therefore uncertainty of gait is the first symptom observed. The child
is usually backward in learning how to walk, even when two, three, or
four years intervene between this acquisition and the first decided
appearance of the disease. In the unquestionably congenital disease the
act of walking is always imperfectly performed, and the original
imperfection gradually deepens into a noticeable uncertainty of gait,
and finally into real paresis. It is noticed that the child falls very
frequently--at first only when running, afterward even while standing.
He then begins to experience difficulty in going up stairs: pulls
himself up by the {560} bannisters, and usually drags one leg
completely. After a while it becomes quite impossible for him to go up
stairs except on his hands and knees.
[Footnote 22: Billroth relates an altogether exceptional case of a
limited pseudo-hypertrophy with lipomatous degeneration, localized in
the hamstring and adductor muscles of one thigh, in a girl seventeen
years old. The only generalized lesion was an immense development of
subcutaneous fat (_Archiv für klin. Chir._, Bd. xiii.).
Dyce Brown (_Edin. Med. Journal_, 1870) relates a case, also in an
adult of twenty-six years, where hypertrophy of the thigh-muscles is
said to have preceded by three weeks that of the calves.]
These symptoms all point to failure of power in the gastrocnemii
muscles, whose function it is to raise the heel from the ground in
running, to steady the heel by their tension during the act of
standing, and to raise the foot with considerable force during the act
of going up stairs. In descending a staircase or any inclined plane
great tension is required of these same muscles, and this act should
therefore be even more difficult than that of ascension. But it does
not seem to have been as carefully studied.
Attention is not often directed to the infirmity at this early stage,
especially if the child be very young, since the apparently excellent
development of the legs satisfies the parents that nothing serious can
be the matter, and the falling is explained by childish awkwardness.
Not infrequently, indeed, this is really due to a rachitis which has
preceded the degenerative lesion, and at the early stage of the latter
a diagnosis from the less severe disease is always required, and is
sometimes difficult to make.
The following test may be applied in doubtful cases: The child (if old
enough) is requested while standing to rise on the tips of his toes.
This act necessitates a powerful effort on the part of the sural
muscles, and of this, even at an early stage of degeneration, they are
generally incapable.
Functional weakness may precede for several years all visible
alteration of the muscles; the child may not learn to walk at all until
two or even three years of age; then walks badly until five or six,
when, for the first time, the calves begin to enlarge. More often the
paresis precedes the hypertrophy by only a few months or weeks, or the
symptoms occur simultaneously. A certain amount of hypertrophy will be
overlooked; but when the calves enlarge sufficiently to render the
child's stockings too tight, attention is forcibly called to the
change. The enlargement is more marked at the upper part of the calf,
so that the symmetry of the leg is deranged by it. Often, however, the
impression of vigor conveyed by the appearance of the child's legs is
with difficulty dispelled by the discovery of their functional
weakness.
Eulenburg[23] affirms that the consistency of the muscle is soft and
doughy, recalling, when grasped in the hand, a lipomatous tumor. This
description, however, does not apply to the early stage of the disease;
for then the hypertrophied muscles feel extremely hard to the touch;
there is even a stony hardness (Duchenne fils); somewhat later, the
hypertrophy continuing, these muscles "seem to make hernial protrusions
through the skin" (Duchenne). This appearance is most marked when the
subcutaneous fat is atrophied; when, as happens especially in the adult
cases,[24] the diseased muscles are covered by a thick layer of
subcutaneous fat, their protrusion is concealed. A rapid exchange of
the hardness characterizing the first stage of the lesions for a
lipomatous softening is of bad omen, as indicating a more rapid and
irresistible march in the disease (Mobius).
[Footnote 23: _Ziemssen's Handbuch_, Bd. xii.]
[Footnote 24: See case by Billroth, quoted p. 853, note.]
At this early stage the electrical reactions of the enlarging muscles
are all intact. Disturbances of sensibility, however, are not uncommon.
Especially frequent are pains in the back and loins and stabbing pains
in the lower limbs. These pains sometimes follow the track of the {561}
crural or sciatic nerves; at other times they appear in the joints;
sometimes are limited to the affected muscles. The pains are diminished
by repose and a recumbent position, but are greatly aggravated by
movement. Paræsthesias, or a feeling of cold and formication, are also
observed--never anæsthesia. Seidel[25] has found the cutaneous
sensibility to be intact, as also the sense of space and pressure. The
temperature sensibility has not been tested. The temperature of the
affected part is, according to Eulenburg, often lowered several
degrees. This statement probably refers to the advanced degree of
degeneration. At an earlier stage Ord[26] found the temperature of the
calves to be increased.
