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addition, different rates of change in test performance
were found over time in patients versus controls, such
that the performance of patients improved toward
normal over time. For example, the improvement over
time was faster for patients than for controls on verbal
memory but slower for patients than for controls on
motor speed/dexterity.
No significant group- or age-related differences were
revealed for recognition vocabulary (these results are not
included in Figs and ).
Effect of Radiation Dose on Neuropsychological
Performance
Motor speed and dexterity (Purdue Pegboard
2-Hand).—Among patients, motor speed and dexterity
decreased with increasing mean radiation dose to the
hippocampus (main LME analyses: left hippocampus,
dose: P ¼ .049, visit: P ¼ .023; right hippocampus,
dose: P ¼ .032, visit: P ¼ .014). Test performance also
decreased with increasing mean dose to the temporal
lobes (main LME analysis: left temporal lobe, dose:
P ¼ .033, visit: P ¼ .021; right temporal lobe, dose:
P ¼ .015, visit: P ¼ .017). At 6-month follow-up, raw
scores decreased with increasing doses to the left
and right hippocampi and temporal lobes (for all,
P , .045). At 15-month follow-up, the relationship
was significant for the temporal lobes (left, P ¼ .020;
right, P ¼ .010) and at 27-month follow-up, for the
right hippocampus (P ¼ .036). Figures and illustrate
decreased motor speed/dexterity with increasing radia-
tion doses to the hippocampi and temporal lobes, respec-
tively, at 6-month follow-up. There was no significant
effect of mean dose to cerebrum (P ¼ .46) or SVZ
(P . .3) on performance. There was no significant
difference in performance on the test of motor speed
between patients with infratentorial versus supratento-
rial tumors (P ¼ .37 at 6 mo, P ¼ .55 at 15 mo, and
P ¼ .59 at 27 mo).
Verbal learning (WJ-III Memory for Words).—
Although the main analysis for verbal learning indicated
an overall effect of dose to cerebrum on test performance
(dose, P ¼ .022; visit, P ¼ .013; AgeRT × Dose,
Fig. 2. Age- and time-related changes in neuropsychological performance (raw scores) in patients and controls. The black “+” symbols
represent individual control data points and the gray “×” symbols represent individual patient data points. The results of the LME
regression analyses of age- and time-related differences in test scores between patients and controls are presented as solid lines. The
individual lines represent changes in test scores over time (27 mo) for patients (gray lines) and controls (black lines) of different ages.
Raw scores in both groups increased with age on the Purdue Pegboard 2-Hand test (1A), WJ-III Memory for Words (1B), Bead Memory
(1C), and visual perception test (1D) (all P , .001). Improvement in test performance on the Purdue Pegboard 2-Hand, WJ-III Memory
for Words, and visual perception tests over the 27-mo period was most prominent in younger children. However, despite overall
improvement over time, younger patients had more pronounced cognitive deficits.
Redmond et al.: Radiation to neural progenitor niches and neurocognitive outcomes
364 NEURO-ONCOLOGY † M A R C H 2 0 1 3
at Universitaet Leipzig, Institut fuer Informatik/URZ, Bibliothek on August 25, 2014
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