstruction, and auditory brainstem response approach. Several morphological specializations of the auditory system of the silver perch were found, including expansion of the utricular and lagenar otoliths, close proximity between the saccules and the utricles, deeply grooved sulci on the saccular otoliths, two-planar saccular sensory epithelia, and a unique orientation pattern of sensory hair cell ciliary bundles on the saccular sensory epithelium. It was determined that the silver perch can detect up to 4 kHz, with lowest auditory thresholds between 600 Hz and 1 kHz. Audition in the silver perch is comparable to that in the goldfish (Carassius auratus), a hearing "specialist." The morphological specializations of the inner ear and swim bladder of the silver perch may be linked to its enhanced hearing capabilities. The findings of this study support the proposal that sciaenids are excellent model species for investigating structure-function relations in the teleost auditory system.

Air Sacs↗
PubMed1971

Inner ear morphology: advances in assessment.

The study of inner ear morphology has been substantially augmented by the development of the surface preparation technique and the scanning electron microscope. The former represents an old technique revitalized, while the latter is a new method providing dramatic stereoscopic images at the cellular level. More precise knowledge of inner ear sensory cells and their innervation is now being obtained and hence better understanding of function continues to evolve. The early fixation of human postmortem material circumvents many artefacts; however, there are legal and ethical questions to be settled before this is done routinely. The photomicrographs are from specimens prepared by the author.

Autopsy↗
PubMed1999

Congenital malformation of the inner ear associated with recurrent meningitis.

Congenital deformities of the labyrinth of the inner ear can be associated with meningitis and varying degrees of hearing loss or deafness. A recurrence of meningitis is due to the development of a fistulous communication between the subarachnoid space and the middle ear cavity, and can prove lethal. An illustrative case of a 4-year-old Japanese girl with bilateral severe hearing loss, recurrent meningitis and malformations of the inner ear and stapes footplate is presented. Removal of the stapes during tympanotomy provoked a gush of cerebrospinal fluid. The defect was repaired successfully, and there has been no further episodes of meningitis to date.

Anti-Infective Agents↗
PubMed1995

The influence of unilateral vertebral artery occlusion on brainstem and inner ear blood flow in rat.

We investigated the influence of unilateral VA occlusion on blood regulation in the brainstem and the inner ear, using laser-Doppler flowmetry in rat. Chemical control was evaluated by blood flow response to CO2 inhalation, and autoregulation by that to induced hypotension. The results were as follows: i) Unilateral VA occlusion impairs chemical control and autoregulation of brainstem blood flow and affects autoregulation in the inner ear. ii) Unilateral VA occlusion damages the potential for blood flow regulation more strongly in the brainstem than in the inner ear. These results suggest that occlusive disease within the vertebro-basilar system leads to the impairment of blood flow regulation in both the brainstem and the inner ear-more strongly in the brainstem-possibly contributing to symptoms such as vertigo and hearing disturbance, at least in certain groups of patients when hemodynamic factors such as systemic hypotension are added.

Animals↗
PubMed1990

Inner ear cholesteatoma and the preservation of cochlear function.

Labyrinthine destruction by direct cholesteatoma invasion has always been considered a serious threat to the inner ear function. A number of reports in the literature have cited both patients who had preservation of hearing despite widespread erosion of the labyrinth by cholesteatoma and patients who had retained auditory function despite surgical removal of the matrix from the labyrinth. In most cases the vestibular portion of the inner ear was invaded but cases of cochlear involvement have been described as well. Twelve cases with pre-operative auditory function preservation despite extensive labyrinthine destruction treated at our Institution are reported. Seven cases retained cochlear function post-operatively. Possible explanations of this occurrence and implications of related with hearing preservation in the presence of widespread inner ear destruction by chronic inflammatory disease are discussed.

Adult↗
PubMed2003

Lack of pendrin expression leads to deafness and expansion of the endolymphatic compartment in inner ears of Foxi1 null mutant mice.

Mice that lack the winged helix/forkhead gene Foxi1 (also known as Fkh10) are deaf and display shaker/waltzer behavior, an indication of disturbed balance. While Foxi1 is expressed in the entire otic vesicle at E9.5, it becomes gradually restricted to the endolymphatic duct/sac epithelium and at E16.5 Foxi1 expression in the inner ear is confined to this epithelium. Histological sections, paintfill experiments and whole-mount hybridizations reveal no abnormality in inner ear development of Foxi1(-/-) mice before E13.5. Between E13.5 and E16.5 the membranous labyrinth of inner ears from null mutants starts to expand as can be seen in histological sections, paint-fill experiments and three-dimensional reconstruction. Postnatally, inner ears of Foxi1(-/-) mice are extremely expanded, and large irregular cavities, compressing the cerebellum and the otherwise normal middle ear, have replaced the delicate compartments of the wild-type inner ear. This phenotype resembles that of the human sensorineural deafness syndrome Pendred syndrome, caused by mutations in the PDS gene. In situ hybridization of Foxi1(-/-) endolymphatic duct/sac epithelium shows a complete lack of the transcript encoding the chloride/iodide transporter pendrin. Based on this, we would like to suggest that Foxi1 is an upstream regulator of pendrin and that the phenotype seen in Foxi1 null mice is, at least in part, due to defective pendrin-mediated chloride ion resorption in the endolymphatic duct/sac epithelium. We show that this regulation could be mediated by absence of a specific endolymphatic cell type--FORE (forkhead related) cells--expressing Foxi1, Pds, Coch and Jag1. Thus, mutations in FOXI1 could prove to cause a Pendred syndrome-like human deafness.

