the end of the second year of life, and rarely even later. The disease can be recognized from the fact that the patients learn to walk late and imperfectly, and that they are easily fatigued in walking. The muscles of the calf generally are greatly increased in size, so that they have been designated athletic or herculean

FIG. 28.-Pseudohypertrophy of the muscles of the calves in a man 30 years old; from a photograph (personal observation, Zurich clinic).

(Fig. 28). On palpation they feel nodular and hard like lobules of fat, and, as a matter of fact, the enlargement of the muscles of the calf is dependent upon the progressive substitution of masses of fat for the atrophied muscle-fibers, so that the loss of muscular tissue is not merely neutralized, but is even exceeded. It is, therefore, not surprising that the apparently hypertrophied

muscles are incapable of any considerable degree of activity. The extensors of the thighs and the gluteal muscles also present evidences of pseudohypertrophy. The remaining muscles of the legs, however, the muscles of the back, and also those of the arms are thin and atrophic. In the dorsal decubitus the feet occupy the position of pes varo-equinus. In walking the patient raises the feet high in order to avoid striking the ground with the toes, and the gait becomes uncertain and waddling. Atrophy and weakness of the muscles of the back give rise in the standing posture to lordosis in the lumbar region, and kyphosis in the dorsal region of the spinal column. On attempting to sit down the patient rather drops, and if he be requested to arise from a sitting position upon the floor to the erect posture, he will first make twisting and turning movements with the upper part of the body; then he will support himself upon his arms, then rest upon the knees, and then climb upon his legs and thighs with his hands. The muscles of the face generally remain uninvolved. The mechanical and the electric irritability of the affected muscles is diminished quantitatively in accordance with the degree of atrophy. Indications of degenerative electric reaction do not appear. Fascicular muscular twitching is not observed. The layer of subcutaneous fat generally is unusually thick over the pseudohypertrophic muscles. The skin is, as a rule, cyanotic, bluish, and marbled, and feels cold. The knee-jerk is diminished in consequence of involvement of the extensor of the thigh, or it may be wholly abolished. The duration of the disorder may extend over many years. Under such circumstances muscular contractures not rarely develop. Death results from some accidental disease or from excessive exhaustion.

JUVENILE MUSCULAR ATROPHY.

Juvenile muscular atrophy is, in the first place, attended with wasting and resulting weakness in the muscles of the shoulder-girdle and the chest. The greater and the lesser pectoral, the greater anterior serratus, the rhomboid, the trapezius, and the latissimus dorsi especially undergo atrophy. In consequence of paralysis of the serratus the inner borders of the shoulder-blades stand off from the back (p. 156, Fig. 29), and if the arms are elevated from below the elbows, the scapulae are readily displaced upward, so that the head sinks to a certain degree between them. The scapulaæ thus exhibit an excessive range of displacement and of movement. Wasting and weakness of the muscles of the back give rise in the standing posture to lordosis in the lumbar region and kyphosis in the dorsal region of the vertebral column. They render extremely difficult change from the recumbent to the erect posture. In the upper arm, especially the biceps, the brachialis internus, the long supinator, and, at a later period, also the triceps, undergo atrophy,

while of the muscles of the forearm the extensors become involved. The flexors and the small muscles of the hand, however, remain unaffected. In the lower extremities, which generally are involved much later than the arms, the glutei, the quadriceps of the thigh, and the tensor of the fascia lata, and in the leg the anterior tibial, undergo atrophy. Naturally, the power of walking is as a result

greatly disturbed. In walking the patient lifts the legs high, and the gait is waddling. In addition to the muscular atrophy hypertrophy of other muscles takes place, particularly in the deltoid, the supraspinatus, the infraspinatus, and the muscles of the calf. In contrast with the wasted muscles of the upper arm, the deltoid region is conspicuous on account of its unusual fulness (Fig. 29),

and a similar disproportion exists between the atrophied muscles of the thigh and the gluteal muscles, on the one hand, and the hypertrophied muscles of the calf on the other hand. The affected muscles feel firm, do not exhibit fascicular contraction, but only simple quantitative diminution in electric irritability, and no reaction of degeneration. Sensory disturbances, as well as paralysis of the bladder and the rectum, do not occur. The muscular atrophy most commonly begins on both sides, but its commencement is not rarely so gradual that it cannot often be determined with certainty. The duration of the disease generally extends over many years. The patients become progressively more helpless, and death finally occurs in consequence of excessive exhaustion or of some intercurrent disease (pneumonia, pulmonary tuberculosis).

INFANTILE MUSCULAR ATROPHY.

The disease begins with wasting of some of the muscles of the face, particularly the sphincter of the eye and of the mouth. As a result the palpebral fissure is so wide that the eye appears about to bulge through it, while the lips remain open and form a proboscis-like protrusion. The forehead is smooth and free from wrinkles, and the entire facial expression acquires a stupid character. The appearance has therefore been designated myopathic facies. In laughing the extent to which the mouth is widened is conspicuous. Gradually, but occasionally only after the lapse of more than five years, the atrophy extends to the muscles of the shoulder-girdle, the arms, the back, and even the legs. Especially the greater and the lesser pectoral, the trapezius, the deltoid, the biceps, the internal brachial, the triceps, the long supinator, the radial extensor of the carpus, and the dorsal extensors are in-, volved, and corresponding deformities and functional disturbances result in consequence. Muscular hypertrophy, however, does not occur. In other respects the conditions are much the same as in cases of pseudomuscular hypertrophy and juvenile muscular atrophy.

Diagnosis. The recognition of myopathic muscular atrophy is not difficult, for in contradistinction from spinal progressive muscular atrophy the disorder generally begins in childhood, is an hereditary or familial disorder, and does not present either fascicular twitching in the hypertrophied muscles or degenerative electric reaction. It further does not involve the small muscles of the hands, which are most commonly attacked in cases of spinal muscular atrophy, and bulbar symptoms are never present. The absence of degenerative electric reaction distinguishes the disease also from neural muscular atrophy and from muscular atrophy in consequence of acute or chronic polyneuritis, as well as from spinal paralysis of childhood. The commencement and the distribution

ww

156

while o The fle unaffect much l and th under

zriety of myopathic mus

om from anatomic lesion Derves is distinctive of all The changes in the muscudomuscular hypertrophy. lasia of the interfibrillary he muscular fibers progresbecome hypertrophied. The haracterized by marked transat of nuclear multiplication. -y, fatty degeneration, fibriltion, and vacuolation. An - may take place in the interrently hypertrophied muscles. y the interstitial connective while in cases of infantile musfibers are not encountered, the at little increased, and develop

Salar atrophy is unattended with fe; nevertheless the prognosis is n is helpless in the face of a dishe tendency to advance, and finally work and movement.

known, and also internal remedies checking the progress of the disThe best results can be expected hopedic appliances.

ASIVE MUSCULAR ATROPHY. tomic Alterations.-Neural progressive myopathic muscular atrophy, is usually

sease, which generally begins in early Is more commonly than girls. It depends normal predisposition on the part of the ttle is known with regard to the anatomic -on and atrophy of the medullary sheaths of --she reported to have been found, while the uninvolved, or at any rate has exhibited de

the columns of Goll. An observation has, ntly reported in which the spinal cord and the were found intact, and atrophy was demonstra

#ted muscles.

...and Diagnosis.-The disease begins insidiously, shy of the peroneal, the common extensor of the