Preoperative Cerebellar Mutism Syndrome in an Adult Female With a Fourth Ventricle Epidermoid Cyst: A Case Report and Review of the Literature

Cerebellar mutism syndrome (CMS) is typically a postoperative complication of posterior fossa tumor resection, especially in pediatric medulloblastoma. We report a rare case of preoperative CMS in a 67-year-old woman with a fourth ventricle epidermoid cyst. She presented with dizziness, gait instability, emotional lability, and speech arrest. MRI revealed a multilobulated mass occupying the fourth ventricle and extending into the cerebellar hemispheres. After total surgical resection and ventriculoperitoneal shunt placement, histopathology confirmed an epidermoid cyst. The patient progressively regained speech and gait stability, with complete speech recovery and no recurrence at three-year follow-up. This case suggests that mass effect on the dentato-thalamo-cortical pathway can produce reversible preoperative CMS in adults and that recognition of this entity is essential for surgical planning and prognosis.