Chapter M: M——, was a stout Irish woman about forty years of age. She had (22)

[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.

While the symptoms thus far considered as marking the origin and progress of tabes dorsalis are more or less constant, and although some of them show remarkable remissions and exacerbations, yet may in their entity be regarded as a continuous condition slowly and surely increasing in severity, there are others which constitute episodes of the disease, appearing only to disappear after a brief duration varying from a few hours to a few days: they have been termed the crises of tabes dorsalis. These crises consist in disturbances of the functions of one or several viscera, and are undoubtedly due to an error in innervation provoked by the progressing affection of the spinal marrow and oblongata. The most frequent and important are the gastric crises. In the midst of apparent somatic health, without any assignable cause, the patient is seized with a terrible distress in the epigastric region, accompanied by pain which may rival in severity the fulgurating pains of another phase {836} of the disease, and by uncontrollable vomiting. Usually, these symptoms are accompanied by disturbances of some other of the organs under the influence of the pneumogastric and sympathetic nerves. The heart is agitated by violent palpitations, a cold sweat breaks out, and a vertigo may accompany it, which, but for the fact that it is not relieved by the vomiting and from its other associations, might mislead the physician into regarding it as a reflex symptom. In other cases the symptoms of disturbed cardiac innervation or those of respiration are in the foreground, constituting respectively the cardiac and bronchial crises. Laryngeal crises are marked by a tickling and strangling sensation in the throat, and in their severer form, which is associated with spasm of the glottis, a crowing cough is added.[22] Enteric crises, which sometimes coexist with gastric crises, at others follow them, and occasionally occur independently, consist in sudden diarrhœal movements, with or without pain, and may continue for several days. Renal or nephritic crises are described[23] as resembling an attack of renal colic. The sudden disturbances of bladder function have been described as vesical crises, and recent French observers have observed so-called _crises clitoridiennes_ in female tabic patients which were characterized by voluptuous sensations. All of these symptoms have these in common: that they last but a short time, that their disappearance is as rapid as their advent, and that they depend for their distribution on the attitude of the disease in the cord. The vesical crises are more apt to occur early than late in the disease and where the belt sensation is in the hypogastric region. The gastric and enteric crises are usually found when the belt is in the epigastric level, and the bronchial, cardiac, and laryngeal crises when it is in the thorax and neck. Some connection has been observed between the occurrence of the lightning-like pains and these crises. Thus, a sudden cessation of the former is sometimes the forerunner of the latter. It is also found that one variety of these crises disappears to give way to another: this is particularly noticed with the bronchial crises, which often cease suddenly, to be followed by vomiting.

[Footnote 22: Krause, in a paper read before the Society of Neurologists at Berlin (_Neurologisches Centralblatt_, 1885, p. 543), found either laryngeal crises or other laryngeal symptoms, such as demonstrable ataxia of movement of the vocal cords, in 13 out of 38 cases. This proportion would be far too high for tabes in general; his cases were probably advanced ones. He established the interesting fact that the laryngeal crisis may sometimes be provoked by pressure with a probe on the superior laryngeal nerve at its laryngeal entry-point. Jastrowitz claims to have determined the existence of actual paralysis of the vocal cords with the crises, but Krause concludes from the experimental inductibility of the crisis that it cannot be due to a posticus paralysis. In a discussion on the subject Remak affirms that a unilateral paralysis of the crico-arytenoideus posticus may be an early or the earliest symptom of tabes. It seems, however, that in all cases where he determined such paralysis there had been disturbances of function of other cranial nerves in unusual severity at about the same time.]

[Footnote 23: They must be extremely rare: they have not occurred in a single one of my 81 private cases, nor do I recall one in clinic or dispensary experience.]

There is some analogy between the exceptionally-occurring mental disturbance of tabic patients and the crises. Like them, it resembles a disturbance of innervation, in this instance the centres regulating the cerebral circulation appearing to be at fault. It also seems as if in cases of this character the direction of the mental disturbance were determined in some sense by the emotional relations of the oblongata, for the insane outbreak usually consists in a brief but extreme outburst either of a {837} depressed and melancholiac or an expansive maniacal or delirious outburst. It is a very rare occurrence, and usually limited to the latest stages. Much more common is the development of paretic dementia, but this is to be regarded rather as a complication than an integral feature of tabes. Most tabic patients retain their mental equilibrium to the last moment; some develop truly heroic resignation to their terrible sufferings and gloomy prospects; and a few, becoming irritable, petulant, and abnormally selfish, show the effect of invalidism manifested equally with other chronic diseases.

