PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Hearing Loss, Functional”

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 73 records · Page 4Linked to original sources
PubMed1998

Cochlear origin of hearing loss in MELAS syndrome.

There have been few studies investigating the mechanism and nature of the hearing loss that occurs in the mitochondrial disorders. We studied 18 patients with the MELAS A3243G point mutation from four different kindreds. Pure tone audiometry, speech discrimination testing, acoustic reflexes, tympanometry, and brain stem auditory evoked responses were performed to localize the site of pathology in the auditory pathways. In 12 patients, we performed electrocochleography and otoacoustic emissions to assess cochlear involvement. Neuroimaging and promontory nerve stimulation were performed to exclude retrocochlear pathology. Audiological testing confirmed sensorineural hearing loss in 14 of the 18 patients studied; hearing loss was usually gradual in onset, was symmetrical, and initially affected the higher frequencies. In some patients, there were features that distinguished the hearing loss from presbyacusis, including a young age at onset, asymmetrical involvement, stepwise progression, and partial recovery. We treated one patient who had profound bilateral hearing loss with cochlear implantation; this restored good functional hearing. Hearing loss in MELAS syndrome appears to be due to dysfunction of the cochlea, probably resulting from metabolic failure of the stria vascularis and outer hair cells. Cochlear implantation is a therapeutic option worth considering in those patients who become deaf.

Adolescent↗
PubMed2004

Long-term sensorineural hearing loss induces functional changes in the rat auditory nerve.

Loss of cochlear hair cells in the rat initiates degenerative change within the primary auditory neurons (ANs) of the cochlea. These degenerative changes include loss of peripheral processes, demyelination and ultimately cell death. This pathology will affect the biophysical processes involved in action potential generation and propagation to an electrical stimulus via a cochlear implant. We measured the response properties of ANs, with particular reference to their refractory behaviour, in normal, short- (9 weeks) and long-term (> 52 weeks) deafened rats. AN loss was moderate in the short-term and severe in the long-term deafened animals. AN activity was elicited using a brief electrical stimulus delivered via a bipolar electrode array implanted into the cochlea. The general response properties of ANs recorded from deafened cochleae were similar to those observed in normal cochleae, i.e. a monotonic increase in the probability of firing and a decrease in response latency and temporal jitter with increasing stimulus intensity. However, the absolute refractory period was significantly prolonged in animals deaf for > 12 months (P = 0.0026). Deafened animals also exhibited a highly significant increase in threshold compared with normal controls (P < 0.001). These functional changes have implications for recipients of cochlear implants and potential therapies directed toward halting or reversing AN pathology.

Acoustic Stimulation↗
PubMed2002

[Equilibrium function in patients with acute sensorineural hearing loss].

Equilibrium function was investigated with computer-assisted stabilography (CS) in patients with acute neurosensory hypoacusis. This new diagnostic tool was employed in combination with extended vestibulometric and audiologic examinations. Correlations were found between stabilographic and vestibulometric findings. CS is recommended as a method of screening diagnosis in examination of patients with imbalanced equilibrium.

Acute Disease↗
PubMed1977

Auditory reaction times for functional and nonfunctional hearing loss.

Differences in decision processes as measured by auditory reaction times of simulated or actual functional hearing-loss subjects and nonfunctional subjects were investigated. Sensation level data are presented that reflect marked differences between such individuals with regard to probability of response, and means and standard deviations of auditory reaction times. Means and standard deviations of auditory reaction times for nonfunctional subjects are greatly reduced when compared with results obtained by simulated or actual functional subjects. Probability of response data was less effective in differentiating functional from nonfunctional subjects. Individuals who were trained to simulate hearing loss responded in a manner similar to functional patients. The results of this study suggest that auditory reaction time measures can be employed to determine the existence or nonexistence of functional hearing loss with considerable accuracy.

Audiometry↗
PubMed2000

The role of a family history in King Kopetzky Syndrome (obscure auditory dysfunction).

King Kopetzky Syndrome (KKS) is a common condition in which individuals with normal audiograms complain of hearing difficulties, particularly in noisy places. Several studies have shown many patients with KKS to have a family history of hearing problems. In 82 consecutive patients with KKS and normal middle ear function, we compared the performance of those with and without a family history of hearing impairment on a number of sensitized tests. Those with a family history were more likely to have notches on Audioscan testing (p < 0.005) and these notches were broader than those found in patients with no family history (p < 0.05). There was also a tendency for those with a family history to be more likely to have notches on DPOAEs (p < 0.07), and the reproducibility of the TOAEs was poorer in those with a family history. Psychological testing showed males with a family history to have higher scores on free-floating anxiety (p < 0.01) and obsessionality (p < 0.05).

