although the muscles have been flaccid to the last. In the rare cases (mentioned on p. 480) in which muscles, with atonic atrophy, become rigid towards the end of the process, it is probable, as the tenderness suggests, that the rigidity is idiopathic, due to the changes in the muscles, and is not dependent on the central nervous system. It may be the result of the increase in the interstitial connective tissue, and the longitudinal division and fibrillation by which the muscular fasciculi come to resemble bundles of connective-tissue fibres. It is also possible that similar idiopathic muscular changes may ultimately, in tonic atrophy, maintain and increase the rigidity that is primarily dependent upon the spinal cord.

It has been mentioned that the cases in which the legs present the simple palsy and spasm, or the tonic atrophy, which indicate degeneration of the pyramidal tracts, have been separated by Charcot, and termed "amyotrophic lateral sclerosis," the separation being based on the assumption that in such cases the primary lesion is the degeneration of the pyramidal tracts, and that the affection of the grey matter is secondary or "deuteropathic," even where the atrophy is atonic. We have seen also that this assumption is unwarranted so far as the atonic atrophy is concerned. It is probable that the pyramidal tracts are degenerated, if not constantly, at any rate in such a very large proportion of the cases of progressive muscular atrophy, that Charcot's distinction is, in effect, giving a new name to an old disease, and that the sequence is not that indicated by the name. Whether there are indications of lateral sclerosis or not, depends on the circumstance whether the degeneration of the pyramidal fibres is or is not more extensive than the complete degeneration of the nerve-cells that causes atonic atrophy. If the latter is universal, the pyramidal tracts may be totally degenerated, and yet there may be none of the characteristic indications of such degeneration. On the other hand, both arms and legs may be the seat of the spastic paralysis that indicates pyramidal degeneration, and atonic atrophy may be limited to a few muscles of the hands. Between these we have every gradation, in degree and distribution, of atonic atrophy, spastic paralysis, and tonic wasting.

The process in the grey matter has been regarded by some as a chronic inflammation. The occasional rapid increase in the symptoms may be thought to be justification for this view; but the process in general is at the degenerative extremity of the series of nerve-lesions. The principle involved in this question has been already discussed, and we have seen that, whatever be the nature of the primary process, we must recognise secondary tissue changes of independent energy, and that a distinct process of inflammation may occasionally form part of these (see p. 396). The significance of the occurrence of inflammation may therefore easily be overrated, so far as concerns the question of the process, and the tissue-elements in which the disease begins.

DIAGNOSIS.-The simultaneous and gradual onset of weakness and

wasting, the slow but progressive increase and extension of the symptoms, render the diagnosis of the developed malady simple and easy. At the onset, when only a single muscle or group of muscles is affected, the question arises whether the atrophy is local or is the commencement of a wider affection. Local atrophy is said sometimes to occur from great over-use of a muscle, especially one of the small muscles of the hand, but such a cause is extremely rare, and only to be suspected on the clearest indications.

As a rule, the local atrophy from which the affection has to be distinguished is that due to disease of the nerves. The wasting from disease of single nerves or at a plexus (as the brachial) is sufficiently distinguished by its limitation, coupled with its rapid onset and associated sensory symptoms. Much more difficult is the distinction of some forms of multiple neuritis. The difficulty presents itself chiefly in two forms:-(1) When the spinal affection begins as subacute atrophic palsy (see p. 483). (2) When neuritis affects chiefly motor branches, as in the arms in lead-poisoning, or in the legs in alcoholism, &c. In the first case it is necessary to wait for signs of slower wasting in other parts than those first affected before a diagnosis can be made. In the second, a careful search will generally reveal other symptoms of neuritis, and a known cause is usually obtrusive.

In pachymeningitis of the cervical region, with considerable damage to the nerve-roots, the wasting in the arms may resemble that of progressive muscular atrophy, and there is often weakness with rigidity in the legs, but the wasting is less chronic in onset, and is always accompanied by distinctive sensory symptoms,-by acute pains and usually by anesthesia, irregular in distribution. The same distinctions suffice for the diagnosis in diseases of the nerve-roots of the cauda equina, as by a tumour. This may cause slow wasting in the legs, but there is always severe pain and loss of sensibility. Chronic disseminated myelitis may cause wide-spread muscular atrophy, but is distinguished by the presence of symptoms of irregular damage to other structures in the cord. The diagnosis from syringo-myelia will be considered in the account of this disease.