In addition to the visceral crises there are other disturbances of innervation of a nutritive or trophic character which are characteristic of tabes. There is scarcely one of the eruptions or other changes which are attributable to central nervous disease which may not occur at some one or other period of this disease. Thus, herpetic eruptions may occur independently or in conjunction with lancinating pains, in one case even corresponding to the area of the belt sensation. Discoloration of the skin or hair, the latter turning gray or white in circular[24] or in irregular patches, spontaneous falling of the nails, spontaneous hemorrhages in the matrix of the nail, ichthyosis,[25] purpura, diffuse œdemas, localized perspiration sometimes associated with sudamina and accompanied by ecchymoses, muscular atrophies, bullæ, and pemphigus-like eruptions, have been noted by various observers. As yet, they are to be regarded rather as clinical curiosities than as constant features, as diagnostic criteria, or as presenting special indications for treatment. The trophic disturbances affecting the bones and joints and a peculiar ulcerative process known as the perforating ulcer of the foot are better studied, and, ranking among the most formidable and striking manifestations of tabes, merit special consideration. The tabic joint affection, first described by Charcot as a trophic manifestation of tabes, is usually located in the hip or knee, but almost any joint, including the temporo-maxillary articulation, may be its seat. The earlier or lighter forms consist in serous exudations with or without active local manifestations resembling those of synovitis; but the commoner and graver form consists in actual deformity of the articular surfaces, such as enlargement or atrophy, sometimes supplemented by the formation of osteophytes. In addition, spontaneous dislocations occur in a manner which is often quite surprising.[26] As a type of such an occurrence the following may serve: A tabic patient presented a synovial swelling of the left knee of truly enormous dimensions; as soon as this became reduced a distinct crepitus was elicited, and both the femoral and tibial articular surfaces found enlarged. The whole process occupied only a few days; the lateral ligaments were then found so relaxed that the leg could be freely moved in every direction.

[Footnote 24: Rossolymmo, _Archiv für Psychiatrie_, xv. p. 727. I have never observed this symptom as beautifully developed as in a case of spinal irritation, in which the possibility of the existence of any organic disease could be positively excluded. Bulkley has observed albinism.]

[Footnote 25: In three cases by Ballet et Dutil, _Progrès médicale_, May 19, 1882.]

[Footnote 26: Boyer (_Revue de Médecine_, 1884, p. 487) records a case where the hip became luxated spontaneously as an early symptom.]

The connection between the morbid process in the spinal cord and these remarkable arthropathies is as yet unexplained; and as Charcot's original {838} proposition, that they can be always referred to lesions in the anterior horns of the gray matter, has not been sustained, some of the German clinicians, notably Strümpell, are inclined to attribute them, in part at least, to ordinary results and accidents due to the anæsthesia and its disturbing effect on voluntary and automatic joint protection. A controversy arose which was participated in by the Clinical Society of London,[27] and evoked opinions from nearly all the eminent neurologists of Europe. The result of this thorough discussion has been to establish the joint affection as a true tabic symptom due to the same morbid process which underlies the less enigmatical symptoms of the disease. One of the best reasons for regarding these joint lesions as of trophic origin is the fact that they are associated with textural bone-changes by which they become either unduly soft or brittle, and therefore exposed to apparently spontaneous fracture. Cases of fracture of almost every long and some of the short bones are recorded, among the most remarkable being one by Dutil,[28] where fracture of the radius occurred without adequate cause in the initial period of tabes; and one by Krönig,[29] in which the patient, who had been tabic for eight years, broke a lumbar vertebra while catching himself in the act of falling down stairs.