Animals↗
PubMedDate not supplied

Low-field magnetic resonance imaging of the canine middle and inner ear.

A series of low-field magnetic resonance images of the normal canine middle and inner ear are presented to serve as a reference. A completely balanced steady-state gradient echo pulse sequence with a slice thickness of 0.9 mm can be used to acquire images of the relevant structures within and neighboring the inner ear. These were the cochlear duct, semicircular ducts, vestibule, facial and vestibulocochlear nerves, as well as the temporal sinus. Within the middle ear, no applied sequence was able to allow identification of the auditory ossicles or the tympanic membrane.

Animals↗
PubMed1998

RT-PCR analysis of mRNA expression of natriuretic peptide family and their receptors in rat inner ear.

To assess the possible physiological role of the atrial natriuretic peptide (ANP) family, we investigated the expression of mRNA of ANP, brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and their receptors in rat inner ear using the reverse transcription-polymerase chain reaction method. ANP and CNP message bands were detected in the inner ear, but the BNP message band was not. Amplification products of the expected sizes of ANP-A, ANP-B and ANP-C receptors were detected in the inner ear. These results suggest that natriuretic peptide family may influence the function of the inner ear through the ANP-A, ANP-B, and ANP-C receptors.

Animals↗
PubMed1996

High-resolution T2-weighted MR imaging of the inner ear using a long echo-train-length 3D fast spin-echo sequence.

The purpose of this study was to assess the value of a long echo-train-length 3D fast spin-echo (3D-FSE) sequence in visualizing the inner ear structures. Ten normal ears and 50 patient ears were imaged on a 1.5T MR unit using a head coil. Axial high-resolution T2-weighted images of the inner ear and the internal auditory canal (IAC) were obtained in 15 min. In normal ears the reliability of the visualization for the inner ear structures was evaluated on original images and the targeted maximum intensity projection (MIP) images of the labyrinth. In ten normal ears, 3D surface display (3D) images were also created and compared with MIP images. On the original images the cochlear aqueduct, the vessels in the vicinity of the IAC, and more than three branches of the cranial nerves were visualized in the IAC in all the ears. The visibility of the endolympathic duct was 80%. On the MIP images the visibility of the three semicircular canals, anterior and posterior ampulla, and of more than two turns of the cochlea was 100%. The MIP images and 3D images were almost comparable. The visibility of the endolymphatic duct was 80% in normal ears and 0% in the affected ears of the patients with Meniere's disease (p < 0.01). In one patient ear a small intracanalicular tumor was depicted clearly. In conclusion, the long echo train length T2-weighted 3D-FSE sequence enables the detailed visualization of the tiny structures of the inner ear and the IAC within a clinically acceptable scan time. Furthermore, obtaining a high contrast between the soft/bony tissue and the cerebrospinal/endolymph/ perilymph fluid would be of significant value in the diagnosis of the pathologic conditions around the labyrinth and the IAC.

Adult↗
PubMed2000

[Pneumatic external counterpulsation (PECP): a new treatment option in therapy refractory inner ear disorders?].

