Pre-operative and intra-operative risk factors of post-operative cerebellar mutism syndrome in pediatric patients undergoing posterior fossa tumor surgery: a systematic review

Purpose: Surgical removal of posterior fossa tumors can lead to the development of post-operative cerebellar mutism syndrome (pCMS), with the incidence of long-term deficits being more evident in the pediatric population. Our study aims to offer an in-depth overview of the pre-operative and intra-operative risk factors associated with pCMS reported in the literature. Methods: The MEDLINE, Google Scholar, Scopus, and Cochrane Library databases were systematically searched for studies that included patients aged < 18 years, diagnosed with posterior fossa tumors, who developed pCMS after surgical resection, for inclusion in the qualitative analysis. Results: Sixty-one studies incorporating 5653 patients were included. Tumor type, site, extension, invasion, in addition to radiological predictors, pre-operative hydrocephalus, patient age, gender, and pre-operative language impairment were assessed as risk factors in this thorough review. Medulloblastoma diagnosis, high-grade histopathology, and midline location were identified as significant predictors of pCMS. Moreover, vermis incision, superior cerebellar peduncle involvement, and gross total tumor resection were notable intra-operative risk factors. Only a few studies identified protective factors that reduced the risk of developing pCMS. Conclusion: This study offers the most comprehensive qualitative analysis to date of the key contributing factors associated with the development of pCMS. These findings may guide healthcare professionals in deciding the optimal approach to posterior fossa tumor surgeries in children.