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
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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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    opposite. What the function of this column is, is not known. It decreases in size at the lower part of the medulla, and disappears in the arciform fibres, as my specimens show. There is no proof that it conducts painful sensations, only surmise. Another possible channel for the transmission of sensory impulses upwards is the grey matter. This is Schiff’s view, and there is much to support it from pathological observations, notably cases of syringo-myeliaalthough Weiss’s experiments on the Dog, and those of Brown-Sequard, distinctly oppose such a theory. But it is possible to conceive that the grey matter is connected at difierent levels by a series of short ascending commissural connecting fibres. The sensory elements are thus brought into relation with one another, just as we believe the motor cell elements are. Above a hemisection there is always a very extensive degeneration in the whole of the lateral column except the crossed pyramidal tract, which degeneration diminishes upwards until none is left except that belonging to the two long tracts of the lateral column. Of course, some of these degenerated fibres are fibres on their way to form these two tracts, as I have previously shown ; but the great bulk are short ascending internun- cial fibres. So far, I have only dealt with the experimental side of the question. I have still to give a brief resume of the more important facts which clinical practice and patho- logical examination afford. On the experimental side, we have little difficulty in exactly localizing the lesion, and the fallacies arise when we come to test the results of it, for nothing is more diffi- cult than to test the different forms of sensibility in animals. This objection, however, which is always raised by purely clinical observers, is not so great in the Monkey as in the Dog, as I think the results of my experiments show. On the other hand, experimental physiologists retort—the lesion in clinical cases can never be localized with any degree of precision, as it arises from accident or disease, and, unfortunately, with very few exceptions indeed, the post-mortem examination and subsequent microscopical research have either not been made at all, or inefficiently, so that the exact nature of the lesion has been involved in obscurity. I * Di’. Bloc states that the microscopic changes consist in a neoplastic hyperplasia of the neuroglia of the grey or gliomatous matter, or a myelitis. The chief seat of the pathological change is around the central canal and in the gelatinous substance of Rolando. “ If one examines the state of the sensibility one observes this peculiarity, almost pathognomonic, that, while sensibility to touch is perfectly retained, sensibility to pricking, as well as that to heat and cold, are completely abolished, not only in the upper extremities, but over more or less extensive areas, and sometimes over the whole body.” “ These forms of sensibility are unaffected—sensibility to touch, the muscular sense, and the special senses.”— ‘Brain,’ Part III., 1890: “ Syringo-Myelia,” by Dr. Paul Bloc, Chef des Travaux Anatomo-Patholo- giques a la Salpetriere ; translated by H. W. Marett Tims, M.B. Edin. Cases of syringo-myelia have been recorded by Leyden and Dr. Henry Berkeley, in which the loss of sensation and the paralysis were on the same side. “ Syringe-Myelia,” by Henry J. Berkeley, M.D., Baltimore. ‘Brain,’ Part 48 ; vide also a paper by Joffroy and Achard, “ Nouvelle autopsie de maladie de Morvan,” ‘ Archives de Medecine Experimentale,’ 1891.