for the most characteristic evidence of the disease, the ataxia, would
be equivalent to reviewing almost every mooted question in spinal
physiology. It is to be borne in mind that ataxia is a collective term
designating any inco-ordination of movement which is independent of
motor paralysis. It may be due to abolition or impairment of tactile
perception; it may be due to loss of the muscular sense; it may be due
to hampered motor co-ordination; and, finally, it may be due to a
disturbance of the space-sense. In my opinion it is only in
exceptional cases that any one of these factors can be positively
excluded. Occasionally, one has been noted when the ataxia was grave
but the tactile sense was unimpaired, or where the muscular sense was
perfect but ataxia was well developed. The difficulty with most such
records is that no discrimination is made as to the kind of ataxia
present. That loss of skill which the patient shows when he shuts his
eyes and attempts to perform certain movements without their aid is
undoubtedly due to diminished sensation, either tactile or muscular,
and usually both. The inability to stand with the eyes closed is
probably a cerebellar phenomenon, and in this respect we are on the
way to return to Duchenne's opinion. It is true that the cerebellar
organ is healthy in most tabic subjects, but its centripetal informer,
the direct cerebellar tract, is either itself involved or affected in
its origin in the columns of Clarke. But, besides the static ataxia
and that motor ataxia which can be neutralized by the use of the eye,
there is another disturbance, which, as Erb and his followers hold,
cannot be accounted for on the strength of any sensory disturbance. It
consists in an interference with the proper succession and rhythm of
movement. It seems as if that automatic mechanism by which the
individual or grouped muscular contractions engaged in locomotion
follow each other with the smoothness of the action of
perfectly-fitting cog-wheels were disturbed; the correct
after-movement is hesitated over or skipped, or even takes place at
the wrong moment, neutralizing some other step in the co-ordination
required. The tendency of physiologists and pathologists is to
attribute this form of ataxia to the disease of the intrinsic
co-ordinating apparatus of the cord itself. The experiments of
Tarchanoff on a headless duck, and the determination of the existence
of cursorial co-ordinating tracts uniting the brachial and lumbar
nuclei in mammals, as well as the observations made on automatic
co-ordinate movement in decapitated criminals, demonstrate the
existence in the cord of such an apparatus. The combination of the
ganglionic centres which underlies this co-ordination {849} is
affected by the so-called short tracts of the cord,[48] and it is
precisely a portion of these which are involved in the lesion of the
column of Burdach. A number of arguments have been advanced against
regarding the lesion of this column, or indeed any of the lesions of
the posterior column, as explaining the ataxia-producing effect of
tabes. Westphal has interposed some potent objections. He holds that
lesion of these columns will be found more frequently when
examinations shall no longer be limited to those cases where disease
is suspected because ataxia was observed during life. He found
extensive disease of the posterior columns in sufferers from paretic
dementia who did not exhibit the characteristic ataxic gait of tabes.
I believe this objection can be met by the very cases cited by
Westphal in its support. Where the spinal disorder preceded the
cerebral—that is, where paretic dementia occurred as a complication of
tabes dorsalis—true locomotor and static ataxia had been present
before the insanity exploded. On the other hand, where the spinal
disease followed the cerebral, typical ataxia did not ensue. This
would seem to indicate that the destruction of cortical control is
inimical to the development of typical tabes. Leyden has made a
suggestion in the same direction when he attributes the lesser
manifestness of locomotor ataxia in tabic females to their inferior
cerebral organization.[49] A more convincing proof of the correctness
of this conclusion is furnished by the fact that if the pathological
process, after destroying the posterior columns and producing ataxia,
invades the voluntary motor tract, the ataxic symptom becomes less
palpable.[50] This antagonism between lateral-column and
posterior-column lesion is frequently exemplified in the combined
forms of sclerosis. It would seem, then, that where the brain is
healthy and the controlling voluntary tracts are unimpaired, the
ataxia is aggravated, supporting the beautiful theory of Adamkiewicz,
which assumes that the locomotor ataxia is due to a disturbance of the
balance normally existing between the psycho-motor centres and those
controlling the muscular tone as well as those mediating reflex
excitability.[51]
[Footnote 48: Intersegmental tracts.]
