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At least 19 recordsLinked to original sources
PubMed1988

A new technique for interpreting the BAER in cochlear disease.

We found, by studying 20 normal ears and 34 ears with cochlear disease, that the brainstem auditory evoked response (BAER) wave I latency was a good predictor of the I-V interval (r = -0.67, p less than 0.001), whereas hearing loss had little predictive value. The normal and hearing-loss groups generated regression lines (wave I latency vs I-V latency) that did not differ significantly from each other. A normal range of I-V intervals can be established for any wave I latency, increasing the sensitivity of the BAER.

Brain Stem↗
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↗
PubMed1989

[A study using laser-Doppler velocimetry of modifications of the labyrinthine microcirculation induced by chemical and physical stimuli].

Vasomotor activity induced by physical and chemical stimuli in the cochlear microcirculation was evaluated by laser-doppler flowmetry. Cochlear flow changes were studied after pharmacological administration and noise exposure. The reaction of cochlear microcirculation after drug administration is similar to that observed in the brain. After phenylephrine injection the authors observed an increase of cochlear blood flow, contrary to that observed in the peripheral vessels. The authors studied the difference in time-activity and quantitative effect of several drugs commonly used in cochlear vascular diseases. Cochlear flow decrease after exposure to noise is proportional to the stimulus intensity and the exposure time.

Animals↗
PubMed1989

Clinical applications of evoked acoustic emissions: results in normally hearing and hearing-impaired subjects.

Click-evoked otoacoustic emissions were recorded in a group of normally hearing subjects (n = 52 ears) and a group of patients demonstrating several common types of sensorineural hearing loss (n = 85 ears) in order to study the clinical applicability of acoustic emissions. In the normally hearing population, all ears demonstrated acoustic emissions that could be elicited at intensities below the normal subjective threshold for the sequence of clicks (mean, -5.2 dB hearing level [HL]). Sixty-seven percent of the normal ears showed long (greater than 20 ms) click-evoked emissions, and spectral analysis showed a broadband spectral component with several narrowband frequency peaks. In patients with sensorineural hearing loss, the incidence of acoustic emissions decreased and the detection threshold increased linearly with increasing threshold. No emissions were elicited from ears exhibiting subjective click thresholds greater than 35 dB HL. Hearing-impaired ears showed a significantly higher proportion of short duration emissions and a significant reduction in the mean number of narrowband frequency peaks in comparison to the controls. Therefore, acoustic emissions can be used as a reliable technique for objective study of normal micromechanical activity within the cochlea and for detection of subtle changes in cochlear disease. However, they have not been demonstrated to be useful in differentiating cochlear disease.

Acoustic Stimulation↗
PubMed1989

Autoimmune disease and cochlear pathology in the C3H/lpr strain mouse.

The C3H/lpr autoimmune strain mouse is a model for spontaneous systemic lupus erythematosus. Inner ear structure and function were examined during systemic autoimmune disease progression to identify correlated auditory system pathology. Onset of the systemic disease occurred at 2-3 months of age and was characterized by elevated serum immune complexes, cryoglobulins, and antinuclear antibodies. Coincident with the onset of autoimmune disease was degeneration of the stria vascularis. Early edema of the stria occurred in the apex and progressed basalward with duration of the disease. By 10 months of age, stria vascularis area was smaller and auditory brainstem response thresholds were elevated. No degeneration of hair cells was seen at any age, suggesting that the stria vascularis may be the primary anatomic site of autoimmune auditory damage in this mouse model.

Age Factors↗
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↗
PubMedDate not supplied

Recent advances in cochlear blood flow measurements.

Changes in blood flow to the inner ear have been thought to influence or underlie a number of cochlear diseases, including some forms of noise-induced hearing loss, sudden hearing loss, and Meniere's disease. Recently, important advances have been made in two technologies for the study of cochlear blood flow. The first is in the area of vital microscopic studies of cochlear microcirculation, and the second is based on the introduction of laser technology in the form of laser Doppler flowmetry. In this report, measurements are given of changes in cochlear circulation caused by carbon dioxide breathing, intravenous phenylephrine injection, systemic hemodilution, positive end expiratory pressure, and direct electrical stimulation of the cochlea. From these changes, we observe that cochlear blood circulation responds to systemic blood pressure alterations and is subject to local flow control mechanisms. Linearity and speed of response of the laser Doppler instrumentation also are shown. These advances show promise for contributing to our knowledge of control mechanisms of inner ear blood flow and for revealing the influence of various pharmacologic agents of potential clinical value.

Animals↗
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↗
PubMed1988

Retrograde cochlear neuronal degeneration in human subjects.

The purpose of this study was to identify the structural changes in the organ of Corti that correlate with retrograde cochlear neuronal degeneration. Thirty-eight temporal bones with excellent histological preparation from 23 subjects having hearing losses caused by cochlear disease were selected for study. Cytohistograms were prepared for inner and outer hair cells, inner and outer pillar cells, inner phalangeal cells, and cochlear neurons. The extent of neuronal degeneration was found to be directly related to the extent of injury to inner pillar cells and inner phalangeal cells, but not to loss of inner or outer hair cells. In most cochleas the loss of dendritic nerve fibers exceeded the loss of cell bodies. The findings support the concept that retrograde neuronal degeneration is initiated by injury to the dendritic nerve fibers, secondary to collapse and/or degeneration of the inner pillar cells and inner phalangeal cells.

Adult↗
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↗
PubMed1987

Effect of galactose and isosorbide on cochlear blood flow.

Cochlear blood flow in the rabbit was determined before and after injection of hyperosmotic solutions of galactose and isosorbide. After doses similar to those which can produce hearing improvements in patients with Ménière's disease, cochlear blood flow was increased by 30-60%.

Animals↗