Intellectual impairment after treatment for medulloblastoma and astrocytoma in childhood: the Brazilian experience.

ABSTRACT

BACKGROUND: This study investigated the impact of posterior fossa tumors and their respective treatments, and the impact of clinical and sociodemographic variables, on the intelligence quotient (IQ) of Brazilian children. METHODS: Twenty patients took part in the study, of which 13 were diagnosed with astrocytoma (average age at evaluation 10.2 y) and 7 with medulloblastoma (average age at evaluation 9.2 y). The first subgroup was submitted exclusively to tumor resection surgery and the second subgroup underwent surgery, chemotherapy (Vincristine, Cisplatine, and Carmustine), and radiotherapy (total dose of 54 Gy). The Wechsler Intelligence Scale for Children (WISCIII) was used. RESULTS: The following statistically significant effects were identified treatment modality on performance intelligence quotient scores (P=0.02) and processing speed index (PSI) (P=0.01); presence of hydrocephalus at diagnosis on verbal intelligence quotient (P=0.04); tumor localization on perceptual organization index (P=0.03); time interval between diagnosis and neuropsychological evaluation on PSI (P=0.05) and freedom from distraction index (P=0.03); and level of parental formal education on full scale IQ (P=0.02). CONCLUSIONS: Exposure to radiotherapy has a significant effect on processing speed and consequently on global intellectual capacity. The impact on intelligence of clinical and sociodemographic variables such as tumor localization, time interval between diagnosis and cognitive evaluation, and parental level of formal education is confirmed in the specific setting of a developing country.