Olga Vassilievna Leonova, later Leonowa-von Lange (fl. 1890–1910) born 1851 or 1859 was a physician and embryologist known for her studies of neuroembryology and congenital disorders, specifically those affecting the brain, spinal cord, eyes and limbs. Leonova was one of the first female scholars to work in Constantin von Monakow's laboratory ("Labörli"), founded in 1885, the origin the Zürch Brain Research Institute Brain Research Institute of Zurich University. (von Monakow, 1970) Leonova, born in Russia, studied medicine in Moscow, St. Petersburg, Vienna and Leipzig. Later she did research work at the Imperial University of Moscow's cutting-edge neurobiology laboratories. Her research focussed on stillborn infants with congenital brain disease (anencephalia, anophthalmia, amyelia). Here she described the connection between central nervous system damage and congenital eye disease. She earned her doctoral degree before 1904, published at least 12 scientific papers between 1890 and 1909 but did not show further scientific development (Refs.). After a head start into the European neuroscience scene in 1894 as the only lady scientist presenting at the 66. central conference of German speaking naturalists and physicians in Vienna, she later apparently lost the support of the science community. This may partly be due to her argumentative, almost belligerent style of writing. Her work was cited for a short period and the forgotten. She eventually resided in a villa in Laufenburg, Germany, at the border to Switzerland, and became arrested in 1914 as a Russian spy. After two years she was allowed to move to Zürich. <ref>Förstl H: Olga von Leonova (1851-?): A Neuroscientist Vanishes. Der Nervenarzt 4, 2021, pp 371-374 https://doi.org/10.1007/s00115-020-01009-5> < von Monakow, C: Vita mea. Huber, Bern.> Olga von Leonova's papers: 1890 Ein Fall von Anencephalie. Ueber den feineren Bau des Rückenmarkes eines Anence- phalus. Archiv fuer Anatomie und Physiologie (Anat. Abth.) 403–422 1893a Ueber das Verhalten der Neuroblasten des Occipitallappens bei Anophthalmie und Bulbusatrophie und seine Beziehungen zum Sehact. Archiv fuer Anatomie und Physiologie (Anat. Abth.) 308–318 1893b Zur pathologischen Entwickelung des Centralnervensystems. (ein Fall von Anence- phalie combiniert mit totaler Amyelie). Neurologisches Centralblatt 7: 218–227; 8: 263–267 1894a Contribution a l’etude de l’evolution pathologique du systeme nerveux. Anencephalie totale combine avec une amyelia et un rhachischisis totaux chez un embryon humain. Moscou Soc Nat Bull 7: 191–198 1894b Die Sinnesorgane und Ganglien bei Anencephalie und Amyelie. (zweiter Fall von totaler Amyelie). Verhandlungen der Gesellschaft deutscher Naturforscher und Aerzte, 2. Hälfte, Neurologisches Centralblatt 13: 176–177