limited to, or most intense in, the spinal cord, and those in which
the brain is chiefly or exclusively involved, and hence they speak of
a spinal, a cerebral, and a cerebro-spinal form. This discrimination
is not sufficiently supported by clinical evidence to be of any
practical value. Each case is to be studied by itself during life and
after death, and to be regarded as one of a series in which the lesion
may be concentrated in any one segment of the cerebro-spinal axis. It
seems that when the sclerotic foci are limited to or chiefly located
in the spinal cord, the clinical signs are less pronounced than where
the brain is seriously involved; those cases in which the symptoms are
latent, or so vague that they cannot be distinguished from spinal
irritation or spinal exhaustion, have been found to be of the spinal
type. The cases of this character thus far observed are not
sufficiently numerous to justify the creation of special
subdivisions.[115]
[Footnote 115: According as the formation of the sclerotic foci
preponderates in a given segment of the nervous axis, the early signs
of the disease may consist in disturbances of the cerebral or the
spinal functions, and we may speak accordingly of a cerebral or spinal
invasion type. But the principle of classification adopted by several
recent writers, which would rank the spinal type among the spinal
diseases, the cerebral type among the cerebral diseases, and which is
compelled to erect a third category for the reception of the
cerebro-spinal type under the name of cerebro-spinal diseases, is a
bad one. Modern pathology recognizes the existence of affections which
involve whole fibre-systems, which are intracerebral in one and
intraspinal in other parts of their course, such as tabes and
amyotrophic sclerosis, which would therefore have to rank among the
cerebro-spinal, and not among the spinal affections, with which the
authors referred to classify them.]
CLINICAL HISTORY.—Prodromal.—Disseminated sclerosis is usually
inaugurated by a long initial period in which the symptoms are not
characteristic, and in which, unless there be decisive pupillary or
optic-nerve symptoms present, the nature of the disease is not
recognized. The patients feel weak and tired; walking is difficult,
and an element of unsteadiness suggests the development of a tabic
disorder. In other cases ankle-clonus is found and tremor of the foot
on extension (dorsiflexion); it is discovered that the unsteadiness is
due to weakness or to rigidity of the muscles, and thus the impression
of a developing spastic paralysis may be created. But symptoms on the
part of the cranial nerves soon show that the case is one of
disseminated sclerosis. Sometimes a marked belt sensation is
developed, and other forms of paræsthesia are not uncommon; nay, the
symptoms of spastic paralysis and tabes {875} dorsalis may be mingled.
Diplopia of the same transitory character as in tabes usually
accompanies the gradually-developing speech trouble. The reflex and
mechanical excitability of the muscles is increased in all cases where
the lateral column is extensively involved and the gray substance of
the cord is—as it usually is in the main—intact. In some cases a
slight tap on the knee when held in the position required to
demonstrate the knee-jerk produces oscillatory movements of the limb;
as the patient endeavors to suppress these they become more violent,
extend to the trunk and head, and may eventually involve the opposite
side. In those cases which show the cerebral-invasion type headache,
vertigo, and speech disturbance, temporary darkening of the visual
field, and loss of memory are the earliest symptoms directing
attention to the existence of serious disease.
Whether the spinal or the cerebral symptoms preponderate, they
continue increasing slowly and with temporary variations, which are
particularly marked in the cerebral-invasion type. As a rule, the
sensory disturbances are not pronounced at this time, but later, after
the initial symptoms have existed for a few years, they become
intense, and often extremely distressing. Those most complained of by
the patient are neuralgic, lancinating, and other pains. The
lancinating pains are, as a rule, not as severe as those of tabes
dorsalis, but they are apt to be associated with a dull heavy pain
which is located in a whole extremity, referred to the deep
structures, and very persistent. This diffuse pain sometimes occupies
all of the lower half of the body. As in tabes, the pain may be
regarded the forerunner of anæsthesia, which rarely, however, reaches
a high degree or an extensive distribution. Its distribution, like
that of the other peripheral symptoms of disseminated sclerosis, is
commonly irregular. Like the motor disturbance, which at this period
consists in a combination of paretic and spastic—occasionally of
ataxic—symptoms, it is most marked in the lower extremities.
