On the pathology and treatment of convulsive diseases / [by R. B. Todd].

  • Todd, Robert Bentley, 1809-1860.
Date:
1849
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Licence: Public Domain Mark

Credit: On the pathology and treatment of convulsive diseases / [by R. B. Todd]. 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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    would occur in an epileptic convulsion. The orly way in which such excitation of the muscular system could be produced, would be through the blood. Now a stimulus operating through the blood directly upon the muscles would be very unlikely to produce active contractions alternating with relaxations, such as occur in epi- leptic convulsions ; on the contrary, it would give rise to permanent or tetanic contractions. The cramps with which the muscles of a limb are affected just prior to gout fixing itself in the joints, might be taken as an example of such a contraction induced in muscle by a morbid excitant con- veyed to it by the blood; but even these, although often severe and extremely pain- ful, are very partial. Yet I confess that this explanation of a phenomenon so simple as that of cramp is rather far-fetched ; and this becomes at once apparent, when we reflect that a stimulus operating upon a nerve is a much more effective excitant than one operating directly upon a muscle. Take, for example, the best stimulus of muscular contraction, the galvanic force,—the contrac- tions excited by passing a galvanic current through the twentieth part of an inch of the main nerve of a limb are much more power- ful than those developed by the direct appli- cation of the galvanic power to the muscles themselves. The argument, then, may be thus briefly stated:—We know by experiment that a cause operating upon a very small portion of the nervous system, may produce conside- rable muscular disturbance, not of one, but of several muscles ; but that the same cause, acting on the muscular system directly, is much less effective, nor does such a stimulus excite several muscles by acting only upon one. Is it not, then, going too far for the ex- planation of such a phenomenon as muscular cramp, to pass by the nerve, and to limit the influence of the cause to the muscle itself? Is not this argument alone sufficient to direct us to search first in the nervous sys- tem for the immediate exciting cause of the muscular convulsions ? Nor is there any reason why both systems should not be influenced by the same excitant, which, even though it were more especially accumu- lated upon the muscular system, would, in all probability, act primarily and most effec- tively on the nerves, and throvyh them on the muscles, which, from their already ex- cited state, would respond the more readily to this stimulus. This is probably the case in poisoning by strychnine, one of those energetic substances which, if introduced into the blood in only a very minute quantity, seems to multiply itself* : thus to become diffused with ex- traordinary rapidity through the blood, affecting the two great tissues which are mainly concerned in the manifestation of the vital forces, — muscle and nerve, — but evincing a greater affinity for the latter than the former, and therefore acting with greatest energy upon it. I have felt it necessary to deal with this point thus early in our discussion of the pathology of convulsive diseases, in order that we might, by the elimination of a ques- tion, which more or less encumbered the problem proposed, attend exclusively to in- quiring into the nature and situation of the changes in the nervous system which give rise to the clinical phenomena of the convul- sive diseases already referred to, of which the convulsed state of the muscles is only one. I do not pretend to have exhausted this question, nor to have answered all the argu- ments stated with great perspicuity and ability by a distinguished Fellow of this College, Dr. J. A. Wilson, of St. George's Hospital. All that I have said goes only to show that the advocates of the muscular doctrine are so far unphilosophical in their mode of procedure, as they neglect the more simple and obvious explanation of the phenomena, and adopt a more complicated and obscure method. In considering the share which the nervous system takes in the development of the clini- cal phenomena of convulsive affections, I must ask your assent to certain pro- positions respecting the mode of action of the nervous system in health, which the present state of knowledge warrants us in assuming to be proved. 1. That the nervous system, accumulated in masses, and spreading by its nerves throughout the body, mingling with the proximate elements of the various tissues, consists chiefly of a proximate element, of complex composition—namely, albumen, in combination with phosphorus and certain fatty substances, all well suited to the maintenance of constant and lively chemical action. 2. That this material is developed in two forms,—the vesicular or grey nervous matter, the fibrous or white,—and that the combination of these two different kinds of nervous matter, differing probably both in chemical composition, and in the form of their elementary parts, but more strikingly * Or it is not unlikely tlint strychnine,prussic acid, anil certain otlicr substances remnrknblo lor the rapiUily as well us the energy of tlieir ac- tion, may immeilintely on their introduction into tlie blood assume the gaseous form wliicli is higlily favourable to rapid dillusioii.