Contralateral Suppression of Transient-Evoked Otoacoustic Emissions in Children With Sickle Cell Disease

Auditory Neuropathy Spectrum Disorder in Individuals with Sickle Cell Anemia: Case Study

The present study attempted to understand the association between Auditory neuropathy spectrum disorder (ANSD) and Sickle cell anemia (SCA) and to recognize possible causative factors for the presence of ANSD in SCA individuals. Two cases, 24 years male and 17years female with a laboratory-confirmed diagnosis of Sickle cell anemia underwent detailed audiological evaluation i.e., pure tone audiometry, speech audiometry, immittance audiometry, otoacoustic emission, and auditory brainstem responses. Audiological evaluation revealed a bilateral moderate low-frequency sensorineural hearing loss in male and bilateral moderately severe sensorineural Hearing loss in female case with elevated Speech Recognition Threshold and poor Speech Identification Scores. 'A' type tympanogram with the absence of Acoustic reflexes and the presence of Otoacoustic emission with no distinct and reproducible peak V in Auditory Brainstem Response (ABR) at 90 dBnHL with the presence of ringing cochlear microphonics on polarity reversal collectively indicating bilateral ANSD in both cases. ANSD and SCA are reported to have a genetic basis of etiology. There might be possibilities that one genetic condition may be common in manifesting both conditions or one genetic condition can cause the presence of another genetic condition or can exaggerate the evolution of another genetic condition. Also, abnormal ABR findings indicate the possibility of neuropathological involvement in isolation or in combination with genetic abnormalities that need detailed investigation to understand non-genetic causative factors. Thus, paved the path for further research in this line and might provide better rehabilitative options.

Dizziness, Falls, and Hearing Loss in Adults Living With Sickle Cell Disease

Objective:

The aim of this study was to assess the prevalence of reported dizziness/imbalance, frequency of falls, and hearing loss in adults with sickle cell disease (SCD) and determine the relationship of these self-reported problems both during and in the absence of an SCD crisis. Also, the impact of educational level and health insurance on seeking treatment services, as well as the relationship of falls to stroke, legal blindness, and other orthopedic problems, was assessed. Interrupted blood flow to shared vestibular and auditory arteries supports the notion of increased likelihood of balance deficits and increased falls in this population.

Design:

A cross-sectional survey study design was used. Adults living with SCD responded to a questionnaire that was distributed online and through traditional mail.

Study Sample:

Adults living with SCD ( N = 135) participated in the study.

Results:

Responses revealed 70% of participants with SCD experienced dizziness/imbalance and 23% reported hearing loss. Furthermore, 33% of participants reported falling one or more times in the last year. The prevalence of dizziness/imbalance, falling, and hearing loss in the respondents with SCD was much higher than that of the general population of the United States. Additionally, for dizziness and falling, the prevalence was higher not only than the national average but also for persons over 65 years of age. A significant association was demonstrated between dizziness/imbalance and hearing loss as well as dizziness/imbalance and falls for adults living with SCD. In fact, participants with self-reported hearing loss were 5.2 times more likely to also report dizziness/imbalance. They were 4.9 times more likely to fall if they also reported dizziness/imbalance. Numbness of the feet was revealed to significantly impact the likelihood of falling in this disease population and should be further studied. Regarding SCD crisis status, dizziness/imbalance and falls were more likely to occur outside of SCD crisis than during a crisis. Furthermore, pain levels were significantly associated with dizziness/imbalance only when respondents were in crisis and not in the absence of a crisis. In crisis, higher pain levels were reported from respondents who also reported dizziness/imbalance than from those who did not report dizziness. No significant relationship was revealed between hearing loss and falls.

Discussion:

These results provide justification for patient and health care provider education regarding appropriate referrals for vestibular/balance assessments and provision of fall prevention strategies. Future studies on balance and SCD are encouraged.

No Change in Medial Olivocochlear Efferent Activity during an Auditory or Visual Task: Dual Evidence from Otoacoustic Emissions and Event-Related Potentials

The medial olivocochlear (MOC) system is thought to be responsible for modulation of peripheral hearing through descending (efferent) pathways. This study investigated the connection between peripheral hearing function and conscious attention during two different modality tasks, auditory and visual. Peripheral hearing function was evaluated by analyzing the amount of suppression of otoacoustic emissions (OAEs) by contralateral acoustic stimulation (CAS), a well-known effect of the MOC. Simultaneously, attention was evaluated by event-related potentials (ERPs). Although the ERPs showed clear differences in processing of auditory and visual tasks, there were no differences in the levels of OAE suppression. We also analyzed OAEs for the highest magnitude resonant mode signal detected by the matching pursuit method, but again did not find a significant effect of task, and no difference in noise level or number of rejected trials. However, for auditory tasks, the amplitude of the P3 cognitive wave negatively correlated with the level of OAE suppression. We conclude that there seems to be no change in MOC function when performing different modality tasks, although the cortex still remains able to modulate some aspects of MOC activity.