[Footnote 25: _Loc. cit._, p. 32.]
[Footnote 26: _Med.-Chir. Trans._, 1874, 1877.]
Reflex excitability is maintained, not only in this, but in the second
stage of the disease, except in the patellar tendon, where it is
abolished after the quadriceps extensor has been invaded. This fact may
be of importance in diagnosticating paresis depending on incipient
pseudo-hypertrophy from that which would be caused by a mild anterior
poliomyelitis.
No symptoms of the third kind (deformity) appear in the first period of
the disease. The second is ushered in either by the first perceptible
degree of hypertrophy in the calves (Duchenne) or by increase of the
hypertrophy, which may have already begun during the first period of
paresis, and by extension of this to other muscles.
This extension of the lesion is indicated by further derangement in the
functions of station and locomotion. To steady himself the child
instinctively widens his base of support by placing the feet far apart,
and thus straddles while walking in a manner that is highly
characteristic. A second peculiarity is an oscillating movement of the
trunk from side to side. The trunk is carried over to the side of the
foot planted on the ground, the so-called active limb, and while the
passive limb is being swung forward. A third peculiarity of attitude,
already exhibited in station, but exaggerated by the act of walking, is
lordosis. The lumbar portion of the spine, with the abdomen, is carried
forward; the shoulders are carried backward, so that a plumb-line
dropped from them falls behind the sacrum. Thus, the walk of the
patient becomes highly characteristic--the feet planted so far apart;
the lumbar portion of the trunk projecting forward; the body
oscillating at each step from side to side.
At this stage the act of rising from a sitting or recumbent position
becomes more difficult than walking. If near a support, the child
always tries to draw himself up by his arms; if a fixed support be
lacking, he first gets on his hands and knees, and then, grasping each
thigh alternately with one hand, is enabled to get first one foot and
then the other on the floor. He then seizes the thighs by successive
grasps, each higher than the other, pressing back the flexed hip- and
knee-joint as he does so. By this method of apparently climbing up his
own thighs the patient is finally enabled to extend his body and arrive
at an upright position.
This attitude of the hands, on the knees, and subsequently on the
thighs, during the act of rising, is pathognomonic of
pseudo-hypertrophy, for it is observed in no other disease.
Corresponding with this increased disturbance in function is the
increased visible alteration in the muscles of the lower extremities.
The muscles on the anterior part of the legs are not always attacked,
but often {562} become hypertrophied and paretic contemporaneously with
the gastrocnemii. After these, hypertrophy of the glutæi comes next in
frequency. The quadriceps extensor of the thighs may become paretic,
and even perfectly paralyzed, without showing any sign of enlargement.
In many cases, however, hypertrophy proceeds regularly up the limbs,
and invades the thighs simultaneously with the buttocks.[27] The exact
proportion of cases is difficult to ascertain, because the history is
often imperfect, and at the time of observation the quadriceps extensor
is frequently atrophied, even when it has been hypertrophied at an
earlier date. The thinness of the thighs is then all the more
conspicuous from the hypertrophy of the calves below and of the
buttocks above. The sacro-lumbales and quadratus lumborum muscles are
also frequently enlarged, next in order to the quadriceps extensor
femoris, which, as seen, is rather less often hypertrophied than are
the gluteal muscles.
[Footnote 27: Cases in which the calves and thighs are alone described
as hypertrophied: those by Kaulich, Griesinger, Sigmund, Wagner,
Wernich (2d), Lutz (1st and 2d), Foster, Stoffella, Eulenburg (2d).
Cases of hypertrophy of calves with atrophy of thighs: those by
Eulenburg (1st), Lutz (3d), Adams, Barth (2d), Knoll, Friedreich,
Gowers (1st, 4th, 5th, 9th, 10th, 11th, 12th, 14th). In Rakowac's case,
as also Barth's, the glutæi were also hypertrophied.
