Note on the results of circumsection of the motor cortex / by E.A. Schafer.

  • Sharpey-Schäfer, E. A. (Edward Albert), Sir, 1850-1935.
Date:
1901
Catalogue details

Licence: In copyright

Credit: Note on the results of circumsection of the motor cortex / by E.A. Schafer. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    [From the Proceedings of the Physiological Society, Jan. 26, 1901.] Note on the results of circumsection of the motor cortex. By E. A. SCHAFER. The observations recorded were done in collaboration with Dr R. S. Woodworth. Their object was to test in the monkey the results obtained by Marique and by Exner and Paneth in the dog, but incidentally one experiment has been made in the cat and one in the dog. In one monkey and one cat a complete extirpation of a motor area was made for the sake of comparing the symptoms in the circumsected ■cases. In two successive experiments on one monkey a cut was made through the pia mater and the most superficial part of the cortex alone, the cut circumsecting the arm area and avoiding large vessels. These experiments both gave no noticeable result. In four other experiments on monkeys the cut around the arm area was deep enough not only to penetrate the grey matter, but to pass some distance into the white matter. In all four there was considerable hsemorrhage both superficial and deep. In three out of the four there was motor paralysis of the opposite arm, and in two of these cases there was also paresis of the leg: in one no paralysis was noticeable. In none was there any appreciable persistent sensory paralysis (tactile), but one showed homonymous hemianopsia persisting 14 days; when the animal was killed. The motor paralysis was in all cases less marked than with extirpation of the area. In three of the four cases the circumsected area was exposed just prior to the killing of the animal, and explored with the faradic current; the time after the operation being from a fortnight to three weeks. In all, movements of the paralysed arm were obtained, but it required a stronger stimulus to elicit them than was the case with those of the normal side. The circumsected area had for the most part a pale or yellowish appearance, but in one which was examined in sections prepared by the Nissl method, the giant pyramidal cells were not smaller nor less numerous than those of the surrounding motor region, and showed an increased amount of tigroid or chromatic substance. In all which have been examined by the Marchi method there is extensive degeneration down the pyramidal tract.