The Impact of Hearing Loss on Cognitive Outcomes among Children Treated with Radiation Therapy for Ependymoma

Abstract Background Sensorineural hearing loss (SNHL) is a common adverse treatment effect among pediatric brain tumor survivors. Neurocognitive functioning among children for whom radiation therapy (RT) is the primary SNHL risk factor has received limited attention. Accordingly, this study investigated neurocognitive outcomes as a function of SNHL among children treated for ependymoma with RT. Methods Prospective, serial, neurocognitive and audiology assessments were conducted with 145 children diagnosed with ependymoma and enrolled on a Phase II trial of conformal photon RT (NCT00187226; 53% female; 83% White; mean age at RT = 5.04 ± 4.47 years). SNHL was dichotomized as normal/mild-to-moderate or severe (Chang grade 2b vs. ≥2b). Cognitive risk was assessed for participants with severe SNHL in either ear who completed neurocognitive assessments at least one year after hearing loss (n = 50). Results At pre-RT baseline, full scale IQ (FSIQ), verbal learning, and communication were lower than normative expectations (p .05), with a significant decline in FSIQ, estimated IQ (EIQ), reading, and communication over time. FSIQ and communication skills were worse among children with severe SNHL across all time points (p .05). EIQ showed greater decline over time in those with severe SNHL (p .0005), even after accounting for age at RT and pre-RT chemotherapy. Conclusions Severe SNHL was associated with worse intellectual functioning and communication skills across time points among pediatric ependymoma survivors. The decline in EIQ suggests increased risk related specifically to hearing loss. Severe SNHL following RT for ependymoma, even if only in one ear, is a cognitive risk factor requiring monitoring and intervention.