the legs in the "peroneal type" has coexisted with that of the arms in the "juvenile form" in several recorded cases. Thus, the possibility must be recognised that the cases of this type vary, even more than their characters suggest, in the degree in which the morbid tendency acts upon nerve or muscle, or both, as well as the degree in which its activity is spontaneous or induced. Hence, the cases may here be only partly out of place, some perhaps not at all; and their position, as forms of "neuritis," might be equally open to exception. the The progressive character of the cases of this type is commonly pronounced, and, even if slow, it renders the prognosis gloomy, and scope for treatment small. So far as anything can be done, it is by the measures already mentioned in the account of the treatment of the maladies to which the cases approximate, the primary disease of the nerves on the one hand, and of the muscles on the other. MUSCULAR HYPERTROPHY. The occurrence of a true hypertrophy of muscles, as a condition of disease, is exceedingly rare. In most cases in which the muscles are enlarged, the increase in size is due to a growth of interstitial tissue, fatty or fibrous, such as has been described in the chapter on pseudohypertrophic paralysis. We have seen that muscular fibres larger than normal have been described in that disease, and also in some cases of simple atrophy. When this increase in size has been met with only in excised fragments, it is possible that the condition may have been due to a vital contraction excited by the process of excision, and such evidence of hypertrophy is certainly inadequate;† only when it is found after death, can its occurrence be regarded as beyond question. Nevertheless, true hypertrophy of fibres is a change that may be expected to be occasionally met with in cases that are due to a congenital tendency, and its presence, even in muscles that are the seat of atrophy, need, therefore, excite no surprise. It was met with by E. g. by Hoffmann, Berlin. klin. Wochenschr,' 1887, No. 22; and Eisenlohr, 'Neur. Centralbl.,' 1889, p. 565. Since the above was written, the doubt there expressed has been confirmed by an observation made for me by Dr. H. R. Spencer. A fragment of the gastrocnemius of an amputated leg was excised immediately after the amputation, and the fibres were compared with those of the muscle twenty-one hours later. In order to ascertain more definitely whether a vital contraction persisted as an apparent increase in size, a part of the excised fragment was separated and faradised. The average size of the fibres in the muscle was 7 inch, in the fragment excised inch, in the fragment faradised inch. Since the division of the nerve during the amputation may have caused some contraction, it is possible that the difference in size produced by excision may be even greater than these figures represent. [I leave the above note unchanged because, since it appeared in the first edition, the observation and doubt have been fully confirmed by various observers, e. g. by Oppenheim and Siemerling, 'Med. Centralbl.,' 1889, No. 39.] Bruck in a remarkable case of general muscular enlargement in an idiotic child, in whom it apparently developed after birth. The affection first showed itself in the tongue, but the muscles presented spasmodic contractions, and the case, like most of the kind, was evidently anomalous in its features. Muscular bypertrophy has been found in the singular malady described in the next section (Thomsen's disease). It has also been met with, in very rare instances, as a widespread or partial condition, usually associated, strange to say, with either diminished power or with a morbid readiness of fatigue. The muscles most frequently affected have been those of the shoulder and upper arm, or of the thigh and calf, on one side or on both. It has also been observed in the glutei, spinal muscles, and trapezii. The causes are obscure, but it has been ascribed to over-exertion. The diameter of the fibres has been increased to double the normal, a maximum of 6th inch having been met with (Eulenberg), whereas the normal maximum may be taken as th inch. An increase of the nuclei has been observed, without any overgrowth of the interstitial tissue. The condition is manifested by an increase in the size of the muscles, which are also firm. The circumference of the limb is greater than normal, and when the change is unilateral, the difference between the limbs of the two sides may be very striking. The maximum circumference of the calf has been as much as seventeen inches. The muscles are soon exhausted, and have been weak in some cases, while in others there has been abnormal strength for brief exertion. The electrical, mechanical, and myotatic irritability of the muscles has usually been found unaltered. The disease may be suspected if a marked increase in size in an adult is accompanied by impaired power of sustained exertion; if the muscles are firm, and