of disturbed sensation are noted. Certain parts of the extremities
feel numb or are the site of perverted feelings. The soles of the
feet, the extremities of the toes, the region about the knee-pan, and
the peroneal distribution, and, more rarely, the perineum and gluteal
region, are the localities usually affected.[3] In a considerable
percentage of cases the numbness and tingling are noted in the little
finger and the ulnar side of the ring finger; that is, in the digital
distribution of the ulnar nerve. The early appearance of this symptom
indicates an early involvement of the cord at a high level. Some
parallelism is usually observable between the distribution of the
lightning-like pains when present and the anæsthesia and paræsthesia
if they follow them. With these signs there is almost invariably found
a form of illusive sensation known as the belt sensation. The patient
feels as if a tight band were drawn around his body or as if a
pressure were exerted on it at a definite point. This sensation is
found in various situations, according as the level of the diseased
part of the cord be a low or high one. Thus, when the lower limbs are
exclusively affected or nearly so the belt will be in the hypogastric
or umbilical region; if the upper limbs be much involved, in the
thoracic region; and if occipital pain, anæsthesia of the trigeminus,
and laryngeal crises are present, it may even be in the neck.
Correspondingly, it is found in the history of one and the same
patient: if there be a marked ascent—that is, a successive involvement
of higher levels in the cord—the belt will move up with the
progressing disease. This occurrence, however, is less frequently
witnessed than described. In the majority of cases of tabes
disturbances of the bladder function occur very early in the disease.
Hammond indeed claims that in the shape of incontinence it may be the
only prodromal symptom for a long period.[4]
[Footnote 3: In the exceptional cases where the initial sensory
disturbance is marked in the perineal and scrotal region I have found
that the antecedent fulminating pains had been attributed to the
penis, rectum, and anal region; and in one case the subjective sense
of a large body being forcibly pressed through the rectum was a marked
early sign.]
[Footnote 4: _New England Medical Monthly_, 1883.]
I have under observation a patient who has been compelled to use the
catheter daily for years, who has gradual disappearance of the
knee-jerk and reflex iridoplegia, but who has presented no other
evidence of tabes during the year and a half he has been watched.
Among the exact signs of tabes, reflex iridoplegia and abolition of
the knee-jerk are probably the earliest to appear. It may be assumed
with safety that in ninety-nine out of a hundred cases both the
inability of the pupil to respond to light and the absence of the
knee-jerk will be found long before ataxia is developed. Cases are
recorded where no other positive signs were found, and no other signs
of the disease developed for a number of years,[5] and others where
disappearance of the knee-jerk was the very first indication.
[Footnote 5: Westphal, also Tuczek, _Archiv für Psychiatrie_, xiii. p.
144.]
The opinion of observers as to the frequency of double vision as an
early symptom of tabes is far from being unanimous. The majority of
writers speak of it as rare, but it is probable that this usually
transient symptom is forgotten by the patient, or because of its
apparent triviality {830} escapes notice. The patient while looking at
an object sees a double image of the latter. This may last for a few
seconds, minutes, or hours, and rarely for a day or week.[6] A
distinct history of this symptom was given by 58 out of 81 patients in
whom I recorded the oculo-motor signs. By far the most important of
the exact prodromal signs of tabes are two symptoms—one involving a
special faculty of co-ordination, the other the reflex movements of
the pupil. One or both of these must be present to justify the
diagnosis of incipient tabes.[7] The disturbance of co-ordination
consists in an inability of the patient to stand steadily when his
eyes are closed. The majority of healthy persons when tested in this
way may show a little swaying in the beginning, but eventually they
stand as steadily as they do with open eyes, and there is no
subjective feeling of uncertainty as to falling. But the tabic patient
exhibits oscillations, and makes efforts to overcome them which,
instead of neutralizing, usually aggravate them and betray the great
disturbance of his equilibrium. It is not as if he swayed merely
because he is uncertain of his upright position, but as if some
perverted force were active in throwing him out of it. It is found to
be a pronounced feature even in cases where the patient with open eyes
is able to walk nearly as well as normal persons, and experiences no
trouble in performing intricate evolutions, such as dancing, walking a
line, or even walking in the dark—faculties which the patient is
destined to lose as his disease progresses.[8]
[Footnote 6: It has been asserted that the severer and more persistent
diplopias are found with tabes dependent on syphilis.]
