Reduced Fractional Anisotropy of Superior Cerebellar Peduncle is Associated With Persistent Ataxia in Children Undergoing Resection of Posterior Fossa Tumors

Abstract

Abstract INTRODUCTION Persistent neurological deficits are seen in over 60% of children after resection of posterior fossa tumors. The goal of this study was to determine if these deficits are associated with persistent structural injury to white matter tracts. METHODS Demographic, clinical, and imaging data were reviewed for children undergoing resection of posterior fossa tumors at a tertiary care pediatric hospital. Preoperative, early postoperative (within 48 h of injury) and follow-up diffusion tensor imaging (DTI) were analyzed. Fractional anisotropy (FA) of the middle and superior cerebellar peduncles (SCP) were measured using manual regions of interest. Mean FA values before and after surgery were compared using paired sample T-test. Preoperative, postoperative and follow-up FA values were compared between patients with and without persistent neurological deficits. Statistical significance was set at P < .05. RESULTS A toal of 20 patients (12 male, mean age 6.1 ± 4.1 yr) were included in this study. A total of Twelve patients (60%) underwent a trans-vermian approach and 15 patients (75%) underwent gross total resection. All patients had preoperative DTI scans, and follow-up DTI scans were available for 18 patients at a median duration of 19.7 mo (range 4-57.9 mo). Compared to preoperative DTI, FA of the left SCP was significantly reduced on early postoperative DTI scans (0.44 ± 0.07 vs 0.53 ± 0.1, P = .003). Significant reduction in left SCP FA on follow-up DTI was seen in patients with persistent ataxia at follow-up (0.43 ± 0.1 vs 0.55 ± 0.1, P = .016). Patients with persistent ataxia at follow-up (n = 10) had significantly lower FA of the left SCP at follow-up compared to patients who recovered from early postoperative ataxia (n = 4) (0.43 ± 0.1 vs 0.55 ± 0.04, P = .04). CONCLUSION Reduced FA of the SCP is associated with persistent ataxia at follow-up in children undergoing resection of posterior fossa tumors.