the affection of the lips must be carefully distinguished from that due to the bulbar palsy so commonly associated with spinal atrophy. Of the distribution of the wasting, that of the latissimus and lower half of the pectoralis, and the escape of the hand-muscles, are the most important characteristics, although they are not, by themselves, conclusive, since they are sometimes met with in spinal atrophy. But the most important distinctions between spinal and idiopathic atrophy, whenever they are available, depend upon the symptoms of a lesion of the cord, or of the bulbar nuclei. Especially significant is the excess of the knee-jerk which results from lateral sclerosis, a conclusive indication of spinal disease, rendering the spinal origin of the atrophy all but certain. The distinction from the pseudo-hypertrophic form has been already considered; that from the peroneal type will be presently mentioned. PROGNOSIS.-The extreme variations in the course of the disease render the prognosis in any individual case both uncertain and difficult to formulate. Speaking generally, chronicity favours arrest, and the later the symptoms appear, the slower will be their progress. The prognosis is distinctly less grave in the simple atrophy than in the "juvenile" atrophic variety of the pseudo-hypertrophic disease, and in a considerable number of cases, perhaps one half, the malady has not appeared to shorten life. Even in cases that begin during youth it is therefore possible that the patient may reach old age. It seems also to be better in the cases that do not involve the facial muscles. TREATMENT. It is not yet clear that idiopathic muscular atrophy can be influenced by treatment in any considerable degree. Most published records of cases are almost silent on the subject, and the disease is so rare that few individuals have an opportunity of forming an opinion. It might be assumed that the essential cause of the disease, a congenital tendency, withdraws it from the range of therapeutics, but the course of the malady is very different from that of some other diseases which own a similar cause. The extreme variations in the date of onset, the fact that the disease may not be manifested until late in life, and the long period that may intervene between its onset and extension, all suggest that other influences co-operate with the congenital tendency in determining the development of the malady. It is quite possible, therefore, that the first inference from the history of the disease may not be altogether correct, although it must be admitted that we have not as yet any evidence that the disease is susceptible of influence from drugs. Electrical treatment and massage have been thought to do good and even to produce arrest (Erb), but the variable tendency of the malady renders the evidence of arrest insufficient. If voluntary exercise is practicable, this is a far more efficient stimulus to muscular growth than any electrical application, and it is probable that such exercise, carefully persevered in, may do something to prevent the occurrence of the malady in those predisposed to it, and even to retard its progress in those who are 34 VOL. I. already attacked. In this connection it is noteworthy that very few of the sufferers have been engaged in occupations that involve active muscular exertion. Over-exertion should, however, be carefully avoided. The general health should be attended to, and any defect removed as speedily as possible, both in those who suffer and in those who are related to sufferers, since, as we have seen, depressing influences may apparently excite the development of the disease, and it is therefore reasonable to suppose that they may accelerate its course, and lessen any tendency there may be for the morbid process to become stationary. THE PERONEAL TYPE OF FAMILY AMYOTROPHY. The name "peroneal type" has become current as the most convenient designation for the variety of muscular atrophy, occurring in early life, to which it was applied by Dr. Howard Tooth in a Thesis published in 1886.* This was the means of calling general attention to the form, of which, however, an account had been published shortly before by Charcot and Marie,† and many cases had been previously described, in most instances without recognition of their special character. The cases of this form present certain resemblances to the idiopathic atrophies just described-resemblances sufficiently important to have led to the description of these cases in association with the primary myopathy, embracing, as they do, the age of the sufferers, the occurrence of the disease in members of the same family, its gradual onset, and its very slow but progressive course. Yet this position must be regarded as provisional only, and probably erroneous. The distribution of the wasting involves a constant difference from the idiopathic muscular affections, and some of the cases, otherwise inseparable from the rest, present features that indicate