Diagnosis of Neoplastic and Paraneoplastic Cerebellar Ataxia

Abstract

Acquired cerebellar ataxia encompasses various diseases. Neoplastic causes have specific characteristics. First, because of the limited space in the posterior fossa, these tumors are considered as critical brain lesions. Clinically, patients with cerebellar tumors frequently present with signs of intracranial pressure, such as headache, vomiting, or decreased level of consciousness. Second, the incidence and the type of cerebellar tumors vary considerably with age. Pilocytic astrocytomas and medulloblastoma are common cerebellar neoplasms in children. Conversely, the most frequent cerebellar tumors in adults are metastases. However, in a context of a systemic cancer and in absence of brain metastase, paraneoplastic cerebellar ataxia (PCA) must be considered. In the past 20 years, several antibodies directed against neuronal and tumoral antigens have been described in association with PCA, leading to the description of different subtypes of PCA based on the associated antibodies, the clinical evolution, and the type of associated tumor. The purpose of this chapter is to present the main etiologies of neoplastic and paraneoplastic causes of acute cerebellar ataxia in children and adults.