Longitudinal assessment of ataxia in children following surgical resection of posterior fossa tumours

OBJECTIVES To report the natural history of ataxia in the first two years following surgical resection of a posterior fossa tumour (PFT). METHODS 20 children (mean age 9.9 years, range 5-15 years) who had undergone resection of a posterior fossa tumour were assessed using the Scale for the Assessment and Rating of Ataxia (SARA), Brief Ataxia Rating Scale (BARS) and the Pediatric Evaluation of Disability Index (PEDI) at the following time points; initial post-operative period, then at 3 months, 1 and 2 years post operatively. RESULTS The assessments demonstrated a rapid improvement in ataxia between initial and 3 months post-operative assessments, quantified by both the SARA and BARS (mean reduction in scores 4.8, 4.6 respectively). There were additional gradual improvements at 1 year (mean reduction SARA 0.6, BARS 0.2) and 2 years post operatively (mean reduction SARA 0.9, BARS 0.9). Return of function behaved similarly, quantified by a rapid increase in PEDI scores between initial and 3 month assessments (mean increase in score 26) and gradual increases at 1 and 2 years (mean increase 2, 2.5 respectively). There was a trend for children with medulloblastoma to demonstrate higher ataxia scores than children with low grade gliomas (mean initial post-operative scores 13.4 and 8.5 respectively). CONCLUSIONS The largest change in ataxia scores and functional mobility scores (PEDI) is demonstrated within the first 3 months post operatively. Ongoing gradual improvement in ataxia and mobility function was observed at 2 years. These results have implications for management of children with PFT