Sensorineural hearing loss in adults with sickle cell anaemia

Sensorineural hearing loss (SNHL) is one of the known complications of sickle cell disease (SCD). However, there is paucity of information on SNHL as a complication of SCD, especially in sickle cell anaemia (SCA) in our environment, hence this study. This was a prospective study of pure tone audiological assessment of 167 adult SCA patients in stable condition attending the adult Sickle Cell Clinic and 100 apparently healthy Haemoglobin AA adults as control in the University College Hospital, Ibadan. Their ages ranged from 15 to 56 years for SCA and 15 to 65 years for the controls, with a mean age of 24.2 (+/- 8.2) and 28.7 (+/- 11.9) years respectively. There were 94 females (56.3%) and 73 males (43.7%), fifty-two females (52%) and forty-eight males (48%), with a M:F ratio of 1:1.3 and 1:1.1 for SCA and controls respectively. Sensorineural hearing loss (SNHL) was observed in a total of 178 ears in 110 SCA patients and 68 ears in 47 controls with a prevalence of 66% and 47%, respectively. Sixty-eight patients (62%) and twenty-one controls (44.7%) had bilateral impairment, although only 18 SCA patients (11%) perceived hearing impairment. High frequency loss (4000-8000 Hz) was commonly affected in both the SCA patients and controls as compared to other frequency ranges. Low frequency range was involved in ten ears (9%) especially the right ear of some SCA patients. Decibel hearing level (dBHL) loss was in the mild range (26-40 dBHL) in 103 (58%) and 53 (78%) ears in the SCA and controls, respectively. Five patients had severe and profound dBHL loss. The range of dBHL loss was 26-43 dBHL especially in the high frequency range bilaterally for both the SCA and controls. Mean binaural hearing of 13 dBHL was recorded in both the SCA and controls for each octave frequency bilaterally in those with normal hearing while 26 and 23 dBHL were for those with impaired hearing respectively. Also, the mean dBHL for both ears was observed to be progressively worse with increasing age groupings, more especially in SCA patients. There was no significant correlation between the severity of hearing loss and the frequency of vaso-occlusive crisis. It is hoped that this study would have increased the awareness that SNHL is a common complication of SCA in our patients. There is thus the need for periodic evaluation of the auditory function of SCA patients in our environment.