Sensorineural hearing loss in sickle cell disease-A prospective study from Oman

Background: Sickle cell disease (SCD) is characterized by intermittent episodes of vascular occlusion and end-organ damage. Neurologic symptoms are frequent and auditory involvement is not unexpected. Aim: To study the prevalence and pattern of hearing loss in Omani patients with SCD. Methods: We conducted a prospective case control study on SCD patients attending the outpatient department. Age and sex matched normal volunteer blood donor controls were recruited after an informed consent and Medical Ethics Committee approval. Pure tone audiometry was performed in all cases studied. Results: Forty-six SCD patients (15 males, 32.6%) aged 16-45 years with a mean age of 26 years ± 6.9 and 29 controls (10 males, 34.4%) aged 16-39 years with a mean age of 25.24 ± 8.2 were enrolled in this study. The average hearing thresholds of SCD patients were consistently higher than controls in all frequencies tested in both ears. Of the 92 ears tested in SCD patients, 29.34% had SNHL. Ten patients had bilateral SNHL; whereas 3 and 4 cases had SNHL in left and right ears, respectively. All the control subjects had hearing thresholds within normal limits. Summary/Conclusions: The study reveals a significant incidence of sensorineural hearing loss (SNHL) in SCD patients (36.95%), although the patients were clinically asymptomatic. The hearing loss was worse in the right ears and had a female preponderance. Also, the hearing loss was more severe at the higher frequencies, 2,000-8,000 Hz in SCD patients. HbS, HbF, or low hemoglobin levels did not discriminate SCD patients with SNHL, and the role of hemoglobin F in the cochlea is still not clear. Regular audiometric assessment should therefore be recommended in SCD patients routinely.