Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cochlear Diseases”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

Type II collagen-induced autoimmune ear disease in mice: a preliminary report on an epitope of the type II collagen molecule that induced inner ear lesions.

To identify the epitope on the type II collagen molecule that induced autoimmune ear disease, electrophysiological and histological studies were carried out in DBA/1J mice immunized with native chick type II collagen (Clln) and cyanogen bromide (CNBr) peptide 1I (CB-I1 peptide) that was cleaved from chicken type II collagen with CNBr digestion. Four months after immunization, three of six Clln-immunized mice and five of six CB-I1 peptide-immunized mice developed moderate hearing loss. No control animals showed hearing loss. The pattern of hearing loss was characteristic of progressive deafness. Furthermore, the immunized mice showed temporal lesions involving atrophy of the Corti organ and degeneration of the spiral ganglion, in proportion to the level of the hearing loss. Because similar inner ear lesions were induced by immunization with Clln and CB-I1 peptide, CB-I1 peptide contains at least one epitope that induces autoimmune inner ear disease in collagen II-induced disease on the chick type II collagen molecule involved in pathogenesis of autoimmune ear disease. CB-I1 peptides were concluded to contain the epitope that induces autoimmune inner ear disease in collagen IIn-induced disease.

Animals↗

Effectiveness of hyperbaric oxygen therapy in patients with acute and chronic cochlear disorders.

Over the course of 18 months 359 patients with defined acute and chronic inner ear disorders who had not responded to treatment with medication were given hyperbaric oxygen (HBO) therapy. The inner ear diseases of the patients were divided, based on the duration of their conditions, into four symptomatic groups. Of the patients who had had hearing loss for less than 3 months, noticeable improvement or complete recovery was seen in 13% (20 dB in at least three test frequencies); 25.2% showed an improvement between 10 and 20 dB. Changes up to 10 dB or less were not considered to be positive. Patients with a pretreated hearing loss for more than 3 months had markedly less benefit from HBO therapy. Two percent regained normal hearing function. In 30% an improvement of more than 10 dB was achieved. For patients who had suffered from tinnitus for less than 3 months excellent improvement was seen in 6.7% and noticeable improvement in 44.3% expressed by means of a visual analog scale. In 44.3% the tinnitus was described as unchanged. Patients who had had tinnitus for more than 3 months before HBO therapy showed a less favorable response to HBO. In none of the patients did the tinnitus disappear; 34.4% of the patients described a noticeable improvement in their complaints.

Acute Disease↗

Effects of chronic cochlear damage on threshold and frequency tuning of neurons in AI auditory cortex.

We describe the effects of long-term cochlear lesions on the frequency response properties of AI cortical neurons in the cat. Young animals were treated with amikacin to produce bilateral, basal to mid-turn cochlear lesions. After 12-24 months the response properties of single neurons or small unit clusters in primary auditory cortex were recorded in anesthetized animals. Responses to stimulus frequency and intensity were mapped in detail and frequency threshold curves (FTCs) and Q10dB values were derived. Subsequent to recording experiments, scanning electron microscopy of the sensory epithelium was used to characterize the degree and extent of the cochlear damage. In normal control animals, Q10dB values were, on average, lower than those derived by others from cochlear nerve fibre recordings in the same species. In amikacin-treated animals, deterioration was evident in the threshold and tuning properties of cortical neurons, particularly in those cells whose input originated in damaged cochlear regions. Often, neurons associated with 'normal' cochlear areas (as assessed by scanning microscopy) also had poor frequency tuning compared with controls. As an animal model of sensorineural hearing loss, we consider the cat with long-term cochlear lesions to be more appropriate than animals with acute or short-term pathology. We also suggest that in making physiological-psychophysical correlations, neural responses from the central auditory system (e.g. cortex) should perhaps be given more consideration than data derived at the cochlear level.

Amikacin↗

[Intratympanic interval therapy of Menière disease with gentamicin with preserving cochlear function].

For the effective treatment of Menière's disease, gentamicin should be administered at most three times: on days 1, 8 and 15. More than 50% ( n=30) of 57 patients seen between 1997 and 2000 only needed a single dose of gentamicin to obtain a sufficient reaction (single shot-therapy). Vertigo attacks were controlled in 95% of our 57 patients and there were no substantial hearing losses. Four patients lost 15 dB. Tinnitus (46%) and ear pressure (69%) could be controlled or improved. The intratympanic injection-technique (single dose=0.3 ml=12 mg) performed under local anaesthesia is simple and superior to any other procedure. The peak concentration of gentamicin is reached after 2-6 days (average 4.6 days). As soon as signs of inner ear reaction are observed, treatment has been effective and must be stopped immediately to avoid over-intoxication and damage to the cochlea.