From primary muscular atrophy, "idiopathic atrophy," "muscular dystrophy," as it has been termed, the diagnosis is sometimes easy, sometimes very difficult. It is easy in the pseudo-hypertrophic form, and often also in the atrophic variety (the cases in which no muscles are large), on account of its characteristic distribution, its course, the age at which it begins, and the tendency to affect many members of a family, and males more than females-features that will be presently described. Whenever several cases of muscular atrophy occur in a family, or during childhood or youth, the probability is great that they are idiopathic and not spinal. Indeed, the idiopathic form is to be suspected whenever muscular atrophy begins under twenty, unless there are distinctive spinal symptoms. But cases are sometimes met

with in which idiopathic atrophy begins in adult life, and the distinc tion of such cases may be very difficult, and will be better understood after a perusal of the account of this disease.

PROGNOSIS.-The progressive character of the malady renders the prognosis, in every case, grave and uncertain. The chief guide is the observed tendency of the morbid process, both the fact of its actual advance and the energy it manifests. At the same time, there is a possibility of arrest, greater in middle life than in old age. Some increase of atrophy in the parts already affected may occur for a short time after the process in the cord has ceased to spread-the muscular wasting going on until it corresponds to the changes in the nerves that have already taken place. The prospect of arrest seems to be greater in the cases in which the wasting is strictly symmetrical and nearly simultaneous on the two sides, than in those in which it is irregular, and attacks the second side when it has attained a marked degree in the first. Spontaneous cessation unfortunately seldom tends to occur until an advanced stage is reached; but, as the result of treatment, arrest may take place at any stage. The danger to life is chiefly proportioned to the interference with the muscles of respiration, and to the indications of implication of the medulla. Bulbar symptoms increase the gravity of the prognosis, especially when definite weakness can be recognised. Slight vague difficulty in articulation may remain stationary for years, and does not necessarily render the prognosis worse, especially if the atrophy elsewhere does not increase rapidly. If the malady ceases to advance, the prospect of any recovery depends on the rate at which the disease has progressed. Recent rapid loss of power may be to some extent recovered from, especially when the muscles present the degenerative reaction. Wasting that has existed for six months will probably persist unchanged. In a typical chronic case there is little hope of any actual recovery of tissue or power. The effects depend on a slow destruction of nerve-elements, the renewal of which seems to be impossible.

TREATMENT.-The first important element is to secure favorable conditions of life, and to maintain the general health as perfect as possible. Fresh air and gentle exercise are important, but all fatiguing exertion should be avoided, and likewise all mental strain. When the patient becomes helpless, great care is necessary. Bedsores in this disease mean inattention, and may always be avoided.

Only one method of treatment has, in my own experience, shown itself capable of arresting the disease, not indeed in all, but in more than half the cases in which it has been employed. It is the admin

At first I regarded the apparent result with doubt, but careful and repeated observations have made it impossible to consider the arrest of the disease as other than the direct effect of the treatment. It may be asked, Why should not a larger dose by the mouth be equally effective? A large dose involves risk of over-stimulating the nerve-elements, and doing barm rather than good; it is quite different from a small dose acting suddenly.

istration of strychnia by hypodermic injection. In seven almost consecutive cases, in middle life, this treatment has been followed by arrest within a month of its commencement, and the arrest has been permanent in all the cases but one. In the senile cases the treatment

has failed, but in most of them the disease was in an advanced stage, and the lumbar cord had begun to suffer. In some of the cases in which the result was prompt and distinct, strychnia given by the mouth had failed. It is conceivable that the different result is due to the fact that the agent is brought into more rapid contact with the nerve-elements, perhaps in purer form. Its action may possess greater momentum, as it were, and may thus exert an influence on the nutrition of the nerve-elements much more considerable than when it is slowly absorbed from the alimentary canal. One injection daily has been given, at any convenient place. The nitrate is the most convenient salt, one hundredth of a grain at first, quickly increased to one fortieth. It is not wise to give a larger quantity, lest the nerveelements should be over-stimulated; although, in their damaged state, they may be unable to manifest the influence, it may yet do harm. When the malady is apparently arrested, it is well to intermit the injections for one week in three or four. Other nervine tonics seldom exert a distinct influence, but those that are useful in other degenerative diseases, as tabes, may be given by the mouth at the same time as the injections are employed. In a malady so grave, it is desirable to neglect nothing that may possibly exert a beneficial influence.