Adult↗
PubMed2002

Hearing loss, hearing handicap, and functional health status between African American and Caucasian American seniors.

This investigation examined the relations among hearing loss, handicap perception, and functional health status of 152 African American and Caucasian American seniors ranging in age from 60 to 89 years. Subjective measures were obtained from self-report scores on the Hearing Handicap Inventory for the Elderly (HHIE), the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), and demographic profiles. Results indicated the following: (1) both subject groups exhibited nearly identical degrees of sensorineural hearing loss consistent with presbyacusis; (2) African American seniors reported significantly lower levels of completed education than did Caucasian American seniors; (3) differences between groups in self-report scores of hearing handicap (HHIE) were not statistically significant; (4) differences across groups in self-report scores of functional health status (SF-36) were not statistically significant; and (5) increasing levels of hearing loss produced significantly higher HHIE scores and significantly lower SF-36 scores in each group. These findings are discussed.

Acoustic Impedance Tests↗
PubMed1984

Past, present, and future applications of the auditory middle latency response.

For many years (auditory) middle latency response (MLR) reportedly has been an excellent electrophysiological procedure for estimating frequency specific auditory thresholds. Currently the 40 Hz potential, a derivative of the MLR, holds even greater promise for threshold testing. MLR also appears to have potentially valuable applications in the evaluation of functional hearing loss and assessment of higher auditory function. However, MLR is not without controversy. Questions of origin, filtering effects, and its use in pediatric assessment are current issues surrounding applications of MLR. The following article analyzes the values and limitations of MLR within the framework of past, present, and future research and clinical uses.

Acoustic Stimulation↗
PubMedDate not supplied

Alleged inner ear trauma: compensation pending.

The English literature on the incidence of nystagmus in normal subjects and in patients with head and/or neck injuries is reviewed. The authors present a series of 202 patients with alleged vestibular trauma. The incidence of spontaneous and positional nystagmus would seem to be no greater in patients with alleged vestibular trauma than that found in the normal subjects, suggesting that these patients do not have objective evidence of vestibular trauma. Objective criteria for diagnosing vestibular abnormalities by electronystagmography are presented. At least 22% of a series of 2408 patients were found to have a functional hearing loss. The importance of looking for functional overlay in patients involved in litigation cases is stressed.

Adolescent↗
PubMed1977

[The possibilities of Electric Response Audiometry in Medical Legal Assessment (author's transl)?].

A case of nonorganic hearing loss combined with noise-induced hearing loss and the necessity of differentiating them by Electric Response Audiometry in legal assessment is described. A second example deals with monaural functional hearing loss induced by ill-treatment. Finally is reported on a bilateral neurinoma of the acoustical nerve with an extrem auditory fatique and the impossibility to detect evoked potentials.

Adult↗
PubMed1997

Effects of otitis on hearing in dogs characterised by brainstem auditory evoked response testing.

Hearing function was measured in normal dogs and in dogs with otitis using brainstem auditory evoked response testing. Data were obtained from 86 normal ears and from 105 ears with otitis, categorised into four degrees of severity. The data were analysed to illustrate the differences between the hearing function in the normal and abnormal ears and to estimate the degree of impairment associated with differing degrees of pathology. While severe hearing loss seemed to be present in the dogs with more severe otitis, only two individuals were identified as being totally deaf in the affected ears and no dogs were identified in which the cleaning and examination processes had caused damage to hearing function. Cleaning the ear canal produced measurable improvements in hearing in several dogs, indicating the profound effect of physical obstruction of the external ear canal by debris. It is concluded that most dogs with chronic otitis externa are not totally deaf and that the hearing impairment that does occur has the characteristics of conductive hearing loss.

Animals↗
PubMedDate not supplied

Hearing loss from acute carbon monoxide intoxication.

A case of fluctuating sensorineural hearing loss from acute carbon monoxide (CO) poisoning with presentation of a U-shaped audiogram is reported. Acute CO intoxication seems to involve vestibular function more frequently than auditory function. Hearing loss is uncommon, but when present, may often display a U-shaped audiometric curve. Decrease in hearing sensitivity probably results from hypoxia to the cochlea, VIII nerve and brain stem nuclei. Fluctuation in hearing sensitivity may be an early manifestation of acute CO exposure, and requires periodic audiometric examination until the hearing has stabilized.

Acute Disease↗
PubMed2004

When is a conductive hearing loss not a conductive hearing loss? Causes of a mismatch in air-bone threshold measurements or a "pseudoconductive" hearing loss.

