PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cochlear Diseases”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed1992

[Progressing cases from low tone sudden deafness to Menière's disease--cochlear impairment in the so-called pre-Menière's disease period].

Among 80 patients with low tone sudden deafness (LTSD) who visited our department over the past 15 years, there were 6 cases (7.5%) who subsequently progressed to Menière's disease. The clinical and audiological processes of the 6 patients were studied in detail and the following results were obtained. (1) In these 6 patients, the time between onset of LTSD and the diagnosis of Menière's disease ranged from 4 months at the shortest to 6 years and 8 months at the longest, 2 years and 9 months on average. (2) Two pattern types were seen in the change from LTSD to Menière's disease: changing within a short period of time after recurrence of an LTSD-like attack, and changing after more than one year without recurrent attack. (3) The monoattack-nonrecovered type of LTSD and the recurrent type of LTSD within three months after the onset (short-term prognosis) frequently progressed to Menière's disease. (4) There were no close relationships between subjective symptoms and audiological features in the pre-Menière's disease period (from the onset of LTSD to the recurrence of vertigo with cochlear symptoms). (5) The 6 patients showed various audiogram shapes at the time of progression to Meniere's disease; 3 cases with the slightly rising type, 1 with the high frequency-impaired type, and 2 with the moderate, gradual and flat type. (6) Of the 6 patients, 3 had good hearing during long term observation. At least 2 patients seemed to have the mild type of Menière's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Hearing disorders in sickle cell disease: cochlear and retrocochlear findings.

The auditory system was assessed in 34 adult subjects with sickle cell disease using standard audiometric test techniques. The study results indicate that patients with sickle cell disease are at risk for retro-cochlear as well as cochlear dysfunction of the auditory system. However, there is no consistent audiometric pattern that is pathognomonic of sickle cell disease. The test results indicate that auditory status should be carefully monitored in all adult patients with sickle cell disease.

Acoustic Impedance Tests↗
PubMedDate not supplied

[Correlation between audiometric and electronystagmographic results in Menière's disease].

Cochlear and vestibular functions of 30 patients suffering from Méniere's disease have been analyzed through audiometric and electronystagmographic studies. Auditive thresholds in low, medium and high frequencies have been correlated with the results of the caloric and pendular tests. Statistical analysis has demonstrated that there is no significant relationship between caloric and pendular reflectivity and hearing loss in the mentioned frequencies. In conclusion, in Méniere's disease hearing losses and vestibular alterations follow a different pathologic pattern.

Adult↗
PubMedDate not supplied

[The working conditions and health status of miners in Donets Basin coal mines].

Data are reported on working conditions of coal miners considering the main physical (dust, noise, vibration, microclimate) and chemical environmental professional factors and their prognosis up to the year 2005. The authors analyze professional morbidity (pneumoconiosis, dust-induced bronchitis, vibration disease, cochlear neuritis etc.) and diseases with temporary loss of the working capacity invalidity and mortality of miners. The relation between working conditions and health status of miners were analyzed.

Absenteeism↗
PubMed1990

[Acoustic oto-emissions. Clinical uses].

Otoemissions are acoustic signals emitted by the cochlea in response to a short acoustic stimulation (click) that may be recorded with a miniaturized microphone placed within the external auditory canal. They reflect the active mechanisms of the cochlea as they relate to the contractile properties of the outer hair cells, which determine the cochlear properties of sensitivity to and selectivity of frequencies. We have been studying for 5 years the clinical applications of otoemissions in over 500 patients. Otoemissions in 100% of normal ears may be recorded, and the detection threshold is generally 10 dB lower than the psycho-physiological threshold. In pathology, otoemissions present a practical interest in the following applications: objective investigation of perception hearing loss, early screening of cochlear disease consecutive to administration of ototoxic drugs, or sound-induced trauma; exploration of Meniere's disease; study of modifications induced by osmotic substances; diagnosis of retrocochlear disease; quick objective assessment of cochlear function in the newborn and the child.

Acoustic Stimulation↗
PubMed1992

[Preoperative vestibular diagnosis in therapy of Menière's disease].

Surgical treatment of Meniere's disease is indicated in patients with severe attacks who have failed drug therapy. A decision between a conservative or destructive procedure demands firstly exclusion of patients with non-otogenic diseases, bilateral disease or complete unilateral loss of function, and secondly assessment of the laterality of the disease, of residual labyrinthic function and of vestibular compensation. A total of 185 patients with Meniere's disease were investigated. All of them had a history and clinical signs that indicated surgery. Canal function, otolith responses and vestibular compensation were examined, in addition to routine preoperative tests as recommended by the Committee on Hearing and Equilibrium of the American Academy of Ophthalmology and Otolaryngology. Of the 185 patients 22% had findings that contraindicated surgery, 4% suffered from Meniere's disease in the opposite ear, 6% showed no signs of vestibular compensation and 12% had dead labyrinths on the side of the cochlear disease. No caloric response was elicited from the labyrinth by thermal bilateral testing in 25% of the 185 patients. In patients who were thought to have dead labyrinths based on routine caloric tests, residual canal function was detected by means of 20 degrees C stimulation in the prone and supine position. Without extensive vestibular testing the indications for surgical treatment of Meniere's disease will be incorrect in 47% of patients.