[Footnote 7: Not even the absence of the knee-jerk ranks as high as
these two signs. Aside from the fact that this is a negative symptom,
it is not even a constant feature in advanced tabes.]
[Footnote 8: It does not seem as if the disturbance of static
equilibrium were due merely to the removal of the guide afforded by
the eyes, for it is noted not alone in patients who are able to carry
out the average amount of locomotion in the dark, but also in those
who have complete amaurosis. Leyden (_loc. cit._, p. 334) and Westphal
(_Archiv für Psychiatrie_, xv. p. 733) describe such cases. The act of
shutting the eyes alone, whether through a psychical or some occult
automatic influence, seems to be the main factor.]
In most cases of early tabes it is found that the pupil does not
respond to light; it may be contracted or dilated, but it does not
become wider in the dark nor narrower under the influence of light. At
the same time, it does contract under the influence of the
accommodative as well as the converging efforts controlled by the
third pair, and in these respects acts like the normal pupil. It is
paralyzed only in one sense—namely, in regard to the reflex to light;
just as the muscles which extend the leg upon the thigh may be as
powerful as in health, but fail to contract in response to the reflex
stimulus applied when the ligamentum patellæ is struck. For this
reason it is termed reflex iridoplegia.[9] It is, when once
established, the most permanent and unvarying evidence of the disease,
and is of great differential diagnostic value, because it is found in
comparatively few other conditions.
[Footnote 9: It is also known as the Argyll-Robertson pupil. Most of
the important symptoms of tabes are known by the names of their
discoverers and interpreters. Thus, the swaying with the eyes closed
is the Romberg or Brach-Romberg symptom; the absence of the
knee-phenomenon, Westphal's or the Westphal-Erb symptom; and the
arthropathies are collectively spoken of as Charcot's joint disease.]
In a number of cases ptosis of one or both eyelids is noted at an
early stage of the disease. It is usually temporary, and coincides as
to time with the diplopia, if present.
Patients presenting some or all of the subjective and objective {831}
manifestations of tabes mentioned may continue in a condition of
otherwise comparative health, enabling them to attend to their
vocation for from one to twenty years, and it is not improbable that
the pre-ataxic period may extend over nearly a lifetime. In a less
fortunate minority of cases some of the most distressing evidences
usually marking the last stages of the disease are found developed at
the onset. Thus, cases are known where optic nerve-atrophy preceded
the true tabic period by ten or more years; others in which trophic
disturbances, manifested in spontaneous fractures of bones[10] or
violent gastric crises, or even mental disturbance, inaugurated tabes
dorsalis, instead of closing or accompanying the last chapter of its
history, which is the rule.
[Footnote 10: Berger, _Deutsche medizinische Wochenschrift_, 1885, 1
and 2.]
