thus imbecility and epilepsy on the one hand, or albinism on the other, should be occasionally associated with the disease.

DIAGNOSIS. The diagnosis of the disease is usually easy, if its characters are known. The peculiarity of gait and the mode of rising from the floor, the age of the patient, and the progressive character of the impairment, are in themselves sufficient to suggest the affection, and examination reveals enlargement and often contraction of the calfmuscles, and a change in the size of others, which confirm the diagnosis. The mode of rising is not absolutely pathognomonic, and it has misled even good observers; it is occasionally acquired in other diseases in which there is a gradual weakening of the extensors of the hip and knee. It is met with equally in the simple idiopathic atrophy, but is so rare from any other cause as to be of very great diagnostic suggestiveness.

Of the condition of the muscles, that which is most characteristic is the combination of enlargement of the infraspinatus with a wasting of the latissimus and lower part of the pectoralis. I pointed out some years ago that this condition, which is seldom absent, is of very high diagnostic importance, and subsequent observations have fully confirmed the opinion. Next in importance is the enlargement of the calf-muscles, especially in combination with contracture that cannot be overcome. In general, the enlargement and diminution of neighbouring muscles is very significant, but it must be remembered that they may be gravely diseased, and yet of normal size, or from the first smaller than normal. In such cases they are often hard, and the distribution of the affection is the same as that of the double change in typical cases. Such cases illustrate the relation of this form and the simple atrophy described in the next section.

The disease with which confusion is most common is the so-called "congenital spastic paraplegia" (p. 441). Both diseases affect children; in both there are weakness of the legs and contraction of the calf-muscles, and in both the muscles are frequently large. The chief distinctions have been already mentioned. The most important are the preservation and excess of the knee-jerk in spastic paraplegia, the tendency to spasm of the legs,-the facts that the contracture is active and can be overcome, that the patient does not rise from the ground in the way peculiar to pseudo-hypertrophic paralysis,-and the opposite tendency of the two diseases. Spinal muscular atrophy is only likely to be confused with the simple atrophy.

Between the two forms of idiopathic atrophy, the distinction is scarcely one of diagnosis proper; it is rather a question of the category in which a case should be placed. The most important distinction is the freedom of the calf-muscles from enlargement in the atrophic form. The face is not affected in pseudo-hypertrophy as it so often is in idiopathic atrophy, except only in some intermediate instances. If more than one member of a family is affected, some of the sufferers Pseudo-hypertrophic Muscular Paralysis,' London, 1879.

will usually present characteristic symptoms of the special form, for it is remarkable with what constancy the two types generally remain distinct (see p. 403).

PROGNOSIS.-In the case of any child with pseudo-hypertrophic paralysis, the prognosis is most grave. It is almost certain that each year will bring increasing disability, and that the patient will not. reach adult life. It is only when the disease develops late, and the symptoms do not become considerable until after twenty years of age, that there is a possibility that the disease may not attain its ultimate degree, but even in such cases this hope is seldom realised. In any case, and at any age, it is unlikely that the patient will live more than seven years after the power of standing is lost.

TREATMENT. As a congenital developmental malady, pseudo-hypertrophic paralysis is one of those diseases in which medicine is necessarily powerless to cope with the essential elements of the process. As may be, therefore, expected, no drug has been found to exert an influence on the course of the affection, although such nervine tonics as phosphorus and arsenic have been thought sometimes to retard for a time the progress of the weakness. The stimulation of the muscles by electricity has been employed and advocated, but, however sedulously employed, no distinct result follows the use of either faradism or voltaism. It must be remembered, moreover, that electricity is a very feeble agent in stimulating the growth of muscular fibres, compared with the physiological stimulus of voluntary effort. Muscular exercise may reasonably be looked to in order to make up, in some degree, what is lacking in this disease, and does seem to have some influence in retarding the failure of power. It may perhaps induce further growth, or greater power in the muscular fibres that have not yet suffered, or actually supplement the defective trophic energy. When muscular exercise is stopped, there is certainly a quicker failure of strength. Hence it is desirable that the patient should carry out carefully planned gymnastic exercises, so arranged as to call into action the muscles that most need help. These, thoroughly persevered in, have seemed, more than any other means, to retard the disease. Although they have not in any case arrested it, the trouble that is necessary to arrange the method is certainly well spent. Rubbing and massage improve the circulation, and tend, especially when combined with passive movements, to lessen the tendency to muscular contraction and consequent deformities.

