The authors report the unusual case of a 7-year-old child, one of the youngest reported to date, who developed repeated episodes of sympathetic hyperactivity after surgical resection of a midbrain glioma. These paroxysmal events were similar to previously described diencephalic seizures. However, there was no evidence of epileptogenic activity on electroencephalography, and radiologic imaging did not reveal hydrocephalus or intraparenchymal hemorrhage. In this report, clinical features are described of this patient, along with the novel use of clonidine--a sympathetic blocking agent--in his treatment, published reports are reviewed on diencephalic seizures, and steps are recommended in the treatment of a patient who presents in this manner. The authors believe that diencephalic seizures can present with a spectrum of autonomic features, and treatment should be tailored with the appropriate pharmacologic blockade.