Impairment of executive functions in pediatric posterior fossa tumor survivors

Purpose: Apart from controlling motor function the cerebellum modulates higher cognitive and emotional functions. We investigated executive functions in pediatric posterior fossa tumor survivors.

Patients and Methods: We assessed planning, information processing and facets of attention as well as intelligence in 40 pediatric patients with posterior fossa brain tumors (mean age 14.63yrs, SD 5.03). Patients suffered from low grade tumors (LGCT) treated with surgery only (n=17) or malignant tumors (HGCT) requiring adjuvant treatment (n=23). The Amsterdam Neuropsychological task program (ANT) evaluated information speed, divided and shifting/alternating attention whereas the Tower of London-test (TOL) discerned forward thinking abilities. IQ was determined using the Wechsler Intelligence Scale.

Results: Planning abilities of HGCT-patients did not differ from LGCT-patients. Still, HGCT patients scored significantly worse than the normal population. ANT revealed deficits in terms of errors and information processing speed in both patient groups. Increasing complexity of attention tests revealed significant deficits in LGCT survivors. Performance IQ in HGCT survivors was significantly lower than in LGCT patients. There was no correlation between TOL scores and performance IQ.

Conclusion: Pediatric posterior fossa tumor survivors exhibit impairments in forward thinking, information processing and aspects of attention regardless of form of treatment that are increased by chemo- and radiotherapy-associated toxicity. This pattern of executive function loss underscores the role of the cerebellar damage in both patient groups.

E. Koustenis is supported by KINDerLEBEN e.V. and S. Rueckriegel was supported by Kind-Philipp-Stiftung.