The influence of muscular exercise renders it very important to maintain locomotion as long as possible. The ability to stand and walk is generally lost, through the contraction of the calt-muscles, some time before the muscular weakness would take the patient off his feet. In such cases, tenotomy may restore the power of walking for some years, and when the contracture returns, its removal has, a second time, enabled walking to be resumed. The operation is thus distinctly beneficial, and should be performed as soon as the actual

need for it arises, and division of the tendon is far better than any imperfect substitute.

During the later stages of the disease great care is required to preserve the patient from catarrh, which helps to excite the pulmonary mischief that so often ends life. Similar care is also needed during any intercurrent malady which the patient may contract.

SIMPLE IDIOPATHIC MUSCULAR ATROPHY.*

The cases in which there is no muscular enlargement, in which wasting is manifest from the first in the size of the muscles, are much more rare than the pseudo-hypertrophic disease. They belong to several types, more or less distinct, of which the most common is that to which Erb has given the name of “juvenile," and of which most instances are probably the pseudo-hypertrophic disease without muscular enlargement; others are more special since the lower leg muscles have suffered but little. A more striking variety is that which is characterised by the affection of the muscles of the face in addition to those of the shoulder girths-the "facio-scapulohumeral type" of Landouzy and Déjérine. In a third variety the affection begins in the legs and is peculiarly slow in course. Some other types may ultimately be differentiated, but it is important to recognise the fact that even those that we can now distinguish, as the most pronounced in their features, do not keep entirely distinct. They are connected, by intermediate forms, not only with each other, but even with the pseudo-hypertrophic disease. But these are very rare; as a rule the two latter types remain distinct in the families in which they occur, and this is the justification for their separate description. In those families in which simple muscular atrophy occurs, however numerous the cases, however different the distribution of the disease, and however various the ages at which it begins, cases rarely present the distinctive characters of pseudo-hypertrophic paralysis.

The most important writings on the subject (besides those specially quoted) are those of Duchenne in Électrisation Localisé' (p. 60 of Poore's translation, published by the New Sydenham Society); Barsickow, ‘Inaug. Dissert.,' Halle, 1872; Leyden, Klin. d. Ruckenm. Krank.,' Bd. ii, p. 525; Möbius, "Hered. Nervenk.," Volkmann's Klin. Vorträge,' No. 171; Landouzy and Déjérine, Revue de Méd.,' 1885, pp. 81 and 251; Marie and Guinon (a series of cases observed at the Salpêtrière), ib., 1885; Sachs, New York Med. Journ.,' Dec. 15th, 1888; Hitzig, Berlin klin. Wochenschr.,' 1888; Singer, Zeitscn. f. Heilk.,' Bd. viii. Especially valuable are the papers by Erb, Deut. Archiv f. klin. Med.,' Bd. xxxiv, 1884, and 'Neurol. Centralbl.,' July 1st, 1886, with numerous later writings. Bibliographical references, &c., will be found also in Tooth's Thesis on the Peroneal Type,' and in my Lecture on Pseudo-hypertrophic Paralysis (1879), and in Sach's article (loc. cit.).

E.g., case described and collected by Marie and Guinon (loc. cit.), connecting the pseudo-hypertrophic form with both the juvenile and the facial.

There is less constant separation between the simple "juvenile " and the facial forms. Although they often keep distinct, the affection of the face has been absent in a few cases in a family in which it was the first part to be affected in most sufferers. Thus a man with simple atrophy, beginning at fourteen in the shoulder- and thighmuscles, whose face was unaffected, had a daughter who began to suffer at eleven, and in whom the face, scapular, and arm muscles were involved. The peculiar "peroneal type" is not included in this outline, and the statements here made do not apply to it.