In the majority of cases there is a peculiar tremor, which usually
presents the character to which Charcot directed attention—namely,
that it increases when the patient attempts to carry out a voluntary
movement, and disappears, or at least diminishes, when the muscles of
the part in question are at rest. This is the important symptom known
as the tremor on intended movement or intention tremor. One of the
time-honored means of testing it is to order the patient to take a
glass of water and pass it to his mouth. While he reaches out for it
some oscillatory unsteadiness is observed, but on grasping, this is
increased, and on raising the glass the oscillations increase till he
spills the water; if he succeeds in carrying it to his mouth, there is
a clattering against the teeth, and but for the steadying aid of his
mouth he would throw it aside by the violence of the disturbing
movements. In incipient cases this intention tremor is best shown with
delicate movements, and the more distinctly the more slowly they are
performed. It has been suggested that the peculiar character of the
lesion of disseminated sclerosis has some relation to the intention
tremor. It is a remarkable feature of the morbid process that it
leaves the axis-cylinder comparatively intact, beyond any other form
of myelitis or encephalitis. The myelin, however, is destroyed, and
the consequence is that the naked axis-cylinders lie in a newly-formed
connective tissue, which has not the same faculty the myelin has of
{876} isolating the nervous impulses conducted through the
axis-cylinders. The result is, that when a nervous impulse, such as a
voluntary movement, travels through a sclerotic focus, it may become
deflected to neighboring fibres going to another muscle or muscular
bundle than the one intended to be innervated. An unintended motion
results; the patient makes a stronger effort, intended for the right
channel, but again it slips off, to use a coarse simile, and thus a
number of erroneous messages are transmitted, and an equal number of
disturbing motions respond to these messages.
Whether this histological explanation be correct or not, the tremor is
probably due to the lesion of the peduncular tracts of the brain. At
least, this is rendered plausible for the tremor on intended movement,
which indicates an interference with the transmission of voluntary
impulses. Whether, as Pasternatzky[116] claims, the extreme muscular
oscillation seen in advanced cases is due to irritation of the
cortical motor fields, it is impossible to decide. No strong evidence
can be adduced in favor of his view. A few cases have been described
(Schüle, Jolly, and Greiff); and, in my opinion, such are far more
numerous than is usually supposed, where the tremor did not have the
so-called characteristic feature of ceasing in conditions of rest,
claimed by Charcot, but continued as in paralysis agitans.[117] A
collection of cases by Erb, Ordenstein, and Greiff shows clearly that
with a typical dissemination of sclerotic foci in the cord the tremor
on intended movement may be entirely absent, while no case is known
where the crus and pons were involved to a similar extent in which it
was absent. So it seems that a cerebral lesion is necessary to produce
this symptom in its characteristic form.
[Footnote 116: _Jahrbücher für Psychiatrie_, iii. 3, 1882.]
[Footnote 117: For several years I had been puzzled by the fact that
Charcot's formula failed to correspond to the clinical picture in the
majority of cases, and I registered such cases as incipient multiple
sclerosis or as a connecting group between paralysis agitans and that
disease.]
In advanced cases of disseminated sclerosis the intention tremor
becomes generalized; previously noticed, perhaps, only in one arm, it
now affects all the limbs and the muscles which maintain the trunk and
head in static equilibrium. The result is, that even when the patient
is at rest sitting in a chair, his body, and particularly his head,
are agitated by a violent and coarse tremor, which is increased on
rising and walking, as well as on attempting to use the hands.
Delicate mechanical occupations become impossible, and the handwriting
shows a characteristic change, the forward strokes of the letters and
the curvilinear back strokes, as well as the dots and crosses,
registering the tremor of the hand in their peculiar irregularity.
The speech is usually rough and broken, and sometimes enunciation is
impeded in a peculiar way, the patient appearing to scan his words.
Krause[118] has found relaxation of the vocal cords in a remarkable
degree to underlie the change in phonation. The scanning of speech
appears to be due to impeded innervation of the lips and tongue. When
the patient is told to protrude his tongue, he does so either in
spasmodic instalments of movement or with a sudden jerk after delay.