Anti-Bacterial Agents↗

Paget disease and sensorineural hearing loss associated with spiral ligament degeneration.

HYPOTHESIS: Previously unreported cystic degeneration of the spiral ligament in cases of Paget disease. BACKGROUND: About 70% of cases of Paget disease involve the skull, with hearing affected in approximately 50% of these. The hearing impairment may be sensorineural, mixed, or, rarely, only conductive. The etiology and pathogenesis of the hearing loss are not yet understood, and reports in the literature are inconsistent regarding the pathologic changes responsible for sensorineural hearing loss. Of six pairs of temporal bones from patients with Paget disease in the temporal bone collection of a research institution, two pairs have abnormalities not previously associated with sensorineural hearing loss or Paget disease. We report the histopathologic findings in these temporal bones. METHODS: The temporal bones were fixed in formalin, decalcified in ethylenediaminetetraacetic acid, embedded in celloidin, and sectioned in the horizontal plane at a thickness of 20 microm. Every 10th section was stained with hematoxylin-eosin and mounted on glass slides. The sections were examined by light microscopy. RESULTS: Cystic degeneration of the spiral ligament, primarily in the basal segment, was found in both cases. Endolymphatic hydrops and a small endolymphatic sac with calcification of the perisaccular tissue were found in one case. CONCLUSIONS: Cystic degeneration of the spiral ligament has not been previously reported and may be unique to Paget disease. This is consistent with recent literature showing a previously unsuspected role of the spiral ligament in sensorineural hearing loss.

Aged↗

[From gene to disease; a progressive cochlear-vestibular dysfunction with onset in middle-age (DFNA9)].

DFNA9 is an autosomal dominant genetic inner-ear hearing impairment that starts to show itself in the 3rd and 4th decades of life. This hearing impairment may be of a different degree of severity in each ear. Progression of hearing loss is about 3 dB/year. In about one in three patients severe vestibular symptoms similar to those in Ménière's disease are present as a result of a progressive impairment of the vestibular system. Several mutations were found in the COCH-gene on chromosome 14. There are indications that some of the mutations disrupt the folding of the cochlin protein, an important component of the extracellular matrix in the inner ear. DNA-diagnostics confirming the diagnosis ofDFNA9 are possible.

Adult↗

Altered immunoregulations in otosclerosis: presence of autoantibodies in otosclerotic sera samples.

A current concept of the etiopathogenesis of otosclerosis is an immune response. The purpose of this study was to determine if autoantibodies were present in sera samples from patients with known otosclerosis. Organ non-specific total antinuclear antibodies (tANA) were determined in 98 sera samples by the immunofluorescent method in 47.9% of otosclerotic patients versus 5% in controls. The most frequent specific antinuclear antibody was antibody to native deoxyribonucleinic acid and antibody to ribonucleoprotein. Tissue-specific antibodies to native-collagen type II molecule (ACA II) were determined by counter-immunoelectrophoresis in the same sera samples and were detected in 54% versus none in healthy sera. There was no correlation between the presence of these two autoantibodies. In patients with tANA present, a statistically significant depletion of cochlear function was noted. The presence of ACA II showed no connection with hearing loss. The present study showed some alteration in immunoregulatory markers in otosclerotic patients and the possibility that ANA may play a role in the pathogenesis of otosclerosis-induced perceptive deafness.

Acoustic Impedance Tests↗

Chemical labyrinthectomy and cochlear implantation for Menière's disease--an effective treatment or a last resort?

The surgical management of Menière's disease presents a difficult and controversial problem and includes various procedures ranging from 'placebo operations' to vestibular nerve section. The situation is even more complex in the case where the only hearing ear is affected. We present a case of severe debilitating vertigo due to Menière's disease that was treated by chemical labyrinthectomy and cochlear implantation. This unique management strategy allowed restoration of useful hearing and relief of vertigo.

Audiometry, Pure-Tone↗

Auditory brainstem implant (ABI): new frontiers in adults and children.

