Cerebellar mutism syndrome (CMS) occurs in 8–29 % of children undergoing posterior fossa tumor surgery. Its main symptoms are mutism and emotional lability. Although it is always transient, recovery time can be lengthy with long-term cognitive sequelae. There is no approved drug treatment for CMS, but some drugs are used in everyday medical practice. One of these is fluoxetine, which has been used for many years in our institution. The main objective of this study was to establish the safety profile of fluoxetine in this condition.

The records of patients admitted to the pediatric intensive care unit after brain surgery at Angers University Hospital from 2010 to 2020 were reviewed. Children aged 2 years and older who underwent a posterior fossa tumor surgery and were diagnosed with CMS were included. Data on patient characteristics, prescription of fluoxetine treatment, side effects if any, and complete mutism duration were collected.

Among 246 patients admitted to the pediatric intensive care unit for brain surgery during the study period, 23 had CMS and eight were prescribed fluoxetine. No serious adverse event related to fluoxetine was reported. Complete mutism duration did not differ significantly between the fluoxetine group and the non-fluoxetine group(p = 0.22). However, the treatment was initiated after recovery from complete mutism in half of the treated patients.

This study suggests a positive safety profile of fluoxetine used in postoperative CMS. It does not answer the question of whether the treatment is effective for this indication. A randomized controlled trial based on a syndrome severity scale should be conducted to provide a more reliable assessment of the efficacy and safety of fluoxetine.