The same delay and apparent halting are noticed in the mimic
expressions that are observed {877} in speech. The features sometimes
express an emotion opposite to the one experienced by the
patient.[119]
[Footnote 118: _Neurologisches Centralblatt_, 1885.]
[Footnote 119: This symptom is found where there are other reasons for
suspecting the existence of large foci in the pons. I have observed it
in one case of tumor of this region, and one of a focal disease of
undetermined anatomical nature in the same location, in a remarkable
form. In the former case the patient not only exhibited the facial
contortions of hearty laughter when she felt as if about to break out
in tears, and broke out in tears when she felt amused, with perverse
regularity, but both emotional manifestations occurred simultaneously.
The other case is still under observation. There was complete
anarthria in the first, and nearly complete anarthria in the second
case—a fact not unrelated to the inferred site of the lesion, and
which may be associated with the fact that where the perverse mimic
expression occurs in disseminated sclerosis the speech-disturbance
often has an anarthric character.]
Whether diplopia occur as an early symptom or not, nystagmic
oscillation of the eyeballs is commonly found in the developed
affection. This nystagmus is usually universal, noted in associated
movements in every direction, and aggravated by excitement, by
constrained positions, and by any act of innervation of the
eye-muscles. It may be looked upon as an intention tremor of the
latter, and attributed to sclerotic foci in the cerebral axis,
particularly in the tegmental part of the pons varolii.
The deep reflexes are in some cases but slightly affected. Where
spastic phenomena preponderate, they are exaggerated, and where the
posterior root-zones are involved in the lesion, they may be, as in
tabes dorsalis, diminished or absent. The nutrition of the muscles is
not impaired in the early stages, and indeed most functions which
depend for their proper performance on the intact condition of the
gray substance, such as the power of retaining the urine, micturition,
and the functions of the rectum, are properly performed at this
period. The cutaneous reflexes are not markedly abnormal in the
majority of cases. They sometimes become diminished in the last
stages.
In cases regarded as disseminated scleroses and similar disorders
approximating the combined form of sclerosis, Westphal[120] noticed a
paradoxical muscular phenomenon which is the reverse in action of the
tendon reflexes. It is best observed in the tibialis anticus: if the
foot be extended (dorsiflected)—in other words, if the origin and
insertion of this muscle be approximated—the muscle contracts firmly,
keeping the foot in the enforced position, as if frozen into that
attitude. The same occasionally occurs if the patient voluntarily
extends his foot. Westphal observed the same phenomenon in the disease
described by him in which the symptoms of disseminated sclerosis are
present, but the corresponding lesion is not visible.[121]
[Footnote 120: _Archiv für Psychiatrie_, x. p. 243.]
[Footnote 121: _Ibid._, xiv. p. 132. It is a noteworthy fact that this
sign has been observed by its discoverer also in paralysis agitans.]
In a number of cases the mind becomes involved. Simple dementia is the
commoner condition, and some indication of passive mental enfeeblement
is found sooner or later in the history of the disease in the majority
of cases. In addition, there may be a morbid emotional condition,
usually in the direction of depression. I have been struck by the
frequent association of a melancholic state with large foci in the
oblongata. When it is borne in mind that the patient exhibits tremor
and speech-disturbance in addition to his mental trouble, it will be
understood that with some modifications of the typical signs the case
may simulate one of paretic dementia; and there are cases in which it
is exceedingly difficult to decide {878} whether they belong to an
aberrant type of disseminated sclerosis or to the sclerotic type of
paretic dementia. There are some which constitute veritable
connecting-links between the two affections.[122]
[Footnote 122: Zacher, _Archiv für Psychiatrie_, xiii. p. 168; the
writer, _Journal of Nervous and Mental Diseases_, April, 1877, and
_Insanity, its Classification, Diagnosis, and Treatment_, p. 240.]