neuritis. The disease may have, as an antecedent, an acute specific disease-a circumstance that has the same significance. The facts ascertained concerning this form must, therefore, be carefully excluded from our generalisation regarding the idiopathic atrophy. In this form, males suffer about twice as frequently as females. It generally begins in the second half of childhood, and very seldom after twenty, although cases have been described beginning as late as forty. It is occasionally hereditary, and still more frequently collaterals suffer, several brothers and sisters being affected. The wasting is first apparent in the extensor longus pollicis, or extensor communis digitorum, or in the peronei muscles. According to Tooth, it very often begins in the latter, and occasionally in the gastrocnemius, The Peroneal Type of Progressive Muscular Atrophy,' London, Lewis, 1886. By Friedreich, Eichhorst, Oppenheimer, Ormerod, and others. A table of thirty collected cases (some doubtful) is given by Tooth. but it is probable that it occurs simultaneously, or even earlier, in the small muscles of the foot, where it readily escapes observation. Such early atrophy in the feet has, indeed, been actually found in some cases that came under observation at an early stage.* The calf-muscles suffer subsequently, and still later those of the thigh, especially the vastus internus. The unequal affection of the muscles of the leg causes the early development of club-foot, which, especially in children, becomes a characteristic symptom.† The arms are only invaded, in most cases, some years after the legs, so slow is the course of the disease. The intrinsic muscles of the hands (thenar, hypothenar, and interosseal muscles) are first attacked, and subsequently those of the forearm; sometimes the extensors and sometimes the flexors suffer first and most; while the supinator longus remains normal, and so do the muscles of the shoulder, neck, back, and face. The atrophy is often symmetrical, but occasionally the muscles on one side waste first and most. The claw-like deformity of the fingers may result from the affection of the intrinsic muscles of the hand. This is so rare in early life from any other cause, that its significance is considerable, and almost distinctive when combined with the deformity of the feet just mentioned. The case shown in Fig. 162 was probably an example of this type. FIG. 162.-Advanced muscular atrophy, probably of the "peroneal type." The affected muscles (especially in the hand) occasionally present slight fibrillation. Their electric irritability is diminished sooner, and Hoffmann, Arch. f. Psych.,' xx, p. 660; Joffroy, Gaz. Hebd.,' 1886, No. 18. + See Sachs, Brain,' Winter part, 1889. It was given in the last edition as an example of simple atrophy. The patient was a man aged twenty-seven at the time of his death (in University College Hospital). No history of any analogous case in his family could be ascertained. The affection began at the age of fourteen, when his feet began to turn in so that he walked on the outer side of the foot, and soon he noticed gradual wasting of the legs, which slowly progressed, and about the age of twenty-four the arms also began to suffer. When first seen, a few months before his death, the muscular atrophy was universal, and the subcutaneous fat had also disappeared. Even the hands were greatly wasted; there was a hollow in the position of the thenar eminence, just as in progressive muscular atrophy, and the interosseal muscles were also greatly wasted. There was slight fibrillation. The intercostals were paralysed. The wasting of the legs was extreme; the maximum circumference of the calf was in greater degree, than in the ordinary idiopathie atrophy, while a still greater difference is presented by the fact that faradie irritability may early become extinct, and that there may be a distinct reaction of degeneration. In connection with this, should be noted the important fact that cutaneous sensibility, though often normal, is sometimes impaired or lost, especially over the region in which the atrophy is greatest, or upon the soles of the feet. Pains occur in some cases, and so also do spontaneous spasmodic contractions, especially in the muscles of the thigh. The muscle-reflex action is lessened or lost in the affected regions, but there may be extensive atrophy below the knees, without loss of the knee-jerk, if the thigh-muscles are preserved. Cutaneous reflex action presents considerable variations, and is preserved more often than would be expected. Vaso-motor disturbance sometimes occurs (Sachs). The nature of these cases has still to be demonstrated. Their very slow course, the time of life at which they begin, and the affection of several members of the same family, are features analogous to the idiopathic atrophy, but a marked contrast to this is presented by the tendency of the malady to succeed an acute specific disease, measles, and this also may appear as a family