Sensorineural Hearing Loss in Children with Sickle Cell Disease: A Series of Four Cases

Background

The World Health Organization defines hearing loss as hearing thresholds of 20 dB or more in one or both ears. There is a paucity of literature on hearing impairment in individuals with sickle cell disease (SCD). Vaso-occlusion caused by sickled erythrocytes resulting in hypoxia of the organ of Corti and cochlear damage is hypothesized to cause hearing impairment in SCD. (Abdelmahmuod et al., 2020; Rissatto-Lago, 2022) Sensorineural hearing loss (SNHL) and conductive hearing loss (CHL) prevalence in the general population in the United States is estimated to be 11.6%, with both ears being equally affected. (Rein et al., 2024) SNHL accounts for most cases of hearing loss in SCD, and its prevalence in SCD is greater than in the general population. In pediatric patients with SCD, the SNHL prevalence ranges from 3.8% to 28.8%. (Lago et al., 2018) Furthermore, a French study focusing on pediatric patients with SCD reported that even children with normal hearing were found to harbor auditory processing disorders and subclinical audiology issues. (Bois et al., 2019) SCD-related hearing loss may be underdiagnosed in this patient population, as periodic audiology screening is recommended only for those on iron chelation therapy.

Method

This is a case series describing 4 pediatric patients (<18 years of age) with SCD not on chelation therapy, who were diagnosed with SNHL based on clinical symptoms and confirmed by a diagnostic audiogram. Demographic, laboratory, imaging, healthcare utilization, and medication use data for these patients were extracted from the Sickle Cell Clinical Research and Intervention Program (SCCRIP; NCT02098863) database, and clinical characteristics, audiological data, and outcomes for these patients were extracted from medical records by retrospective chart review.

Results

All 4 patients with SNHL had normal newborn hearing screenings and were screened for hearing loss based on symptoms and/or clinical suspicion. Other risk factors for SNHL, such as history of pneumococcal infections, noise-induced hearing loss, trauma, malignancies, genetic disorders, and exposure to ototoxic medications were ruled out. The age at diagnosis of hearing loss ranged from 5 to 16 years. Three patients had HbSS, and one had HbSC genotype. All 4 patients were on hydroxyurea therapy, with fetal hemoglobin levels ranging from 8% to 40%. Three of the 4 patients had moderate to severe hearing loss at the time of the audiology diagnosis and were prescribed hearing aids. High healthcare utilization was noted in these individuals, with the average annual number of emergency department visits and hospital admissions before the SNHL diagnosis ranging from 1 to 4 and 2 to 6, respectively. Three patients had sickle retinopathy, and 3 patients had obstructive sleep apnea.

Conclusion

In this case series, we highlight 4 patients with SCD with SNHL without an identified etiology, suggesting that the underlying SCD pathophysiology may be contributing to the development of SNHL in this patient population, and may present early in life. In this case series, all 4 patients were not on chelation therapy and not receiving screening audiograms, hence were diagnosed only when their symptoms were severe (moderate-severe deafness). Given the high prevalence of SNHL and subclinical hearing impairment in SCD reported in the literature, early and periodic routine audiology screening should be considered for all patients with SCD. Prospective studies of larger cohorts should be conducted to ascertain the role of SCD as an independent risk factor for SNHL, identify other risk factors in this population, and evaluate the role of SCD disease-modifying therapies in preventing SNHL in this patient population.

Takemoto:Novartis: Other: DSMB; Novo Nordisk: Research Funding; Pfizer: Research Funding; Merck: Consultancy, Honoraria. Rai:Global Blood Therapeutics: Consultancy.