Muscular atrophy

“ The disease is transient, and there are no mental symptoms.
Progressive muscular atrophy has been observed as far back as Hippocrates, but it is only in recent times that we have had any definite knowledge of the subject. It is divided into four types, the hand type (causing the griffin-or claw-hand, or the ape-hand) ; the juvenile type (generally in the muscles of the shoulder and arm) ; the facial type; and the peroneal type. Generalized progressive atrophy leads to a condition that simulates the appearance of a "living skeleton." ”

“ I am inclined to believe, especially in the light of Charcot's21 and of Erb's22 recent studies, that the true spinal form of progressive muscular atrophy is a disease of adult life, and that the majority of cases reported as occurring in early life are instances either of what Erb calls the juvenile form of progressive muscular atrophy or of pseudo-hypertrophic paralysis. ”

“ PROGNOSIS.—The course of progressive muscular atrophy is never rapid—essentially chronic. Recovery in a well-established case is not to be expected, although it is rare for any one to die of the direct effects of the disease. It is often arrested in its course, and remains at a standstill for years. The wider its distribution and the more numerous the foci of involvement, the more rapid is its course ”

“ Infantile paralysis, which often appears suddenly, muscular atrophy, which develops slowly, progressive and chronic atrophy of the muscles, are also forms of muscular disease, combined with destruction of the accompanying nerve tissue.
A special group of muscular diseases consists of amyloid (fatty) degeneration of vital muscle substance, as for instance of the heart, the kidneys, the liver. These are also caused by faulty composition of the blood, which does not feed the muscles with the substances required and thus causes them to degenerate by developing too much fat. ”

“ The weight of the limb or a portion of it, by stretching paralyzed muscles, often aggravates their atrophy. This is most likely to occur with the paralyzed deltoid when the arm is unsupported, and with the anterior tibial muscles when the foot is allowed to drop.
Muscular atrophy occurs in the spinal paralysis of adults as well as in children; but in the latter alone does the atrophy extend to the bones and cartilages, tendons, fascia, ligaments, and blood-vessels. The osseous projections to which the muscles are attached waste ”

“ If d is destroyed, the fibres from b and c perish with it, and the result is paralysis and atrophy of the muscle and degeneration in the motor nerve—e.g. poliomyelitis anterior. If b is destroyed, the muscle atrophies, and paralysis is a secondary result—e.g. progressive muscular atrophy. If c is destroyed, the nerve degenerates, and paralysis and atrophy of the muscle are secondary results—e.g. neuritis with reaction of degeneration. If a is destroyed, voluntary power is lost, but reflex power remains, and no atrophic changes occur—e.g. lateral sclerosis. ”

“ From section, disease, atrophy or degeneration of nerves or nerve centres, the muscles, which they normally innervate, waste, often to an extreme degree. As examples of this we see the atrophy of the triceps extensor cruris and other groups in hæmoglobinuria, of the intrinsic laryngeal muscles in roaring, of the muscles supplied in neurectomy, and of groups of muscles in myelitis, broken back, lead paralysis, and scapular muscular atrophy. True to the law of wasting of physiologically inert organs, the nerves are atrophied and degenerated, and often also the bones, joints and skin. ”

“ The pseudo-muscular hypertrophy of children so strikingly resembles in many particulars the progressive muscular atrophy of adults that the theory of their essential identity could not fail to suggest itself. ”

“ If the muscular atrophy was degenerative, then the atrophy was never replaced; but, according to Charcot, some cases of atrophy were simple and accordingly curable. If, however, 61the spinal cord itself became involved in the meningeal inflammation, then phenomena of transverse myelitis set in with a spastic paraplegia and involvement of the bladder and rectum. Muscular atrophy never developed in the legs, at least in typical cases. ”

“ It was thought he was simulating (since there was no muscular atrophy) , and he was sent to the neurological center, where under anesthesia the joint was found free. This man developed, when the knee was bent, extraordinary cracklings in the joint, and he showed pain unequivocally, making a defensive movement, partly reflex, partly voluntary, when the leg was flexed beyond a certain point. There was 3.5 cm. atrophy in the thigh, a reflex atrophy due to the joint disorder. There were no other signs of hysterotraumatic contracture. ”

“ Progressive muscular atrophy, as previously mentioned, bears a close resemblance to professional muscular atrophy (Onimus) , which may be considered one of the forms of copodyscinesia. The resemblance, together with the few points of difference, may be best seen in the form of a table, thus:
The ordinary course of symptoms in this disease is not always followed out, and occasionally the resemblance of the initiatory symptoms to one of the forms of copodyscinesia is great ”

“ Symptomatology.—When muscular atrophy is not extensive no particular evidence of this condition may be manifested while the subject is at rest, but where muscular waste has occurred, the nature of the ailment is at once recognized. Since the femoral nerve supplies the quadriceps femoris muscles, it follows that when the psoic portion of this nerve becomes diseased, the stifle loses its support, and in a unilateral involvement when the subject attempts to walk on the affected member, the stifle sinks down for want of support and the leg collapses unless weight is caught up with the other leg. ”

“ Histological changes in atrophied muscles vary somewhat in character in different diseases, and vary much in degree at different periods of the atrophy. An early appearance is the presence of proteinaceous and of fatty granules or molecules in the sarcous substance. Later, the muscular fibres become reduced in size, lose their striation, and show inequalities; the interstitial connective tissue becomes active and increases in amount, at the same time that fat is deposited. ”