[Footnote 27: The question was formally raised by Morrant Baker at the December meeting in 1884, and the discussion participated in by Charcot himself. Among the opponents of Charcot's theory were Jonathan Hutchinson and Moxon, the latter of whom administered a sound and well-merited criticism regarding some of the premature, if not sensational, announcements of the distinguished French neurologist. He compared the joint lesions of tabes to decubitus: just as the latter can be avoided by a proper protection of the exposed parts, so the former would not occur if the joints could be kept in a, surgically speaking, normal state. Moxon seems to have forgotten, in suggesting this comparison, that there is a form of decubitus which will occur independently of the greatest care and in spite of every measure taken to arrest it, and which can be attributed only to an obscure but active perversion of nervous nutritive control. Barwell, Paget, Herbert Page, Broadbent, and McNamara agreed that the joint lesions are not of surgical or rheumatic origin, but essentially signs of the nervous affection. Although Barwell's claim, that the rheumatic and tabic joint diseases are essentially different, because the former is hyperplastic and the latter is atrophic, is not borne out by all cases of tabic joint disease, some of which are certainly hyperplastic, yet the other reasons advanced for regarding these affections as distinct, and considering the joint affection of Charcot as a trophic disorder, far outweighed those advanced by the opponents of this view. In fact, the only ground the latter had to stand on was the fact that Charcot's asserted anatomical foundation was found to be chimerical.]

[Footnote 28: _Gazette médicale de Paris_, 1885, No. 25.]

[Footnote 29: _Zeitschrift für klinische Medizin_, 1884, vii., Suppl. H.]

Another reason for considering the arthropathies as of central origin is their chronological association with other signs whose trophic origin cannot be disputed, such as unilateral sweats and œdemas and visceral crises. They are also found to correspond in many cases to the lancinating pains both in location and time.

The feet of an advanced tabic patient usually appear deformed; the extremities of the bones, particularly at the metacarpo-phalangeal articulation, are thickened, and the axis of the foot as a whole is bent. It is a question how far this deformity may be due to persistent faulty innervation of the muscles going to the foot and to ensuing mechanical influences. A most pronounced deformity found in a few cases has been designated by Féré as the tabic foot.[30] It consists in the thickening of the tissues on the inner side of the foot, obliterating its arch in such a manner that in standing the plantar surface is everywhere in contact with the floor. {839} With this the tarso-metatarsal and the metacarpo-phalangeal joints of the great toes appear greatly swollen.

[Footnote 30: Pied tabétique—_Revue de Médecine_, 1884, p. 473.]

There is less dispute concerning the nature of the so-called perforating ulcer of the foot. This lesion occurs only in cases where the central or peripheral nervous apparatus is diseased; thus, it may occur with neuritis, and it is therefore unanimously regarded as due to morbid nervous influences. In tabes it may follow an exacerbation of the fulminating pains. It consists in a swelling of the tissues of the foot; the skin becomes firm and thickened; deep sinuous ulcers are then developed, showing but slight if any tendency to granulate, and which extend down to the bone, the latter usually remaining unaffected.[31] In a few cases more remarkable accidents due to disturbed nutrition have been noted. Thus, J. Hoffmann records a subcutaneous rupture of the Achilles tendon, and in another case the spontaneous discharge of all the teeth of the upper jaw within about a week's time.[32]

[Footnote 31: Like most of the manifestations of advanced tabes, the perforating ulcer may occur exceptionally as a pre-ataxic symptom. Thus, Suckling (_British Medical Journal_, 1885, April 4, p. 693) mentions its preceding the development of tabes proper by one year.]

[Footnote 32: _Berliner klinische Wochenschrift_, 1885, No. 12. In this unique case the loosening and falling out of the teeth preceded the tabes by a year. Demange, who observed the same phenomenon in two cases, found that the ascending root of the fifth pair was involved. The only analogous observation in my experience relates, like the bleaching of the hair in circular patches, to a case of spinal irritation: here the gums and alveolar borders underwent atrophy, exposing the roots of the teeth to beyond the normal alveolar border: first the right upper row, then the right lower row, and finally the teeth on the left side in the same order, showed this condition; only the most posterior fell out.]

