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1.
J Hum Nutr Diet ; 31(5): 683-688, 2018 10.
Article in English | MEDLINE | ID: mdl-29578256

ABSTRACT

BACKGROUND: Nutritional screening tools recommended for the general hospitalised population do not always adequately detect malnutrition risk in patients with kidney disease. The present study assessed the validity and reliability of the Nutrition Impact Symptoms (NIS) score as a nutrition screening tool for hospitalised inpatients prefer in nephrology wards. METHODS: Nutritional status was classified using Subjective Global Assessment (SGA). NIS scores were calculated from the total score of responses to questions assessing symptoms impacting upon nutritional status from the patient-generated SGA. Concurrent validity of NIS score was assessed using a receiver operating characteristic curve to predict malnutrition risk against SGA. Predictive validity was examined against length of hospital stay (LOS) and 30-day re-admission using Poisson and logistic regression, respectively. Inter-rater reliability of NIS scoring between assessors was determined using intraclass correlation. RESULTS: In 143 patients [90 males; mean (SD) age 57.8 (15.8) years], malnutrition prevalence was 38% (54/143) using SGA (rating B/C). Predicting malnutrition risk with an NIS score of ≥3 had a sensitivity of 0.89 and a specificity of 0.65 (area under the curve = 0.81 [95% confidence interval (CI) = 0.74-0.88]). For each 1-point increase in NIS score, the model predicted a 1.9% rise in the risk of an increased LOS (P = 0.002). Thirty-day re-admission was not associated with NIS score. Inter-rater reliability was moderate (mean difference = 0.53; intraclass correlation coefficient = 0.74; 95% CI = 0.57-0.85). CONCLUSIONS: Nutrition impact symptoms score is a valid stand-alone nutrition screening tool for identifying malnutrition risk in nephrology inpatients and is associated with LOS.


Subject(s)
Hospital Units/statistics & numerical data , Kidney Diseases/complications , Malnutrition/diagnosis , Nutrition Assessment , Patient Admission/statistics & numerical data , Adult , Aged , Female , Humans , Inpatients/statistics & numerical data , Length of Stay , Logistic Models , Male , Malnutrition/epidemiology , Malnutrition/etiology , Middle Aged , Nephrology/statistics & numerical data , Nutritional Status , Prevalence , Reproducibility of Results , Risk Assessment/methods , Risk Assessment/statistics & numerical data , Sensitivity and Specificity
3.
Audiol Neurotol Extra ; 6(2): 20-39, 2016.
Article in English | MEDLINE | ID: mdl-27990155

ABSTRACT

This study examined potential prevention of music-induced temporary threshold shift (TTS) in normal-hearing participants. A dietary supplement composed of ß-carotene, vitamins C and E, and magnesium was assessed using a randomized, placebo-controlled, double-blind study design. Dosing began 3 days prior to the music exposure with the final dose consumed approximately 30-min pre-exposure. There were no group differences in post-exposure TTS or music-induced decreases in distortion product otoacoustic emission (DPOAE) amplitude. Transient tinnitus was more likely to be reported by the treatment group, but there were no group differences in perceived loudness or bothersomeness. All subjects were monitored until auditory function returned to pre-exposure levels. Taken together, this supplement had no effect on noise-induced changes in hearing. Recommendations for future clinical trials are discussed.