“ The attention of the sufferer is first attracted by the power of the hand becoming weakened, and then there is found to be a wasting of certain of its muscles, particularly those of the ball of the thumb. Gradually other muscles in the arms and legs become affected in a similar manner, their atrophy being attended with a corresponding diminution in power. Although sometimes arrested, this disease tends to progress, involving additional muscles, until in course of time the greater part of the muscular system is impli cated, and a fatal result ensues. ”

“ The degenerative reaction which we have seen takes place in muscles the continuity of whose nerves have been destroyed, or in which degenerative changes have taken place in consequence of injury to their nerves, is never found in muscles paralyzed from the brain. In spinal paralysis resulting from transverse myelitis the electrical excitability of the nerves and muscles may be increased or diminished, but there is no degenerative reaction. In progressive muscular atrophy a careful electrical examination may discover the degenerative reaction in the affected muscles ”

“ These effects are transient, and after they have disappeared it may be impossible to say whether a dislocation has existed on a living body, unless, as sometimes occurs, especially in the shoulder joint, there may be a temporary or permanent paralysis of a nerve and muscular atrophy. ”

“ The tendons inserted into the enlarged bones have been found proportionately over-developed. The muscles, however, are seldom hypertrophied, and occasionally, as in Busch’s case, they may undergo an atrophy secondary to the impaired mobility of the joint. In a case of von Fischer’s, muscular hypertrophy was demonstrated, but no evidence of increased power was present ”

“ The restriction of a healthy muscle causes it partially to lose its functioning ability, and habitual restraint and unnatural pressure brought to bear upon the muscles of the trunk result in local congestion and in displacement of special organs. Lungs, liver, and intestines, together with the organs of reproduction, suffer from the constrictive effects of the corset, and lack of nourishment, due to restricted circulation thus produced, causes atrophy of muscular tissue, since the latter is not adequately rebuilt. ”

“ It is true that long inaction may result in atrophy of the muscular structure, but this is, I am convinced, a rare exception to the rule that in hysterical paralysis there is maintained a complete integrity of the muscles of the organ, even though the parts have been for years in a state of inaction. For some reason, the nutrition is maintained much better than in paralysis from other cases. ”

“ A progressive atrophy of muscles associated with progressive weakness and various disabilities of movement is soon recognized in the relation of cause and effect; but the parents whose first child looks like an infant Hercules, with abnormally large calves and buttocks, cannot for some time appreciate any connexion of this condition with a muscular weakness which is manifested in various ways. The child stands with its feet widely separated; it waddles along rather than walks; it falls easily and rises with difficulty, having to use the hands to push against the floor ”

“ But, we may add, in progressive atrophy this does not become manifest until the muscles have been for many years subjected to the strain of constant employment: in pseudo-hypertrophy the nutritive failure appears early in the flagging of the developmental forces at the moment that these are strained in muscular growth.
It would perhaps be more correct to ascribe the error of development to a perversion of nutritive forces rather than to their weakness. For there is no arrest in the general development of the limbs, such as occurs after infantile spinal paralysis: the bones grow normally ”

“ Thus, in the case of the heart, when affected with fatty degeneration, there is atrophy of the proper muscular texture, which, however, being largely replaced by fatty matter, the organ may undergo no diminution in volume, but may, on the contrary, be increased in size. Atrophy is usually a gradual and slow process, but some times it proceeds rapidly. ”

“ It is curious that the majority of cases are males, and that it is transmitted by women who are not themselves its subjects. Many different clinical types have been described based upon the age of onset, the groups of muscles first affected, and the presence or absence of apparent hypertrophy; they are however all varieties of one affection, and in a case where there is an apparent enlargement of muscles there is really atrophy of the contractile muscle, fibres and overgrowth of fat and interstitial fibrous tissue; consequently this form of the disease is called pseudo-kypertrophic paralysis. ”

“ The subject of progressive muscular atrophies is now undergoing close study, and a large number of cases are not dependent upon lesions of the anterior horns, but are due to changes in the muscles themselves. ”

“ Sometimes a muscle disappears entirely; usually the connective-tissue elements, including the interstitial cellular and adipose tissue, undergo proliferation, so as to mask the wasting of the muscles to some extent.
The morbid process in the nervous system is also a simple degenerative process. The nerve-fibres and cells atrophy first, and the connective-tissue proliferation which marks the sclerotic change of the diseased area is a secondary process. There is still considerable dispute among authorities as to which segment of the motor-conduits the degeneration begins in. ”

“ The actual structural change is the visible effect of the law that over-use of a muscle produces over-growth or hypertrophy. This is not a law of disease, but of purposeful utility, designed to meet emergencies of life. Still there is a further law in nature, that long-continued excessive use of any muscle leads to a form of hypertrophy28 which cannot maintain its vitality, but degenerates. Arteries must be treated as muscles, for their muscular coats contract and dilate, as circumstances demand, under the control of the nervous system. ”

“ A muscle used and released will keep normal, an unused muscle atrophies and and an overused muscle hypertrophies. There is a normal use and disease which must be maintained of a weak, dying flesh body results.
In the life of our modern civilization the ordinary individual does not use more than two-thirds of his muscular system, nor does he use one-third of his lung space. A few important muscles are made to do all the work, the rest lie dormant or, at the best, try to urge themselves upon the attention through lameness, weakness or stiffness. ”

“ The muscle-engine, in like manner, deteriorates if it is allowed to stand idle. Sometimes this occurs in disease. In paralysis the limb cannot move, and the inactive muscles waste, become thin and flaccid, and undergo curious molecular changes, converting the muscular matter into fatty-like particles. ”