scholarly journals Early Indices of Reduced Cochlear Function in Young Adults with Type-1 Diabetes Revealed by DPOAE Fine Structure

2019 ◽  
Vol 30 (06) ◽  
pp. 459-471 ◽  
Author(s):  
Christopher Spankovich ◽  
Glenis R. Long ◽  
Linda J. Hood
Keyword(s):  
Type 1 Diabetes ◽  
Young Adults ◽  
Fine Structure ◽  
Otoacoustic Emissions ◽  
Normal Hearing ◽  
Cochlear Function ◽  
Hearing Sensitivity ◽  
Distortion Product ◽  
Type 1 Dm

AbstractThe relationship between type-1 diabetes mellitus (DM) and cochlear dysfunction remains inconclusive.The purpose of this study was to examine otoacoustic emissions (OAEs) in normal-hearing young adults with type-1 DM as compared with matched controls and identify potential covariates influencing OAE findings.Cross-sectional study.N = 40 young adults aged 18–28 years including individuals with type-1 DM (n = 20) and age–gender matched controls (n = 20) with normal hearing sensitivity.Measures of pure-tone threshold sensitivity and OAEs, including distortion product otoacoustic emissions (DPOAEs), transient evoked OAEs, and DPOAE fine structure, were compared between groups. Covariates such as noise exposure and DM-related factors (e.g., duration of disease, glycated hemoglobin levels) were considered. Statistical analysis included analysis of variance and linear regression.Measures of hearing sensitivity and auditory function in both groups were comparable for all assays, except DPOAE fine structure. A reduced number of fine structure peaks and component amplitudes were found in the type-1 diabetes DM group with the primary difference in the reflection component.The results indicate that reduced cochlear function in young adults with type-1 DM can be revealed using DPOAE fine structure, suggesting potential clinical applications of DPOAE fine structure in early identification of cochlear pathology. Potential factors underlying these findings are discussed.

scholarly journals Does Vincristine affect Cochlear function in children with acute lymphoblastic leukaemia?

2016 ◽  
Vol 27 (1) ◽  
pp. 3-7
Author(s):  
Suchetha Rao ◽  
Ranjith Kumar ◽  
Jayashree Bhat ◽  
Nutan Kamath
Keyword(s):  
High Frequency ◽  
Otoacoustic Emissions ◽  
Lymphoblastic Leukemia ◽  
Statistical Significance ◽  
Pure Tone Audiometry ◽  
Cochlear Function ◽  
Hearing Sensitivity ◽  
Distortion Product ◽  
High Frequency Audiometry

Context: Vincristine chemotherapy has dose dependent ototoxicity. Early detection of ototoxicity is better with otoacoustic emissions and high frequency audiometry than conventional pure tone audiometry. The study was done to see if vincristine treatment interferes with hearing sensitivity in children.Methods and Material: A prospective study was conducted on twenty-three children with acute lymphoblastic leukemia (ALL) on Multi Center Protocol (MCP 841).These were subjected to conventional audiometry, high frequency audiometry and distortion product otoacoustic emissions (DPOAEs) before starting chemotherapy. The follow up audiological evaluation after early intensive phase chemotherapy (approximately 6 months) was conducted in thirteen children, who received 12 doses of vincristine (1.4 mg/m2), cranial irradiation of 1800cGy (>3 years) as per protocol and antibiotics as per clinical demands.Results: Baseline audiological evaluation was normal. Follow-up evaluation DPOAEs showed a declining tendency, however changes did not reach statistical significance. Differences in median hearing thresholds prior and post treatment in higher frequency audiometry were also minimal which was not statistically significant. Conventional audiometric thresholds were not altered.Conclusions: The reduction in the signal noise ratio of DPOAE, and reduced hearing sensitivity in high frequencies in post chemotherapy in comparison with baseline measures cannot be ignored though it has failed to reach the level of statistical significance. children on vincristine should have a pre chemotherapy and follow up audiological evaluation with DPOAE The results of the present study needs to be strengthened by including larger sample and long term follow up.Bangladesh J Medicine Jan 2016; 27(1) : 3-7

Age is a determinant of acute hemodynamic responses to hyperglycemia and angiotensin II in humans with uncomplicated type 1 diabetes mellitus

2010 ◽  
Vol 299 (1) ◽  
pp. R206-R214 ◽  
Author(s):  
David Z. I. Cherney ◽  
Heather N. Reich ◽  
Judith A. Miller ◽  
Vesta Lai ◽  
Bernard Zinman ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Older Adults ◽  
Type 1 Diabetes ◽  
Young Adults ◽  
Vascular Dysfunction ◽  
Ang Ii ◽  
Hemodynamic Responses ◽  
Hemodynamic Function ◽  
Type 1 Dm