4.
Noise Health ; 13(55): 432-43, 2011.
Article in English | MEDLINE | ID: mdl-22122960

ABSTRACT

Noise-induced hearing loss (NIHL) is a significant clinical, social, and economic issue. The development of novel therapeutic agents to reduce NIHL will potentially benefit multiple very large noise-exposed populations. Oxidative stress has been identified as a significant contributor to noise-induced sensory cell death and NIHL, and several antioxidant strategies have now been suggested for potential translation to human subjects. One such strategy is a combination of beta-carotene, vitamins C and E, and magnesium, which has shown promise for protection against NIHL in rodent models, and is being evaluated in a series of international human clinical trials using temporary (military gunfire, audio player use) and permanent (stamping factory, military airbase) threshold shift models (NCT00808470). The noise exposures used in the recently completed Swedish military gunfire study described in this report did not, on average, result in measurable changes in auditory function using conventional pure-tone thresholds and distortion product otoacoustic emission (DPOAE) amplitudes as metrics. However, analysis of the plasma samples confirmed significant elevations in the bloodstream 2 hours after oral consumption of active clinical supplies, indicating the dose is realistic. The plasma outcomes are encouraging, but clinical acceptance of any novel therapeutic critically depends on demonstration that the agent reduces noise-induced threshold shift in randomized, placebo-controlled, prospective human clinical trials. Although this noise insult did not induce hearing loss, the trial design and study protocol can be applied to other populations exposed to different noise insults.


Subject(s)
Hearing Loss, Noise-Induced/prevention & control , Micronutrients/administration & dosage , Military Personnel , Oxidative Stress/drug effects , Adult , Ascorbic Acid/administration & dosage , Ascorbic Acid/blood , Ascorbic Acid/physiology , Audiometry, Pure-Tone , Cross-Over Studies , Female , Hearing Loss, Noise-Induced/blood , Hearing Loss, Noise-Induced/physiopathology , Humans , Magnesium/administration & dosage , Magnesium/blood , Magnesium/physiology , Male , Micronutrients/blood , Micronutrients/physiology , Otoacoustic Emissions, Spontaneous/drug effects , Otoacoustic Emissions, Spontaneous/physiology , Oxidative Stress/physiology , Sweden , Vitamin E/administration & dosage , Vitamin E/blood , Vitamin E/physiology , Young Adult , beta Carotene/administration & dosage , beta Carotene/blood , beta Carotene/physiology
5.
Int J Audiol ; 50 Suppl 1: S21-31, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21288064

ABSTRACT

We report pure-tone hearing threshold findings in 56 college students. All subjects reported normal hearing during telephone interviews, yet not all subjects had normal sensitivity as defined by well-accepted criteria. At one or more test frequencies (0.25-8 kHz), 7% of ears had thresholds ≥25 dB HL and 12% had thresholds ≥20 dB HL. The proportion of ears with abnormal findings decreased when three-frequency pure-tone-averages were used. Low-frequency PTA hearing loss was detected in 2.7% of ears and high-frequency PTA hearing loss was detected in 7.1% of ears; however, there was little evidence for 'notched' audiograms. There was a statistically reliable relationship in which personal music player use was correlated with decreased hearing status in male subjects. Routine screening and education regarding hearing loss risk factors are critical as college students do not always self-identify early changes in hearing. Large-scale systematic investigations of college students' hearing status appear to be warranted; the current sample size was not adequate to precisely measure potential contributions of different sound sources to the elevated thresholds measured in some subjects.


Subject(s)
Hearing Loss/epidemiology , Students/statistics & numerical data , Universities/statistics & numerical data , Acoustic Stimulation , Adolescent , Adult , Analysis of Variance , Audiometry, Pure-Tone , Auditory Threshold , Chi-Square Distribution , Female , Hearing Loss/diagnosis , Hearing Loss/physiopathology , Humans , MP3-Player , Male , Music , Prevalence , Risk Assessment , Risk Factors , Self Report , Sex Factors , Young Adult
6.
Laryngoscope ; 112(11): 1997-2001, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12439169

ABSTRACT

OBJECTIVES: To summarize the findings relevant to otolaryngology from the annual meeting of the Blood-Brain Barrier Disruption Consortium in Gleneden Beach, Oregon, March 10, 2001. STUDY DESIGN: Summaries are provided by the speakers, as well as related data from the published literature. Findings in otology and oncology regarding ototoxicity that were discussed at the meeting are included. RESULTS: Data considered included physiological research, animal studies, and clinical trials that relate to platinum-based chemotherapy and prevention of toxicity. CONCLUSIONS: The dose-limiting side effects of platinum-based chemotherapy are preventable, but questions about the effect of the protective agents on oncological efficacy remain. Strategies for prevention of chemotherapy-induced toxicity include temporal or anatomical separation of cisplatin or carboplatin from sodium thiosulfate, D-methionine, or N-acetyl-cysteine. Clinical application of these methods has begun. The mechanisms presumably involve free radicals or drug conjugation, or both. Understanding the role of free radicals in medicine is likely to become important in the future.


