2029 Background: Neurological side effects associated with childhood brain tumors and their treatments contribute to long term neurocognitive morbidity. The aims of this study were to identify the incidence of sensorineural hearing loss (SNHL) in a large sample of children treated for malignant brain tumors, and to evaluate the potential relationship between SNHL and intellectual functioning following the completion of treatment. Methods: We conducted a prospective follow-up study at a single center with review of 119 patients treated for embryonal brain tumors at the Hospital for Sick Children, between 1996-2015, to analyze the impact of significant SNHL (Chang > 2b) on intellectual function. Hearing was assessed post-treatment (median age: 13.5y (+4.5)) and the median age for neurocognitive testing was 12.8y (+ 4.1). The median interval from time of diagnosis was 5.8y (+ 3.7). Results: Severe SNHL was identified in half the patients (50.4%, n = 60/119). We identified a subset of patients (n = 61) who had assessments of intellectual function. In this cohort, intellectual function was significantly poorer in the group with severe SNHL, even after controlling for the effect of craniospinal radiation (severe SNHL 22.4 Gy + 13.3, no or mild hearing loss 20.4 Gy +12.8) and boost dose and volume. Children experiencing severe SNHL had lower overall IQ (severe SNHL 72.4 + 16.6; no/mild hearing loss 92.0 + 20.5) p < 0.001 and in significantly lower verbal comprehension (severe SNHL 78.7 + 15.9; no/mild hearing loss 94.7 + 13.8) p < 0.001, and working memory (severe SNHL 78.2+ 17.6; no/mild hearing loss 94.8 + 16.4) p < 0.001, scores. Conclusions: Hearing loss is a much more significant complication in children with embryonal brain tumors than previously estimated. We show the profound impact of hearing loss on intellectual deficit in children. Namely, patients with severe SNHL have difficulty using and understanding verbal language, and they have a reduced ability to concentrate and manipulate information in short-term memory. Our results have implications on future trial designs and follow-up of children treated for embryonal brain tumors.
MEDU-34. INTELLECTUAL OUTCOME IN CHILDREN WITH SENSORINEURAL HEARING LOSS FOLLOWING TREATMENT FOR EMBRYONAL BRAIN TUMORS.