UNLABELLED: Previous studies have considered only patients with neurofibromatosis type 2 (NF2) older than 12 years as candidates for an auditory brainstem implant (ABI). Our study expands the potential criteria to include both children and adult subjects with other cochlear or cochlear nerve malfunctions who either would not benefit at all from a cochlear implant (eg, cochlear nerve aplasia or avulsion) or whose benefit was or would be severely compromised (eg, cochlear ossification, cochlear fracture). STUDY DESIGN: In our department, over the period from April 1997 to September 2002, 29 patients, 20 adults and 9 children, were fitted with ABIs. Their ages ranged from 14 months to 70 years. Thirteen subjects had tumors, 10 NF2 and 3 solitary vestibular schwannoma, and 16 patients had a variety of nontumor (NT) cochlear or cochlear nerve diseases. A retrosigmoid-transmeatal approach was used in T and a retrosigmoid approach in NT patients. The electrode array was inserted into the lateral recess of the fourth ventricle and correct electrode positioning was monitored with the aid of electrically evoked auditory brainstem responses (EABRs). RESULTS: Correct implantation was achieved in all patients. No complications were observed due to implantation surgery or related to ABI activation or long-term use. Auditory sensations were induced in all patients with various numbers of electrodes (from 5 to 15). Different pitch sensations were identifiable with different electrode stimulation. Closed-set word recognition, open-set sentence recognition, and speech tracking scores achieved by the patients are reported in detail. The auditory performance of the patients showed significantly better outcomes than controls (Multicentric European clinical investigations on ABI with NF2). CONCLUSION: We have shown that the indications for the ABI can be extended to include NT patients with severe cochlear and/or cochlear nerve abnormalities. The degree of auditory benefit varies as a function of the underlying pathological conditions, with NT subjects exhibiting significantly better outcomes than the T patients.

Adolescent↗

Electronystagmographic findings and recovery of cochlear and vestibular function in patients suffering from sudden deafness with a special reference to the effect of anticoagulation.

The study included 80 patients treated for sudden deafness over the last 5-7 years. Case history, laboratory findings, pure-tone audiogram and electronystagmography (ENG) findings were noted. If any abnormalities had been recorded in ENG studies, the studies were redone. ORL status was redefined and audiograms were obtained in all patients. When becoming ill, the 80 patients had not differed from the normal population in common cardiovascular risk factors. None of them had had signs of viral infection (paired serum samples had been taken at 2-week intervals; routine examinations had been done for common viral antigens). As many as 31 of the 80 patients with acute hearing loss had had abnormalities such as spontaneous nystagmus (PN), hypoexcitability (HE) and directional preponderance (DP) in the bithermal caloric tests (+44 degrees C, + 30 degrees C) of their ENG studies. Twenty of the 31 patients still had abnormal ENG studies after 5-7 years. Only 1 subject had positional nystagmus, and none had subjective vertigo. Patients with an abnormal ENG study showed a poor recovery of the speech reception threshold, whereas those with a normal ENG study showed slightly significant (p less than 0.05) recovery.

Administration, Oral↗

Lesion site in sudden deafness: study with electrocochleography and transiently evoked otoacoustic emission.

We examined electrocochleogram (ECochG) and transiently evoked otoacoustic emission (TEOAE) on five cases of sudden sensorineural hearing loss which had no abnormalities detected on diagnostic imagings and showed complete recovery of hearing. At the initial examination, three cases showed a broadened wave 1 with prolonged latency in the auditory brainstem response (ABR) at 90 dB HL. The ECochG AP showed a broad waveform, low amplitude, and high threshold. CM threshold, although increased, was relatively well preserved compared with hearing threshold measured with conventional pure-tone audiometry. The thresholds in TEOAE examination were similar to those for CM and preserved better when compared with pure-tone audiometric thresholds. These findings suggest that the location of the disorder in these three cases involved not only the cochlea but also the retrocochlear auditory pathway. The other two cases showed normal ABR waveforms at 90 dB HL at the initial examinations. ECochG examination showed that a normal AP in one case and a smaller amplitude AP, an elevated threshold, and normal waveform of AP in the other ear. CM thresholds coincided with the conventional audiometry thresholds. These findings suggest that hearing loss in these two cases involved primarily the sensory hair cells.

Acoustic Stimulation↗

Pathophysiology of the Meniere attack: facts and theories.

A pathophysiological interpretation is discussed of the clinical findings that in one out of three cases at the onset of Meniere's disease the cochlear and vestibular symptoms start simultaneously and that during the course of Meniere's disease most attacks show both cochlear and vestibular symptoms. It is concluded that the Meniere attack is not caused by a slowly expanding endolymphatic system that finally ruptures or leaks, but that the pathogenesis of the attack is different from that of the underlying endolymphatic hydrops.

Ear, Inner↗

Sudden cochlear hearing loss in a patient with Behçet's disease.

A Behçet's disease patient developed sudden cochlear hearing loss during a flare of her disease. Prednisone and cyclosporin therapy was ineffective, probably because it was initiated late. Sensorineural hearing loss is a rare but underrecognized complication of various forms of vasculitis such as Wegener's granulomatosis, polyarteritis nodosa, giant cell arteritis and Behçet's disease. Its importance lies in the need for an early diagnosis, since prompt treatment with steroids and immunosuppressive agents may lead to restoration of hearing.

Behcet Syndrome↗