Subject(s)
Antineoplastic Agents/adverse effects , Antioxidants/pharmacology , Carboplatin/adverse effects , Cisplatin/adverse effects , Head and Neck Neoplasms/drug therapy , Hearing Loss/chemically induced , Hearing Loss/prevention & control , Platinum Compounds/adverse effects , Animals , Blood-Brain Barrier , Humans , Methionine/pharmacology , Thiosulfates/pharmacology
7.
Am J Med Genet ; 108(4): 295-303, 2002 Apr 01.
Article in English | MEDLINE | ID: mdl-11920834

ABSTRACT

Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous group of polyneuropathies characterized by degeneration of peripheral nerves, resulting in distal muscle atrophy, sensory loss, and deformities of hands and feet. We have studied 34 individuals in a large 84-member four-generation central Illinois family with autosomal dominant Charcot-Marie-Tooth and deafness. Nerve conduction velocities are consistent with type 1 CMT. Audiological evaluation revealed both auditory neuropathy and cochlear involvement in affected individuals. There is increasing clinical severity and younger age of onset of CMT and deafness with each progressive generation, suggestive of anticipation (P < 0.05). The proband, a female diagnosed at birth with hypotonia, bilateral vocal cord palsy, swallowing incoordination, and hearing impairment, died at age 18 months. Another individual died at the age of 3 months from hypotonia later attributed to CMT. Genetic analysis indicated that affected individuals in this family do not have the common 1.4 Mb duplication associated with type 1A CMT; however, all affected individuals have a unique G to C transversion at position 248 in coding exon 3 of the peripheral myelin PMP22 gene located on chromosome 17p11.2-p12. This mutation is predicted to cause an Ala67Pro substitution in the second transmembrane domain of PMP22, consistent with the molecular cause of the CMT phenotype. However, it does not explain the cochlear component of the deafness, the clinical observation of anticipation, and other features in this family.


Subject(s)
Charcot-Marie-Tooth Disease/pathology , Deafness/pathology , Adolescent , Adult , Charcot-Marie-Tooth Disease/genetics , Child , Child, Preschool , DNA/chemistry , DNA/genetics , DNA Mutational Analysis , Deafness/genetics , Family Health , Fatal Outcome , Female , Hearing Tests , Humans , Infant , Male , Middle Aged , Mutation , Myelin Proteins/genetics , Pedigree , Sural Nerve/pathology , Sural Nerve/ultrastructure , Trinucleotide Repeats/genetics
8.
Audiology ; 40(5): 253-64, 2001.
Article in English | MEDLINE | ID: mdl-11688544

ABSTRACT

The present study has evaluated the use of distortion product otoacoustic emission (DPOAE) responses in the detection of cisplatin-induced ototoxicity in a Sprague Dawley rat animal model. The cisplatin was administered as a 16 mg/kg, dose introduced by a slow 30-min intraperitoneal infusion. Data from three DP-gram protocols, DPOAE input-output responses at 8 kHz, and auditory brainstem responses (ABRs) at 8, 12 and 16 kHz were collected before and 72 h after treatment. The post-treatment ABRs at 16 kHz showed the greatest mean threshold shift of 33.6 dB. The post-treatment DP-gram data showed significant reduction of the signal to noise ratios in the majority of the frequencies tested, across all tested protocols. The data suggest that the most sensitive DPOAE procedure for the early detection of the cisplatin-induced ototoxic damage is the DPOAE I/O protocol. Morphological analyses indicated that the inner hair cells remained intact, while several types of alterations were observed in the arrangement of the stereocilia in the outer hair cells.