The disturbance of co-ordination above spoken of as manifested in the
inability of the patient to stand well with his eyes closed is the
first step in the development of the characteristic ataxia which marks
the full-blown affection. The patient finds that he tires more and
more on slight exertion—not because his muscles are weak, but because
he has to make more voluntary effort than a person in health. He finds
that he stumbles easily—is unable to ascend and descend at the
curbstone or to walk over an irregular surface with ease. Going down
stairs is peculiarly irksome. “I would rather,” aptly said one
patient, “troubled as I am in walking, go a mile in the street than
walk up three flights of stairs; but I would rather go up six flights
of stairs than walk down one.” Soon the patient notices that walking
in the dark becomes more a feat of relative skill than the easy,
almost automatic, act it was in health. His vocation, if it was one
involving the use of the feet, becomes irksome, difficult, and finally
impossible, and in a number of cases the upper extremities are also
involved.[11] Delicate motions, such as those required in needlework,
in writing, and by watchmakers, musicians, opticians, and lapidaries,
are clumsily performed; even coarser movements, such as buttoning the
clothes and carrying a glass filled with water to the mouth, are
performed in an uncertain and clumsy manner. Meanwhile, the
disturbance of motion in the lower limbs progresses. Difficult as it
formerly was for the patient to stand on one foot or with both feet
together while the eyes were closed, he is now unable to do either
with the eyes open. He straddles in his walk, or, in order to overcome
the element of uncertainty involved in moving the knee-joint, keeps
this joint fixed and walks with short, stiff steps. If ordered to halt
suddenly while thus walking, the patient sways violently, and makes
movements with his hands or arms to recover his balance, in some cases
staggering and even falling down. He shows a similar unsteadiness when
told to rise suddenly from a chair or to mount one, and it becomes
impossible for him to walk backward. Later on, it will be found that
his feet interfere in walking. He has lost the power of gauging the
extent and power of his motions to such a degree that he may actually
trip himself up. To neutralize in some way this element of uncertainty
of his steps, the patient is compelled to exaggerate all his
ambulatory movements, and there results that peculiar gait which was
the first symptom directing attention to the {832} disease to which it
is due. The feet are thrown outward, and violently strike the ground;
the heel touches the latter first, and the patient appears as if he
were punishing the ground and stamping along instead of walking. The
reason for his adopting these tactics are twofold. In the first place,
he has a subjective sense of walking in a yielding substance, as if on
a feather bed, air-bladders, cushions, or innumerable layers of
carpet, and he therefore makes efforts to touch firm bottom. In the
second place, his motor inco-ordination, in so far as it is not the
result of anæsthesias, is greatest in those segments of his limbs
which are farthest removed from the trunk, and which, enjoying the
greatest freedom of combined motion, are also most readily disturbed.
His uncertainty is therefore greater in the toes than in the ankle,
greater in the ankle than in the knee, and greater in the knee than in
the thigh: he prefers to touch the ground with the heel to touching it
with the toes, and to move his limb in the hip than in the knee-joint.
As the patient advances in life even this limited and clumsy form of
locomotion becomes impossible: he takes to his bed, and it is found
that he loses all sense of the position of his lower and occasionally
of his upper limbs. He is unable to tell which limb overlies the other
when his leg is crossed—unable to bring one limb in parallel position
with another without the aid of his eyes. If told to touch one knee or
ankle with the toes of the other side, his limb oscillates around
uncertainly, and makes repeated unskilful dashes at the wrong point,
and ultimately all but the very coarsest muscular co-ordination
appears to be lost, even when the supplementary aid of the eyes is
invoked.
[Footnote 11: Cases in which the upper extremities are intensely
involved in the beginning are uncommon, and those in which they are
more intensely involved than the lower, or exclusively involved, may
be regarded as pathological curiosities.]
Together with this gradual impairment and abolition of co-ordination,
which has given the name of locomotor ataxia to the disease, but not
always in that strict parallelism with it on which Leyden[12] based
his theory of inco-ordination, the sensory functions proper become
perverted and impaired. Usually the determinable anæsthesias are
preceded by subjectively perverted sensations, such as the numbness
already referred to, or even by hyperæsthesia. Usually, all categories
of cutaneous sensation, whether special or pathic, are impaired in
advanced tabes; the points of the æsthesiometer are not readily
differentiated; the patient is unable to correctly designate the
locality which is touched or pinched; the pain-sense is occasionally
so much blunted that a needle may be run through the calf of the leg
without producing pain, and in some cases without being appreciated in
any form. Even if the pain-sense be preserved, it will be found that
its appreciation by the patient is delayed as to time. Not
infrequently bizarre misinterpretations are made of the impressions
acting on the skin. One of these, the feeling as if the patient were
standing on carpet, cushions, or furs, whereas he may be standing on
stone flagging, has already been mentioned as a factor in the
disturbed locomotion of the patient. In the later period, numerous
perversions of this kind are noted: to one of these, already mentioned
by Leyden, Obersteiner has called renewed attention. It consists in a
confusion of sides; the patient when pricked or touched on one foot or
leg correctly indicates the spot touched, but attributes it to the
wrong side.[13]
[Footnote 12: _Klinik der Rückenmarkskrankheiten_, Band ii.]
