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Observations on the Pathology and Cure of Rheumatism.
By William BALFOUR, M. D. Edinburgh.
Tantum, quantum quisque potest, nitatur.-Cic. [From the Edinburgh Medical and Surgical Journal, for April, 1815.] SYDENHAM was the first who favoured mankind with a distinct and accurate history of rheumatism. Before his time it seems to have been confounded with gout; since that period it has maintained its ground as an idiopathic disease, and has long been as well understood as any other, the proximate cause of which can be matter of conjecture only.
Concerning the proximate cause of rheumatism various opinions have been entertained. Dr. Macbride and others imagine it to consist in a peculiar acrimony; others in a lentor of the fluids; and Dr. Cullen supposes it to be, in the acute species, a phlogistic diathesis of the blood, with a peculiar affection of the muscular fibre; but in the chronic, "an atony both of the blood vessels and of the muscular fibres of the part affected, together with a degree of rigidity and contraction in the latter, such as frequently attends them in a state of atony."
That in acute rheumatism a phlogistic diathesis of the system prevails, admits not of doubt, and that there is an affection of either the muscular fibre, or of the cellular membrane, or VOL. VI.
of both, is equally certain. An atony, in the chronic species, of the muscular fibres, or of the cellular membrane, must also be admitted. But which of these it is, the muscular fibre, or cellular membrane, that, in either species of the disease, is primarily affected, is a matter not quite so manifest. To ascertain this point with any degree of clearness, a review is necessary of the structure and functions of these organs themselves; and I am not without hopes of being able to adduce facts, in the history of cases hereafter to be detailed, which render it highly probable that there is in rheumatism, chronic as well as acute, an affection of the aponeurosis of the muscles, and perhaps of the whole cellular substance connected with them, which forms a principal part of the proximate cause of the disease.
The cellular membrane abounds every where in the human body. It covers the whole, and connects every part. The cele, brated Haller, indeed, considers it as constituting the greater part of the whole mass. All the blood-vessels receive a coat from it, from the aorta, where it emerges from the heart, to the minutest capillary that enters a tendon. The nerves are composed of fasciculi
, and these again of filaments or fibrillæ. The cellular membrane furnishes a sheath to every nerve, a covering to every fasciculus, and every filament is a tube of the same substance, filled with medullary matter; and on the parieties of this tube are ramified, and are supposed to secrete the medullary substance it contains, those capillaries, of exquisite minuteness, which are continuations of the arteries seen to penetrate the fasciculi. A muscle, whatever be its length, breadth, or thickness, is not a mass of homogeneous substance, but, like the nerves, is formed of many fasciculi. These fasciculi are themselves composed of fibres so delicate
and numerous, as to be divisible ad infinitum. At all events, their minuteness is such as to have hitherto set at defiance the cover their ultimate division. But, incalculably minute as are these fibrillæ, they are supplied with vessels and nerves, and inclosed in a cellular sheath, upon which perhaps the vessels and nerves terminate. They are also connected to each other by means of cellular membrane, to form the fasciculi, which in their turn, are enveloped in a common sheath of the same sub
stance, similar to that which covers the muscle, and separate it from all other parts.
The structure of the cellular tissue is extremely vascular. Mascagni considered its laminæ as consisting entirely of lymphatics; Ruysch, by his injections, reduced the membranes and cellular substances into a net-work purely arterial, the texture of which was so close as to leave no observable space for any other vessels. Hence he concluded, that capillary arteries formed the basis of membranous and cellular tissues. The truth, however, lies between the opinions of these two celebrated physiologists. For, if one set of vessels only are injected, they become distended, compress and conceal the neighbouring parts; and we know, that lymphatic absorption and arterial exhalation take place from all the internal surfaces, by which is proved the existence of both arteries and absorbents in membranes and cellular tissue.
From these data it may justly be inferred, that the functions of the cellular membrane are not merely mechanical; that it does not merely cover, connect, divide, suspend, but that it serves a purpose in the animal economy, essential to the healthy functions of the parts on which it is so liberally bestowed. It is not consistent with common sense and reason to suppose, that a substance formed as is the cellular tissue of vessels, which carry on, if I may so express myself, the business of life in every part of the body, can remain sound, when the muscular fibre is affected with disease. It is infinitely more rational to conclude, that the affection of the muscular fibre is a consequence of the affection of the cellular substance, whose functions seem, from its universal diffusion, subservient to those of every other organ. For if, as we have seen, the cellular membrane is formed of capillary arteries and absorbents, the balance between their functions being in any degree overset, must produce corresponding phenomena. Thus, if the absorbents of a muscle carry off more than the arteries deposit, permanent contraction, in every direction of that muscle, must be the consequence.
