NA

A retrospective chart review was performed on 125 patients who underwent resection of a posterior fossa brain tumor within the past 5 years. Twelve patients were diagnosed with CMS. Of those, four patients were given a trial of amantadine due to illness severity and lack of improvement with intense rehabilitation.

The median age for the study was ten years old. Two patients had Medulloblastoma (WNT), one Medulloblastoma (Group 3), and one Pilocytic Astrocytoma (KIAA1549-BRAF). The average time to diagnosis of CMS was 6.75 days from the time of tumor resection. The range for initiation of amantadine was 16-322 days from CMS diagnosis. Improvement in mobility was the most noted benefit of treatment, followed by improvement in speech. Constipation was the most common side effect.

Amantadine was chosen as an adjunctive therapy for our patients due to its historic success in treating traumatic brain injury. While not proven, it is proposed that amantadine acts as an indirect dopamine agonist. Therefore, it may improve outcomes, as it is thought that dopaminergic cells are damaged during posterior fossa tumor resection. WNT and Group 4 medulloblastoma patients have the highest rate of occurrence of CMS. However, similar molecular correlation for other posterior fossa brain tumors remains unclear. Amantadine may prove to be an adjunct to rehabilitation strategies in improving patient outcomes. A large, randomized control trial further investigating the molecular makeup of posterior fossa tumors and its association with the severity of symptoms, as well as the efficacy of amantadine, is warranted.