[Anti-neuronal antibodies and central nervous system diseases: contribution to diagnosis and pathophysiology]

Antibodies against antigens found in the central nervous system have been evidenced in several neurological diseases. The most well-known are associated with paraneoplastic neurological diseases (Anti-Hu, Yo, Ri amphiphysin, Tr, CV2 and Ta antibodies). Some of these antibodies are specific for certain types of cancer or neurological syndromes and are highly useful diagnostic tools for the clinician. They have contributed to the hypothesis that these paraneoplastic neurological syndromes involve autoimmune cross reactions between tumoral and nervous system antigens. They are however most unlikely pathogenic on their own. Anti voltage-dependent calcium channel antibodies associated with Lambert-Eaton syndrome which is paraneoplastic in only 60 p. 100 of the cases are also observed in cases of paraneoplastic cerebellar atrophy. Anti-GAD antibodies are seen in non-paraneoplastic stiff man syndrome and in certain progressive cerebellar atrophies. Antibodies reacting with different glutamate receptors are detected in different neurological diseases including Rasmussen's encephalitis. Finally, antibodies are described in diverse conditions such as amyotrophic lateral sclerosis, Sydeham chorea or Gilles de la Tourette syndrome. The significance of the antibodies observed outside the context of paraneoplastic syndromes is not well understood, but the anti-GAD antibodies associated with progressive cerebellar disorders and autoimmune polyendocrinopathies could be an expression of the autoimmune nature of certain neurological degenerative processes affecting the central nervous system.