Subject(s)
Antineoplastic Agents/adverse effects , Cisplatin/adverse effects , Cochlea/drug effects , Otoacoustic Emissions, Spontaneous/drug effects , Animals , Antineoplastic Agents/administration & dosage , Auditory Perception/drug effects , Auditory Threshold/drug effects , Cisplatin/administration & dosage , Cochlea/ultrastructure , Evoked Potentials, Auditory, Brain Stem/physiology , Hair Cells, Auditory, Inner/drug effects , Hair Cells, Auditory, Inner/ultrastructure , Hair Cells, Auditory, Outer/drug effects , Hair Cells, Auditory, Outer/ultrastructure , Injections, Intraperitoneal , Male , Random Allocation , Rats , Rats, Sprague-Dawley
9.
J Am Acad Audiol ; 11(7): 361-7, 2000.
Article in English | MEDLINE | ID: mdl-10976497

ABSTRACT

This case report describes the audiologic and medical diagnostic evaluations, results, and treatment options in a patient with a classic presentation of immune-mediated sensorineural hearing loss, commonly called autoimmune inner ear disease (AIED). It reviews findings of the basic battery, immittance audiometry, transient otoacoustic emissions, and auditory brainstem response measures and medical findings over more than 2 years. AIED generally causes asymmetric bilateral sensorineural hearing loss with atypical configuration. Although hearing loss is generally fluctuant, the overall pattern is usually rapid progression, particularly in the absence of early medical intervention. Word recognition is usually disproportionately poor. In our case, otoacoustic emissions and auditory brainstem responses suggest both cochlear and retrocochlear involvement and may initially appear to be inconsistent with pure-tone thresholds. Audiologists must be familiar with AIED because early identification is critical. Additionally, an immunologic basis may be a factor in other disorders, including many cases of Meniere's disease.


Subject(s)
Autoimmune Diseases/complications , Ear Diseases/complications , Hearing Loss, Sensorineural/etiology , Adult , Anti-Inflammatory Agents/therapeutic use , Audiometry, Pure-Tone/methods , Auditory Threshold/physiology , Evoked Potentials, Auditory/physiology , Evoked Potentials, Auditory, Brain Stem , Hearing Loss, Sensorineural/diagnosis , Hearing Loss, Sensorineural/drug therapy , Hearing Loss, Sudden/etiology , Humans , Male , Methylprednisolone/therapeutic use , Otoacoustic Emissions, Spontaneous/physiology , Severity of Illness Index
10.
Anticancer Res ; 20(6B): 4205-9, 2000.
Article in English | MEDLINE | ID: mdl-11205249

ABSTRACT

BACKGROUND: To evaluate the use of D-methionine(D-met) as a cytoprotectant in the context of clinically relevant doses of cisplatin. MATERIALS AND METHODS: Forty five Fischer rats were injected intraperitoneally with 10(6) NuTu-19 cells and treated as follows: group 1 was the control group and received no treatment, group 2 received cisplatin 4 mg/kg and group 3 received cisplatin 4 mg/kg plus D-met. There were two groups that received high dose cisplatin. Group 4 received cisplatin 8 mg/kg and group 5 received cisplatin 8 mg/kg plus D-met. Treatment was initiated four weeks after injection of the NuTu-19 cells, and consisted of four weekly intraperitoneal injections. Serum BUN and creatinine levels in the high dose groups evaluated nephrotoxicity and clinical outcome was measured by mean survival using Kaplan Meier analysis. RESULTS: There were no significant elevations in serum BUN or creatinine levels in any of the rats treated with high dose cisplatin. In the animals given cisplatin 8 mg/kg plus D-met, death from toxicity was prevented and all animals completed four treatments. In contrast, only two animals in group 4 (cisplatin 8 mg/kg alone) completed 4 treatments. There was a significant improvement in survival for the animals given D-met. (p = .0001) In all treated groups except for group 4, there was an improvement in survival compared to the control group. When comparing groups 2 and 3 (4 mg/kg +/- D-met), there was a subjective decrease in tumor response for group 3 but mean survival was not statistically different. (91 vs. 81 days; p = 0.07) A comparison of groups 2 and 5 revealed no survival benefit using high dose cisplatin with D-met. (91 vs. 79 days; p = 0.10). CONCLUSIONS: Our results indicate that D-methionine provides cytoprotection against cisplatin toxicity without significant compromise of antitumor activity. All though D-methionine allowed for significant dose intensification of cisplatin above standard doses, there was no survival advantage noted in this group of animals. The indications for its use in the treatment of ovarian cancer remain to be determined.