tendency. This feature resembles the causation of multiple neuritis, and the electrical reaction of degeneration is conclusive proof of preponderant changes in the motor nerves, while anesthesia demonstrates that, in some cases, the sensory fibres are also affected. In such cases, a peripheral neuritis, motor or total, of extremely chronic course and peculiar origin, must be recognised as the only possible lesion, and it was actually found, in one case, by Friedreich, and in another by Gombault. If this is the cause of the symptoms in some instances, the question arises whether it is not the lesion in all the cases of this peroneal type. Such a lesion is conceivable; the degenerative form of neuritis. presents every degree of chronicity, and may be limited to the motor fibres and to certain muscles. This pathology was advocated, as the probable one, by Tooth, who pointed out that it would also enable us to understand the occurrence of fibrillation, which is extremely rare in the idiopathic atrophies. It is, indeed, asserted by Hoffmann that not only are the peripheral nerve-fibres the seat of a primary degeneration, but that this change ascends the nerves to the anterior aud posterior roots, and involves, in a secondary manner, the elements of the spinal cord, especially the fibres of the posterior median columns (which continue the path from the muscles) and the motor cells of the anterior cornua. But we do not know how far the premature only seven inches; the feet were everted, the sole hollowed, and the toes flexed. The patient died from diarrhoea. The muscles were found to be small and pale. The chief microscopical change was intense granular and fatty degeneration of the fibres. A very few normal fibres were seen in some muscles. There was no increase of interstitial tissue. Microscopical examination revealed no morbid changes in the spinal cord. The nerves, unfortunately, were not examined. failure of nutrition is a secondary process, transmitted from below, or how far it is the result of a defect in vital energy, shared by the central as well as the peripheral nerve elements. The intimate relation between the motor nerves and the muscular fibres should also be kept in view in this connection. There may be a morbid tendency in the nerves similar to that of the muscles, including a liability to early slow degeneration, analogous to that which the muscles present, and equally prone to occur in several members of a family. But it is desirable that the neuritic nature of the affection should be placed on a broader basis of ascertained fact before it is allowed expression in the name given to the disease. It should also be remembered as possible that the atrophy may be idiopathic in some cases, while in others it may be secondary to such a neuritis as above mentioned. There is nothing difficult, or even anomalous, in the conception of a congenital tendency to premature failure of nutrition in the peripheral nerve fibres, like that which, in the pyramidal fibres, seems to underlie "hereditary ataxy," or which, on the other hand, in the muscles, is the apparent cause of idiopathic atrophy. Further, if the lesion is really neuritic, we can understand that an acute specific disease like measles should occasionally be its excitant, although its occurrence in families shows that a congenital tendency must be called into activity by the virus, and the cases must be distinguished from those in which a pure neuritis is induced by the influence of the poison of the specific disease. An acute specific disease, the virus of which is known to be capable of inducing the degeneration of "parenchymatous" neuritis, may readily excite this state in each of several members of the same family, if a congenital tendency to it exists in them. It may readily evoke that which it could, even alone, produce. According to this theory, a tendency to nerve degeneration, acting alone, may lead to the early failure of nutrition of the nerves, while the wasting of their muscular fibres may be either a consequence or a concomitant, in part or altogether. Thus, the muscles may atrophy because the nerves have degenerated, or because they also have a tendency to atrophy, or from both causes combined. Nerve and muscle may alike share the congenital imperfection in some cases, while in others its primary incidence is on the nerves alone, the muscles suffering in consequence of the changes in the nerves. congenital association may sometimes be even more extensive, and a tendency to the early failure of structures in the central nervous system may be conjoined, giving rise to cases of complex aspect and character. It is especially important to note, in this connection, the occurrence of cases that occupy an intermediate position, and combine the characters of this and the myopathic types. Such combined cases are usually partial only, but such partial cases, when combined, ultimately cover the whole intermediate ground. For instance, the condition of |