Hyperglycemia is associated with hemodynamic changes in type 1 diabetes (DM), acting in part through renin-angiotensin system activation. Since aging is associated with vascular dysfunction in DM, we hypothesized that acute hemodynamic responses to clamped hyperglycemia and infused ANG II would be exaggerated in older adults compared with a group of adolescent/young adults with type 1 DM. Renal hemodynamic function, blood pressure, and arterial stiffness were assessed in adolescent/young adults ( n = 34; mean age: 18 ± 3 yr) and older adults ( n = 32; mean age: 45 ± 9 yr). Studies were performed during clamped euglycemia (4–6 mmol/l) and hyperglycemia (9–11 mmol/l). Renal and systemic hemodynamic responses to ANG II were measured during clamped euglycemia in diabetic subjects. ANG II responses were also assessed in a cohort of non-DM subjects ( n = 97; mean age: 26; age range: 18–40 yr). Older DM adults exhibited higher baseline blood pressure, arterial stiffness, and renal vascular resistance, and lower glomerular filtration rate (GFR) and effective renal plasma flow, compared with adolescent/young DM adults ( P < 0.05). Clamped hyperglycemia was associated with exaggerated peripheral and renal hemodynamic responses uniquely in older DM adults; only GFR increased in adolescent/young DM adults. ANG II infusion also produced exaggerated vasoconstrictive responses in older DM adults vs. adolescent/young DM adults ( P < 0.05). The independent effect of age on hemodynamic responses to hyperglycemia and ANG II was confirmed using multivariate regression analysis in DM subjects ( P < 0.05), and results were still significant when participants were matched for DM duration. Age-related alterations in hemodynamic function and ANG II response were not observed in healthy non-DM control subjects. Acute hemodynamic responses to clamped hyperglycemia and ANG II were exaggerated in older subjects with type 1 DM, highlighting an important interaction between age and factors that contribute to the pathogenesis of acute vascular dysfunction in DM.

Cochlear Sources and Otoacoustic Emissions

2010 ◽  
Vol 21 (03) ◽  
pp. 176-186 ◽  
Author(s):  
Tiffany A. Johnson
Keyword(s):  
Fine Structure ◽  
Otoacoustic Emissions ◽  
Stimulus Frequency ◽  
Normal Hearing ◽  
Clinical Applications ◽  
Clinical Test ◽  
Similar Amount ◽  
Distortion Product ◽  
Stimulus Parameters ◽  
Coherent Reflection

Current understanding suggests that there are two different mechanisms by which otoacoustic emissions (OAEs) are generated in the cochlea. These mechanisms include a nonlinear-distortion mechanism and a coherent-reflection mechanism. Distortion product OAEs (DPOAEs) are believed to include contributions from both mechanisms, while stimulus frequency OAEs (SFOAES), at least at low and moderate levels, are believed to be generated primarily by the coherent-reflection mechanism. In the case of DPOAEs, the interaction of the two mechanisms produces a series of alternating peaks and valleys in the response level when recorded in small frequency increments. This pattern of peaks and valleys typically is referred to as fine structure. There has been much speculation that the interaction of the two mechanisms and the resulting fine structure limits the clinical test performance of DPOAEs. There are few data to address this speculation. Here, we review the literature that describes the cochlear source mechanisms and their potential relationship to clinical applications. We then present results for preliminary data collected in a group of 10 normal-hearing subjects where we explore the influence of common approaches to setting DPOAE stimulus parameters on the resulting fine structure. These preliminary results suggest that, at the moderate stimulus levels used in clinical applications, each of the different stimulus parameters results in a similar amount of fine structure and, therefore, fine structure cannot be eliminated through manipulation of stimulus parameters. We also review the results of some preliminary efforts to identify stimulus parameters that can be used to record SFOAEs (OAEs generated by the reflection mechanism). The potential clinical applications of SFOAEs have received little attention in the literature. By identifying stimulus parameters producing robust responses in normal-hearing ears, it may be possible to more fully evaluate clinical applications of SFOAEs.

scholarly journals Distortion Product Otoacoustic Emissions (DPOAEs) In Tinnitus Patients

