ssive, with poor prognosis. Total surgical removal is usually not possible, and response to radiation therapy is poor. Astrocytoma Presentation similar to glioblastoma multiforme but course more protracted, often over several years. Cerebellar astrocytma, especially in children, may have a more benign course. Prognosis is variable. By the time of diagnosis, total excision is usually impossible; tumor often is not radiosensitive. In cerebellar astrocytoma, total surgical removal is often possible. Medulloblastoma Seen most frequently in children. Generally arises from roof of fourth ventricle and leads to increased intracranial pressure accompanied by brain stem and cerebellar signs. May seed subarachnoid space. Treatment consists of surgery combined with radiation therapy and chemotherapy. Ependymoma Glioma arising from the ependyma of a ventricle, especially the fourth ventricle; leads early signs of increased intracranial pressure. Arises also from central canal of cord. Tumor is not radiosensitive and is best treated surgically if possible. Tumor Clinical Features Treatment & Prognosis Brain stem glioma Presents during childhood with cranial nerve palsies and then with long-tract sings in the limbs. Signs of increased intracranial pressure occur late. Tumor is inoperable; treatment is by irradiation and shunt for increased intracranial pressure. Cerebellar hemangioblastoma Presents with disequilibrium, ataxia of trunk or limbs, and signs of increased intracranial pressure. Sometimes familial. May be associated with retinal and spinal vascular lesions, polycythemia, and hypernephromas. Treatment is surgical. Pineal tumor Presents with increased intracranial pressure, sometimes associated with impaired upward gaze (Parinauds syndrome) and other deficits indicative of midbrain lesion. Ventricular decompression by shunting is followed by surgical approach of tumor; irradiation is indicated if tumor is malignant. Prognosis depends on hist...