COURSE.—Tabes dorsalis is to be regarded as an extremely chronic affection. Its development, as previously stated, is insidious,[33] and the symptoms demonstrating the advent of the disease may be so slight for many years that the patient does not regard himself as ill or as likely to become so. In this condition he may remain for ten or more years; and there are cases recorded where the exact signs of the incipient stage were well marked, and yet no ascertainable progress was made in a period of such long duration that the inference naturally follows of a much longer prospective period in which the patient would not have become ataxic. There may be distinguished two forms of invasion: the more frequent is marked by the development of the terebrating, fulgurating, and fulminating pains, to which, sooner or later, the abolition of the pupillary and certain other deep reflexes is added. In the vast majority of cases they are found absent when the physician's attention is directed to the question of the existence of spinal disease. In about one-fifth of the cases pain is at no time a prominent feature of the disease, and may be, as is established by the cases cited, entirely absent. In these patients the first symptoms noted are muscle-tire on slight exertion. Usually, the evidences of disturbed sensation and innervation begin in one extremity or preponderate in it, but symmetry is soon established. The same is noticed in the extension of the morbid process: when the ulnar distribution is involved—which is the first danger-signal on the part of the cervical enlargement of the cord—usually one side is first involved, but the other soon follows, and becomes affected in equal or nearly equal degree. In the {840} overwhelming majority of cases the disease manifests itself in the lower extremities first, remaining limited to them for a long period, and if extending to the upper extremities doing so in much slighter intensity than in the lower. Gull, Leyden, and others have observed cases where the arms were first and chiefly involved; but this is extremely rare. Cases of a simultaneous involvement of the upper and lower extremities are more frequently noted. The symptoms detailed above are developed in varying order in different patients, and the line has been already indicated which separates the progressive from the episodial features of the disease. Even in the ataxic period the patients may remain in a comparatively stationary period for many months and years.[34] The general bodily nutrition is usually good, and the muscular strength, as such, rarely affected to any noteworthy extent until the extreme phase of the disease is reached. Even the formidable-appearing crises and trophic disturbances, though occasionally fatal, are not always so. The direct danger from the disease proper, so far as life is concerned, is in the possible development of cystitis and pyelitis, of the malignant bed-sore, and of delirium and coma, the latter of which is occasionally found to be due to cerebral hemorrhage—a lesion which some writers regard as possibly due to some impalpable influence of the spinal disease on the cerebral circulation.[35]

[Footnote 33: Cases of acute locomotor ataxia have been described. In no instance are they pure or typical, and the last case of the kind published in America, beginning, as it is evident from the account, with signs of general myelitis, illustrates the impropriety of utilizing one or a few symptoms as determining nomenclature.]

[Footnote 34: Thirteen patients are now under my observation, or I have been able to obtain reliable medical information concerning their condition, who have been in the ataxic period since the date of my first examination, varying from a year to seven years ago. Not one of these patients is materially much worse than at that time. Two only died, both being bedridden at the time they came under observation. Of the first group, three have shown more or less lasting improvement in respect to special symptoms, as will be detailed in connection with the treatment.]

[Footnote 35: In a case of sudden death, with an asthma-like seizure, of a tabic patient under the charge of T. A. McBride, I found an intense injection of one (the right) vagus nucleus, the color of the ala cinerea and of the nucleus on section being almost black.]

MORBID ANATOMY AND PHYSIOLOGY.—Our knowledge of the structural disease underlying the symptoms which comprise the clinical picture of tabes dorsalis is perhaps the clearest in the domain of spinal pathology. Not alone the commencement of the morbid process and every stage of its subsequent encroachment on the spinal cord, but also its relations to special symptoms, have been demonstrated in numerous cases by some of the most careful German and French investigators.

In advanced cases of tabes the disease of the spinal cord is so evident that it was noted even by earlier observers, the region of the cord lying between the posterior nerve-roots being altered in color, consistency, and dimensions. It is gray instead of white, hard instead of soft, and considerably shrunken. The gray discoloration of the surface appears to be complete in the lumbar and lower dorsal region; it is less intense in the upper dorsal and cervical part of the cord; and often shows a division into three streaks, of which one, in the middle line, occupies both columns of Goll, while on either side another extends in the inner side of the posterior root-entry. The posterior roots themselves are frequently atrophied, and exhibit a firmer consistency and darker color than in health. On making cross-sections of the spinal cord it is found that the gray discoloration extends inward, involving more or less of the posterior columns in well-defined areas. Microscopic examination shows that the myelin of the nerve-tubes is either destroyed or atrophied, and the axis-cylinder is found to be affected in the same way, usually presenting alterations in its {841} refraction and diameter where it is not entirely destroyed. In the maximum foci of disease the conducting elements of the cord are nearly destroyed, and their place is occupied by a firm connective substance made up of wavy bundles, enclosing here and there a few atrophied axis-cylinders with wasted myelin-sheaths. The blood-vessels participate in the morbid process, at least as far as the larger vessels are concerned: these are sclerotic, their lumen appears contracted, the adventitial sheath is hypertrophied and occupied by a nucleated, fibrillar connective substance. The capillaries are sometimes normal, or participate in the morbid process to the extent of a thickening of the extra-endothelial sheaths which is either hyaline or fibrillary, and may show inflammatory cell-proliferation. It is evident that the increase of connective tissue in the posterior columns is not merely a relative one, due to the condensation of the normal neuroglia after the disappearance of the normal nerve-tubes, but is the result of actual proliferation. Opinion is somewhat divided as to whether this is to be considered as an inflammatory interstitial proliferation or as a more passive development of tissue compensating for the destroyed conducting elements. My own observations incline me to the belief that in syphilitic tabes the morbid process is essentially interstitial, while in non-syphilitic tabes it is parenchymatous, the disease beginning in the nerve-tubes proper. Perhaps the controversies between pathologists as eminent as Schultze, Tuczek, Rumpf, Zacher, Kahler-Pick, Rosenstein, and Adamkiewicz—who are rather evenly divided into opposing camps, one maintaining the parenchymatous, the other the interstitial, origin of the disease—may be solved when we learn to distinguish between the non-syphilitic and syphilitic cases, which is clinically, as yet, impossible. The difficulty of deciding what is a parenchymatous and what is an interstitial disease of the cord is considerably enhanced by the fact that the neuroglia, which by some at least is regarded as an interstitial connective tissue, is derived, like the nerve-substance proper, from the upper or neuro-epidermic germ-layer of the embryo, and not from the mesoblast, which furnishes all other connective substances in the body.