the patient does not manifest other indications of pseudo-hypertrophic paralysis. The diagnosis can, however, only be made with certainty by the microscopical examination of an excised fragment, and even then subject to the reservation mentioned on the previous page. The meagre facts regarding the course of the disease suggest that it usually persists without getting either better or worse. Treatment appears to have but little influence upon it. A singular case has been reported by Eulenberg,† which differs in many particulars from the form of disease above described, and illustrates the complex relations of enlargement of the muscular fibres and its connection with degenerative processes. A man, aged thirtysix, presented an enormous enlargement of the muscles of the left Auerbach, Virchow's Archiv.,' Bd. liii, pp. 234 and 397; Berger, Deut. Archiv f. klin. Med.,' Bd. ix, 1872, p. 363; Friedreich, Ueber Prog. Muskelatrophie, &c.,' 1873; Eulenberg, Real-Encyclopädie,' Bd. ix, p. 354. A very similar case is described by Pal, Wien. klin. Wochenschr.,' 1889, No. 10. Deutsch. Med. Wochenschrift,' 1885, No. 12. leg, which were soft and flabby and weak, with lowered irritability. The condition had slowly developed after a fall on the back at ten. which caused imperfect paraplegia, motor and sensory. A year later, during pleurisy, he had thrombosis of the left femoral vein. In an excised fragment of the gastrocnemius, the muscular fibres were large, the maximum being th of an inch; they presented fatty and vitreous degeneration, and fat was seen between the fasciculi. The muscles of the other leg were somewhat wasted, but the fibres were also enlarged and degenerated. It would appear as though the condition had resulted from a traumatic lesion of the spinal cord, and had been intensified in the left leg by the influence of the thrombosis and resulting vascular disturbance. THOMSEN'S DISEASE; MYOTONIA CONGENITA. The malady thus designated may be considered here, notwithstanding the obscurity of its nature, because it agrees with the diseases last described, in that the symptoms are muscular, and that the disease seems often congenital and occurs in families. It has been named after the physician whose description gained for it general notice, and who is himself its subject, but it had been previously described by Leyden, and hinted at, long ago, by Sir Charles Bell. It is not always congenital, and "Transient Myotone" would be a more exact name. The disease is characterised by a peculiar rigidity of the muscles, which comes on when they are first put in action after a period of rest. The rigidity is transient, and when it has passed off, it does not return as long as exertion is continued. The malady is often hereditary, and usually affects several members of the same family. In that of Thomsen, cases can be traced through five generations. It appears to be more common in Scandinavia and Germany than in France • Bell's Nervous System,' Case 184, p. 436. The objections to cognominal nomenclature of disease are certainly reduced to a minimum when the first describer of a rare disease is also its subject. The most important papers on the disease are those of Leyden, ‘Klinik der Ruckenmark-kr., 1874, Bd. i, p. 128; Thomsen, 'Arch. f. Psychiatrie,' Bd. vi, 1876, p. 702, also ⚫Centralbl. f. Nervenkr.,' 1885, p. 193; Bernhardt, Virchow's Archiv,' Bd. lxxv, 1879, p. 516, and Centralblatt f. ervenkr.,' 1885, p. 122; Ballet and Marie, Arch. de Neur.,' 1883, No. 13; Möbius, Schmidt's Jahrb.,' Bd. excviii, 1883; Ringer and Sainsbury, ‘Lancet,' 1884, pp. 767, 816, and 860; Erb, Die Thomsen'sche Krankheit,' Leipzig, 1886, also Deut. Archiv f. klin. Med., 1890, xlv, p. 529; Seifert, ib., xlvii; Marie, in Encyel, des Sc. Méd.,' 1886; Hale White, Brain.' April, 1886, and Guy's Hosp. Rep., vol. xlvi (a very valuable paper, with bibliography); Jacoby, Journ. of Neur. and Ment. Dis.,' 18.7. xiv, p. 23; Jolly, 'Südwest. Neurol.,' Baden, June, 1890; Buzzard, Lancet,' 18S7. or England, but it is a rare disease; and although a considerable number of clinical cases have now been recorded, there has been no post-mortem examination. There is little to attract attention in the slighter forms, and the rarity of these may ultimately be found to be less than at present appears. Both sexes suffer. In most cases the symptoms have been first noted in childhood, between four and ten years of age, sometimes even in the cradle. They increase during the period of muscular development, and then remain stationary. A few patients have seemed free until about the period of puberty, but even in such instances it is probable that the tendency was congenital in origin, since the cases occurred in families, other members of which suffered earlier. But in a few cases symptoms apparently identical with those of the congenital disease have come on in early manhood after some exciting cause-in one case a lightning stroke, in another a sudden alarm ✦ Severe and