Factors predicting “postoperative cerebellar mutism syndrome’’ after posterior fossa tumor excision in pediatric patients

Abstract

Background: Central tumor location, brain stem involvement, and medulloblastoma have been implicated as risk factors for pediatric postoperative cerebellar mutism syndrome (pCMS) by most researchers. However, conflicting results have been reported for surgical factors, such as the extent of excision, surgical approach, and the need for cerebrospinal fluid diversion. The role of emergency or elective surgery is also not well established. Aim: To assess the role of surgical factors as a risk for pCMS. The secondary variables assessed include patient profile, histopathology, radiological features, and the effect of pCMS on patient survival. Materials and Methods: Overall, 162 consecutively operated patients with posterior fossa tumor (PFT) from July 2012 to March 2020, younger than 16 years of age, were included in the study. The study population was divided into two cohorts: the pCMS group and the non-pCMS group for statistical analysis. A P-value of less than 0.05 was considered statistically significant. Results: In the sample size of 162 patients, 129 patients were included for analysis. There were 11 patients in the pCMS group. Emergency surgery was found to be a significant risk for pCMS (P = 0.021). There was a trend toward statistical significance for the need for preoperative cerebrospinal fluid diversion. The extent of resection and surgical approach were not found to be statistically significant factors. Central tumor location and contrast enhancement were significant radiological risk factors (P < 0.05). Conclusion: Aggressive tumor resection causing iatrogenic injury to the cerebellar circuitry and the brain stem is the most important risk factor for pCMS. Patients with pCMS have adverse survival outcomes.