2021 ◽  
Author(s):  
Hend F. Alshabory ◽  
Takwa A. Gabr ◽  
Mona A. Kotait
Keyword(s):  
Otoacoustic Emissions ◽  
Direct Consequence ◽  
Normal Hearing ◽  
Distortion Product Otoacoustic Emissions ◽  
Control Group ◽  
Study Group ◽  
Input Output ◽  
Sound Stimulation ◽  
Hearing Sensitivity ◽  
Distortion Product

Abstract Introduction Tinnitus is the perception of sound in the absence of external sound stimulation. There is a general agreement that it is a direct consequence of irreversible and permanent cochlear damage. Objectives The present work is designed to study the distortion product otoacoustic emissions (DPOAEs) in tinnitus patients with normal hearing in comparison with normal hearing control and to study any possible correlation between DPOAEs recording and patients' complaints. Methods The present study included 80 subjects divided into 2 groups: Control group: consisted of 30 normal-hearing adults not complaining of tinnitus and Study group: consisted of 50 normal-hearing adults complaining of tinnitus. The methodology includes full audiological history, otoscopic examination, basic audiological evaluation, DPOAEs including both DP-gram and DPOAEs input/output functions. Results Basic audiological evaluation showed within normal hearing sensitivity in both groups, however, with significant higher hearing thresholds in tinnitus patients at all frequency ranges. The Tinnitus Handicap Inventory Questionnaire showed mean scores of 35.2 ± 16.9 in the study group. The DP-gram showed higher amplitudes in the control group when compared with tinnitus patients. The DPOAEs input-output functions at different frequencies (1, 2, 4 and 6kHz) also showed higher amplitudes at all frequencies and different input levels. The slope of the I/O function tends to be steeper in tinnitus cases. Conclusion Patients with tinnitus might have neural dysfunction at either the level of the cochlea, as shown in reduced DPOAE levels, and changes in the normal DP-I/O function recorded in the present work.

scholarly journals Comparison of Otoacoustic Emissions in Asymptomatic Diabetes Mellitus and Normal Hearing Control Groups

2019 ◽  
Vol 42 (2) ◽  
pp. 12-20
Author(s):  
Suwimol Ruencharoen ◽  
Chanchai Jariengprasert ◽  
Montip Tiensuwan ◽  
Chardpraorn Ngarmukos
Keyword(s):  
Diabetes Mellitus ◽  
Hearing Impairment ◽  
Otoacoustic Emissions ◽  
Pure Tone ◽  
Normal Hearing ◽  
Control Group ◽  
Diabetic Patients ◽  
Control Groups ◽  
Cochlear Function ◽  
Distortion Product

Background: Diabetes mellitus (DM) is a chronic metabolic disorder. Previous studies reported the hearing impairment of diabetes patients as a progressive bilateral symmetrical sensorineural hearing loss (SNHL) of gradual onset which predominantly affected the higher frequencies, and found that diabetic patients had unsatisfactory hearing thresholds than nondiabetics in the same age group. For the use of evoked otoacoustic emissions (EOAEs) as a clinical test of hearing, EOAEs are sound which can be recorded in the outer ear canal and give objective information about preneural, mechanical elements of the cochlear function. Objective: To compare the otoacoustic emissions of asymptomatic DM patients with a normal hearing control group. Methods: All subjects received a routine audiologic evaluation which consisted of pure-tone air-bone conduction tests, tympanograms, and stapedius acoustic reflex tests. OAEs were measured in 30 asymptomatic diabetic patients with a mean age of 55.73 years and an age-matched 30 subjects normal hearing control group with a mean age of 50.87 years. Results: The pure-tone thresholds at 3, 4, 6, and 8 kHz; transient-evoked otoacoustic emissions (TEOAEs) amplitudes at 1, 1.5, 2, and 3 kHz; and the distortion product otoacoustic emissions (DPOAEs) amplitudes at 1, 1.5, 2, 3, 4, and 6 kHz were significantly different (P < .05) between the asymptomatic and control groups. Conclusions: This study suggested that diabetic patients had a significant hearing impairment. SNHL is gradually progressive and is a common condition in DM patients and their thresholds for hearing are higher at higher frequencies.

scholarly journals Estimation of outer hair cells function in chronic bilateral tinnitus patients with normal hearing using distortion product otoacoustic emissions

2021 ◽  
Author(s):  
Aras Karimiani ◽  
Nematollah Rouhbakhsh ◽  
Farzaneh Zamiri Abdollahi ◽  
Shohreh Jalaie
Keyword(s):  
Hair Cells ◽  
Otoacoustic Emissions ◽  
Normal Hearing ◽  
Outer Hair Cells ◽  
Distortion Product Otoacoustic Emissions ◽  
Control Group ◽  
Distortion Product Otoacoustic Emission ◽  
Frequency Range ◽  
Cochlear Function ◽  
Distortion Product

