Mathematical skills in children with pilocytic astrocytoma

Pediatric patients with circumscribed cerebellar pilocytic astrocytoma (PA) tumors generally perform within the normal range on neuropsychological tests after a complete tumor resection. The outcome in academically relevant abilities such as mathematics, which in adults involve some cerebellar functions, is however much less understood. The aim of this study is to retrospectively investigate the neuroplasticity of mathematical skills and associated cognitive functions following cerebellar resection of PA in pediatric patients.

Twenty-two children (mean age = 11.2 + 1.8), including 11 PA patients (females = 6) and 11 healthy controls (females = 6), were administered a battery of mathematical (MaT) and neuropsychological tests. Single-case statistical analyses were carried out (Crawford's t) as well as between-group comparisons (Wilcoxon test). Spearman correlations between MaT and neuropsychological tests were calculated.

Thirty-six percent of the patients showed difficulties in some mathematical tasks, 50% of them within a broader cognitive deficit. Verbal working memory was associated with MaT performance both in patients and controls while, crucially, visuospatial memory, and visual-motor integration were associated with MaT in patients only. Among patients, MaT correlated negatively with tumor size and positively with the interval surgery test.

The results evince an overall recovery of mathematical abilities despite PA in the majority of patients. This functional reestablishment is supported by visuospatial and visuomotor integration functions that contribute to set up emerging mathematical skills in these patients. Higher levels of compensation are found in more developed tumors as compared to smaller ones.