Subject(s)
Antineoplastic Agents/administration & dosage , Cisplatin/administration & dosage , Disease Models, Animal , Methionine/pharmacology , Animals , Antineoplastic Agents/adverse effects , Blood Urea Nitrogen , Cisplatin/adverse effects , Creatinine/blood , Drug Evaluation, Preclinical , Female , Ovarian Neoplasms/drug therapy , Rats , Rats, Inbred F344
11.
Hear Res ; 138(1-2): 13-28, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10575111

ABSTRACT

D-Methionine (D-met) protects against cisplatin (CDDP)-induced hearing loss and outer hair cell loss (Campbell et al., 1996). However, D-met's protective effects on the stria vascularis has not been previously investigated. The purpose of this study was to examine, using semi-quantitative analysis, whether D-met also protects the stria vascularis. We removed a basal turn section of the stria vascularis from five groups of five male Wistar rats each: (1) a CDDP-treated control group receiving a 30 min i.p. infusion of 16 mg/kg CDDP, (2) a saline-injected control group receiving an equivalent volume of saline, and (3) three groups injected with either 75, 150, or 300 mg/kg D-methionine (D-met) i.p. 30 min prior to receiving the 16 mg/kg CDDP dosing. Using transmission electron microscopy and light microscopy, we analyzed strial volume (i.e. edema), marginal cell damage classification (bulging and/or compression), and relative optical density (ROD) ratios (i.e. depletion of marginal cell cytoplasmic organelles). All three levels of D-met provided complete protection against marginal cell bulging and/or compression but only partial protection against strial edema. At 300 mg/kg, D-met significantly reduced ROD ratio degradation in the spiral prominence and middle stria vascularis regions. In Reissner's membrane region, values from the D-met pretreated group were not significantly different from either the treated or untreated control groups suggesting only partial protection for that area. Protection of marginal cell cytoplasmic organelles was also noted. In summary, D-met partially or fully protects the stria vascularis from several types of CDDP-induced damage.


Subject(s)
Cisplatin/antagonists & inhibitors , Cisplatin/poisoning , Methionine/pharmacology , Stria Vascularis/drug effects , Animals , Cochlear Diseases/chemically induced , Cochlear Diseases/prevention & control , Edema/chemically induced , Edema/prevention & control , Evoked Potentials, Auditory, Brain Stem , Hair Cells, Auditory, Outer/pathology , Male , Microscopy, Electron , Optics and Photonics , Rats , Rats, Wistar , Stria Vascularis/pathology
12.
Hear Res ; 124(1-2): 44-59, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9822901

ABSTRACT

Cisplatin (CDDP) is a very effective chemotherapeutic agent but is highly ototoxic. Most studies have focused on the effects of CDDP on the outer hair cells. The purpose of this study was to examine changes in the stria vascularis in cisplatin treated male Wistar rats and to provide semiquantitative analysis of the results. We removed a section of the stria vascularis from the basal turn of five control and five CDDP (16 mg/kg) treated rats. Using transmission electron microscopy (TEM) we analyzed: (1) changes to the strial tissue as a whole; and (2) intracellular changes in the marginal cells. We also subjected the samples to semiquantitative analysis using the MCID, focusing on three aspects of strial profile abnormalities; the number of abnormal marginal cells in CDDP treated tissue, intracellular strial edema and densitometry. Controls appeared normal, but many pathologic changes were apparent in the experimental group. Results from the semiquantitative analysis indicate cisplatin has a deleterious effect on the stria vascularis including strial edema; bulging, rupture and/or compression of the marginal cells and depletion of the cytoplasmic organelles.