Reliability of contralateral suppression of otoacoustic emissions in children

OBJECTIVE

The purpose of the study was to determine the reliability in children of the medial olivocochlear reflex when measured as decibels of suppression of transiently evoked otoacoustic emissions (TEOAEs) by contralateral acoustic stimulation (CAS).

DESIGN

TEOAEs with and without CAS (white noise) were measured. In each subject, measurements were performed twice. Of particular interest was the suppression of TEOAEs by CAS and its reliability. Reliability was evaluated by calculating the standard error of measurement (SEM) and minimum detectable change (MDC).

STUDY SAMPLE

Fifty-one normally hearing girls aged 3-6 years.

RESULTS

The average global TEOAE suppression was around 0.6 dB. The highest reliability was for global values, with SEM of 0.2 dB and MDC of ±0.55 dB for the standard 2.5-20 ms recording window and slightly higher values for an 8-18 ms window. The worst reliability in the studied group was for the 1 kHz half-octave frequency band. Additionally, ears without spontaneous otoacoustic emissions had higher suppression levels than those with, but they also had lower signal-to-noise ratios, which may limit their clinical utility.

CONCLUSIONS

The current study shows that, under the studied paradigm, TEOAE suppression does not have satisfactory reliability since MDC was similar to the level of suppression.

Contralateral suppression of otoacoustic emissions in pre-school children

BACKGROUND

Contralateral suppression of otoacoustic emissions (OAEs) may serve as an index of the medial olivocochlear (MOC) reflex. To date, this index has been studied in various populations but never in pre-school children. The purpose of this study was to fill this gap and describe how the MOC reflex affects the properties of transiently evoked OAEs (TEOAEs) in this age group. In addition, the influence of the presence of spontaneous OAEs (SOAEs) in the studied ear on the suppression of TEOAEs was also investigated.

METHODS

TEOAEs with and without contralateral acoustic stimulation (CAS) by white noise were measured in 126 normally hearing pre-school children aged 3-6 years. The values of response levels, suppression by CAS, and signal-to-noise ratios (SNRs) of TEOAEs were investigated for the whole signal (global) and for half-octave frequency bands from 1 to 4 kHz. Only ears with SNR >6 dB were used in the analyses. SOAEs were acquired using the so-called synchronized SOAEs (SSOAEs) technique.

RESULTS

Ears with SSOAEs had higher response levels and SNRs than ears without SSOAEs, and suppression was lower (0.58 dB compared to 0.85 dB). Only 22% of all studied ears had an SNR >20 dB, a level recommended in some studies for measuring suppression. There were no significant effects of age or gender on TEOAE suppression.

CONCLUSIONS

Suppression levels for pre-school children did not differ appreciably from those of adults measured under similar conditions in other studies. Taken together with no effect of age in the data studied here, it seems that there is no effect of age on TEOAE suppression. However, we did find that the presence of SSOAEs had an effect on TEOAE suppression, a finding which has not been reported in earlier studies on different populations. We suggest that the presence of SSOAEs might be a crucial factor related to MOC function.

Dysfunction of the auditory system in sickle cell anaemia: a systematic review with meta-analysis

OBJECTIVES

To describe the occurrence of both peripheral and central auditory system dysfunction in sickle cell anaemia (SCA) patients and discuss the different mechanisms hypothesised to be responsible for these alterations.

METHODS

An electronic search was conducted using PubMed Central^® (MEDLINE), LILACS^® and Scopus^® databases. This systematic review was performed in accordance with the PRISMA statement. Original observational studies that utilised audiological tests for auditory system evaluations in SCA were included.

RESULTS

A total of 183 records were found in the databases searched. Twenty-one of these studies met the inclusion criteria. Pooled prevalence of sensorineural hearing loss (SNHL) was 20.5% (CI: 10.3-33%). Retrocochlear involvement was detected with the auditory brainstem response, which assesses integrity of the cochlea, 8th cranial nerve and brainstem structures. In addition, the increase in otoacoustic emission amplitudes in SCA patients indicates changes in cochlear micromechanics and precedes the expression of a detectable cochlear pathology.

CONCLUSION

The prevalence of the SNHL is higher than in the general population. Dysfunction of the auditory system may be present in SCA patients, with the most probable mechanism being the presence of circulatory disturbances resulting from the chronic inflammatory state of the disease.

The emergence and prevalence of hearing loss in children with homozygous sickle cell disease

OBJECTIVES

Many children with sickle cell disease (SCD) experience the effect of cochlear insult due to hemolytic anemia and vaso-occlusion that accompanies the disease. As a result, hearing sensitivity eventually decreases. The purpose of this study was to investigate the emergence of hearing loss and the prevalence of such in children with homozygous SCD.

