Brain tumors are relatively uncommon and have a prevalence rate of 12 per 100,000 persons/year (Deangelis and Rosenfeld 2010). Symptoms of brain tumors may comprise both generalized and focal conditions. Common generalized symptoms include headaches, projectile vomiting, vertigo, cognitive decline, and personality changes. Focal symptoms tend to correspond to the anatomical localization of the tumor, and include focal seizures, hemiparesis, visual defect, and aphasia.
Movement disorders usually result from pathological alterations in the connectivity of the basal ganglia. Consequently, basal ganglia tumors are often associated with movement disorders such as dystonia, chorea, parkinsonism, and/or tremor. In addition, certain movement disorders can be caused by tumors in other brain regions. For instance, supratentorial tumors can cause parkinsonism, tremor, and dystonia (Krauss et al. 1991a; Krauss et al. 1995). Brainstem tumors are also associated with parkinsonism (Pohle and Krauss 1999), cervical dystonia (Krauss et al. 1997), and hemifacial spasm (Inoue et al. 1995). It is striking that tumors, particularly those affecting the basal ganglia or brainstem, may often cause mixed movement disorders, such as dystonia plus parkinsonism or tremor, dystonia plus chorea, tremor plus myoclonus, and many other combinations (Leenders et al. 1986; Poewe et al. 1988; Krauss et al. 1992).