On dilatation of the pupil from stimulation of the cortex cerebri / by J. Herbert Parsons.

  • John Parsons
Date:
1901
Catalogue details

Licence: In copyright

Credit: On dilatation of the pupil from stimulation of the cortex cerebri / by J. Herbert Parsons. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    sphenoidal convolution pricking of the opposite ear, head and eyes turn to the opposite side, pupils dilate widely.” In dogs, “(7) On the frontal division of the second1 external convolution (coronal convo- lution) the movements of the eyeballs I have found to be divergent, associated with contraction of the pupils.” “ (12) On the precrucial division of the sigmoid gyrus the eyes widely opened with dilatation of the pupils In one or two instances I have seen the eyeballs converge, but in all cases the pupils were dilated.” “ (13) On the parietal and posterior division of the second1 external convolution movement of the eyeballs to the opposite side the pupils occasionally contract.” Similar results were obtained upon jackals, equivocal results on rabbits. In cats he only occasionally obtained constriction, but does not state that he ever obtained dilatation. In pigeons the most constant effect of any was an intense constriction of the opposite pupil on stimulating the middle of the convexity of the hemisphere. Horsley and Schafer (1> obtained hemiplegia, accompanied by great dilatation of the right pupil and constriction of the left, in a monkey in which the anterior part of the right marginal convolution and almost the whole of the motor area had been removed. Schafer(5), in exciting the visual centre in monkeys, besides ocular movements, obtained movements of the eyelids, etc., which, he states, “ have not been constant in my experiments, nor have the changes in the pupils which are sometimes observed accompanying the movements of the eyes. I have occasionally obtained from stimulation on or near the quadrate lobule marked constriction of the pupils More usually, however, the movements whatever the part stimulated, are accompanied by dilatation of the pupil.” Beevor and Horsley(6) state: “In the vast majority of instances there was no movement of the pupils ; when it occurred dilatation was always noted. This dilatation of the pupils exists simply in association with turning of the head and eyes to the opposite side. It appeared to be represented most round the horizontal limb of the precentral sulcus, but we did not observe it many times.” They<7> also obtained dilatation of the pupils on stimulation of the fore part of the internal capsule. In the orang-outang they <8> expressly state that there was no dilatation of the pupils from stimulating the brain anterior to the precentral sulcus. Fran50is-Franck and Pitres'9' obtained dilatation of the pupil in the dog from excitation of the anterior branch of the sigmoid, and the 1 The third convolution of most authors. 26—2
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