Functional Laterality↗
PubMed1991

Hearing loss and pneumococcal meningitis: an animal model.

Clinical studies of predisposing factors in the development of hearing loss secondary to bacterial meningitis have produced conflicting results. An animal model of meningogenic labyrinthitis was developed for more precise study of these parameters. Rabbits were inoculated intrathecally with 10(5) pneumococci to induce meningitis. Hearing thresholds were measured using auditory-evoked responses to 1 kHz, 10 kHz, and click stimuli before infection and every 12 hours thereafter. Profound deafness occurred in all subjects at an average of 48 hours following infection. The incidence and severity of hearing loss was strongly correlated with the duration of meningitis. Temporal bone histology revealed acute inflammation of all perilymphatic spaces including the cochlear aqueduct. This model demonstrated that the risk and severity of hearing loss increase with the duration of meningitis and suggested that the cochlear aqueduct is an anatomic pathway for the extension of infection from the cerebrospinal fluid to the cochlea. The implications for therapy in humans is discussed.

Acoustic Stimulation↗
PubMedDate not supplied

[Experimental perilymphatic fistula: the electrocochleographic findings].

The aim of the present study was to evaluate the effect of experimental perilymphatic fistula on cochlear electrophysiological responses. Six albino guinea pigs, in which recording electrodes were implanted in order to record the electrocochleogram, were used. Experimental protocol investigated cochlear responses before the induction of the fistula in the round window membrane perforation and then two month later. Compound action potential thresholds increased immediately after perforation of the round window membrane. The thresholds rapidly recovered. This phenomenon was accompanied by clear-Out reduction in amplitude upon suprathreshold stimulation. This latter observation associated with a decrease in the amplitude of the threshold seems to be a specific audiologic sign of the fistula. The clinical implication are discussed.

Acoustic Stimulation↗
PubMed1979

Histopathology of 30 non-operated acoustic schwannomas.

Thirty of 1720 temporal bones from the Wittmaack's Collection contain nonoperated acoustic neuromas, 22 of them large tumors. Histologically, each tumor has to be considered as an individual. Most of the tumors show a mixture of Antoni type A and B. Tumor vascularization is pronounced in half the cases. Vessels of the internal acoustic meatus are found in all cases. Protein contents of the perilymphatic spaces is medium to pronounced in 23 of 30 cases in comparison to the small protein contents of the healthy side. Ganglion geniculi is invaded in 11 cases (9 von Recklinghausen's disease), Ganglion Scarpae in 26 cases (9 von Recklinghausen's disease), and Ganglion spirale in 9 cases (7 von Recklinghausen's disease). Cochlear and vestibular nerve fibers within the internal auditory meatus were affected by the tumor in 28 of 30 cases, the facial nerve only in 11 cases, among them 9 cases of von Recklinghausen's disease. Twenty-six of 30 schwannomas have a portion within the cribriform area of the cochlea fundus, which explains the limitation to radical tumor surgery without damage of the cochlear nerve. These histological findings explain the site of damage of hearing to expand between the cochlea to the auditory brain stem nuclei, and support the audiological experience that a correlation of "acoustic neuroma" and "retrocochlear lesion" is often not correct.

Adolescent↗
PubMed1990

Labyrinthine ossification after meningitis: its implications for cochlear implantation.

Labyrinthine ossification can be found in a high percentage of patients with profound deafness resulting from bacterial meningitis. Radiographic evidence of ossification can be found as early as 2 months after the acute infection, indicating that the intracochlear process probably begins much earlier. If long, intracochlear cochlear implants are to be most successfully used in these patients, an aggressive approach to clinical management following the meningitis should be taken. Illustrative case reports and suggested guidelines for evaluation and treatment are given.

Calcinosis↗
PubMed1990

Imaging for cochlear implants.

Insertion of a sound amplification device into the round window niche (extracochlear implant) or into the coils of the cochlea (intracochlear implant) can give significant benefits to some carefully selected, severely deaf patients. Imaging has an essential role in selective and pre-operative assessment. Severe otosclerosis and post-meningitic labyrinthitis ossificans are common causes of deafness in these patients and can be demonstrated by computed tomography (CT). The most suitable side for operation can be assessed. We describe our experiences with 165 patients, 69 of whom were found suitable for implants. Thin (1 mm) section CT in axial and coronal planes is the best imaging investigation of the petrous temporal bones but the place of magnetic resonance scanning to confirm that the inner ear is fluid-filled and polytomography to show a multichannel implant in the cochlea is discussed. No implants were used for congenital deformities, but some observations are made of this type of structural deformity of the inner ear.