Subject(s)
Antineoplastic Agents/poisoning , Cisplatin/poisoning , Stria Vascularis/drug effects , Animals , Cochlear Diseases/chemically induced , Cochlear Diseases/pathology , Cytoplasm/drug effects , Cytoplasm/ultrastructure , Edema/chemically induced , Edema/pathology , Male , Microscopy, Electron , Organelles/drug effects , Organelles/ultrastructure , Rats , Rats, Wistar , Reference Values , Stria Vascularis/pathology
13.
Can J Exp Psychol ; 51(2): 85-98, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9340077

ABSTRACT

Three experiments examined performance of four-choice reaction tasks using stimulus and response arrays oriented along parallel or orthogonal axes. All used a procedure in which pairs of locations were precued in advance of the target stimulus. Responses were slower for orthogonal than for parallel stimulus-response sets, but the pattern of relative precuing benefits was similar. Complete transfer occurred when the stimulus array was changed from an orthogonal to a parallel orientation with respect to the response array after three sessions of practice. Transfer was also evident when the orientation of the response array was changed from orthogonal to parallel with respect to the stimulus array, as long as the assignment of stimulus locations to fingers was not altered. The results suggest that coding in the four-choice task is by relative location regardless of whether the stimulus and response sets are oriented orthogonally, and that an additional transformation operation to align the frames of reference is performed for orthogonal orientations.


Subject(s)
Form Perception , Reaction Time , Space Perception , Cues , Humans , Practice, Psychological , Psychomotor Performance , Transfer, Psychology
14.
Hear Res ; 102(1-2): 90-8, 1996 Dec 01.
Article in English | MEDLINE | ID: mdl-8951454

ABSTRACT

Cisplatin (CDDP) is a widely used chemotherapeutic agent. Unfortunately, CDDP is highly ototoxic. We tested D-methionine (D-Met), a sulfur containing compound, as an otoprotectant in male Wistar rats. Complete data sets were obtained for five groups of five animals each, including a treated control group (16 mg/kg CDDP), an untreated control group (administered an equivalent volume of saline) and three groups that received either 75, 150, or 300 mg/kg D-Met 30 min prior to the 16 mg/kg CDDP dosing. Auditory brainstem response (ABR) thresholds were obtained in response to clicks, and 1 kHz, 4 kHz, 8 kHz, and 14 kHz toneburst stimuli, before and 3 days after drug administration. Scanning electron microscopy (SEM) was used to examine the outer hair cells of the apical, middle and basal turns of the cochlea. Animal weight was measured on the first and final day. D-Met provided excellent otoprotection even at the lowest level with complete otoprotection obtained for the 300 mg/kg dosing as measured by both ABR and SEM. D-Met also markedly reduced weight loss and mortality. All animals receiving D-Met (15/15) survived to the end of the study period as opposed to only 5/10 of the treated controls.


Subject(s)
Antineoplastic Agents/toxicity , Cisplatin/toxicity , Evoked Potentials, Auditory, Brain Stem/drug effects , Hair Cells, Auditory, Outer/drug effects , Methionine/pharmacology , Poisoning/prevention & control , Acoustic Stimulation , Administration, Oral , Analysis of Variance , Animals , Antineoplastic Agents/administration & dosage , Auditory Threshold/drug effects , Cisplatin/administration & dosage , Dose-Response Relationship, Drug , Evoked Potentials, Auditory, Brain Stem/physiology , Hair Cells, Auditory, Outer/cytology , Hair Cells, Auditory, Outer/ultrastructure , Male , Methionine/administration & dosage , Methionine/therapeutic use , Microscopy, Electron, Scanning , Poisoning/mortality , Rats , Rats, Wistar , Stereoisomerism , Tissue Fixation , Weight Loss/drug effects
15.
Proc AMIA Annu Fall Symp ; : 398-402, 1996.
Article in English | MEDLINE | ID: mdl-8947696

ABSTRACT

OncoLink is a cancer information resource on the World-Wide-Web (WWW) that provides a wide variety of information for cancer patients and healthcare providers. Since its introduction in March, 1994 it has enjoyed success as demonstrated by an over 31-fold increase in usage as of February, 1996. Current utilization exceeds 1.1 million accesses per month. The content of OncoLink has also expanded greatly, with new items being added daily. In addition, OncoLink has been the recipient of numerous awards from a variety of agencies and organizations. During this period of rapid growth, the complexity of managing and maintaining OncoLink has likewise increased. This work may be divided into three categories: content editing, technical (or production) editing, and web site maintenance. Consequently, we have developed numerous administrative procedures to handle this workload. After implementing these new administrative strategies, we were able to greatly reduce the need for face-to-face meetings of our Editorial and Production Staffs. This paper describes our experience with developing efficient strategies for managing the daily operation of OncoLink during a period of rapid growth.