METHODS

A large pediatric database was utilized to gather audiometric outcomes in children with homozygous SCD. Children were identified by primary diagnosis ICD codes. Demographic and audiometric data was drawn to determine presence, type, degree, and laterality of hearing loss. Hearing loss was defined as an elevated audiometric threshold >15 dB HL for pure tone air conduction audiometry or >20 dB HL minimal response level for sound-field testing.

RESULTS

One hundred and twenty-eight children were identified. The prevalence of hearing loss ranged from 28.8% to 50.8% depending on the calculation method (i.e., individual vs. ear specific prevalence and any elevated threshold vs. a three-frequency pure tone average). Conductive hearing loss and bilateral loss were most prevalent. The degree of hearing loss ranged from slight to profound. The mean age of identification of sensorineural hearing loss was 9.6 years.

CONCLUSION

The prevalence of hearing loss in children with homozygous SCD is higher than in normal children. Regular hearing assessments of children with SCD is warranted and should be advocated in early infancy and as part of their ongoing care.

Hidden hearing loss in children and adolescents with sickle cell anemia

OBJECTIVE

To evaluate the auditory system for hidden hearing loss (HHL) and its association with clinical variables and endothelial dysfunction (ED) in children and adolescents with sickle cell anemia (SCA).

METHODS

Participants included 37 patients with stable SCA and 44 healthy controls (HC group) (aged 6-18 years) with hearing thresholds ≤ 20 dB (dB) were evaluated for pure tone audiometry, tympanometry, acoustic reflex, otoacoustic emission, and auditory evoked potentials. Laboratory analysis of the lipid profile, and C-reactive protein levels and endothelial function using ultrasonographic imaging of the brachial artery to assess flow-mediated dilation were performed.

RESULTS

The SCA group presented with a higher rate of increased contralateral acoustic reflex thresholds, compared to those in the HC group at all frequencies and in both ears (p < 0.05). There were significant differences in the brainstem auditory evoked potentials between the SCA and HC groups. In the SCA group, the waves III and V latencies were increased (p = 0.006 and 0.004 respectively), and the I-III and I-V interpeak intervals were longer (p = 0.015 and 0.018 respectively) than those in the HC group. There was no association between the audiological measures and clinical and metabolic variables and sickle cell anemia complications including endothelial function and therapy.

CONCLUSION

In conclusion, our findings suggest that damage in the auditory system in SCA patients can be present involving retrocochlear structures, causing functional deficits without deterioration of auditory sensitivity.

Does Contralateral Inhibition of Transient Evoked Otoacoustic Emissions Suggest Sex or Ear Laterality Effects?

PURPOSE

The purpose of this study was to examine contralateral inhibition of transient evoked otoacoustic emissions (TEOAEs) in young adults with normal hearing as a function of ear and sex.

METHOD

Young female (n = 50) and male (n = 50) adults with normal hearing participated. TEOAEs were measured bilaterally with 80 dB peSPL nonlinear clicks and 60 dB peSPL linear clicks with and without a contralateral broadband noise elicitor at 65 dB SPL. Absolute TEOAE inhibition and normalized TEOAE inhibition (i.e., percentage of inhibition) were examined.

RESULTS

With both 80 and 60 dB peSPL evoking stimuli, there were significant main effects of ear and sex (p < .05). TEOAE levels were larger in women and in the right ear. There were no statistically significant main effects of ear and sex on absolute TEOAE inhibition (p > .05). Significant main effects of ear and sex were, however, found with normalized TEOAE inhibition (p < .05; greater in men and in the left ear). Statistically significant negative correlations and significant linear predictive relations were found between TEOAE levels and normalized TEOAE inhibitions in both ears (p < .001). There is no evidence of the same with absolute inhibition of TEOAEs (p > .05).

CONCLUSIONS

If one considers that efferent inhibition of TEOAEs is an absolute quantity, the significant effect of ear and sex on normalized inhibition and the negative association and linear predictive relationship between TEOAE level and inhibition can be viewed as spurious effects. As such, contralateral inhibition of TEOAEs does not suggest sex or ear laterality effects.

The Hyperactivity of Efferent Auditory System in Patients with Schizophrenia: A Transient Evoked Otoacoustic Emissions Study

OBJECTIVE

Electrophysiological studies, which are mostly focused on afferent pathway, have proven that auditory processing deficits exist in patients with schizophrenia. Nevertheless, reports on the suppressive effect of efferent auditory pathway on cochlear outer hair cells among schizophrenia patients are limited. The present, case-control, study examined the contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in patients with schizophrenia.