[Footnote 49: In one out of three female eases I found the active
disturbance of gait as severe as in males, but Leyden's observation is
supported by all who have seen a sufficiently large number of female
cases.]
[Footnote 50: Not because of paresis altogether, for it diminishes
materially out of proportion to the paresis.]
[Footnote 51: _Archiv für Psychiatrie_, x. p. 545. There is another
observation which bears in this direction: James of Boston observed
that absolute deaf-mutes in a large percentage of cases are
insusceptible to vertigo or to the allied phenomenon of sea-sickness.
Certainly, the auditory nerve is a space-sense nerve; its
physiological elimination is, however, accompanied by an immunity
against a symptom which may be an evidence of disturbed space-sense
transmission. In like manner, the destruction of the central
perceptive and voluntary centres in the paretic dement inhibits the
legitimate results of posterior spinal sclerosis.
The degeneration of the crossed-pyramid tracts in typical tabes seem
to be strictly an atrophy from disuse, perhaps facilitated by the
general malnutrition of the cord. It is limited to that part supplying
the most or solely affected extremities. Thus, where the lower
extremities are alone grossly involved it is totally degenerated in
the lumbar area, and only in its outer parts in higher levels. As if
to fortify this comparison by analogous observations from every great
segment of the nervous axis, a similar inhibiting influence of pyramid
lesion on co-ordinating disturbance (muscular sense) is noted in
secondary degeneration of the interolivary layer; when uncomplicated
with pyramid lesion (Meyer and my own case,) ataxia is present; when
so complicated (Schrader, Homén) it is not observed, even if
determinable.]
{850} Lissauer[52] has recently determined the existence of a
degeneration of certain fine nerve-fibres, apparently derived from the
outermost of the radicles into which the posterior nerve-roots divide
on entry. They are situated on that border of the apex of the
posterior horn which is in contact with the lateral column, and were
found degenerated in all cases except such as were in the initial
period. No symptomatic relation has been claimed for this lesion.
[Footnote 52: _Neurologisches Centralblatt_, 1885, No. 11.]
One of the most important questions which have grown out of the
pathological studies of tabes is the relationship between the lesions
and the not infrequently observed restoration of functions which had
been more or less seriously impaired in an earlier period of the
disease. Even those symptoms which ordinarily comprise the continuous
and essential clinical background of tabes may exhibit remarkable
changes in this direction. I have two well-established
observations—one of tabes of eight years' standing, the other of more
recent date—in which that symptom which, once established, is the most
constant, the reflex iridoplegia, disappeared, to reappear in two
months in one case where it had been associated with myosis, and to
reappear in eight months in the other, repeating this oscillation the
following year. I have now under observation a tabic patient in the
sixth year of his illness who two years ago had a return of both
knee-phenomena to a nearly normal extent, to lose them in two months,
and to regain the reflex on the left side four months ago, retaining
it up to the present. These three cases were of syphilitic subjects.
In a fourth advanced non-syphilitic tabic patient, whose ataxia had
reached a maximal degree, I found a return of both knee-phenomena for
three days after its absence had been established by medical examiners
for over a year, and had probably been a feature for a much longer
period. Hammond the younger and Eulenburg have reported similar cases.
Nothing is more surprising to those unfamiliar with the progress of
this disease than to find gross ataxia or the electrical pains and
anæsthesia to disappear or nearly so; and the alleged success of more
than one remedial measure is based on the fallacious attributing to
the remedy what was really due to the natural remittence of the
disease-process or of its manifestations. The financial success of
quacks and the temporary but rapidly evanescent popularity of static
electricity, Wilsonia belts, and like contrivances are owing to the
hopefulness inspired in the credulous patient by the mere coincidence
of spontaneous improvement and the administration of a new remedy,
supplemented, it may be, by the influence of mind on body in his
sanguine condition. It is to be assumed that the influences which are
at work in provoking the trophic and visceral episodes of tabes are of
an impalpable character, and that all theorizing regarding the reason
of their preponderance in one and their absence in another case are as
premature as would be any speculation regarding their rapid
development and subsidence in the history of one and the same case.