It is regarded as well established that the sclerosis of the areas of the spinal cord which are affected is preceded by a stage of granular degeneration.[36] This is supported by the facts that the sclerotic areas are surrounded by a zone in which sclerosis has not yet developed, but which is in a state of granular degeneration, and that in more advanced tabes this belt is also found sclerosed. In paretic dementia, a disease whose complicating cord affection closely resembles that of locomotor ataxia, a granular degeneration of the posterior columns is very common in earlier periods, while in later periods a sclerotic tissue is found in the same locality.

[Footnote 36: Westphal, _Archiv für Psychiatrie_, ix. p. 725.]

I regard these observations as opposed to the assumption of Strümpell that tabes is a system-disease of the cord in the sense in which he employs that term. In his fascinating and suggestive thesis on the systemic affections he cites the observations of Tuczek made on the posterior sclerosis ensuing from ergotism as confirming his view that special systems of nerve-fibres are separately vulnerable to special morbid influences. The remarkable correspondence between the topographical distribution of the lesion of ergotin tabes described by Tuczek and the characteristic areas {842} of sclerosis found in the column of Burdach in ordinary tabes, seems to justify a very different conclusion. Ergot exerts its morbid influence through a disturbance of nutrition. Just as it produces gangrene by constriction of the nutritive vessels of the fingers and of whole extremities, so it produces interference with nutrition of those nerve-elements in the cord which are most liable to suffer from general arterial constriction. These are presumably those portions which are supplied by the longest and narrowest arterial stems—a condition obtaining in precisely those parts of the cord which are affected both in ergotin tabes and in ordinary tabes.

It has also been supposed that the morbid process began in the posterior roots and crept in with these, thence extending upward.[37] This view is opposed by the fact that there is no constant relationship between the root lesion and the cord lesion; the sclerosis of the root-zones within the columns of Burdach I found to be absolute in at least one case where the outer nerve-roots were not distinctly affected.[38]

[Footnote 37: Takacs is the most recent defender of this view.]

[Footnote 38: The root lesion may, like that of the column of Goll, according to a minority of the interpreters, be a secondary process, for in ergotin tabes (Tuczek) both are usually intact.]

In typical tabes the sclerotic process begins in a special triangular field of the posterior column in the lumbar enlargement of the cord. The innermost of the posterior rootlets run through this field, which has been designated by the French school as the posterior root-zones, and the rootlets become exposed to all the vicissitudes which the conducting tracts are destined to undergo in consequence. Throughout the remainder of the cord it is the involvement of the root-zone which indicates the advance of the affection upward. At a time when the lesion is comparatively slight in the cervical level, manifesting itself by a slight grayish or reddish streak to the naked eye, a faint, pale discoloration in chromic-acid specimens, a deeper stain in carminized, and a pallor in sections stained by Weigert's method, the affected part in the lumbar region has undergone great shrinkage; scarcely a single myelin-tube is preserved to receive Weigert's stain within the affected area; the latter involves nearly the entire field between the cornua, and absorbs carmine deeply, so that it is difficult to differentiate the gray and white substance in carminized sections. A small part of the posterior column which most closely adjoins the posterior (gray) commissure remains free in all cases; so also does a small laurel-leaf-shaped field bisected by the posterior median septum. Examination with higher magnifying powers, aided by the modern improved methods of preservation and staining, reveals that the gray substance of the posterior segment of the cord is usually more or less diseased. In advanced cases the gelatinous as well as the spongy part of the posterior gray horn, and even the posterior gray commissure, undergo such considerable atrophy that they may occupy but half the normal area. In some cases the columns of Clarke appear to be involved quite early in the disease.[39]

