Cognition before and after chemotherapy alone in children with chiasmatic-hypothalamic tumors

Studies on adults with cancer, with or without CNS involvement, have shown that chemotherapy (CT) can affect cognitive functions. Two studies on children with optic pathway gliomas, involving the hypothalamus in some cases, and treated with CT according to various protocols reported the children maintaining a good IQ (no other cognitive abilities were tested). Among 18 children with chiasmatic-hypothalamic tumors (CHT) given front-line CT treatment at our institute using the same protocol (cisplatin and etoposide), we screened eight children for cognitive sequelae, correlating their test performance with several clinical variables (age at diagnosis and at time of treatment, time elapsing since treatment, and tumor volume reduction). The neuropsychological evaluation involved measuring IQ in all eight children and cognitive flexibility in three before CT (T1), then testing IQ, attention, memory and executive functions after CT (T2). The group as a whole showed no signs of any decline in IQ from T1 to T2, except for some WISC items, but IQ deteriorated severely in three patients with NF1 (only suspected in one case). At T2, the whole sample performed within normal range, except for two children showing a significantly worse result in two specific tests. The parents of the other 10 children, reported no substantial changes in their children's behavior and intellectual vivacity in a semistructured telephone interview conducted in cooperation with the children's teachers. CT alone as front-line treatment for CHT does not appear to have a negative effect on IQ and numerous neuropsychological tests. Some skills were more affected than others in our sample (albeit with a very low statistical significance of the impairment), and some patients seemed to be more vulnerable than others after CT. The multifactorial origin of such cognitive impairments is discussed. This type of study needs to be repeated in larger, but nonetheless carefully selected groups of patients.