Cases of hypertrophy, calves, thighs, glutæi, and sacro-lumbales
muscles: Duchenne (1st, 5th, 6th, 7th, 8th, 12th, the last being the
miniature Hercules, in which all the muscles were hypertrophied except
the pectorals), Heller (2 cases), Benedikt (1st, 2d, 3d, 4th; in the
5th the sacro-lumbales atrophied), Gowers (13th, 20th), Pekelharing.
Cases with hypertrophy of the calves and glutæi, with atrophy of the
thighs: Berend, Duchenne fils (hypert. sacro-lumbales), Duchenne (3d,
4th, 10th).
Cases of atrophy of all but calves: Spielmann, Gowers (7th), Hammond (2
cases).
Cases of hypertrophy of calves and deltoids, atrophy of all other
muscles: Ross (2 cases).]
The flexor muscles of the leg are much less often affected than these;
the adductors and the ileo-psoas rather more frequently. Paresis and
moderate hypertrophy of the abdominal muscles, though relatively rare,
are observed. Thus, from the foot up to the spinal column the morbid
imminence is pronounced on the side of the extensor muscles. The
liability to invasion on the part of the flexors is greatest at the
foot, where dorsal flexion is early impeded, and diminishes upward
toward the abdomen.
Most important for the theory of the disease is the fact that the
hypertrophic appearance of the muscles is never accompanied by even a
transitory period of increased strength.[28] Some degree of paresis
usually precedes the hypertrophy, and becomes intensified when this
sets in. The two symptoms, however, are by no means proportioned to one
another.
[Footnote 28: In Auerbach's case of true muscular hypertrophy the same
paresis was observed.]
There is another anatomical change in the muscles no less
characteristic of the disease than is their hypertrophy, which
contributes at least as much to the loss of muscular power. This is
atrophy of the muscles, which in the lower extremities is almost
invariably secondary to a stage of hypertrophy, but which occasionally
in the quadriceps extensor constitutes the primary lesion. On the other
hand, the calf-muscles, though occasionally retroceding from a state of
exaggerated hypertrophy, never atrophy below the normal dimensions.[29]
[Footnote 29: Hammond relates a remarkable case where the muscles of
the calves and thighs, having enlarged progressively during about two
years, then began to waste, and continued to do so for three years.
Then a second stage of hypertrophy set in, and continued at the time of
writing (_Treatise on Nervous Diseases_, 6th ed., p. 508).]
It not unfrequently happens that the atrophic and hypertrophic {563}
processes go on simultaneously in the same muscle, and so compensate
each other that the muscle varies little or nothing from the normal
size. This is especially apt to be the case with the pelvic and
lumbo-spinal muscles; and thus functional disturbances will develop for
which the mere appearance of the involved muscles seems to furnish no
sufficient explanation.
The peculiarities which have been described in station, locomotion, and
the act of rising to a vertical position nevertheless all depend on
such anatomical lesions of the muscles of the back and lower
extremities as render the adequate performance of their functions
impossible. Thus, the widening of the base of support by straddling the
legs is necessitated by weakness in all the extensor muscles of the
limbs--the glutæi, quadriceps, and gastrocnemii--which by their tension
should normally provide solid columns for the support of the trunk. The
lordosis begins with the first difficulty experienced in steadying the
heels, but is increased when the gluteals become incapable of extending
the pelvis on the femurs and when the sacro-lumbales are unable to
extend the vertebral column on the pelvis. The backward projection of
the shoulders, effected by the extensors of the upper portion of the
spine, is an instinctive compensation for the lordosis, to prevent the
trunk from falling altogether forward in front of the base of support.
The lateral oscillations of the trunk have been variously explained.
Duchenne attributed them to weakness of the gluteus medius. This
muscle, he asserted, is normally designed to restrain the tendency of
the pelvis at each step to incline toward the leg which is off the
ground.[30] But, in reality, during the act of walking, the pelvis, and
the trunk with it, are inclined toward the leg which is fixed, rotating
upon the head of the femur on that side, and being slightly elevated on
the opposite side, where the leg is being swung forward. This elevation
assists in enabling the swinging leg to clear the ground (Ross,
Hueter). The rotation is accomplished by the gluteal abductors on the
active or fixed side, the femoral extremity of these muscles being
fixed. Weakness of the gluteals must interfere with this rotation, and
should therefore diminish lateral oscillation did this depend on the
rotary movement.
