Paraneoplastic Neurologic Syndromes—An Update on Current Understanding and Future Perspectives

Paraneoplastic neurological syndromes (PNS) are remote effects of tumors on the nervous system. They can strike at single or at multiple sites of the central nervous system (CNS) and the peripheral nervous system, and often appear before the detection of cancer. PNS can be disabling and debilitating and may be either an additional burden to cancer or the cause of death. The PNS Euronetwork group has collected a series of approximately 1,000 patients in several European centers. This study is the largest systematic series of patients with PNS and, for the first time, can answer questions about the most frequent PNS, their detailed symptoms, associated antibodies, and the types of underlying tumors. The clinical course and laboratory findings for many PNS suggest an autoimmune pathogenesis; however, research into this heterogeneous immunological relationship has been evolving over recent decades. The classic syndromes are antigen-target-oriented syndromes such as myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and ion channel-mediated diseases. Onconeuronal antibodies constitute a large group of PNS, characterized by the appearance of specific antibodies, defined cl