[Footnote 13: Allochiria is the term applied by Obersteiner. Hammond
has offered an explanation, which, as it is based on the assumption of
altogether hypothetical nerve-tracts, and not in any sense accords
with positively established facts, is more properly a subject for
consideration in a theoretical treatise.]
{833} While it may be affirmed, as a general proposition, that the
tendency of the tabic process is to abolish sensation below the level
of the disease, there are noteworthy exceptions, not only in
individual cases, but with regard to certain kinds of sensation; nor
do the different kinds of sensation always suffer together. Thus, the
pain-sense may be blunted and the contact-sense preserved, or, more
commonly, the latter blunted and the former exaggerated, so that the
unfortunate patient, in addition to being debarred of the useful
varieties of sensation, those of pressure and space, has the painful
ones exaggerated, as a hyperalgesia. According to Donath,[14] the
temperature-sense is usually blunted in tabes, and a greater degree of
heat or cold can be borne without discomfort than in health; but in
about two-sevenths of the cases studied there was increased
sensitiveness to heat, and in one-seventh to cold. One of the
commonest manifestations is delayed conduction. This interesting
phenomenon has been especially observed in that phase of the disease
where tactile perception is beginning to be blunted. If the patient be
pricked with a pin, he feels the contact of the latter at the proper
moment as a tactile perception, and then after a distinct interval,
varying from one to four seconds, his limb is suddenly drawn up and
his face contorted under the influence of an exaggerated pain. This
fact furnishes one of the chief grounds for the assumption that there
are distinct channels for the transmission of pain and tactile
perception in the cord, and that they may be involved separately or
with different intensity in the disease under consideration. In some
advanced cases it is found that not only the transmission of
pain-appreciation is delayed, but that there are after-sensations
recurring at nearly regular intervals of several seconds, and
accurately imitating the first pain-impression.
[Footnote 14: _Archiv für Psychiatrie_, xv. p. 707.]
To what extent the muscular sense is affected in tabes at various
stages of the disorder is somewhat in doubt. Strümpell[15] by
implication, and other writers directly, attribute the inco-ordination
observed on closing the eyes to the loss of the muscular sense. As
this symptom is also observed in patients who when they lie on their
backs are able to execute intricate movements notwithstanding the
exclusion of the visual sense, and as their uncertainty in an early
stage is not always with regard to the position of their limbs nor the
innervation of individual or grouped muscles, it seems inadmissible to
refer the Romberg symptom[16] to the loss of muscular sense alone.
[Footnote 15: _Lehrbuch der Speciellen Pathologie und Therapie_, p.
193, vol. ii.]
[Footnote 16: It should be designated as static ataxia, in distinction
from locomotor or motor ataxia, which is manifested in unskilled
movements.]
The important part played by eye symptoms in the early stages of tabes
has been already referred to. Reflex iridoplegia is one of these early
and persisting features; it is sometimes complicated with mydriasis,
and occasionally with paralysis of accommodation of one eye. In the
majority of my cases there was spinal myosis, often of maximum
intensity; in a large number there was in addition irregularity of the
outline of the pupil; and where there was mydriasis I found it to be
quite symmetrical, in this respect differing from the experience of
Müller[17] and Schmeichler.[18]
[Footnote 17: _Centralblatt für die Gesammte Therapie_.]
[Footnote 18: _Loc. cit._]
{834} Atrophy of the optic nerve is a common and sometimes, as stated,
the initial symptom of tabes. It is rarely found in its incipient
phase in advanced stages. The patient who escapes involvement of the
optic nerve in the pre-ataxic stage is very apt to escape it
altogether. It is more frequently found either to precede the
pre-ataxic period by months and even years, or to develop during this
period, leading to complete atrophy in the ataxic period, and
sometimes before. Erb calculates that 12 per cent. of tabic patients
have optic-nerve atrophy; he probably includes only such cases in
which the atrophy was marked or led to amblyopia. Including the lesser
degrees of atrophy, it is found in a larger number of patients.