[Footnote 30: _Archives gén._, 1868, p. 28.]
In a case examined by Ross, in which the lateral oscillation was much
marked, contractions of the gluteus medius were distinctly perceptible
to the hand placed just above the great trochanter. In another case,
where the gluteals were entirely destroyed, the oscillation, on the
contrary, was barely perceptible. Ross himself explains the phenomenon
more plausibly as a simple exaggeration of what occurs in normal
locomotion. In this the centre of gravity is necessarily shifted at
each step from the movable to the fixed leg by the inclination of the
trunk and shoulders to the side of the latter. When the legs are placed
far apart the body must incline farther in order to bring the weight in
the same relative position. Moreover, from the weakness of the anterior
tibial muscles the dorsal flexion of the foot, which should take place
at the moment the leg is lifted off the ground, is impeded or rendered
impossible; and the inclination of the pelvis on one side, which
necessitates its increased elevation on the other, thus favors the
swinging of the leg by leaving more room between the trunk and the
ground (Ross).
The curious manner in which pseudo-hypertrophic patients rise from a
{564} sitting or recumbent position has been carefully studied by
Gowers, and minutely analyzed by Ross in an adult case. The act to be
accomplished demands a series of extensions of the leg and pelvis on
the thigh and of the vertebral column on the pelvis. As the extensor
muscles are all paretic, this can only be effected by means of the
muscles of the upper extremities and of the weight of the body, which
the arms compel to serve as a motor force. Thus, from a recumbent
position the patient rolls upon his hands and knees: then, grasping the
knee, he lifts the leg upright with the foot planted on the ground. The
thighs remain strongly flexed, the trunk bent forward over the thighs.
The action of grasping the thighs above the knees, which is so
characteristic, serves to extend them by a double mechanism. In the
first place, the knee-joints are pressed slowly but directly backward.
In the second place, by the intermediary of the arms the weight of the
body is transferred from the upper end of the femur, above the power of
the quadriceps extensor, to the lower end of the lever, near the
fulcrum at the knee. Thus a lever of the third order, with the power
between the fulcrum and the weight, is partly transformed into a lever
of the second order, with the weight between the fulcrum and the power;
and thus the enfeebled quadriceps is able to act to more advantage.
Moreover, when the body inclines so far forward that the centre of
gravity is carried in front of the knees, it then becomes a force
applied to the upper end of the femur capable of extending the knees
without any action of the quadriceps.
When extension of the knee-joints is nearly complete, extension of the
pelvis on the femurs is effected by grasping the thighs alternately
higher and higher. By this manoeuvre the femur is pushed back and the
trunk is pushed up; and thus is compensated the incapacity of the
glutæi to perform their normal action of pulling up the pelvis flexed
on the femurs. Enough power remains in these muscles, however, for a
long time to complete the extension when, by the pushing movement, this
has been nearly effected.
During these actions the patient constantly oscillates the trunk from
side to side as he transfers the centre of gravity from one foot to the
other. In this, the second stage of the disease, and where the same
functional disturbances may arise with very various combinations of
hypertrophy and atrophy in the muscles of the lower extremities, a
third set of symptoms appears--certain deformities, namely, depending
on muscular shrinkage. The earliest, and often the most marked, of
these is talipes equinus. The patient becomes unable to plant his heels
firmly on the ground, and these are gradually drawn up higher and
higher, the patient resting first on the toes, then on the anterior
surfaces of the phalanges; ultimately is unable to stand at all, the
foot being drawn into a line with the leg, and the astragalus not
unfrequently luxated. Some authors explain this deformity by the
preponderating action of the gastrocnemius. The paralysis of this
muscle, which coincides with its hypertrophy, even when not quite
proportioned to it, renders such an explanation highly improbable. The
elevation of the heel is due to the gradual shrinkage of the muscular
tissue which accompanies the pseudo-hypertrophy; and on this account
the talipes is at every stage of its development irreducible.
The other possible deformities in the lower extremities are permanent
{565} flexions at the knee- or hip-joints. Both existed in the case
recently described by Pekelharing.[31] Before the disease has reached
its maximum degree of development in the lower extremities, its
progress has usually been marked in another manner--namely, by the
invasion of the trunk and arms. In cases 19-22 of Gowers's remarkable
series, where four boys out of a family of ten children were affected
by the disease, the hypertrophy first involved all the muscles of the
lower extremities, and then passed to the trunk and arms.[32]
[Footnote 31: _Loc. cit._]
[Footnote 32: Three other boys in this family, and three girls,
remained healthy.]
