Prevalence of Sensorineural Hearing Loss in Pediatric Patients with Sickle Cell Disease: A Meta-analysis

Environmental Risk Factors, Protective Factors, and Biomarkers for Hearing Loss: An Umbrella Review

OBJECTIVE

We aimed to investigate the potential environmental risk factors, protective factors, and biomarkers of hearing loss (HL), and establish a hierarchy of evidence.

DATA SOURCES

Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to June 1, 2023.

REVIEW METHODS

We included meta-analyses of observational studies of associations between HL and environmental risk factors, protective factors, or biomarkers. We calculated summary effect estimates, 95% confidence interval, heterogeneity I2 statistic, 95% prediction interval, small study effects, and excess significance biases.

RESULTS

Of the 9211 articles retrieved, 60 eligible articles were included. The 60 eligible articles identified 47 potential environmental risk and protective factors (N = 4,123,803) and 46 potential biomarkers (N = 173,701). Evidence of association was convincing (class I) for rheumatoid arthritis (RA) and every 1 cm increase in height. Evidence of association was highly suggestive (class II) for human immunodeficiency virus (HIV), diabetes, cumulative noise exposure (CNE), smoking, congenital cytomegalovirus (CMV) infection, combined exposure to organic solvents and noise, non-Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and alopecia areata (AA).

CONCLUSION

In this umbrella review, RA, every 1 cm increase in height, HIV, diabetes, CNE, smoking, congenital CMV infection, combined exposure to organic solvents and noise, non-Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and AA were strongly associated with HL.

Comparing Hearing Loss in Children with Adults Living with Sickle Cell Disease and Sickle Cell Traits

BACKGROUND

Hearing loss is a neurological sequelae associated with sickle cell disease (SCD) and probably sickle cell trait (SCT) in children and adults but remains understudied.

AIM

This study aimed to compare the hearing impairment among children and adults living with SCD or SCT.

METHODS

A comparative cross-sectional study conducted in four departments with SCD outpatient clinic in a tertiary hospital in Nigeria. Participants with Sickle cell disease (HbSS) and Sickle cell trait (HbAS) (cohort) and HbAA (control) had comprehensive ear and hearing assessments for sensorineural hearing loss. Audiometric results were categorized according to WHO classifications and data analysed with Statistical Analysis System (SAS 9.4).

RESULTS

A total of 212 participants (106 cohort and control, respectively), aged 6 months to 55 years, were enrolled. Of these, 35% of children with SCD and 25% with SCT had hearing impairment, while 30% of adults with SCD, 36.1% with SCT, and 11% with HbAA had hearing impairment. There was asymmetry in the hearing impairment, with the left ear more affected in children and the right ear in adults. The odds ratio (OD) of hearing impairment was higher in HbSS (2.48 (95% confidence interval (CI):1.51-4.14); P = 0.0004) and HbAS (2.28 (95% CI: 1.1-4.58); P = 0.02) participants compared with HbAA but was not statistically significant when adjusted for frequency of hospitalization, crises, blood transfusion and routine drugs in HbAS (P = 0.49) unlike HbSS (P = 0.03).

CONCLUSION

The prevalence of hearing loss among children and adults with SCD is higher than in those with HbA genotype. The frequency of hospitalization, crises, blood transfusion and taking routine drugs may influence hearing impairment in SCT but may not in SCD.

Brain MRI findings of prelingually deaf children and cochlear implant outcome: Preliminary results

OBJECTIVE

To estimate the incidence of brain abnormalities in a cohort of prelingually deaf children and whether these abnormalities can impact the hearing outcomes of patients eligible for cochlear implantation (CI).

METHODS

We performed a retrospective review of consecutive medical charts of prelingually deaf children under 12 years of age who underwent brain magnetic resonance imaging (MRI) during their preoperative workup for CI surgery. We used the category of auditory performance (CAP) test and the speech intelligibility rating (SIR) test to assess the hearing and speech performance of the children, respectively.

RESULTS

The MRIs of 285 patients, 174 boys and 111 girls with a mean age of 36.4 (±16) months, were evaluated for this study. We identified 31 patients with abnormal findings (10.88%): (17/31) (54.8%) had MRI brain abnormalities, (9/31) (29%) had inner ear anomalies, and (5/31) (16.1%) had both inner ear and brain abnormalities. The most frequent inner ear anomaly was an enlarged vestibular aqueduct, while white matter lesions were the most common brain abnormality. The CAP and SIR mean score of patients with inner ear anomalies was slightly, but not significantly, higher than those of patients with brain abnormalities.

CONCLUSION

CAP and SIR scores were not significantly different in children with brain abnormalities than inner ear anomalies. These patients can still benefit from CI to improve their overall hearing and speech performance.

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.

Three-Dimensional High-Resolution Temporal Bone Histopathology Identifies Areas of Vascular Vulnerability in the Inner Ear

OBJECTIVES

Hypothesized causes of vestibular neuritis/labyrinthitis include neuroinflammatory or vascular disorders, yet vascular disorders of the inner ear are poorly understood. Guided by known microvascular diseases of the retina, we developed 2 hypotheses: (1) there exist vascular vulnerabilities of artery channels in cases of hypothetical nerve swelling for the superior, inferior, and vestibulocochlear artery and (2) there are arteriovenous crossings that could compromise vascular flow in disease states.

METHODS

Two fully mounted and stained temporal bones were used to render three-dimensional reconstructions of the labyrinth blood supply. Using these maps, areas of potential vascular compression were quantified in 50 human temporal bones.

RESULTS

Although inner ear arteries and veins mostly travel within their own bony channels, they may be exposed (1) at the entrance into the otic capsule, and (2) where the superior vestibular vein crosses the inferior vestibular artery. At the entry into the otic capsule, the ratio of the soft tissue to total space for the superior vestibular artery was significantly greater than the inferior vestibular artery/cochleovestibular artery (median 44, interquartile range 34-55 vs. 14 [9-17], p < 0.0001).

CONCLUSIONS

Three-dimensional reconstruction of human temporal bone histopathology can guide vascular studies of the human inner ear. Studies of retinal microvascular disease helped identify areas of vascular vulnerability in cases of hypothetical nerve swelling at the entrance into the otic capsule and at an arteriovenous crossing near the saccular macula. These data may help explain patterns of clinical findings in peripheral vestibular lesions.