But we have better grounds for explaining the remissions of the ataxia
and anæsthesia.
It is only in the most advanced stages of tabes that the destruction
of the axis-cylinder becomes absolute or nearly so. Contrary to the
opinion of Leyden,[53] who held that the tabic sclerosis differs from
disseminated sclerosis in the fact that the axis-cylinder does not
survive the myelin {851} disappearance, it is now generally admitted
that a certain number of exposed or practically denuded axis-cylinders
may be preserved in the sclerotic fields.[54] It is on the theory that
these delicate channels may be oppressed at one time, perhaps by
inflammatory or congestive pressure, and relieved at another by its
subsidence, that we may assume them to be the channels through which
the now limited, now liberated, functions are mediated. It is also
reasonable to suppose that vicarious action may supplement the
impaired function, and to some extent overcome the disturbing factors.
This is illustrated by the controlling influence of the visual
function—yea, even of the unconscious and ineffectual co-operation of
completely amaurotic eyes—in neutralizing both locomotor and static
ataxia. One patient who was well advanced in the initial period of
tabes, and who had been encouraged to consider the medical opinion to
that effect as the result of an exaggerated refinement of diagnosis,
made repeated tests of the Romberg symptom in his own case, and
deluded himself into the belief that the physician was mistaken
because he succeeded in practically overcoming it with an effort that
too plainly told its own story; but still he overcame it. Certain
peripheral influences have the power of stimulating the dormant
activity of potentially vicarious tracts, and perhaps also the blunted
activity of those whose function is impaired. The outside temperature,
certain barometric conditions, all may exert an influence in this
direction for good or evil.
[Footnote 53: _Op. cit._, p. 328, vol. ii.]
[Footnote 54: Babinski (_Neurologisches Centralblatt_, 1885, p. 324)
notes this feature, and, consistently with the findings of most modern
observers, discovers much more resemblance to disseminated sclerosis
than to the systemic sclerosis with which Strümpell and Westphal (in
part) incline to classify tabes. Similar objections to the
system-disease theory are advanced by Zacher (_Archiv für
Psychiatrie_, xv. p. 340). I may not pass over in silence the fact
that Babinski considers his observations to militate also against
regarding any phase of the tabic sclerosis as a secondary process. But
while it may fairly be asked that a sclerosis to be regarded as
systemic must be shown to be total, this is not necessary for a
secondary process, unless the primary involvement be total also; and
that is not the case in tabes.]
ETIOLOGY.—Authorities are now agreed that no single cause can be
regarded as the sole responsible factor in all cases of tabes, and
that a number of etiological influences are combined in the
provocation of this disease in most instances. When the
distinctiveness of the affection was first recognized it was customary
to attribute it to sexual excesses, and the unfortunate sufferer had
frequently to bear the implied reproach of having brought his misery
on himself, in addition to the hopeless prospect which those who
followed Romberg and other authorities of the day held out to him.[55]
[Footnote 55: This opinion survives in a large portion of the German
laity and in French novels. About the time that the poet Heine was
dying from an organic spinal affection two other prominent literary
characters of Paris were affected with tabes. It so happened that all
three were popularly regarded as libidinous, and one of their leading
contemporaries, whose name escapes me, took occasion to issue a
manifesto addressed to the jeunesse dorée which closed with the
apostrophe, “Gardons à nos moelles.”]
Heredity plays a very slight part in the etiology of tabes. Writers of
ten and fifteen years ago attributed a greater importance to it than
is now done. But this was due to the incorporation with tabes of the
so-called family form of locomotor ataxia—a disease which is now
regarded as a distinct affection.[56]
[Footnote 56: There is but one record of direct heredity (the father
and son being affected nearly at the same time), to my knowledge. It
was observed at the Berlin Hospital by Remak (_Berliner klinische
Wochenschrift_, 1885, No. 7). Both father and son were syphilitic.]
{852} More importance may be attached to individual predisposition,
but thus far no distinct formulation of this factor has been attempted
except by Schmeichler,[57] who offers the suggestion that there are
persons with a predisposition to the development of connective-tissue
proliferation in various organs of the body, and that in them tabes
and other sclerotic affections are consequently more frequent than in
others. This suggestion appears plausible, but it is unconfirmed by
positive observations.