Subject(s)
Computer Communication Networks , Information Services/organization & administration , Information Systems/organization & administration , Medical Oncology , Hypermedia , Information Services/statistics & numerical data , Information Systems/statistics & numerical data , Neoplasms
16.
Am J Otol ; 16(2): 209-15, 1995 Mar.
Article in English | MEDLINE | ID: mdl-8572121

ABSTRACT

The purpose of this study was to evaluate the usefulness of electrocochleography (ECoG) recorded with a tympanic membrane electrode as an adjunctive measure to auditory brainstem response (ABR) in frequency-specific threshold estimation. In a group of 10 normally hearing and 10 sensorineural hearing-impaired subjects, ABR and ECoG were simultaneously recorded in response to tone-burst stimuli centered at 500, 1000, 2000, and 4000 Hz. At each frequency, stimulus intensity was reduced in 12-dB decrements from an initial level of 110 dB SPL until no replicable response could be discerned. Electrocochleography and ABR thresholds were determined at each frequency, and correlation to behavioral audiometric threshold was determined. Input/output functions were also computed. At 2000 and 4000 Hz, both ABR and ECoG thresholds correlated with behavioral audiometric threshold. At 1000 Hz, ABR threshold correlated with behavioral audiometric threshold; ECoG did not. At 500 Hz, neither ABR nor ECoG threshold correlated with behavioral audiometric threshold. Input/output functions were steeper for ECoG than for ABR at all frequencies tested in the normally hearing group.


Subject(s)
Auditory Threshold , Cochlear Microphonic Potentials , Evoked Potentials, Auditory, Brain Stem , Hearing Loss, Sensorineural/physiopathology , Tympanic Membrane/physiology , Case-Control Studies , Humans
17.
Ann Otol Rhinol Laryngol ; 103(6): 474-82, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8203814

ABSTRACT

The present study investigated the effect of altering body position on electrocochleographic findings in the presence and absence of perilymphatic fistula. Three groups of guinea pigs included 1) 10 normal control animals, 2) 10 experimental animals with induced perilymphatic fistula, and 3) 10 control animals with induced perilymphatic fistula. In the first two groups, animals were successively tested in three positions: first with the ventral aspect down, again after 30 minutes with the test ear up, and again after 15 minutes with the test ear down. In the third group, body position was not altered. Stimuli consisted of clicks and 6,000-Hz tone bursts. Data analysis included summating potential (SP) amplitude, action potential (AP) amplitude, and AP threshold for the click stimuli. Only the normal control group showed a significant effect of body position for the SP/AP amplitude ratio. Average change was greater in the experimental group, but high variability precluded statistical significance. Both fistulized animal groups exhibited high variability in the SP/AP amplitude ratio, with and without postural change. The SP/AP amplitude ratio and SP amplitude were significantly larger for the two fistulized groups than for the normal control group. No significant change in threshold occurred across positions for any group.


Subject(s)
Audiometry, Evoked Response , Fistula/physiopathology , Labyrinth Diseases/physiopathology , Perilymph , Posture , Acoustic Stimulation , Action Potentials , Animals , Guinea Pigs
18.
J Am Acad Audiol ; 4(6): 376-83, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8298173

ABSTRACT

Perilymphatic fistula can be difficult to diagnose differentially prior to exploratory surgery. In this study, we investigated a new test technique in four case studies of subjects with perilymphatic fistula and compared our findings to results obtained in 20 normally hearing subjects with no history of vertigo and 10 subjects with Meniere's disease. Recordings from an eardrum electrode were obtained with the subject in an upright position, after the subject had been lying in a horizontal position for 30 minutes with the test ear up and after 15 minutes with the test ear down. Stimuli consisted of high level clicks and tonebursts. Neither the summating potential (SP) and action potential (AP) amplitudes nor the SP/AP amplitude ratio were significantly affected by postural change in either the normal or Meniere's disease group. The perilymphatic fistula subjects, in general, showed greater changes in the SP/AP, particularly for the 6000 Hz tonebursts, than did the other two groups. More data will be needed to determine if these findings are consistent in a large population of perilymphatic fistula patients.