[Footnote 39: Leyden discovered the degeneration in the fibres which in part make up these columns and correctly traced its origin to the posterior rootlets. Lissaner and Zacher (_Archiv für Psychiatrie_, xv. p. 437) confirmed him, the latter finding, as Leyden was the first to discriminate, that the cells may escape while the fibres are materially diminished. Krause claims that the columns of Clarke are constantly affected, but not necessarily in their entire length, the higher levels appearing quite normal at a time when the lower are severely involved (_Neurologisches Centralblatt_, 1884, p. 50).]

{843} The triangular field in the lumbar part of the posterior column, which is one of the typical starting-points of the affection, contains those ascending nerve-bundles which in their cephalic course emancipate themselves from the column of Burdach and constitute the slender columns of Goll. The result is that the degenerative process creeps up these columns at the same time that it ascends in the root-zones and deep portions of Burdach's columns. Some authorities regard this as a mere extension by contiguity;[40] others incline to consider it a secondary degeneration. It may extend to the medulla oblongata, becoming lost in the level where the nucleus of the column of Goll terminates, and is accompanied, at least in those advanced cases in which the upper extremities are involved, by a comma-shaped area of degeneration in the adjoining part of the column of Burdach, which similarly extends into the oblongata and terminates slightly more cephalad. In typical advanced tabes, therefore, the cross-section of the cord exhibits a characteristic distribution of the sclerosis in each level. As this distribution is associated with certain constant symptoms, it is permissible to attempt bringing certain features of the lesion in relation with special features of the disease symptoms. The posterior gray horns and the posterior white columns, together with other fibre-systems connected with them, are much more complicated in structural and physiological relations than the corresponding anterior structures. The relations of the anterior rootlets to the gray substance, and those of the motor ganglionic elements to their controlling tracts, are comparatively simple; those of the posterior roots are very intricate. They run up, in great part, at an angle to the longitudinal tracts; a few pass in directly, and still fewer dip to a lower level. The result is that a section of the cord made in the longitudinal direction through the root-zones, so as to pass from the root-entry to the anterior commissure, shows the column and root-fibres to be woven into each other like a plait. Trabeculæ of connective tissue, dragged in as it were with the posterior roots, fill up the interstices of this labyrinth. They are particularly dense in the lowest part of the lumbar enlargement of the cord, constituting the so-called posterior processi reticulares. It is reasonable to suppose that the overlapping of ascending and descending root-fibres, associated with the presence of an extra amount of connective tissue, imbedded as this fibre-maze is in that part of the cord which is most distant from its lymphatic emunctories, affords a favorable soil for slow inflammatory trouble. This is the primary field of tabic sclerosis, and in it the disease may remain most intense for years, extending but slowly and with diminishing intensity upward, hand over hand, as it were, on the natural ladder which the intertwined fasciculi and their matrix constitute. The longitudinal tracts which lie in and near the root-zones belong to the so-called short fibre systems, uniting the segments of higher and lower levels of {844} the cord with each other. As the sclerotic process ascends it involves the caudal ends of these systems: they consequently undergo secondary degeneration, and, shrinking in their turn, affect the caudal part of the next system above in the same manner. The morbid process in the column of Burdach may therefore be considered as a combination of inflammatory and degenerative changes, the inflammatory products causing a series of short ascending degenerations, and the vulnerable path thus established being followed by a cirrhotic condition in which the connective and vascular structures participate actively. With regard to the reasons for regarding the degeneration of the column of Goll and that of the comma-shaped field near it as a secondary process due to the cutting off of its apparent nerve-supply at the caudal end, and of the posterior nerve-roots or their provisional terminations, they may be stated in this way: When the lesion of the primary field is limited to the lower lumbar or sacral part of the cord, the degeneration of the column of Goll is limited to its postero-internal part; when the upper lumbar and lower dorsal cord is involved, the entire tract is affected; and when the cervical portion is diseased, the supplementary comma-shaped area degenerates. In other words, the projection tract of the sciatic nerve, as far as it is represented in Goll's column, suffers in the first, that of the crural nerves in the second, and that of the brachial nerves in the third instance. In all advanced cases of tabes the affection of the column of Goll is in direct proportion to the altitude of the lesion in the primary field. Symptomatically, it bears an equally constant relation to the ataxia.[41] No case is on record in which these columns were totally degenerated without some motor inco-ordination of the lower extremity having been observed during life; and no case is recorded in which brachial ataxia had been a marked and persistent feature in which the comma-shaped area—area of the column of Burdach—was healthy.