[Footnote 57: _Op. cit._]
Sex appears on a superficial view to be one of the most important
elements. It is generally admitted that at most one female becomes
tabic for every ten males who do so. Of 81 cases in private practice,
I observed but 3 females. Rockwell, Seguin, Birdsall, and Putnam give
similar figures. This comparative immunity is probably due to the fact
that the female is less exposed to over-exertion, to surface chilling
of the feet, to the injurious consequences of sexual excess, and to
syphilis[58] than the male. As a rule, the affection in females is
more insidiously developed, progresses more slowly, is less marked by
crises and trophic disturbances, and not accompanied by as severe
pains and profound disturbance of co-ordination as is the
corresponding affection in males.
[Footnote 58: Whether the shorter vitality of the syphilitic female as
compared with that of the male is a factor in diminishing the
accumulation of chronic tertiary sequelæ in that sex, or whether it be
the lesser vulnerability of the inferior nervous system, I am unable
to decide from the facts at my disposal. In private and clinical
experience I have been struck by the fact that women affected with
syphilis in the same way and under similar circumstances with tabic
syphilitic males develop symptoms of functional disorder of the brain
and cord, such as spinal and cerebro-spinal irritation. My cases
referred to had in no instance any indication of a syphilitic
condition or history, and a distinct and different cause was found in
all three.]
The most important element in creating an acquired predisposition to
tabes is undoubtedly the existence of constitutional syphilis. Some
difference of opinion still exists regarding the proportion of
syphilitic tabic patients, chiefly due to the neglect of Erb—when he
first announced the prevailing view, and which is generally attributed
to him—to differentiate between cases of demonstrated constitutional
syphilis and the so-called spurious or soft chancre. But although
there occurred a reaction against his view which went to as great an
extreme in the opposite direction, the careful and critically
registered statistics accumulated in the mean time strengthen the view
that there are more syphilitic subjects among the tabic than among any
class of sufferers from other nervous affections.[59] Reumont, a
physician at Aix-la-Chapelle, to which place syphilitic patients in
general resort in large numbers, found that of 3400 cases of syphilis,
290 had nervous affections, 40 being afflicted with tabes.
Bernhardt[60] took occasion to examine a group of hospital patients
who were free from tabes, and found that not fully 16 per cent. were
syphilitic, while of 125 tabic patients, over 46 per cent. were
determined to have had positive syphilitic manifestations. Several of
those observers who have paid attention to the question of the
syphilitic origin of tabes have admitted that the more searching their
inquiry the larger the proportion of detected syphilitic antecedent
histories. Thus, Rumpf's earlier table shows 66, and his later 80, per
cent. of such antecedents. This latter figure exactly corresponds to
the percentage of syphilis in my private {853} cases. At a discussion
held by members of the American Neurological Association in 1884,
Webber gave 54, Putnam 49, Rockwell 40, Birdsall 43,[61] and Seguin 22
per cent.[62] as the proportion in their experiences.
[Footnote 59: Excepting always those having the distinctive and
undisputed syphilitic character.]
[Footnote 60: _Archiv für Psychiatrie_, xv. p. 862.]
[Footnote 61: Derived from over five hundred cases which had presented
themselves at the clinic of the College of Physicians and Surgeons.]
[Footnote 62: In the _Archives of Medicine_ he tabulates 54 (private)
cases as follows:
Chancre alone . . . . . . . . . . . . . . . . . 23
Chancre followed by secondary symptoms . . . . 16
Total of those with history of chancre . 39
No history of chancre in . . . . . . . . . . . 15
Total . . . . . . . . . . . . . . . . . . 54]
Of European writers, aside from those already mentioned, Berger claims
43 per cent., and Bernhardt, in commenting on the increasing
percentage obtained by accurate investigation, reports an additional
series of 7 new cases in private practice, all of which were
syphilitic. Fournier, Voigt, Œhnhausen, and George Fisher estimate the
syphilitic tabic patients at respectively 93, 81, and 72 per cent. of
the whole number. The almost monotonous recurrence of a clear
syphilitic history in my more recent records is such that in private
practice I have come to regard a non-syphilitic tabic patient as the
exception. Among the poorer classes the percentage of discoverable
syphilitic antecedents is undoubtedly much less. The direct exciting
causes of tabes, exposure and over-exertion, are more common with them
and more severe in their operation.
