A recent study conducted by St. Jude Children’s Research Hospital has examined the cognitive and communication abilities of children who underwent treatment for the brain tumour ependymoma, aiming to understand the broader implications of treatment on long-term health.
The research identified radiation therapy as a significant factor contributing to hearing loss, which is directly linked to cognitive health. It was observed that children who experienced severe hearing loss demonstrated a more pronounced decline in cognitive measures compared to their peers who did not suffer from hearing loss. This study was published in the journal Neuro-Oncology, underscoring the necessity for more tailored cancer-directed therapies that minimise side effects, alongside adherence to supportive interventions such as hearing aids.
The study involved 145 children treated with radiation for ependymoma, a type of childhood brain tumour. Among these participants, 34% were identified as having severe hearing loss in at least one ear. The research, led by Dr Heather Conklin from the Department of Psychology & Biobehavioral Sciences at St. Jude, found a notable association between hearing loss and poorer intellectual abilities, communication skills, and a greater decline in intellectual ability over time. Interestingly, verbal learning and memory were found to remain stable despite the hearing loss.
Dr Conklin noted, “Hearing loss–associated cognitive decline is often linked to combination therapies or to those who have received both chemotherapy and radiation therapy, yet our findings revealed a significant rate of hearing loss and cognitive decline even in patients who only received radiation therapy.”
Furthermore, Dr Conklin explained that the rates of hearing loss in ependymoma patients are considerably higher compared to those with other brain tumours. This is primarily due to the younger age at which these patients are diagnosed and the likelihood of treatment affecting the cochlea because of the tumour’s location.
The research team also identified that severe hearing loss was associated with various factors, including hydrocephalus (the abnormal accumulation of cerebrospinal fluid in the brain), multiple surgical procedures, pre-radiation chemotherapy, and the young age of the patients. Notably, no associations were found related to sex, race, or socio-economic status.
Hearing loss during critical developmental periods can hinder social interactions and language acquisition; however, there are potential interventions available. Dr Conklin stated, “There are methods to protect hearing; certain medications can safeguard cochlear hair cells during chemotherapy, and advancements in radiation delivery, such as the transition from photon to proton therapy, have enhanced precision and can spare the cochlea from damage.”
Additionally, interventions such as hearing aids, cochlear implants, and targeted academic support have proven beneficial for patients post-treatment. Nevertheless, factors such as discomfort, social stigma, and the complexities of device management pose challenges to increasing adherence to these interventions. Dr Conklin emphasised that in this context, knowledge is indeed power.
She highlighted that many surveyed parents expressed a willingness to prioritise the use of hearing aids if they believed it would positively impact their child’s brain development, which serves as a significant motivator for ongoing research efforts. “Understanding the associated risks can enhance education and improve adherence to recommended interventions,” Dr Conklin noted.
This study provides crucial insights into the long-term effects of treatment for childhood brain tumours and the importance of addressing hearing loss to support cognitive health.