prolonged exertion during two years preceded the onset of very characteristic symptoms in a man of twenty-five, without heredity. In such cases the disease has been apparently acquired. The characteristic symptom is tonic spasm of the muscles when they are put in action after a period of rest. As soon as the patient attempts to move, the muscles become rigid. The rigidity ma make movement impossible while it lasts, or may merely lessen the possible range of movement. After a few minutes, or less, the spasm passes away, to be renewed, but in slighter degree, by a fresh attempt. If the movements are continued, the spasm soon becomes trifling, and does not return until after a period of rest. The longer the rest, the more troublesome is the spasm. The subject can walk for hours without fatigue when it has passed off. The rigidity is sometimes lessened by alcohol and increased by attention and by fear of it; the more the sufferer tries to overcome the stiffness, the less is he able to do so. It is also worse in cold and damp weather. In a severe case, a slight impulse will make the person fall, and it may then be impossible for him, for some minutes, to rise from the ground. The arms are usually less affected than the legs, but in some cases, the rigidity fixes the fingers for a short time on an attempt to use the hand. The muscles of the face are usually free; mastication may, however, be interfered with by the spasm in the muscles of the jaw. Rarely, the tongue or face has been affected; still more rarely the muscles of the eyeball, interfering with its movement and retarding the descent of the upper lid.§ Most voluntary muscles, indeed, seem liable to suffer, even the muscles of the larynx and pharynx; those concerned in the In England cases have been observed by Buzzard, Herschell, Hale White, Banham, and Chapman. + Engel, Phil. Med. Times,' 1833, p. 412; Schönfeld, Berlin. med. Wochenschr.,' 1883, No. 27. processes of respiration, defæcation, micturition, and coitus have also been involved. Sometimes the spasm is greater on one side of the body than on the other. The muscles are always well nourished; they are often, indeed, above the normal size, and possess more than normal strength, but they are sometimes less strong than is normal, even when large. Thomsen believes that the more the muscles are employed the less severe is the spasm, and that a life of active exertion produces some permanent amelioration in the disease. The malady is, however, a source of some disability, and of considerable annoyance; in the words of Thomsen, "it casts a shadow over the lives of the sufferers," and may have caused the mental irritability and hypochondriacal tendency that have been conspicuous in some cases. Careful investigations of the muscular phenomena have been made by several observers and that by Erb is especially instructive. In his case a single brief effort caused tonic contraction which lasted for twenty-five seconds. Momentary electrical stimulation of the nerves caused only a momentary contraction of the muscles, but continued stimulation always causes a prolonged contraction, the "myotonic reaction" of Erb. In certain muscles, moreover, an uninterrupted current caused peculiar wave-like contractions, about one per second, passing from the negative to the positive pole (Erb). Any strong stimulation of the muscle itself caused a prolonged after-contraction.† The irritability of the nerves is generally normal in degree; that of the muscles is normal or increased to voltaism. In some cases the anodal closure contraction has occurred with undue readiness, and the "latent interval" after stimulation has been found unchanged (Hale White) or increased. The muscles are remarkably sensitive to mechanical stimulation, and firm pressure may cause a tonic contraction lasting from twelve to twenty seconds. In all undoubted cases of this disease sensibility has been intact, and the superficial reflexes have been unaltered. Myotatic irritability is normal or increased. Once developed, the condition seems to persist, with little change, through life, but in one case, a female (in whose family were other cases) considerable improvement is said to have followed marriage.§ In some instances, the symptoms are slight, and remain so, even when they begin in early life and occur in the same families as severe Such cases, when isolated, may readily be overlooked. PATHOLOGY.-An examination of the central nervous system bas yet to be made, but it is unlikely to yield results of novelty or im cases. Although Erb, Seifert, and others have noted this, some observers (as Hale White) have failed to obtain the phenomenon. Jolly has found that repeated stimulations by either current, without too long an interval between the successive stimulations, tend to render the after-contractiou less and less evident, until it ceases to occur (Neur. Centralbl.,' 1890. p 438). 025 or '03 sec. instead of '01 (Bluminau, Neur. Cent.,' 1883, p. 679). |