[Footnote 40: It is held by them that the histological character of the change of the columns of Goll is not different from that in the column of Burdach. Zacher (_Archiv für Psychiatrie_, xv. p. 435) urges that it does not resemble true secondary degeneration, beginning in the vessels and connective substance instead of the nerve-fibres. Schultze (_ibid._, xiv. p. 386), on the other hand, recognizes a primary involvement of the nerve-fibres in both of the areas of fascicular degeneration in tabes. The observation of intact axis-cylinders by Babinski in the sclerotic fields is in conflict with the latter's claim, and the various differences of observation and interpretation seem to be reconcilable only on the assumption that there are two different modes of origin, both leading to nearly the same results and occasionally combined in one and the same case.]

[Footnote 41: Krause's case and others show that the ataxia of movement is not influenced by lesion of the column of Clarke; but we are not informed as to the static equilibrium of the patients in whose cords these columns were found intensely affected.]

It is scarcely necessary to seriously consider the suggestion of Strümpell, that the lesion of the column of Goll is in relation with the bladder disturbance.[42] Cases are on record by Wolff and others where this lesion was intense and there was little or no bladder disturbance.[43]

[Footnote 42: _Archiv für Psychiatrie_, xii.]

[Footnote 43: The column of Goll is not present in those mammals which, like the porpoise, have no developed hind limbs, but these animals have urinary bladders.]

If the disease of the column of Goll were a primary systemic affection independent of the disease of the root-field, it would be difficult to understand why it, as well as the likelihood of finding a corresponding degeneration of the direct cerebellar tract, increases with the extent to which this field is involved. This occurrence becomes quite clear when we remember that both the direct cerebellar tract and that of Goll, being centripetal, are under the trophic dominion of the posterior nerve-roots. The opinion is not distinctly expressed, but implied in some writings, that the column of Goll degenerates because of a general transverse cord lesion at a low level; this is not the case in the tabic cord. There is a difference in appearance between that part of the primary field which corresponds to the column of Goll in the lumbar cord and the surrounding sclerosis in early cases: it is more intensely degenerated, more {845} homogeneous in appearance, and more evenly stained. The other part of the triangular field presents a more trabecular appearance. In the specimen represented in the accompanying figure this is easily recognized: the darker field corresponds exactly with the ascending degeneration, which follows compression of the cauda equina,[44] and is the sciatic equivalent of the column of Goll.

[Footnote 44: I have also found that this field corresponds to the column of Goll in its myelinic development: the lumbar part of this column—designated as such by Flechsig—is an entirely different tract, which enjoys a remarkable immunity from disease in tabes.

As illustrating the bearing of the lesion of the column of Goll on the motor ataxia I may refer to two cases which happen to be related side by side by Strümpell (_Archiv für Psychiatrie_, xii. p. 737, Cases 1 and 2). As far as the lumbar segment of the cord is concerned, the distribution of the lesion is similar; but in the one presenting marked motor ataxia the triangular field was slightly diseased, and there was no upward extension of the lesion in the column of Goll. In the other, with marked ataxia, the triangular field was intensely diseased, and ascending degeneration (?) occurred in the sciatic fields of the latter.