The otolaryngologist is sometimes faced with a patient with an apparent conductive hearing loss on audiometric testing who appears to have normal and mobile middle ear structures on ear exploration. Some causes of these "pseudoconductive" hearing losses can be diagnosed without resorting to surgery. This article reviews several possible mechanisms for this condition with diagnostic procedures to distinguish etiologic diseases. Conditions discussed include poor audiometry, functional hearing losses, "third window" causes, obliterated round window, abnormal inner ear connection with the cerebrospinal fluid space, inner ear mechanical conductive hearing loss, and apparent inner ear loss owing to missed middle ear pathology.

Audiometry↗
PubMed2006

Distortion product otoacoustic emission (DPOAE) in tinnitus patients.

The aim of this study was to determine the effect of tinnitus (experiment I) and the combined effect of tinnitus and sensorineural hearing loss (experiment II) on the distortion product otoacoustic emission (DPOAE) for two age groups of tinnitus patients. Tinnitus patients with normal earing, along with normal-hearing control subjects, participated in experiment I. They were divided into two age groups, below 50 and above 50 years. Experiment I showed that the DPOAE levels in the tinnitus patients were lower than those in the normal-hearing (nontinnitus) subjects. The differences depended on the frequency and the age of the patients, suggesting the confounding influence of presbyacusis. The second group of tinnitus patients with increasing and notch-like hearing loss participated in experiment II. They were also divided into two age groups, below 50 and above 50 years. The data from experiment II showed that DPOAE activity well reflects the increasing and notch-like hearing loss functions up to about 40 dB HL. The effect of age on the DPOAE level was clearly noted only for the tinnitus patients with clinically normal-hearing thresholds and was ambiguous for the tinnitus patients with hearing loss.

Adolescent↗
PubMed2006

A novel missense mutation in ACTG1 causes dominant deafness in a Norwegian DFNA20/26 family, but ACTG1 mutations are not frequent among families with hereditary hearing impairment.

The gamma-actin gene (ACTG1) encodes a major cytoskeletal protein of the sensory hair cells of the cochlea. Recently, mutations in ACTG1 were found to cause autosomal dominant, progressive, sensorineural hearing impairment linked to the DFNA20/26 locus on chromosome 17q25.3 in four American families and in one Dutch family. We report here the linkage of autosomal dominant, progressive, sensorineural hearing impairment in a large Norwegian family to the DFNA20/26 locus. Sequencing of ACTG1 identified a novel missense mutation (c.1109T>C; p.V370A) segregating with the hearing loss. Functional analysis in yeast showed that the p.V370A mutation restricts cell growth at elevated temperature or under hyperosmolar stress. Molecular modelling suggested that the p.V370A mutation modestly alters a site for protein-protein interaction in gamma-actin and thereby modestly alters gamma-actin-based cytoskeletal structures. Nineteen Norwegian and Danish families with autosomal, dominant hearing impairment were analyzed for mutations in ACTG1 by sequencing, but no disease-associated mutations were identified. Finally, a long-term follow-up of the hearing loss progression associated with the p.V370A mutation in ACTG1 is provided. The present study expands our understanding of the genotype-phenotype relationship of this deafness gene and provides a sensitive and simple functional assay for missense mutations in this gene, which may assist future molecular diagnosis of autosomal-dominant hearing impairment. Finally, the present results do not indicate that mutations in ACTG1 are a frequent cause of autosomal-dominant postlingual sensorineural hearing impairment in Norway nor Denmark.

Actins↗
PubMed1992

Interaction of click intensity and cochlear hearing loss on auditory brain stem response wave V latency.

Auditory brain stem responses (ABRs) to 95, 80, 60, 40, and 30 dB nHL clicks were retrospectively studied from 103 patients (194 ears) with various degrees of cochlear impairment. Hearing loss and sample size were balanced across gender. Results indicate that the slope of the wave V latency versus 4000 Hz hearing loss function doubles as click intensity is decreased from 80 (0.01 msec/dB HL) to 60 nHL (0.02 msec/dB HL). Overall results indicate a slope increase of 0.0004 msec for each decibel decrease in click intensity from 95 to 30 dB nHL. Intersubject variability increased with increased hearing loss and/or decreased stimulus intensity. The effects of hearing loss on wave V latency are minimal, and intersubject variability is less if high-intensity clicks (greater than or equal to 95 dB nHL) are used. No differences in the effects of hearing loss on wave V latency were seen between males and females. Latency corrections for cochlear hearing loss should, therefore, consider stimulus intensity.

Acoustic Stimulation↗