CMS-04CEREBELLAR MUTISM SYNDROME IN POSTERIOR FOSSA TUMORS: A BETTER UNDERSTANDING FOR A BETTER COUNSELING. A RETROSPECTIVE ANALYSIS OF PEDIATRIC PATIENTS IN UZ LEUVEN FROM 1990 TO 2015

Abstract

Cerebellar mutism syndrome (CMS) consists of mutism, emotional lability, hypotonia and ataxia. It is induced by resection of midline posterior fossa tumors. Little is known about the risk factors of this syndrome in children and the neurocognitive outcome. Methods: The patient database of the University Hospitals Leuven was interrogated for pediatric patients followed between 1990 and2015 using terms as 'posterior fossa tumor', 'mutism' or 'cerebellar syndrome'. 73 patients were included. Results: 75 posterior fossa interventionswere counted.Median age at resectionwas 5.73 (0.30-18.43) years. Postoperative mutism was reported in 26.6%: 'Mutism Group' (MG). In 73.3%, mutism was not reported: 'Non-Mutism Group' (NMG). Average age in theMG was 6.85 years (0.30-14.74), in the NMG 6.09 years (0.48-18.43). Themost commontumor typewasmedulloblastoma(65%) intheMGandpilocytic astrocytoma(44%) in theNMG.Atelovelar approachwas used in 38%, a transvermian in 18%. Postoperative mutism occurred in 28.5% and 30% respectively. Mean total IQ points between intervention and after 2 years (tested in 11/73) declined with 13.6 points in the MG (97.2 vs 83.6, VIQ 97.6 vs 92.2 and PIQ 95 vs 78.2). Mean IQ in NMG remained stable (TIQ 101.8 vs 105.5, VIQ 103.2 vs 109.8, PIQ 102.5 vs 102.5). In theMG 4/5 patients received adjuvant therapy (chemotherapy and/or radiotherapy), in the NMG 3/6 patients. Conclusion: CMS is a frequent postoperative syndrome occurring in 26.6%of the studied interventions. Our data indicate that children withCMS have a more impaired neuropsychological outcome.