Further: case of Kaulich (atrophy of shoulder-muscles, including deltoid, while triceps and biceps hypertrophied); Duchenne fils; Eulenburg and Cohnheim; Heller (2 cases); Wagner (2d case); Wernich (1st case); Lutz (a girl, case much resembling Eulenburg's adult case); Roquette (atrophy of thighs as well); Hoffmann; Russel; Foster (atrophy of muscles of forearm); Chrostek (notwithstanding hypertrophy of tongue); Friedreich (2 cases); Duchenne (2d); Wagner (2d and 3d); Gowers (9 cases); Ross (2 cases).
Gowers attaches diagnostic importance to the early signs of atrophy in the latissimus dorsi and great pectoral muscles. The time of their invasion contrasts with that in progressive muscular atrophy, where the process usually begins in the hands and creeps upward to the shoulder-joint.
Neither the atrophic nor the hypertrophic process is necessarily symmetrical on the two sides of the body, but an approximate symmetry is usually observed. The same muscles are usually affected, and in the same way, but not often precisely to the same degree. Fibrillary contractions often occur in the wasting muscles, but not in those which are hypertrophied. The electrical reactions, however, do not differ greatly in the two states. The faradic contractility diminishes in proportion to the diminution in the contractile mass of the muscle, whether this be concealed by the growth of fat and connective tissue or rendered obvious by the general wasting of the whole. But even when contractions can be obtained, these are often abnormally feeble, and by continual diminution in the number of contractile fibres, and increase in the lipomatous masses overlying them, the electrical irritability is ultimately lost. The excitability of the nerves remains intact, and therefore response may be obtained by an indirect excitation after direct excitation of the muscle fails to elicit one.
Eulenburg has occasionally observed one curious phenomenon in the galvanic reaction of nerves. The anode opening contraction grows weaker or even disappears with a progressively stronger current, and then with a still stronger current reappears. This is due to a cross action of the current on the excitability and on the conductibility of the nerve. At a certain moment the increased excitability is compensated by a corresponding increase in the resistance to conduction, and therefore all electrical response ceases. Later, the resistance remaining the same, the excitability is increased and the reaction reappears.
The symptoms of the first order (disturbance of muscular function) and of the third (deformity) are for a long time less conspicuous in the upper than in the lower extremities. When the arms begin to be paretic the patient is crippled in the characteristic manoeuvres by which, during the earlier period of the disease, he palliates the inefficiency of the lower limbs. When he can no longer push up the trunk by means of his arms, he becomes unable to rise from a sitting position at all. Further progress in the atrophy of the erectores spinæ muscles renders even the act of sitting impossible: the patient can only crouch, and ultimately must remain altogether recumbent. The functions of the hands usually remain unimpaired to the last, so that the unfortunate patient is able to amuse himself with knitting and other light work.
Besides the paralytic cyphosis, scoliosis of a high grade is sometimes, though infrequently, developed. It is due to the lateral oscillations with excessive inclination of the upper portion of the trunk.40
40 Cases of scoliosis from such cause, where inequality of muscular action cannot be invoked as a cause, help to throw light on the real etiology of the idiopathic deformity so often attributed to irregular muscular action.
It is rare that any researches have been made on the nutritive functions in pseudo-hypertrophic paralysis. Seidel41 has analyzed the urine in the two cases (brothers) which form the basis of his memoir. He expected to find a marked diminution in the urea, corresponding to the diminution in the mass and in the functional activity of the muscles. This expectation was based on the assumption, at present considered incorrect, that the elimination of urea is modified by muscular contractions. In the cases examined the actual amount of urea was considerable, rising on several occasions to 40, 43, and 69 grammes in twenty-four hours, and offering, in the first boy, a daily average of 41 grammes. But Scherer estimates that the average elimination of urea in children is, per kilogramme, double that in adults; and on the basis of this calculation the amount of urea eliminated by the patient in question should have been 51 grammes. There was therefore a diminution of about one-fifth.
41 Atrophia Musculorum Lipomatosa, Jena, 1867.