- Patients in unstable condition or with severe intracranial hypertension (ICH). Definition of severe ICH for this study would be the presence of headaches, nausea, and vomiting and papilledema at fundoscopic examination (all of them). Patients in this category can be considered for entrance into the study only after treatment of ICH by ventricle-peritoneal shunting. Patients with CT findings compatible with intracranial hypertension will have neurosurgical evaluation (by non study personal) before study entry.