Results of hemisection of the spinal cord in monkeys / by Frederick W. Mott ; communicated by Professor Schäfer.

  • Mott, F. W. (Frederick Walker), 1853-1926.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Results of hemisection of the spinal cord in monkeys / by Frederick W. Mott ; communicated by Professor Schäfer. 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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    74th flay.—Sensibility to the usual tests perfect on both sides. Muscles of left leg not quite so well developed as those of the right, but not flabby. Movements all performed, but left foot is dragged a little, as if there were some delay in voluntary movements. 77th day.—The animal was angesthetized, and the following experiment was pei’formed, in which I had the valuable assistance of Professor Schafer, as also in others of a similar nature, for it is impossible for one person to carry out such experiments single-handed. The cortex cerebri of the motor area was exposed, and the following notes were made :—faradisation with a moderately strong current of the leg area on the left side, caused well-marked movements of the ordinary character in the right leg, followed by epilepsy. Stimulation of the leg area on the right side, caused, in the first place, movements in the right hallux; secondly, in left ham strings; thirdly, general drawing up of left leg, accompanied to some extent by movements of right leg. More ether was then given, and strong stimulation of the right leg area produced no efliect on the left leg, hut movements in the limb of the same side. The same stimulation of the left side caused very strong movements of the right limb, followed by epilepsy. It is therefore possible that the paradoxical effects may be explained as follows: that the movements evoked in the left leg, in the first instance by stimulation, were due to insufficient narcosis. Subsequent stimulation with a strong current of the leg area on the right side causes flexion and extension of muscles of the thigh and leg of the left side, and also of the right. None of the hallux and toe movements were obtained. It requires a much stronger stimulus to the right side of the brain than to the left to produce an effect. The animal was then killed with chloroform, the spinal cord and brain removed and placed in 2 per cent, solution of bichromate of ammonia. The seat of injury in the cord was not visible to the naked eye. As previously stated, sections were prepared by the Weigekt and Pal methods, after being imbedded in celloidin. In this particular case every segment of the cord was cut, and photo-micrographs showing the extent of the lesion and the degenerations above and below were prepared, as shown in Plate 2. The microscopical examination of the degenerations, and the inferences derived therefrom, will be discussed later on. Case IV. Rheesus $ .—Left hemisection at the 6th dorsal segment, and insertion of a small piece of celloidin into the gap formed by the section. 1st day.—Temperature, right popliteal space, 100°'8 F.; left popliteal space, 100° F.; surface tem- perature, right foot, 88° F.; left foot, 93°'6 F. Complete paralysis of the left leg. No paralysis of the chest muscles noticeable. When tested by electrical excitation the animal seemed to respond to a strong stimulus on both sides. It could not, however, localize on the left (paralyzed) side, whereas it immediately scratched the part on the right side. Testing the animal by this means, as well as by pricking with a needle, was very difficult, owing to its not being tame ; but dipping the feet in hot water gave decisive results. The test was applied as follows :—A vessel containing hot water is raised so that the toes are gradually immersed. Both feet were withdrawn, but the left not so quickly. 4th day.—The animal is doing well. Sensibility te.sted by dipping the feet in hot water, resulting in immediate withdrawal of the right foot, and, after a second or two delay, withdrawal of the left foot. Knee-jerks present on both sides. 8th day.—Animal took some time to catch. The temperature of the right popliteal space was I03°’8 (the high temperature being probably due to the struggle). The thermometer was left in five minutes. While this was done, my assistant kept the left knee flexed, so that no exposure of surface occurred. Temperature of the left side was now taken, and the maximum rise was I01°'4 F. It might be thought