Cochlea↗
PubMed1978

Incidence of Ménière's disease.

The incidence of Ménière's disease in Sweden for the year 1973 has been calculated as one case in a population of 2,163. This gives an overall incidence of 46/100,000. Extrapolating the Swedish incidence data to the population of the United States, there should have been 97,000 cases of Ménière's disease treated as inpatients or outpatients during the year 1973. The incidence in the United States of Ménière's disease, cochlear type, is considered to be even higher. In addition, the Swedish statistic for some other disorders, including otosclerosis, are reported. For otosclerosis, the yearly incidence in Sweden is 12/100,000 or one case in a population of 8,414. This could be extrapolated to 25,000 patients with clinical otosclerosis in the United States for the year 1973. By comparison, Ménière's disease, by stringent diagnostic criteria, is approximately four times as common as clinical otosclerosis. It is also more common than all laryngeal carcinomas, all salivary gland tumors, both benign and malignant, as well as acute epiglottitis and acute nephritis.

Adolescent↗
PubMedDate not supplied

Endolymphatic sac obstruction. Biochemical studies.

Inner ear fluids were studied biochemically in guinea pigs from 1 to 16 weeks after producing endolymphatic hydrops by obstructing the endolymphatic duct. Fluid collected from beneath the footplate showed changes of 50% of the animals indicating distension of the saccule. There was an increase in potassium concentration and decrease in sodium concentration of the collected fluid, indicating a traumatic mixing of endolymph and perilymph produced by rupture of the saccule during collection of the fluid. The smallest changes occurred at one week, and the greatest changes were found four months after endolymphatic sac obstruction. Similar findings were observed in studying inner ear fluids obtained from patients with Ménière's disease. Cochlear endolymph showed biochemical alterations after endolymphatic duct blockage. There was a two- to three-fold increase in sodium concentration and a decrease in potassium concentration with the total ionic concentration remaining approximately the same. Some guinea pigs showed similar changes in vestibular endolymph. This study indicates that in the guinea pig, endolymph obtained in the distended endolymph compartment has a slightly different sodium-potassium ratio as compared to the normal ear. In patients with Ménière's disease there may also be an elevation of endolymph sodium concentration. The significance of this change and hearing loss observed in experimental endolymphatic hydrops and Ménière's disease is open to speculation at the present time.

Animals↗
PubMed1992

Long-term measures of electrode impedance and auditory thresholds for the Ineraid cochlear implant.

Measures of electrode impedance and of detection thresholds for electrical stimuli were extracted from the records of patients implanted with the Ineraid cochlear prosthesis. An analysis of impedance measures, obtained at 1, 12, 24, and 36 months after surgery, demonstrated (a) a significant decrease in impedance over the first year for electrodes that carried current and (b) significant increases in impedance at 24 and 36 months for electrodes that did not carry current. An analysis of detection thresholds, obtained at the same times as the impedance measures, demonstrated that averaged thresholds for the current-carrying electrodes varied no more than 0.5 dB over the 3-year period. These results support the conclusion that stimulation with the Ineraid device does not produce deleterious changes in the electrodes or in the target neural tissue.

Acoustic Impedance Tests↗
PubMed1990

The prognostic value of round window electrical stimulation in cochlear implant patients.

The use of preoperative round window stimulation has been advocated for its possible predictive value in cochlear implant patients. We have attempted to correlate cause of deafness, preoperative radiologic study, and postoperative stimulability and performance with preoperative stimulation. Round window stimulation procedures consisted of measurements of electrical thresholds and comfort levels, gap detection, and temporal difference limen. Radiologic studies were performed using high-resolution computerized semi-axial and coronal tomography with 1.5-millimeter overlapping cuts. Patient performance was measured using a standard audiologic test battery. Sixteen postlingually, profoundly deaf adults who received the Nucleus multichannel cochlear implant were studied. All 16 patients who responded to preoperative stimulation had acceptable CT scans for the ear operated on and stimulated postoperatively with the prosthesis. The lowest level at which a patient could reliably detect a gap between two signals ranged from 10 to 150 milliseconds, which was not predictive. For the temporal difference limen task, the patients who could reliably identify the longer of two pulses when the difference was less than 100 milliseconds did achieve varying amounts of open-set speech discrimination postoperatively. In summary, results indicate that the preoperative psychoacoustic electrical stimulation test battery provides useful information in predicting postoperative performance.

Cochlea↗