Background and Aim: It is not clear if the measurement of distortion product otoacoustic emissions (DPOAE) at frequencies above 8 kHz adds any value in determining the differences in the cochlear function between patients with and without tinnitus. This study aimed to compare DPOAE in the frequency range of 0.5−10 kHz in patients with normal hearing with and without tinnitus. Methods: This comparative cross-sectional study was conducted on 20 individuals with tinnitus and normal hearing as a study group (SG) and a control group (CG) of 20 normal-hearing individuals without tinnitus. The DPOAE was measured with F1/F2 = 1.22 and intensities of F1 = 65 dB SPL and F2 =55 dB SPL in the frequency range of 0.5−10 kHz, moreover in the frequency of tinnitus in SG and corresponding frequency in CG. Results: DPOAE level at 10 kHz did not differ significantly between SG and CG (p = 0.491). However, the mean of overall DPOAE level, DPOAE level at the frequency of tinnitus, and F2 values of 2.5, 5, and 6.298 kHz were significantly lower in SG than CG (p < 0.05). Conclusion: Measurement of DPOAE at 10 kHz did not seem to add any value in determining the differences in the cochlear function between patients with and without tinnitus. However, decreased DPOAE levels at 2.5, 5, and 6.298 kHz which were observed among patients who have tinnitus and normal hearing, indicates some outer hair cells damage that was not detectable by conventional audiometry. Keywords: Tinnitus; normal hearing; outer hair cell; distortion product otoacoustic emission

scholarly journals Determinants of the Audiometric Notch at 4000 and 6000 Hz in Young Adults

2020 ◽  
Vol 31 (06) ◽  
pp. 371-383
Author(s):  
Ishan Sunilkumar Bhatt
Keyword(s):  
Young Adults ◽  
Otoacoustic Emissions ◽  
Noise Exposure ◽  
Hearing Threshold ◽  
Calibration Error ◽  
Cochlear Function ◽  
Cross Sectional ◽  
Distortion Product ◽  
Hearing Thresholds ◽  
Children And Young Adults

Abstract Background Noise-induced hearing loss (NIHL) is often characterized by the presence of an audiometric notch at 3000-6000 Hz in a behavioral audiogram. The audiometric notch is widely used to investigate NIHL in children and young adults. However, the determinants of the audiometric notch in young adults largely remain unknown. Purpose The study aimed to investigate the determinants of the audiometric notch in young adults. Research Design A cross-sectional design was adopted for the study. Study Sample A sample of 124 adults (38 males and 86 females) aged 18-35 years with normal otoscopic and tympanometric findings was recruited. Data Collection and Analysis Hearing thresholds and real-ear sound pressure levels (RESPLs) were obtained with calibrated ER-3A (Etymotic Research, Elk Grove Village, IL) andTDH-50P receivers (Telephonics, Farmingdale, NY). Distortion-product otoacoustic emissions (DPOAEs) were used to evaluate the cochlear function. The external auditory canal (EAC) length was measured using the acoustical method. Noise exposure background (NEB) was estimated using the Noise Exposure Questionnaire. The notched audiograms were identified using: Phillips, Coles, and Niskar criteria. Results The prevalence of notched audiograms was substantially higher for TDH-50P supra-aural receivers than for ER-3A insert receivers. RESPLs at 6000 and 8000 Hz were the major predictors of notched audiograms for TDH-50P receivers. These predictors explained around 45% of the variance in the notched audiograms. The notched audiograms obtained with TDH-50P receivers showed no association with NEB. Individuals with notched audiograms measured using TDH-50P did not show convincing evidence of cochlear dysfunction as assessed by DPOAEs. Individuals with notched audiograms obtained with TDH-50P receivers revealed an average of shorter EAC and a poorer hearing threshold at 6000 Hz. Conclusions The calibration error in the RESPLs at 6000 and 8000 Hz that are likely to be influenced by the shorter EAC was the major determinant of the notched audiograms when the supra-aural transducers were used to measure hearing thresholds. Therefore, the supra-aural receivers should not be used to estimate the prevalence of NIHL in children and young adults when the less restrictive notch identification criteria are used to identify NIHL. Real-ear calibration techniques that are least influenced by the standing waves in the EAC should be preferred when investigating the prevalence of and risk factors for NIHL in young adults.

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