Schmeichler claims as high as 40 per cent.[19] If we regard those
cases in which there is noted progressing limitation of the
color-field of the retina as beginning optic-nerve atrophy, the
majority of tabic patients may be said to have some grade of this
disorder. The ophthalmoscopic changes are quite distinctive: at first
there is noted a discoloration of the papilla and apparent diminution
of the number of arterial vessels; the veins then become dilated; and
finally the papilla becomes atrophied, the vessels usually undergoing
a narrowing after their previous dilatation. In the first stages of
this process visual power is not gravely impaired, but as soon as
shrinkage has set in visual power sinks rapidly to a minimum,
decreasing till only quantitative light-perception remains. This
limited function usually remains throughout, but in a few cases
complete amaurosis ensues. As the field of vision becomes diminished,
the concentric extinction of quantitative perception is preceded by
concentric extinction of color-perception, the color-field for green
being the first to suffer; red follows, and blue remains last.
[Footnote 19: _Archives of Ophthalmology and Otology_, 1883.]
In a large number of cases the only symptoms attributable to a
disturbance of the cerebral functions are those connected with the
motor relations of the eyeball and pupil, and the function and
appearance of the optic nerve. The special senses other than those of
sight and touch are rarely affected. Sometimes there is obstinate
tinnitus, exceptionaly followed by deafness, attributed to atrophy of
the auditory nerve. The development of symptoms resembling those named
after Ménière is not referable with certainty to a disturbance of the
same nerve.
The sexual functions become involved in all cases of tabes sooner or
later. In the majority of cases there is a slow, gradual extinction of
virile power; in a large minority this extinction is preceded by
irritative phenomena on the part of the genital apparatus. Some
patients display increased sexual desire and corresponding performing
powers, but mostly they suffer from erections of long duration which
may be painful, and loss of the normal sensations attending the sexual
orgasm. There is no constant relationship between the intensity of the
general affection and the diminution of sexual power. It is retained
to a limited degree by patients who are barely able to walk, and it
may be entirely destroyed in those who have but entered the initial
period.
The bladder disturbance,[20] which in some forms is usually found
among the initial symptoms, is always a marked feature in the ataxic
period. {835} Usually, there is a frequent desire for micturition,
with more or less after-dribbling; sometimes there is retention,
alternating with involuntary discharge; complete incontinence may
close the scene through the channel of an ensuing cystitis and
pyelitis. With the incontinence of urine there is usually found
obstinate constipation, which may be varied by occasional spells of
incontinence of feces. The crises of tabes often complicate these
visceral symptoms.
[Footnote 20: Contrary to what might be anticipated from the
topographical nearness of the vesical and genital centres in the cord,
the disturbances of bladder function and virile power do not go hand
in hand.]
The reflex disturbances are among the most continuous evidences of the
disease. Of two of these, the disappearance of the patellar jerk or
knee-phenomenon and the inability of the pupil to react to light, we
have already spoken when discussing the initial period. Practically,
it may be claimed that both are always found in typical tabes. It has
been claimed that the patellar jerk may be exaggerated, or even that
its disappearance is preceded by exaggeration. As this disappearance
usually occurs extremely early in the pre-ataxic period, it is
difficult to follow the deductions of those who claim to have watched
an alleged earlier phase of exaggeration. It is more than probable
that cases of combined sclerosis, in which the lateral columns were
affected together with or earlier than the anterior, have been
mistaken for typical tabes. Here, it is true, the jerk is first
exaggerated through the disease of the lateral column, and later
abolished as the lesion in the posterior reflex arch progresses and
becomes absolute.
Other tendinous reflexes[21] suffer with the knee-jerk in the
peripheries corresponding to and below the involved level of the cord.
The cutaneous reflexes are usually abolished, but may be retained in
advanced stages of the disease. The same is true of the cremaster
reflex.
[Footnote 21: Whether the tendon phenomena are true reflexes or not is
a question still agitating physiologists. Opinion inclines in favor of
their reflex nature, and, pathologically considered, it is difficult
to regard them in any other light.]
Opinion is divided as to the electrical reactions in tabes dorsalis.
That qualitative changes never occur in uncomplicated cases all
authorities are agreed, but while Strümpell and other modern writers
claim there is no change of any kind, a number of careful
investigators have found an increased irritability in the initial
period, particularly marked in the peroneal group of muscles (Erb). In
my own experience this is frequently the case, where lightning-like
pains are the only subjectively distressing symptoms complained of.