If the

Local treatment of the muscles has very little influence on the wasting, as may, indeed, be expected from its nature. The most sedulous and skilful use of electricity, voltaic or faradic, fails, as a rule, to produce alone any effect on the course of the disease. malady is progressing at the same rate in each arm, and the muscles of one arm are regularly treated with electricity, while those in the other arm are left alone, no difference can be detected in the rate of wasting on the two sides. It is possible, nevertheless, that electricity sometimes does a little good. In cases in which a rapid loss of power has occurred, and weakness is out of proportion to the wasting, some recovery is possible, and there is no doubt that the excitability of the muscular tissue is maintained for a longer time by galvanism, although the bulk of the muscle may not be influenced. In other cases, all that can be said is that the influence of electricity, properly applied, is in the right direction. Moreover, the disease is one of those in which patients find it hard to believe that electricity cannot help them, and the probability is that their conviction will be fostered by some medical adviser. It is one of the diseases in which unjustifiable assertions are too often made that early electrical treatment would have been successful. It may be well, therefore, if only to satisfy the patient that nothing has been left untried, that a careful course of electrical treatment should be adopted. Faradism may be used 32

VOL. I.

if the muscles are sensitive to it, but if they present any greater irritability to voltaism, it is better to use this. It is immaterial whether the application is confined to the muscles or whether one electrode is placed over the affected part of the spinal cord. The latter method has no disadvantages, but my own observations have failed to confirm the confident statements sometimes made regarding its superiority. It is very important that the current-strength employed should be moderate. Strong applications often cause much subsequent pain, and even increased disability, and should be carefully avoided. I have known a rapid increase of weakness follow a strong application, in a way that convinced the patient at least that the two were connected.

Rubbing and massage of the muscles have been frequently em. ployed, and of this treatment also it may be said that its influence is in the right direction, although usually inappreciable so far as the muscular atrophy is concerned. Combined with passive movement, the influence of rubbing in preventing and diminishing deformities is more distinct. No special bath treatment is of service. When the disease occurs in the subjects of syphilis, specific treatment invariably fails, and I have even known the progress of the disease to be distinctly accelerated by an energetic course of treatment both by iodide and by mercury. It is important that all treatment should be pur sued in moderation, and that its effects should be carefully watched.

ARTHRITIC MUSCULAR ATROPHY.

Articular inflammation is almost invariably attended with rapid wasting of the muscles that move the joint. This occurs equally, whatever be the cause of the inflammation, and whether this is spontaneous or traumatic. It attends chronic as well as acute inflammations, and occurs in animals if joint-inflammation is produced in them.

The muscles that waste are chiefly those which extend the affected joint. The atrophy is well seen in the muscles in front of the thigh, when the knee is inflamed. If the ankle is affected, the calf muscles chiefly waste; if the hip, the glutei; if the wrist, the extensor muscles of the forearm; the triceps when the elbow is affected; the deltoid when the shoulder-joint is inflamed. In rheumatoid arthritis of the fingerjoints, such wasting is usually very conspicuous in the interossei, and especially in the abductor indicis. The atrophy, however, sometimes involves the flexors as well as the extensors, and rarely muscles of the limb that are near but do not move the affected joint. In very rare cases all the muscles of a limb have presented some wasting. Cases

* Valtat, Archives Générales,' 1877, tome xxx, pp. 159 and 321. The subject has been discussed by Vulpian (Leçons sur l'App. Vaso-moteur,' 1875, t. ii) and by Paget ('Lancet,' 1873, vol. ii, p. 727, in a lecture republished in Clinical Lectures and Essays,' 1875, p. 208).