CEREBELLAR MUTISM SYNDROME

Since 1980, a growing number of pediatric patients with mutism followi ng posterior fossa surgery have been recognized. This syndrome typical ly affects children and in rare cases young adults who become mute one or two days after tumor operation but do not show disturbances of con sciousness or language comprehension. The disorder persists for 1 to 4 months. The pathogenesis is still unknown. Of 21 children who underwe nt surgery for large posterior fossa tumors between 1991 and 1995, 6 d eveloped cerebellar mutism. Histologically the tumors were classified as astrocytoma WHO grade I, astrocytoma WHO grade II and ependymoma WH O grade III in one case and medulloblastoma WHO grade IV in three case s.Besides the clinical course, intraoperative findings and CT or MRI d ata are evaluated and discussed considering possible etiological hypot heses. Our own experience and also literature reviews suggest that the lesion of the cerebellar hemispheres might be the most important one of multiple factors causing cerebellar mutism. Generally the syndrome is transient. The diagnosis should not delay adjuvant therapy in patie nts with a malignancy.