Ataxia in children with posterior fossa tumours: a prospective European multicentre cohort study

Purpose Ataxia is the most prevalent motor impairment in children following surgical resection of posterior fossa tumour. The aim of this study was to examine the prevalence, severity, trajectory and risk factors for ataxia in children following surgical resection of posterior fossa tumours. Methods Prospective observational multicentre cohort study, including children (aged < 18 years) undergoing surgical resection of a posterior fossa tumour in 36 European centres across 15 countries. Children were assessed using two ataxia scales; the Brief ataxia rating scale (BARS) and the Scale for the assessment and rating of ataxia (SARA). Assessments were undertaken pre-operatively, post-operative follow up 1 (2-weeks), post-operative follow up 2 (2-months) and post-operative follow up 3 (1-year) after surgery. Results 756 participants who underwent initial surgical management participated in the study, and 122 completed BARS assessment at all timepoints. In this group of children, ataxia was present in 40 (32.8%) participants pre-operatively, and 49 (40.2%) at post-operative follow up 1. Over 90% of participants demonstrated independent walking by 1 year post-operatively (defined by BARS/SARA gait item ≤3). Children with medulloblastomas and post-operative mutism demonstrated more severe ataxia compared to the remaining children. Conclusion Pre-operative ataxia, medulloblastoma and postoperative mutism were identified as the strongest predictors of persistent ataxia. Pre-operative ataxia has been identified for the first time as an indicator of long-term ataxia. This knowledge could be used to identify potential rehabilitation needs and highlights the benefits of an MDT pre-operative assessment.