[Multiple sclerosis and amyotrophic lateral sclerosis. The development of concepts of their etiology and pathogenesis].

The analysis of the results of investigations concerning etiology and pathogenesis of multiple sclerosis and amyotrophic lateral sclerosis performed in Institute of Neurology of Rus. Acad. Med. Sci. There were three main periods of the researches determined mainly by theoretical achievements. For the last years the standards of such investigations have approached fundamental levels and corresponded to the trends of world science.