title: Executive function deficits in pediatric cerebellar tumor survivors.
abstract: OBJECTIVE
  Besides motor function the cerebellum subserves frontal lobe functions. Thus, we investigated executive functions in pediatric posterior fossa tumor survivors.
  
  
  METHODS
  We tested information processing, aspects of attention, planning and intelligence in 42 pediatric posterior fossa tumor survivors (mean age 14.63 yrs, SD 5.03). Seventeen low-grade tumor patients (LGCT) were treated with surgery only and 25 high-grade tumors patients (HGCT) received postsurgical adjuvant treatment. We evaluated simple reaction time, executive functioning, i.e. visuospatial memory, inhibition, and mental flexibility using the Amsterdam Neuropsychological Tasks program, whereas forward thinking was assessed with the Tower of London-test. Intelligence was determined using the Wechsler Intelligence Scale. Ataxia was assessed with the International Cooperative Ataxia Rating Scale.
  
  
  RESULTS
  About one third of each patient group showed forward thinking scores below one standard deviation of the norm. Impaired forward thinking correlated significantly with degree of ataxia (r = -0.39, p = 0.03) but not with fluid intelligence. Both patient groups exhibited executive function deficits in accuracy and reaction speed in more difficult tasks involving information speed and attention flexibility. Still, HGCT patients were significantly slower and committed more errors. Working memory was inferior in HGCT patients.
  
  
  CONCLUSIONS
  Pediatric cerebellar tumor survivors with different disease and treatment related brain damage exhibit similar patterns of impairment in executive functioning, concerning forward thinking, inhibition and mental flexibility. The deficits are larger in high-grade tumor patients. The pattern of function loss seen in both groups is most probably due to comparable lesions to cerebro-cerebellar circuits that are known to modulate critical executive functions.
authors.affiliation: Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Koustenis
authors.affiliation: Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, Germany. Electronic address: Pablo.hernaiz@charite.de.
authors.forename: Pablo
authors.initials: P
authors.lastname: Hernáiz Driever
authors.affiliation: Leiden Institute for Brain and Cognition, Department of Clinical Child and Adolescent Studies, Leiden University, The Netherlands.
authors.forename: Leo
authors.initials: L
authors.lastname: de Sonneville
authors.affiliation: Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, Germany; Department of Neurosurgery, University Hospital Würzburg, Germany.
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Rueckriegel
mesh_terms: D000293:Adolescent; D001259:Ataxia / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D001288:Attention; D002528:Cerebellar Neoplasms / Q000503:physiopathology / Q000523:psychology* / Q000601:surgery; D002648:Child; D056344:Executive Function; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D015192:Infratentorial Neoplasms / Q000503:physiopathology / Q000523:psychology* / Q000601:surgery; D007266:Inhibition, Psychological; D007361:Intelligence Tests; D008297:Male; D008570:Memory, Short-Term; D008606:Mental Processes; D060787:Neoplasm Grading; D009483:Neuropsychological Tests; D011930:Reaction Time; D017741:Survivors
keywords: Cerebellum; Forward thinking; Posterior fossa tumors; Processing speed; Set shifting; Working memory