It is well known, that diseased appearances are often confined to the cellular membrane, and that, when this is the case, the organs or vessels which it surrounds exhibit a morbid action.
It is likewise ascertained, from ample observation and experience, and it goes far in countenancing our theory, that, however insensible the tendons and aponeuroses of muscles are in their sound state, injuries and morbid affections of these parts are accompanied with pains unusually severe. Thus, inflammation of the integuments, and of the subjacent cellular substance and fascia of the fore-arm, sometimes the consequence of blood-letting, occasions not only the most inexpressible sufferings, but not upfrequently renders the arm contracted and rigid for life.
But the knowledge we possess of the functions of the cellular membrane, goes a great way in explanation of the phenomena of rheumatism. We know that it officiates at once as a fascia, a ligament, a mucous gland; and that by it is secreted all the fat and oily substance that is deposited about the joints, upon, between, and in the interstices of the muscles.
In the Srst place, then, the fasciæ of the muscles confine them to their situation parallel with the bones. Were that not the case, a muscle could not contract at all. Destined to act in a certain sphere, if that sphere is lessened, a muscle will either not contract, or its contraction will be of no use. Suppose, for instance, the biceps flexor cubiti, the Sartorius, any rectilineal muscle, was deprived of its natural bandages that confine it to its situation, what appearance would it exhibit in a state of contraction, were it possible to contract at all in such circumstances? A muscle, in contracting, becomes shorter, thicker, harder, rough, and vibrates like a cord when put upon the stretch. It is evident, therefore, that unless a muscle were bound by its fascia or aponeuroses, its contractions would either be very limited, or, in contracting, it would start from its place like the string of a bow. It follows, that a perfect sound state of the fascia of muscles is necessary to their vigorous action; and on the supposition of there being in rheumatism a morbid affection of the aponeuroses of the muscles, are explained the pain and difficulty of motion, in the first stages of the disease at least, of a limb affected with that disorder.
In the second place, the doctrine of a morbid affection of the aponeuroses of, and cellular substance connected with, the muscles, accounts satisfactorily for the debility of the latter,-their
permanent contraction,--their rigidity in chronic rheumatism. Were it not for the cellular membrane lubricating the surface of the muscles, it is impossible they could move upon each other; they behoved to contract simultaneously, and to the same degree, otherwise inflammation and adhesion could not fail to be the consequence of their friction upon each other. If,
. therefore, there should be, from a morbid state of the cellular membrane, a deficiency of that lubricating substance which
facilitates the motion of the muscles, rigidity and pain upon i motion must in proportion be the consequence. Not only so,
if there is a deficiency of the fatty substance, which, in a state of health, is found in a greater or less quantity, deposited between, and in the interstices of the muscles, they must become shorter in proportion, their fibres must approximate nearer to each other in every direction,--for the muscular fibre is not a line of continuous substance extending from origin to insertion; it is made up of many pieces whose ends are connected with each other, laterally, by means of vessels, nerves and cellular substance. What, therefore, has hitherto been deemed a wasting of the muscular fibre, may, with greater propriety, be considered a deficiency of those cushions which give plumpness to every muscle, and symmetry to the whole. Not but that there is a wasting and contraction, or absorption of the molecules of the muscular fibre itself to a certain degree, and also an affection of the nerves of a part affected with rheumatism. For if we reflect, that the fasciculi and fibrillæ of both the nerves and muscles are inveloped in cellular membrane, we must infer, that the apposition of muscular, and the secretion of nervous substance, are performed by the capillary vessels of that membrane. If, therefore, the functions of these vessels impaired, the parts they supply must suffer in their turn. But mere disuse will produce emaciation of a limb. There is no fact in physiology better established, than that action is necessary to circulation, and circulation to nutrition. These are, indeed, matters of daily experience. Emaciation of the muscles must therefore be considered more as a consequence than a cause of rheumatism.
In the third place, the effusions that sometimes take place into the sheaths of the tendons, is a proof that the cellular mem