Sensorineural hearing loss in children with sickle cell anemia and its association with endothelial dysfunction

The association between anemia and sensorineural hearing loss: A review

Anemia affects a third of the world's population and contributes to increased morbidity and mortality, decreased work productivity, and impaired neurological development. In recent years, many studies have found a possible association between anemia and sensorineural hearing loss (SNHL), especially in various types of nutritional deficiency and hemoglobin disorders anemia. Anemia may affect hearing through various mechanisms, including affecting microcirculation in the ear, causing tissue hypoxia in the ear, and through inflammatory and oxidative stress pathways. This review aims to comprehensively analyze the association between various types of anemia and SNHL, including possible biological mechanisms, clinical features, and treatment strategies, and clarify the importance of anemia treatment and management in preventing SNHL.

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.

Association between hearing impairment, school performance and cognitive function in children and adolescents with sickle cell disease

OBJECTIVE

To investigate the association among hearing impairment, school performance, and cognitive function in children and adolescents with sickle cell disease.

METHODS

Thirty-one participants with sickle cell disease (SCD) and 31 healthy participants in the control-comparison group (CG), both aged 8-17 years underwent auditory system evaluation (pure tone audiometry and acoustic reflex), were screened for the risks of (central) auditory processing disorder and dysfunction of cognitive function using the Scale of Auditory Behaviors (SAB) and the Mini-Mental State Examination (MMSE), respectively, and were interviewed to obtain clinical data and data on school performance.

RESULTS

In the SCD group, eight (25.8%) participants presented with sensorineural hearing loss (SNHL). The group with SCD and SNHL presented a higher occurrence of poor school performance than the group of participants with SCD without SNHL (p= 0.016). The MMSE score for aspects related to attention and calculation in the SCD group with SNHL was lower than in the SCD group without SNHL (p= 0.016). In the SAB, the SCD group with SNHL presented a lower score than the SCD group without SNHL in aspects related to academic performance and attention.

CONCLUSION

Hearing impairment in children and adolescents with SCD, specifically SNHL, is associated with poor school performance and enhances the risk of cognitive impairment in terms of attention and calculation.

Sensory Neuroblast Quiescence Depends on Vascular Cytoneme Contacts and Sensory Neuronal Differentiation Requires Initiation of Blood Flow

In many organs, stem cell function depends on communication with their niche partners. Cranial sensory neurons develop in close proximity to blood vessels; however, whether vasculature is an integral component of their niches is yet unknown. Here, two separate roles for vasculature in cranial sensory neurogenesis in zebrafish are uncovered. The first involves precise spatiotemporal endothelial-neuroblast cytoneme contacts and Dll4-Notch signaling to restrain neuroblast proliferation. The second, instead, requires blood flow to trigger a transcriptional response that modifies neuroblast metabolic status and induces sensory neuron differentiation. In contrast, no role of sensory neurogenesis in vascular development is found, suggesting unidirectional signaling from vasculature to sensory neuroblasts. Altogether, we demonstrate that the cranial vasculature constitutes a niche component of the sensory ganglia that regulates the pace of their growth and differentiation dynamics.

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

OBJECTIVES

To determine the prevalence of Sensorineural Hearing Loss (SNHL) attributable to Sickle Cell Disease (SCD) in the global pediatric population and to identify factors contributing to its severity.

STUDY DESIGN

Meta-analysis.

METHODS

We performed a comprehensive literature search for scientific articles in PubMed, Scopus, CINAHL, Web of Science, and the Cochrane Library that reported the incidence of hearing loss in populations under 18 years of age with excluding studies analyzing patients on iron chelation therapy, adults, or those without objective audiological analysis.

RESULTS

We identified 138 initial studies with 17 selected for analysis after applying the exclusion criteria. A total of 1,282 SCD patients and 553 controls were included in the meta-analysis. There was a statistically significant increase in the prevalence of SNHL in children with SCD compared to the general population with a cumulative risk ratio of 3.33.

CONCLUSION

This is the first systematic investigation of the relationship between SCD and SNHL in pediatric patients across the globe. The increased prevalence of SNHL in the pediatric SCD population warrants future research into the predictors of SNHL severity and merits routine audiometric monitoring of SCD patients to reduce the social and developmental morbidity of hearing loss at a young age. PROSPERO Registration #: CRD42019132601. Laryngoscope, 131:1147-1156, 2021.

The Role of Anti-Endothelial Cell Autoantibodies and Immune Response in Acute Low-Tone Hearing Loss

OBJECTIVE

Immunity is associated with acute low tone hearing loss. However, the exact pathophysiology of immunity-mediated acute low tone hearing loss remains unknown. In this study, we evaluated the presence, therapeutic effectiveness, and immunopathological mechanisms of anti-endothelial cell autoantibodies (AECEs) in patients with acute low-frequency hearing loss.

MATERIAL AND METHODS

Forty-nine patients who were treated as inpatients having acute low-frequency hearing loss and additional symptoms, such as ear fullness, tinnitus, dizziness, or hyperacusis, were enrolled in this study. Serum samples from these patients were collected for laboratory serum autoimmunity detection, including AECAs, antinuclear antibodies, immunoglobulin, and circular immune complex. Therapeutic responses to combination therapy in short-term outcome and serum cytokine levels were compared between AECA-positive and AECA-negative patients.

