[Retroviruses and their importance in neurology]

Retroviruses comprise spumaviruses, lentiviruses and oncoviruses. After these taxonomic remarks neurologic-psychiatric-syndromes (multifocal leucencephalopathy, dementia-complex, vacuolar myelopathy and others) are described, that could be observed as manifestations of the "acquired immune deficiency syndrome". Some therapeutic measures are discussed, especially the administration of Zidovudine that shows good temporary results. Essentially Zidovudine works by misleading the Reserve Transkriptase by offering a "Fake-thymidine"--so misleading replication. Lastly the hypotheses concerning multiple sclerosis are put in relation to lentiviruses. Some animal variants of the viruses and their neurotropic features are described. This discovery has lead to those speculations--however, these speculations remain unsecure.