The description of the disease in the upper half of the body may be
distinctly separated from that in the lower half, on account of the
remarkable differences observed in the mode of the muscular
degeneration. In the lower extremities and pelvis primary
pseudo-hypertrophy is the rule; atrophy is almost invariably secondary,
and below the hips is rarely excessive.[33] In the upper part of the
body primary atrophy is the rule for certain muscles, and succeeds
rather early to the pseudo-hypertrophy which affects others. Only a few
muscles habitually hypertrophy, and remain enlarged until a somewhat
advanced period of the disease. The first in this group is the deltoid,
which not unfrequently enlarges simultaneously with the
gastrocnemii.[34] In one case the triceps humeri, and after that the
biceps, are the next most frequently hypertrophied,[35] in some cases
even together with atrophy of the deltoids (2d case Seidel). In
exceptional cases all the muscles surrounding the shoulder-joint,
especially those covering the scapula, are hypertrophied. Thus in the
early case of Coste and Gioga[36] the latissimus dorsi and trapezius
were hypertrophied, together with the deltoids, and even the muscles of
mastication and the tongue. In this case not only the quadratus
lumborum, but also the recti abdominis muscles, were hypertrophied. In
Chrostek's case the tongue was hypertrophied, although all the
shoulder-muscles, and also the sterno-cleido-mastoids, were
atrophied.[37] In Duchenne's third case the temporal and masseter
muscles were hypertrophied, while no alteration of size in any
direction was observed in the arms or shoulders. In Duchenne's twelfth
case all the muscles of the body, including the face, were
hypertrophied, with the single exception of the pectorals. In Barth's
second case, the left sterno-mastoid, the supra and infra spinali,
together with the left deltoid, were hypertrophied.
[Footnote 33: The quadricipites femoris, as already noticed, are not
unfrequently wasted.]
[Footnote 34: See cases of Kaulich, hypertrophy of calves, thighs,
deltoids; Heller, hypertrophy of all muscles of lower limbs, also of
abdomen with deltoids; Benedikt (4th and 6th cases); Friedreich (1st
case); Adams; Gowers (4th and 11th); Ross (2 cases); Brieger. In a case
by Clarke (_Med.-Chir. Trans._, vol. lvii.) the deltoids were observed
to be large seven years after the beginning of the disease. In a case
by Duchenne the enlargement of the deltoids, by great exception,
preceded that of the gastrocnemii by several months.]
[Footnote 35: Cases of hypertrophy triceps or biceps: Seidel (2d),
Rinecker, Griesinger, Wagner (2d, triceps without deltoid), Knoll,
Rakowac, Pekelharing, Spielmann (atrophy deltoid).]
[Footnote 36: _Schmidt's Jahrb._, Bd. xxiv. S. 196. Other cases are
given by Wernich (hypertrophy of rhomboids), Barth, Gowers (11th).]
[Footnote 37: _Oesterreich Zeitschrift f. prakt. Heilk._, 1871.]
In the majority of cases, however, at the time the patient came under
observation all the muscles above the quadratus lumborum were
atrophied, except the deltoids. In the pectoral, which has never been
found hypertrophied, the wasting process always sets in the earliest,
and advances to the greatest extent. The pectoral muscle is thus the
exact antithesis of the gastrocnemius, while the deltoid more nearly
resembles {566} the gastrocnemius than any other muscle of the upper
extremity. After the pectoral the latissimus dorsi, then the trapezius
scapular muscles (including the serratus magnus), those of the arm and
fore arm, the muscles of the neck, are found more or less wasted by the
time the disease is fully developed. The wasting is sometimes extreme,
as in a case described by Gowers, where the patient maintained a
permanently crouching attitude, the spinal column being in extreme
cyphosis, all its processes projecting, from the extreme emaciation of
the trunk.
In Eulenburg's adult case[38] the atrophy began in the hands, and was
regarded by him as a combination of true progressive muscular atrophy
in the upper, with lipomatosis musculorum luxurians in the lower
extremities.[39]
[Footnote 38: _Virch. Arch._, Bd. xlix., 1870.]