CAUSES.-We are able to trace no cause beyond the congenital tendency, already considered, shown by the occurrence of many cases in the same family, and in more than one generation. In one remarkable series recorded by Barsickow, twenty-four cases were distributed through five generations, and the disease was also traced through five generations in a group described by Landouzy and Déjérine. It is very rare for the disease to be confined to one generation, far more rare than for pseudo-hypertrophic paralysis to be so confined. But, as in the case of most congenital hereditary diseases, cases that are apparently isolated are occasionally met with. Such isolated cases are rare, more so, probably, than in the pseudo-hypertrophic form; although wider observation may show that they are more frequent than we now suspect. In the families of the patients shown in Figs. 158-61 and 162 no example of analogous disease could be heard of.

Both sexes suffer; in a few families, females chiefly; in others, males; in most, both have been affected. The age at which the disease first manifests itself is extremely variable. It may begin as early as two or three and as late as sixty years. But the onset is seldom during childhood; in the majority of cases the disease shows itself between fifteen and thirty-five; that is, during the later period of growth and the early period of adult life. Even in the same family, the variations may be extreme; in that described by Barsickow the date of the onset of seventeen cases was known, and was as follows:in one at 12; in four between 15 and 20; in seven between 20 and 30; in three between 30 and 40; in two after 40. A woman, aged fifty-two, began to suffer at 30, but her son at 3 years of age.§ Sex has no influence on the date of onset, nor, as a rule, can any relation be traced between the date and the place at which the wasting begins. When the wasting begins in the face, the disease more frequently commences in childhood than when the first symptoms are in the limbs, but, in some instances, the atrophy has commenced in the face late in life, and this in the same family in which other sufferers have been young. Thus in the sexual proclivity, and in the date of onset, there is a marked difference between this form and pseudo-hypertrophy; the latter

Troisier and Guinon, Rev. de Méd.,' 1889, p. 48. See also Singer, 'Zeit. f. Heilk.,' viii, p. 229.

+ Kreske, Munch. Med. Wochenschr.,' 1886. Landouzy and Déjérine, loc. cit.

§ Ibid.

showing a stronger tendency to affect males, and to manifest itself in childhood. The "juvenile" form, as a rule, presents less difference.

As a rule, no direct exciting cause can be traced. In a few instances the onset has succeeded some other morbid process, such as chlorosis, acute disease, or rheumatic affections due to exposure to cold; and the depression of general health resulting from these may have determined the time of onset, but is not likely to have done more. In other individuals of the same families the disease has developed without the aid of any exciting influence.

SYMPTOMS. The onset is always gradual. Weakness and wasting come on together, and are noticed simultaneously, unless the commencing atrophy is concealed by subcutaneous fat. The atrophy generally begins in the upper arm and shoulder-muscles, having, in the most common "juvenile" form, a similar distribution in these parts to that of pseudo-hypertrophic paralysis. In the facial form, however, this part usually suffers first, as in the lad figured on p. 406. In rare cases the wasting not only begins in the legs, but remains limited or almost limited to them. In the part first affected the disease slowly increases, and thence it usually spreads. The onset may be symmetrical on the two sides, or one side may suffer some time before the other.

Of the arm-muscles, the weakness and wasting are noticed first in the biceps and triceps, and with these the supinator longus often suffers. But examination generally shows that the lower part of the pectoralis and latissimus dorsi are greatly wasted, a loss of which the patient may be little aware, on account of the relative unimportance of these muscles. Sometimes the upper part of the pectora..s, and even the pectoralis minor, are also affected (Fig. 159). The tendency to atrophy of the lower part of the pectoralis and latissimus is a character which, as already stated, is common to this disease and pseudohypertrophic paralysis, but not invariable in either. The deltoids are rarely involved; in many cases they are normal; sometimes they have been thought to be unduly large; in a few instances they have been wasted (Fig. 162). The serratus magnus is often affected (Fig. 161), but may escape, even in a severe case. The supraspinatus and infraspinatus may also suffer, but are often normal or even enlarged; the trapezius and rhomboids have been affected in many cases, sometimes much atrophied (Fig. 161), especially in the "juvenile" form.

The forearm-muscles generally escape, with the exception of the supinator longus. Occasionally there has been some weakness of the long extensors or flexors of the fingers, with or without slight visible wasting. In the case mentioned on the next page, the extensors of the phalanges of the thumb were involved on the left, and the radial extensor of the wrist on the right side. Rarely the forearm-muscles bave been much atrophied. In several instances there has been some atrophy of the small muscles of the hands, the thenar and interosseal