BACKGROUND: The established therapeutic principle for sudden deafness and tinnitus is based on the stimulation of the inner ear perfusion by infusion therapy using vaso-active or hemodilutive agents. Concerning a mechanically induced increase of the inner ear's blood supply, the new technique of Pneumatic External Counterpulsation (PECP) was performed. This technique had already been used successfully in patients suffering from coronary heart disease. Due to an ECG-guided pneumatic compression of the lower extremities during diastole an increase of arterial perfusion of the extracranial supplying brain vessels can be obtained by PECP-treatment. PATIENTS AND METHODS: PECP was used in 33 patients (22 males, 11 females) between 19 and 76 years of age suffering from persisting acute hearing disorders and/or tinnitus after adequate infusion therapy. 3 patients revealed mild complications during PECP-treatment (e.g. thoracic pain) which seemed to be related to the therapeutic regime and disappeared completely after cessation of PECP. 30 patients underwent PECP-treatment on 5 following days for 1 hour. This standardized hourly treatment regime was extended to 10 days in 12 patients. Therapeutic effects were determined by color-coded duplexsonography and pure tone audiometry eventually masking the audiogram. RESULTS: During treatment an increase of 19% flow volume in the internal carotid arteries and of 11% in the vertebral arteries was evaluated using color-coded duplexsonography. In 47% of cases (n = 14) decrease of tinnitus intensity and/or tinnitus appearance with an average of 16 dB was perceived after the end of the treatment series. Hearing threshold increased in 28% of cases (n = 7) with an average threshold shift of 19 dB after PECP-treatment. All patients were examined by pure tone audiometry during the follow-up after 4, 8 and 12 weeks as well as after 6 and 12 months. In all cases the audiometric benefit lasted throughout the follow-up 1 year, after treatment. CONCLUSIONS: The determination of a positive correlation between vascular flow increase in the extracranial brain-supplying vessels during PECP-treatment and the encouraging therapeutic results obtained by audiometry seem to make this new and promising therapeutic option effective, practicable and easy to handle. These preliminary results of the PECP technique should be validated in further studies featuring larger numbers of patients suffering from therapy-resistant inner ear disorders.

Adult↗
PubMedDate not supplied

A segment-interleaved motion-compensated acquisition in the steady state (SIMCAST) technique for high resolution imaging of the inner ear.

MRI, with ever-increasing spatial resolution, recently has depicted progressively more anatomic details of the inner ear and is playing an important role in the diagnostic evaluation of patients with sensorineural hearing loss. We present a three-dimensional (3D) segment-interleaved, motion-compensated acquisition in steady state (SIMCAST) sequence that allows further increase in spatial resolution in reasonable scan times minimizing artifacts due to susceptibility and motion. The sequence uses gradient moment nulling over TR and segmented interleaved acquisition of multiple data sets with different radiofrequency (RF) phase-cycling schemes. Combination of data from multiple acquisitions by averaging and maximum intensity projection were compared. Images of phantoms and in vivo inner ears were obtained with both full and fractional echoes and compared with other high resolution techniques such as three-dimensional gradient-echo and two-dimensional (2D) and three-dimensional fast spin-echo (FSE) sequences. The new sequence achieves improved signal-to-noise ratio (SNR) and spatial resolution resulting in improved depiction of inner ear structures.

Adult↗
PubMed1985

Contralateral hearing loss following inner ear injury: sympathetic cochleolabyrinthitis?

Acoustic tumor surgery provided an ideal model in which to study possible contralateral hearing loss following a destructive surgical procedure on the inner ear. Follow-up audiometric studies were performed on patients with unilateral acoustic tumors who had undergone resection of their tumors. Patients who had obvious causes for contralateral hearing loss, such as chronic otitis media, unrelated otologic surgery, and noise-induced hearing loss, were excluded from this patient population. A total of 380 patients had available pre- and postoperative audiograms. A mean air-conduction threshold (500, 1000, 2000 Hz) of greater than or equal to 20 dB was considered a significant hearing loss. After adjusting these losses for presbycusis, 1.3% of these patients still had a significant contralateral hearing loss. We discuss the possible causes for the development of contralateral hearing loss and examine the possibility that, following surgical manipulation and injury to the inner ear, immunocompetent cells become sensitized to previously unseen inner ear antigens, setting the stage for contralateral inner ear dysfunction. The similarities of this condition to sympathetic ophthalmia are discussed.

Adult↗
PubMed2006

Comparison of three methods for isolation of nucleic acids from membranate inner ear tissue of rats.

BACKGROUND: Mitochondrial DNA mutations have been found in sensorineural deafness. The aim of this study was to compare three methods for extraction of nucleic acid from membranate inner ear tissue of rats. METHODS: Alkaline denaturation, a conventional phenol-chloroform method and Trizol reagent were respectively used to extract the slight nucleic acid from membranate inner ear tissue of rats. We assessed the amount and quality of nucleic acid using a UV-spectrometer and polymerase chain reaction (PCR). RESULTS: The yield and purity (OD260/OD280) of DNA from inner ear tissue using the phenol-chloroform method was the highest of the three methods. Mitochondrial DNA (mtDNA) fragment can be amplified by PCR from nucleic acid prepared by all methods, while no nuclear DNA (nDNA) fragment can be amplified by method of alkaline denaturation. Both nuclear and mitochondrial genes could be amplified by reverse transcriptional PCR from the RNA prepared by Trizol reagent. CONCLUSION: Adequate amount and high-quality of mtDNA, nDNA and RNA were obtained from unilateral membranate inner ear tissue of rats. Method of alkaline denaturation could be chosen when mtDNA without nDNA was needed, while phenol-chloroform method was suitable for extracting total DNA (including nDNA and mtDNA); method with Trizol reagent was suitable for extracting total RNA and total DNA.

Animals↗