Like tabes dorsalis, the progress of disseminated sclerosis is often
marked by episodes. Some of these differ in no way from the visceral
crises of posterior-column sclerosis; every form of these symptoms
found with that affection may occur in the present one, while episodes
involving the cerebral functions are much more common. The latter
manifest themselves as apoplectiform or epileptiform seizures. They
are preceded by headache and vertigo, or, if these be continuously
present, by an aggravation of them; then unconsciousness develops,
either accompanied by convulsions or not, and the face is flushed, the
pulse full and frequent, and the temperature raised. Consciousness
returns in a few hours or a day, the attack rarely lasting more than
two days, and it is found that the patient is hemiplegic. But, unlike
the hemiplegia found after vascular rupture, embolism, or structural
cortical disease, it is rapidly recovered from.
In a case of Gnauck's an attack of scotoma scintillans, associated
with a noise of thunder in the right ear and pricking pains on the
right side of the face, preceded anæsthesia and the formation of a
small defect of the visual field.
There is a close resemblance between these apoplectiform and
epileptiform seizures and those of paretic dementia, not alone in
clinical character, but also in the surprisingly complete and rapid
recovery from the more serious symptoms. But just as in paretic
dementia, especially in its advanced stage, each seizure leaves the
patient somewhat more impaired in mind and body than he was before, so
it is in disseminated sclerosis; each attack marks a step forward in
the invasion of the morbid state.
Eye-trouble is much less frequently a premonitory sign of disseminated
sclerosis than of tabes. A few such cases are on record. Magnan
observed the development of the characteristic symptoms of
disseminated sclerosis fourteen years after an amaurosis which
followed typhoid; and Gnauck reports another in which first a right
ptosis, and then a right amblyopia, preceded the ordinary symptoms. In
exceptional cases this premonitory eye-trouble may, like that of
tabes, rapidly lead to extreme amblyopia or even amaurosis. The visual
disturbances are remarkable for their rapid changes. They appear
within a short period, attain their maximum rapidly, and may
occasionally retrograde as quickly. They develop under two forms—the
central and the peripheral scotoma, or, rather, limitation of the
visual or color field. The former, like the amblyopia of alcoholic and
nicotine intoxication, consists in an inability to differentiate
between red and green in the centre of the visual field. It never, in
my experience, proceeds as far as the toxic amblyopias; that is, to
the complete extinction of vision.[123] The peripheral limitation of
vision may be for both quantitative and qualitative light-perception,
but it is not, as a rule,[124] concentric as in tabes, but
sector-like.
[Footnote 123: Gnauck says that the central color-blindness may become
total, and the red-green blindness extend to the periphery.]
[Footnote 124: Concentric limitation of ten to thirty degrees has been
noted for color-perception.]
{879} The atrophy of the optic nerve in disseminated sclerosis is
typically partial, in the majority of cases manifesting itself as a
sharply-marked discoloration of the temporal half of the papilla. In
others the nasal half of the papilla also becomes discolored, but so
much less intensely that the difference between the earlier involved
and later involved portions is quite easy. It is doubtful whether the
subjective visual disturbance is always an indication of the extent to
which the optic nerve is involved. There are good reasons for
believing those amblyopias and limitations of the field of vision
which show marked remissions and exacerbations to be due to some
dynamic central condition involving the visual centres and tracts.
Thus it has been observed that almost total amaurosis occurred after
an apoplectiform attack, to disappear later on. Occasionally the
amblyopia is bilateral and the optic-nerve lesion unilateral. The
frequency of this affection is stated by Gnauck[125] as follows: In
one half the cases there is diminished vision, and in half this half
optic-nerve atrophy with limitation of the visual field. It is only in
exceptional cases that an optic neuritis can be determined to have
preceded the atrophy.
[Footnote 125: Of 50 cases, 22 had no visual trouble, 8 showed simple
diminution of perception, 5 added limitation, and 15 changes of the
optic disc, a case of total atrophy and amaurosis being included in
the latter.]
The pupils are perfectly normal in some cases; in others myosis of the
spinal type is observed; and this I found to be nearly constant in all
advanced cases. Irregularity in outline and inequality exist in a
small proportion, and reflex iridoplegia is found in about 10 per
cent. of the cases.
