Hemianopic Reaction
Historical document, translated for reference. It reflects medical knowledge of the 1920s–30s and is not medical advice.
Summary
The hemianopic reaction (or Wernicke's phenomenon) refers to the absence of pupillary light response in the part of the pupil corresponding to the non-light-perceiving retina in cases of unilateral optic tract lesions, in addition to homonymous hemianopia.
Encyclopedia entry (1928–1936)
HEMIANOPIC REACTION of the pupil (or Wernicke's phenomenon), consists in the fact that in cases of unilateral lesion of the visual tract (tractus opticus), in addition to the loss of visual field from the corresponding halves of the retina (hemianopia homonyma), there is also an absence of reaction to light (direct and consensual) of that part of the pupil which corresponds to the part of the retina that does not perceive light stimuli. Since the reflex arc for the muscle that constricts the pupil passes through the anterior quadrigeminal body, the Wernicke phenomenon will be absent in case of lesion of the visual pathway behind the quadrigeminal body and the lateral geniculate body (see Visual pathways, centers).
Related articles
Cite this page
“Hemianopic Reaction.” Soviet Medical Encyclopedia. English translation of Bolshaya Meditsinskaya Entsiklopediya, 1st ed. (Moscow, 1928–1936), ed. N. A. Semashko. https://sovietmedicalencyclopedia.pages.dev/article/hemianopic-reaction/