METHODS

Participants were twenty-three healthy controls and sixteen schizophrenia patients with normal hearing, middle ear and cochlear outer hair cells function. Absolute non-linear and linear TEOAEs were measured in both ears by delivering clicks stimuli at 80 dB SPL and 60 dB SPL respectively. Subsequently, contralateral suppression was determined by subtracting the absolute TEOAEs response obtained at 60 dBpe SPL during the absence and presence of contralateral white noise delivered at 65 dB HL. No attention tasks were conducted during measurements.

RESULTS

We found no significant difference in absolute TEOAEs responses at 80 dB SPL, in either diagnosis or ear groups (p>0.05). However, the overall contralateral suppression was significantly larger in schizophrenia patients (p<0.05). Specifically, patients with schizophrenia demonstrated significantly increased right ear contralateral suppression compared to healthy control (p<0.05).

CONCLUSION

The present findings suggest increased inhibitory effect of efferent auditory pathway especially on the right cochlear outer hair cells. Further studies to investigate increased suppressive effects are crucial to expand the current understanding of auditory hallucination mechanisms in schizophrenia patients.

Reliability of measures of transient evoked otoacoustic emissions with contralateral suppression

The reliability of measures of transient evoked otoacoustic emissions (TEOAEs) with contralateral suppression was examined. The effect of test session (i.e., initial test; retest without probe removal; retest with probe removal; and retest 1-2 days post initial test), gender, and ear was examined in 14 young adult females and 14 young adult males. TEOAEs were obtained bilaterally with 60 dB peSPL linear click stimuli with and without a contralateral 65 dB SPL broadband noise suppressor. Absolute TEOAE suppression and a normalized index of TEOAE suppression (i.e., percentage of suppression) were examined. Reliability of these measures was assessed with repeated measures linear mixed model analysis of variance, a coefficient of reliability, and Bland-Altman analyses. There were no statistically significant (p>0.05) main effects of test, gender, and ear or interactions for both absolute dB and % TEOAE suppression values. Cronbach's α were greater than 0.90 across the four tests for both TEOAE measures. Mean test differences or bias (i.e., between the initial and subsequent tests) for absolute and % TEOAE suppression ranged from -0.05 to 0.11 dB and -1.5% to 1.1%, respectively. There was no proportional/systematic bias with the mean differences of the first and subsequent measurements. Data herein were consistent with the view that bilateral TEOAE suppression measures are reliable across test sessions of 1-2 days among females and males and may provide a method to monitor medial olivocochlear efferent reflex status over time.

Cochleopathy in Egyptian adolescents with Type 1 diabetes mellitus

BACKGROUND

Diabetic neuropathy is recognized as the most common clinical picture of nervous system disorders caused by diabetes mellitus (DM). Although peripheral and autonomic nervous system involvements are frequently encountered, data about the incidence of central diabetic neuropathies is limited.

OBJECTIVE

Our study aimed to detect early asymptomatic auditory impairment whether at the level of outer hair cells (OHCs), inner hair cells (IHCs) and or olivo-cochlear bundle and the relationship between these abnormalities and other variables such as diabetes duration, degree of the metabolic control, or presence of microvascular complications.

SUBJECTS AND METHODS

Seventy five adolescents with Type 1 DM and thirty three healthy controls participated in the study. Duration of DM, glycated hemoglobin (HbA1c) levels, microvascular complications were analyzed. All underwent basic audiological assessment to ensure normal hearing and normal middle ear function. Other tests comprised: transiently evoked otoacoustic emissions (TEOAEs) testing OHCs, TEOAEs with contralateral suppression (testing the integrity of olivo-cochlear bundle) and threshold equalizing noise (TEN) testing IHCs as evidenced by dead regions within the cochlea.

RESULTS

Early asymptomatic OHCs involvement as reflected by partial pass in 33.3% of cases with diminished suppression as compared to 9.1% control group. Eleven patients (7.33%) showed positive TEN Test reflecting resistance of IHCs to hyperglycemic injury. Diabetic patients had significantly higher amplitude on TEOAEs with noise suppression when compared to controls (P=0.002). The mean difference in amplitude of TEOAEs before and after suppression was significantly higher in diabetics with microvascular complications when compared to diabetic children without complications at all frequencies (P<0.001 for all). Duration of diabetes and microvascular complications (nephropathy, peripheral and autonomic neuropathy) were not correlated with the lack of suppression except for retinopathy (P=0.02). In contrast, poor metabolic control was associated with poor suppression (r=-0.443, P=0.001).

CONCLUSIONS

Cochleopathy can be detected in a relatively high proportion of subjects with Type 1 diabetes in spite of a normal audiometric hearing threshold. It should be considered as early manifestation of diabetic neuropathy which is related to the degree of metabolic control and retinopathy independent of other microvascular complications.