Quantitative Temporal Bone Analysis of Stria Vascularis, Spiral Ganglion, and Vestibular Ganglion Cells in Sickle Cell Disease at Young Ages

OBJECTIVES: Sensorineural hearing loss (SNHL) and vestibular symptoms in sickle cell disease (SCD) may result from hypoxic damage of inner ear structures, including the stria vascularis (SV), spiral ganglion cells (SGC), and vestibular ganglion neurons (VGN). SV cross-sectional area, SGC counts, and VGN counts were compared between SCD and control groups and correlated with temporal bone histopathology and clinical data. STUDY DESIGN: Hematoxylin and eosin-stained slides from 36 temporal bones were analyzed, including both ears from 6 SCD cases and 12 controls matched for age, sex, and race. A deep learning model was developed to measure SV area, total ear SGC counts, and VGN counts. Single and multivariable analyses were performed to compare histopathologic correlates between groups and available clinical data. RESULTS: The mean age was 19 ± 7.8 years for the SCD group [male: n = 3 (50%); black/African American: n = 6 (100%)] and 19 ± 6.7 years for controls [male: n = 6 (50%); black/African American: n = 10 (83%)]. Mean pure tone averages were normal for both groups (SCD = 12.2 ± 10.4; control = 11.1 ± 7.8, P = 0.84). SV area was similar in the SCD group compared with controls at the basal turn, middle turn, and apex; however, qualitative analysis of individual cases revealed signs of atrophy in a higher proportion of SCD cases. No significant difference was found in SGC (SCD = 25,721 ± 3283; control = 24,585 ± 5016, P = 0.43) or VGN counts (SCD = 20,673 ± 2294; control = 21,275 ± 4948, P = 0.68) between groups. The remainder of cochlear structures were preserved. CONCLUSIONS: SV area, SGC, and VGN populations are preserved in primarily young individuals with SCD and normal hearing. Otopathologic correlates of SNHL in SCD may manifest following the onset of hearing loss.