Subject(s)
Audiometry, Evoked Response , Cochlear Aqueduct/physiopathology , Fistula/physiopathology , Meniere Disease/physiopathology , Posture , Adolescent , Adult , Audiometry , Auditory Threshold , Diagnosis, Differential , Female , Fistula/complications , Fistula/diagnosis , Hearing Loss, Sensorineural/diagnosis , Hearing Loss, Sensorineural/etiology , Hearing Loss, Sensorineural/physiopathology , Humans , Male , Meniere Disease/diagnosis , Middle Aged
19.
Otolaryngol Clin North Am ; 26(5): 903-14, 1993 Oct.
Article in English | MEDLINE | ID: mdl-8233496

ABSTRACT

In summary, the clinician has a variety of protocols available for monitoring ototoxicity. Depending on the patient's risk factors and ability to be tested, the protocol for a given patient may vary. A flow chart reflecting some of the possible decisions and options is presented in Figure 1. Certainly, as we learn more about ototoxicity and the advantages and disadvantages of the various test methods, further refinements of patient and test selection will ensue. Ototoxicity is a rapidly expanding and interesting area. Hopefully, the care of patients receiving ototoxic medications will continue to improve and will ultimately prevent, or at least ameliorate, ototoxic hearing loss.


Subject(s)
Audiology , Hearing Disorders/chemically induced , Hearing Disorders/diagnosis , Audiology/methods , Auditory Threshold/physiology , Child , Cochlea/drug effects , Hearing Tests , Humans , Infant , Otoacoustic Emissions, Spontaneous/physiology
20.
Arch Otolaryngol Head Neck Surg ; 119(7): 767-71, 1993 Jul.
Article in English | MEDLINE | ID: mdl-8318207

ABSTRACT

This study compares noninvasive vs invasive electrodes for electrocochleography in chinchillas. Summating potential (SP) amplitude, action potential (AP) amplitude, and AP threshold, recorded with five types of noninvasive electrodes, were compared with simultaneous bulla recordings. Noninvasive electrodes included a needle electrode over the bulla, gold Tiptrode (Etymotic Research, Elk Grove Village, Ill), Enhancer I (Nicolet Instrument Corp, Madison, Wis), Coats (Lifetech Inc, Austin, Tex) electrode, and a locally constructed tympanic membrane (TM) electrode. Stimuli included 100-microsecond clicks and 6000-Hz tone bursts (with a 1 millisecond rise/fall time and a 5 millisecond plateau). Stimuli were initially presented at 110 dB peak equivalent sound pressure level for the clicks and 100 dB peak equivalent sound pressure level for the tone bursts. Intensity was then decreased in 10-dB decrements until no replicable AP activity was observed. The TM damping for the TM electrode was measured with 0.5, 1, 2, 4, and 6 kHz and click stimuli. The AP was clear and replicable for all electrodes used in the study, although the amplitude was substantially less for the noninvasive electrodes as opposed to the invasive electrode. The invasive electrode provided the largest amplitude SP recording, but SP could generally be clearly recorded with the needle electrode, Enhancer I, and the Coats electrode. The TM electrode and gold Tiptrode provided SP recordings less consistently. The AP threshold could be recorded with all the electrodes in the study and was generally within 10 dB of threshold recorded invasively. Electrode variables, including ease of electrode placement and potential injury, were examined. The Tiptrode and Enhancer I electrodes posed relatively few problems during placement.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Audiometry, Evoked Response/instrumentation , Electrodes , Action Potentials , Animals , Chinchilla , Cochlea/physiology
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