Hearing ability linked to cognitive outcomes in young children with brain tumors

Children treated for brain tumors can experience a range of therapy-related side effects, some of which have long-term implications. Hearing loss is among the most common and clinically significant of these effects and can adversely affect speech, language, and academic performance. Although extensive research has linked hearing loss to cognitive decline in school-aged children, there is a notable lack of knowledge about treatment-associated hearing loss in children under the age of 3 undergoing therapy for brain tumors.

Published in Neuro-Oncology, first and corresponding author Heather Conklin, PhD, Department of Psychology & Biobehavioral Sciences, and senior author Amar Gajjar, MD, Department of Pediatric Medicine chair, sought to address this gap by examining how treatment-related hearing loss affects early brain development during the critical window of learning from 0-3 years of age. Together, they led the first study of its kind to help understand the prevalence, timing, and cognitive impact of hearing loss in this age group.

“In all of our protocols, we study the efficacy of therapy, but just as importantly, we also pay careful attention to side effects. This helps us gain valuable insights into the toxicity of therapy, which in this case was hearing loss,” said Gajjar. “Thus, we can document the impact of hearing loss on neurocognitive outcomes, and based on the results of this study, we will strive to reduce the incidence of hearing loss in the future.”

As part of a five-year prospective study, the research team followed 135 young children newly diagnosed with malignant brain tumors who were treated with chemotherapy. Participants underwent regular hearing evaluations and cognitive assessments to track changes in intellectual abilities, attention, and adaptive skills over time. Outcomes were measured using neurocognitive assessments and parent-reported observations.

After chemotherapy, 67% of patients experienced mild-to-severe hearing loss. Treatment-related hearing loss was associated with declines in IQ and adaptive functioning, as well as increased attention difficulties. Younger age at treatment and lower socioeconomic status were identified as risk factors associated with treatment-related hearing loss.

“Hearing loss is potentially avoidable with adjustments to cancer treatment, and there are methods to aid hearing and support learning in children who experience hearing loss,” explained Conklin. “These findings offer opportunities to improve cognitive and academic outcomes for our youngest survivors.”

The results address a critical gap in understanding the impact of cancer treatment–associated hearing loss on children before they are old enough to attend school. The knowledge gained from this study is critical for informing tailored care strategies and enabling early interventions to support these children better. Additionally, these findings suggest that audiologic monitoring, cognitive surveillance guidelines, intervention strategies, and caregiver education are options to help position young cancer survivors experiencing hearing loss for success later in life.