In this report, the authors describe three patients with malignant gliomas who experienced paroxysmal neurological symptoms triggered by standing. The symptoms were attributed to acute elevations of intracranial pressure, an uncommon phenomenon called "plateau waves." In each instance, the attacks occurred despite the fact that the patient was receiving dexamethasone therapy and stopped promptly with the addition of acetazolamide. Acetazolamide, an orally administered carbonic anhydrase inhibitor, appears to be a specific and effective therapy for this uncommon neurological disorder.