Longitudinal evaluation of neurocognitive function after treatment for central nervous system germ cell tumors in childhood.

BACKGROUND: Central nervous system germ cell tumors (CNS GCT) are typically localized to midline structures of the brain, including the pineal and suprasellar/pituitary regions. Management of these tumors depends on underlying histology (germinoma or nongerminomatous germ cell tumor). Knowledge about neurocognitive outcome in these patients is limited. Longitudinal neurocognitive outcome in CNS GCT patients seen for neuropsychological evaluation at a single institution was explored.
METHODS: Thirty-five patients were seen for neurocognitive evaluation after diagnosis and treatment for a CNS GCT. Mean age at diagnosis was 11.66 years. Tumor location was suprasellar in 12 patients, pineal in 9, bifocal in 10, multifocal in 3, and thalamic in 1. Standardized cognitive tests of intelligence, receptive language, visual-motor ability, memory, and academic achievement were administered. Longitudinal and cross-sectional analyses were conducted.
RESULTS: Intelligence, academic functioning, and receptive vocabulary were not significantly compromised in most patients treated for CNS GCT. Working memory, information processing speed, and visual memory declined significantly over time in all patients. Patients with pineal tumors showed early and stable deficits, whereas patients with suprasellar and bifocal tumors showed more protracted declines from initial average functioning. Patients treated with ventricular versus craniospinal radiation displayed better outcome.
CONCLUSIONS: Although general cognitive abilities appeared stable and intact after treatment for most children with CNS GCT, a significant decline over time in working memory, processing speed, and visual memory was evident. Tumor location appeared to be important in understanding the trajectory of stability and decline in CNS GCT patients, as did radiation field.