RESULTS

Anti-endothelial cell autoantibodies-positive patients tended to show significantly less response to standard therapy compared with AECAs controls (P < .05). Moreover, some serum cytokine levels elevated in both AECAs- and AECAs+ groups. Positive ratio of interleukin-8 and concentrations of macrophage inflammatory protein-1α were found higher in AECAs+ groups (P < .05).

CONCLUSION

The results supported that AECAs might wield influence on the short-term outcome of acute low-tone hearing loss (ALHL) treatment. Furthermore, AECA-mediated acute low-frequency hearing loss possibly involved dysregulation of inflammation process and release of cytokines.

The Relationship Between Sickle Cell Disease and Sudden Onset Sensorineural Deafness

Sickle cell anemia (SCA) is a hereditary hemoglobin (Hb) disorder associated with a very specific molecular lesion, which is the exchange of glutamic acid for valine in the sixth residue of the Hb beta chain, originating the S Hb. It is characterized by intermittent episodes of vascular occlusion and end-organ damage. Progressive organ damage may affect any organ with brain, eyes, pulmonary, hepatobiliary, spleen, genitourinary, and the musculoskeletal systems being the most commonly involved and reported. Other complications of the disease that have not been well described or studied include cranio-orbital syndromes, oropharyngeal syndromes, periodontal disease, and otologic syndromes. Considering the vaso-occlusive nature of sickle cell disease (SCD), the potential for auditory damage is not unexpected. However, the incidence of subjective hearing impairment among SCA is very low and and little is known about the relationship between SCA and hearing loss. Here we report a 43-year-old female with SCA who presented with sudden bilateral hearing loss and generalized body ache and admitted as a case of sensorineural deafness with vascular crisis; she received IV fluid and analgesia and improved after five days from the therapy.

Blood Cell Disorders and the Nervous System

PURPOSE OF REVIEW

This article discusses the epidemiology, diagnosis, treatment, and prevention of neurologic complications of common and rare blood cell disorders.

RECENT FINDINGS

A growing number of preventive treatment options are available for stroke in sickle cell disease. Paroxysmal nocturnal hemoglobinuria and immune thrombocytopenia can lead to stroke. Thrombotic thrombocytopenic purpura frequently causes neurologic symptoms and should be considered in the differential diagnosis of a patient with neurologic symptoms, thrombocytopenia, and hemolytic anemia. Polycythemia vera and essential thrombocythemia are rare causes of stroke.

SUMMARY

This article discusses sickle cell disease and the most recent advances in stroke preventive therapy as well as neurologic complications of paroxysmal nocturnal hemoglobinuria, immune thrombocytopenia, thrombotic thrombocytopenic purpura, polycythemia vera, and essential thrombocythemia.

Association between Anemia and Auditory Threshold Shifts in the US Population: National Health and Nutrition Examination Survey

Existing evidence indicates that both iron deficiency anemia and sickle cell anemia have been previously associated with hearing loss. However, human data investigating the association between anemia and auditory threshold shifts at different frequencies in the adolescent, adult and elderly population are extremely limited to date. Therefore, this cross-sectional study used the dataset from the US National Health and Nutrition Examination Survey from 2005 to 2012 to explore differences in low- or high-frequency hearing thresholds and hearing loss prevalence between participants with and without anemia. A total of 918 patients with anemia and 8213 without anemia were included. Results indicated that low- and high-frequency pure tone average were significantly higher in patients with anemia than that in those without anemia in the elderly, but not in adult or adolescent population. In addition, the prevalence of low-frequency hearing loss but not high-frequency hearing loss was also higher in patients with anemia than in those without anemia in the elderly population. After adjusting various confounders, multiple regression models still indicated that patients with anemia tended to have larger threshold shift. In conclusion, anemia was associated with auditory threshold shifts in the elderly population, especially those vulnerable to low-frequency hearing loss.

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.

Prevalence and nature of hearing loss in a cohort of children with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) may cause injury to any organ, including the auditory system. Although the association of SCD and hearing loss has been described, the nature of this complication is unknown. We sought to establish the prevalence and nature of hearing loss in a referred cohort of children with SCD and to identify correlating disease- or treatment-associated factors.

PROCEDURE

We conducted a retrospective review of patients with SCD < 22 years of age who had hearing evaluations between August 1990 and December 2014. Demographics, audiograms, and disease and treatment variables were analyzed.

RESULTS

Two hundred and ten audiograms among 81 patients were reviewed, and 189 were evaluable. Seventy-two children constituted the referred cohort. Fourteen (19.4%) had hearing loss documented on at least one audiogram. Seven (9.7%) patients had only conductive hearing loss, and the loss persisted for up to 10.3 years. The median age of first identification was eight years. Six (8.3%) patients had hearing loss that was at least partially sensorineural. One patient's hearing loss was ambiguous. All sensorineural hearing losses were unilateral and 4/6 patients had prior documented normal hearing, indicating acquired loss. No correlations were identified.

CONCLUSIONS

Both conductive and sensorineural hearing losses are more prevalent in our study population than those observed in the general pediatric population. In children with SCD, sensorineural hearing loss appears to be acquired and unilateral. Conductive hearing loss was identified in older children and can persist. Serial screening is needed for early detection and more prompt intervention in this population.