Mechanisms of paraneoplastic neurological syndromes.

Introduction. - Paraneoplastic neurological syndromes (PNS) refer to a set of neurological disorders associated with neuronal degeneration in some pat ients with systemic cancers. These disorders are nor related to the tumor m ass or metastasis. Current knowledge and key points. - Evidence argues for an autoimmune react ion against tumor cells which expresses antigens normally present in neuron s. A high percentage of patients with PNS harbors high titers of anti-neuro nal autoantibodies in their serum and cerebrospinal fluid. In addition to t heir clinical interest in diagnosis and pathophysiology, these autoantibodi es provide a unique opportunity to identify genes encoding previously undis covered neuronal proteins which are also expressed by tumor cells. These "o nconeural" antigens have been classified in four groups: neuromuscular junc tion proteins, nerve terminal/vesicle-associated proteins, neuronal RNA bin ding proteins, or neuronal signal transduction proteins. Future prospects and projects. - All of these proteins would play a major r ole in the neuronal,maturation and homeostasis, and for some of them in cel lular proliferation. Better understanding of the exact role of these protei ns would in turn permit better understanding of the mechanisms of neuronal degeneration and tumor cell proliferation in PNS. (C) 1999 Elsevier, Paris.