The proof of a relationship between syphilis and tabes dorsalis does
not rest on statistical evidence alone. A number of observations show
that the syphilitic virus is competent to produce individual symptoms
which demonstrate its profound influence on the very centres and
tracts which are affected in tabes. Thus, Finger[63] showed that
obliteration of the knee-jerk is a frequent symptom of the secondary
fever of syphilis, and that the relation is so intimate between cause
and effect that after the return of the reflex, if there be a relapse
of the fever, the obliteration of the knee-jerk is repeated. Both the
permanent loss of the knee-jerk (Remak) and the peculiar pupillary
symptoms of tabes are sometimes found in syphilitic subjects who have
no other sign of nervous disorder; and Rieger and Foster[64] regard
the syphilitic ocular disturbances, even when they exist
independently, as due, like those of tabes, to the spinal, and not to
a primarily cerebral, disturbance. Another argument in favor of the
syphilitic origin of tabes is derived from the occasional remedial
influence of antisyphilitic treatment. The force of this argument is
somewhat impaired by the fact that the same measures occasionally
appear to be beneficial in tabes where syphilis can be excluded.
Still, the results of the mixed treatment in a few cases of undoubted
syphilitic origin are sometimes unmistakable and brilliant.[65] As
some cases, even of long {854} standing, yield to such measures, while
others, apparently of lesser gravity and briefer duration, fail to
respond to them, the question as to whether syphilis is a direct cause
or merely a predisposing factor may be answered in this way: That in
the former class it must have been more or less directly instrumental
in provoking the disease, while in the latter class it is to be
regarded as a remote and predisposing factor, to which other causes,
not reached by antisyphilitic treatment, became added. The claim of
Erb, that “tabes dorsalis is probably a syphilitic disease whose
outbreak is determined by certain accessory provocations,” is not
subscribed to unreservedly by a single writer of eminence.
[Footnote 63: “Ueber eine constante nervöse Störung bei florider
Syphilis der Secundärperiode,” _Vierteljahrschrift für Dermatologie
und Syphilis_, viii., 1882.]
[Footnote 64: “Auge und Rückenmark,” _Graefe's Archiv für
Ophthalmologie_, Bd. xxvii. iii.]
[Footnote 65: In one case already referred to a return of both
knee-phenomena and complete disappearance of locomotor and static
ataxia were effected after a duration of four years. The treatment was
neglected and the knee-jerks disappeared, and one has now returned
under the resumed treatment, but accompanied by lightning-like pains.
At a meeting of the Société médicale des Hôpitaux, held November 10,
1882, Desplats reported a case in which even better results were
obtained. Reumont (_Syphilis und Tabes nach eigenen Erfahrungen_,
Aachen, 1881) reports 2 out of 36 carefully observed syphilitic cases
cured, and 13 as improved under antisyphilitic treatment.]
The question has been raised whether the influence of syphilis is
sufficiently great to justify a clinical demarcation between
syphilitic and non-syphilitic cases. A number of observers, including
Reumont, Leonard Weber, and Fournier, incline to the belief that there
are more atypical forms of tabes in the syphilitic group. Others,
including Rumpf, Krause, and Berger, are unable to confirm this, but
the former admits, what seems to be a general impression among
neurologists, that an early preponderance of ptosis, diplopia, and
pupillary symptoms is more common with syphilitic than with
non-syphilitic tabes. Fournier[66] believes that syphilitic patients
show more mental involvement in the pre-ataxic period; but it is
evident that he has based this belief on a study of impure forms. The
advent of tabes in syphilitic cases does not in this respect differ
from the rule. The most protracted and severe diplopia I have yet
encountered in a tabic patient is one, now under observation, in the
initial period of the disease, syphilis being positively excluded as
an etiological factor.
[Footnote 66: _L'Éncephale_, 1884, No. 6.]