In support of the view that the comma-shaped area in Burdach's columns is homologous with the fibres of the column of Goll, it is to be advanced that degeneration of this field bears the same relation to symptoms in the distribution of the ulnar nerve that degeneration of the column of Goll bears to sciatic and crural symptoms. Where the initial pains and subsequent tactile and locomotor disturbance were severe, this field was found affected, and most so in the side where the symptoms had been most intense (Friedreich-Schultze's cured cases, _Archiv für Psychiatrie_, xii. p. 234). This area has no direct connection with the root-fields. Secondly, in a primary system disease of the column of Goll, associated with degeneration of the nucleus of the column of Goll, described by Scoli, an irregular encroachment of the column of Burdach was noted. Third, the innermost fibres of the column of Burdach (those belting the nucleus in the oblongata) have the same relation to the interolivary layer which the column of Goll has through its provisional nucleus of termination.

While the evidence of high lesion of the cerebral continuation of the column of Goll, and, what I regard as its homologue, the comma-shaped area of Burdach, together with the constant association of marked degeneration of these columns with motor ataxia, is strong positive proof of its relation to this symptom, there is equally strong evidence negativing its relation to any other of the prominent symptoms of tabes dorsalis. Thus Babesin (_Virchow's Archiv_, lxxvi. p. 74) found degeneration of the posterior columns limited to the column of Goll, and the patellar reflex was not destroyed; the root-fields at the upper lumbar levels were intact. That the columns of Goll have been found profoundly affected without bladder disturbance has been stated previously, and constitutes a stronger argument against Strümpell's view than the frequent observation of bladder trouble in spinal diseases, along with which these columns may be entirely free.]

Among the various constituents of the posterior columns which appear {846} to present a relative immunity to the disease, aside from the area near the posterior commissure and the laurel-leaf-shaped area of the posterior septum, Strümpell noted one which is situated at the periphery of the cord, bordering on the entry-line of the posterior roots and the inner contour of the posterior roots. In the few cases where it was found destroyed there was, what is a comparatively rare thing in moderately severe tabes, complete analgesia. It is not, however, certain that there is a necessary connection between the pathological and clinical fact here. The nerve-roots themselves are involved within the diseased area of the root-zones. The lesion is one of a kind which, affecting a nerve-trunk, would produce first irritation of, then impediment to, and ultimately destruction of, its function. The clinical parallel to this is the occurrence of the lightning-like pains in the earlier phases of the disease, which are followed by delayed pain-conduction, and finally by loss of sensation. Of the rootlets or fibres subservient to the various sensory and reflex functions mediated by the posterior roots, those which convey the centripetal impression normally evoking the patellar jerk appear to be the most vulnerable, or, because of their limited number, the earliest to be destroyed or compressed, with the result of total functional paralysis.[45]

[Footnote 45: It is now conceded that, as Westphal claimed, the patellar jerk is always abolished when the upper lumbar level of the root-zones (bandelettes externes of Charcot) is involved. Tshirijew has shown that the translation of the knee-jerk reflex occurs in a single segment of the rabbit's cord at the homologous level. In transverse sections a distinct fascicle may be seen coursing from the innermost root-fibres toward the antero-intermediate cell-group of the anterior horn; it furnishes a pictorial substratum, if not anatomical proof, for the patho-physiological observation, and harmonizes with the fact that it is the innermost rootlets which usually suffer first. Perhaps the delicacy of this tract accounts for the frequent disappearance of the jerk in old people as a result of senile sclerosis.]

With regard to the interpretation of the various tactile sensory disturbances of tabes and the delayed pain-sense conduction little positive advance has been made. That the lesion of the root-zones and gray substance is responsible for them seems to be the general conclusion of French and German observers. Recent researches have shown that disease of the peripheral nerves (multiple neuritis) may produce sensory phenomena which it had previously been customary to regard as pathognomonic of disturbance of their intraspinal terminations and continuations. At the same time, we are confounded by the observation of Erb, that even retardation of conduction of the pain-sense, which the dictum of Schiff taught us to regard as a sign of disturbed function of the spinal gray matter, is also produced by peripheral neuritis.

Immediately adjoining the gelatinous apex of the posterior horn there is a column of vertical fibres which bear a relation to it resembling that {847} of the ascending root of the fifth pair in the oblongata to the tuber cinereum of Rolando. Sclerosis of this column, as well as of the ascending root in question (Demange), has been found in tabes, and usually in association with pronounced trophic disturbances. In a number of cases (Oppenheim, Eisenlohr, and others) where spasmodic laryngeal crises had been a marked feature during life, lesion of the floor of the fourth ventricle, or atrophy of the pneumogastric nerve, or even of its nucleus, was found. In one case with marked gastric crises I found sclerotic changes of the arteries in the ala cinerea.