Thus far, the symptoms which occur either in a majority or in a large
percentage of cases have been enumerated. The typical course of
disseminated sclerosis may be stated as consisting in their gradual
development and intensification, covering a period of from four to
twenty or more years. There are a number of cases in which so many of
the symptoms regarded as typical are either absent or where some given
symptom-group preponderates over the others to such an extent that
they require special mention.
It is not difficult to understand that disseminated sclerosis may ape
other forms of spinal disease. Its symptoms depend on the location of
the sclerotic foci. If these are situated chiefly in the
crossed-pyramid tract, spastic phenomena will predominate, and the
case may resemble a spastic paralysis.[126] If they be distributed in
both the posterior and lateral columns, the symptoms will resemble
those of a combined form of sclerosis in which the tabic and spastic
signs are associated, as far as they do not, in the nature of the
case, neutralize each other. This was well shown in a case of De
Fleury's. Not infrequently an unusually large focus involves the
entire transverse section of the cord, and the case becomes
complicated by the symptoms of a transverse myelitis. In such a case,
described by Rovigli,[127] a large transverse focus in the cord had
led to ascending secondary degeneration in the column of Goll and
descending degeneration of the crossed pyramid tract. In a large
series, instances of which are related by Kilian,[128] Siemens,[129]
Schultze,[130] Zacher,[131] and Greiff,[132] {880} the disseminated
foci were complicated by a diffuse lesion distributed like that of a
diffuse or fascicular myelitis; and there seems to exist every
connecting-link between ordinary chronic myelitis, strictly so called,
and disseminated sclerosis.
[Footnote 126: Gnauck, _Neurologisches Centralblatt_, 1884, p. 315.]
[Footnote 127: _Rivista sperimentale di Freniatria e di Medicina
leqale_, x. p. 227.]
[Footnote 128: _Archiv für Psychiatrie_, vii. p. 28. He designates
this form sclerosis continua multiplex.]
[Footnote 129: _Ibid._, x. p. 135.]
[Footnote 130: _Ibid._, xi. p. 216.]
[Footnote 131: _Ibid._, xiii. p. 168.]
[Footnote 132: _Ibid._, xiv. p. 287.]
Not only does disseminated sclerosis occasionally imitate or
approximate the regular (fascicular) affections of the cord, as well
as diffuse cerebro-spinal affections, but it may appear under the mask
of a nuclear oblongata paralysis.[133] And cases are on record where,
in addition to the disseminated sclerosis, there occurred sclerotic
atrophy of an entire hemisphere or of its capsular tracts, thus
leading to a hemiplegic resemblance of the motor paralysis. In my
experience the cases presenting the type of a nuclear oblongata
paralysis run a more rapidly fatal course than others. The shortest
history in my series, one of four years, was of such a case. A number
of instances are on record by careful observers—and are probably much
more numerous than is commonly suspected—where no decisive evidence of
spinal or cerebral disease could be detected during life, and yet
disseminated foci of sclerosis existed in the nerve-centres. In such
cases the symptoms may be in the direction of simple nervous
prostration, more commonly of spinal irritation. I have now under
observation a case which for years had been regarded as one of spinal
irritation, and which made that impression on me until I discovered
the existence of optic-nerve atrophy, which was the only indication
that the symptoms depended on gross structural disease.[134]
[Footnote 133: It is customary to speak of symptoms referable to the
oblongata as bulbar. The designation bulbus rachidicus is now
obsolete, and just as we speak of a capsular hemiplegia, a pons
paralysis, or a spinal hemiplegia, so we should say an oblongata
paralysis, discriminating between the nuclear, the neural, and the
tract affections by means of a prefix.]
[Footnote 134: At present the symptoms of disseminated sclerosis are
unmistakable. Cases are mentioned by Strümpell and others in which
they remained indecisive throughout.]
Among the anomalous forms of disseminated sclerosis there is one which
is characterized by the preponderance of paraplegia and contractures
in a combination which is usually found in spinal diseases of a
different type. The coexistence of dementia, however, usually enables
the observer to determine that the lesion is both cerebral and spinal,
although those signs which might enable him to decide the disseminated
focal character may be absent.