Chapter M: M——, was a stout Irish woman about forty years of age. She had (20)

[Footnote 65: I have not seen it noticed anywhere, but it is a fact readily demonstrable in any autopsy made in a well-preserved body that when a short segment of cord is observed at the moment of section the section surface appears pale; but if it be again examined after a few moments, it will show a reddish tinge, marked as a faint injection would be; this tinge distinctly deepens under the eye. I have observed this in specimens which were not held in the hand, so that the influence of pressure can be excluded. Nor do I believe that the elasticity of the tissues is such as to account for the phenomenon.]

In attempting to apply the fact that varying degrees of vascular injection are found on post-mortem examinations of the spinal cord to the elucidation of certain clinical phenomena, we encounter the same difficulties and sources of error that confronted us in the study of nutritive {802} brain disorders. The majority of writers have therefore contented themselves with making a careful clinical study of the mostly subjective signs of disorders which, once designated as spinal anæmia and hyperæmia, are now classified under the non-committal titles of spinal irritation and exhaustion (neurasthenia), as in this volume. A number of these disorders, like the so-called anæmic paralysis of Bouchut, Leroy d'Etiolles, Beroliet, Baimer, and Brandis, would to-day be considered as hysterical or reflex; and a few of the instances cited by their contemporaries as cases of spinal hyperæmia have been since demonstrated to resemble the initial phases of organic diseases of the cord.

The causes of active spinal hyperæmia are either direct, as when the spinal centres are overtasked by muscular strain either through over-exertion or through toxic convulsions, surprised by violent shocks, such as concussion accidents, or collateral, as when a physiological discharge (menstruation) or a pathological one (hemorrhoidal flux) is suddenly checked. A few cases are reported where carbonic-oxide-gas poisoning provoked spinal hyperæmia. But, like the alleged cases of spinal hyperæmia after continued and exanthematic fevers, they were probably cases of incipient or established myelitis. Hammond claims that surface chilling exerts the same congesting influence on the cord which he claims for the brain; but no definite observations have been made in this direction.

Passive spinal hyperæmia has been attributed to obstructive cardiac and chronic pulmonary affections. In such cases, as with most causes acting on the circulation of blood in the nerve-centres, the coexisting cerebral congestion usually masks the spinal. It is a question how far the intense hyperæmia of the cord found in some cases of tetanus, strychnia-poisoning, and the condition called hydrophobia[66] is primary and an indication of neural hyperexcitability, and how far it is secondary to the asphyxia attending the last phases of these convulsive states. The weight of opinion is in favor of an acceptation of the latter as the chief or only factor.

[Footnote 66: In a case of hydrophobia clinically as well marked as has been recorded, which I had the privilege of examining through the courtesy of Kretschmar, both brain and cord were found remarkably anæmic.]

Over-exertion and sexual excesses are frequently followed by a sensation of fulness and tension in the sacral and lumbar regions, which may be relieved by lying prone, while it is aggravated while lying supine.[67] From the location of this pain it is evident that it is not due to congestion of the cord or its membranes, but to fulness of the vertebral and spinal veins of the lower segment of the vertebral column. A similar sensation, which may be relieved by the same change in position or by a hemorrhoidal flux, is complained of by patients suffering from portal obstruction. The veritable symptoms of hyperæmia manifest themselves in the parts which receive their nervous supply from the affected districts. The reflexes are usually more active; paræsthesias of different kinds, such as formication, tingling, and creeping sensations, are common; and {803} there is more or less motor weakness, the limbs feeling heavy and sometimes being the seat of an acute pain. As a rule, these symptoms are limited to the lower half of the body.

[Footnote 67: Although this fact has been questioned, I have no doubt whatever that it is true, from a large number of observations. In many subjects suffering from the results of excessive venery or masturbation, an intolerable, sometimes pulsating, feeling in the lumbo-sacral region is only relieved by raising the lower end of the trunk with the back up. This condition is influenced by a change of residence to a district having a different level above the sea, and consequently a different barometric condition.]

There is very little question when these symptoms exist for any length of time, and become aggravated, that more subtle nutritive changes than are covered by the single term hyperæmia become responsible for them. In a pure hyperæmia the position-test of Brown-Séquard, which shows relief when the patient is upright or prone and aggravation when he is supine, particularly if the gravitation of blood to the cord be facilitated by raising the head and extremities, ought to yield constant results. But in some cases, particularly those of long-standing, the very opposite is noted: the patient's symptoms are aggravated by standing or sitting up, and relieved by lying down. Here there is probably exhaustion or malnutrition of the nerve-elements, rendering them abnormally sensitive to exertion. This view is supported by the fact that molecular disturbances, such as those which probably accompany simple concussion, predispose the patient to the development of the symptoms of spinal hyperæmia, and aggravate them if established previous to such accident.

Hammond,[68] who in his chapter on Spinal Congestion and Anæmia follows rather the older authors, such as Ollivier, than the newer and either more cautious or more sceptical writers on the subject, describes the symptoms of congestion as comprising belt sensations, paraplegia, erections of the penis, muscular twitches, loss of expulsive power, and incontinence of the bladder, paralysis of the abdominal muscles, paralysis of the anal sphincter, loss or abolition of reflex excitability, diminution of electro-muscular contractility, and occasionally hyperæsthesia and shooting pains. It is not doubtful for a moment that if such a case were to occur in hospital experience it would be regarded as one of organic disease, and not incipient, but well-established organic disease of the cord. Those making the diagnosis would have their opinion strengthened if, as Hammond states, the process took place with great rapidity and had a tendency to extend itself and eventually involve the whole cord, or if, as Brown-Séquard is by him cited as stating, bed-sores occurred in addition. Although Hammond describes certain anatomical changes, such as increased development of blood-vessels and distension and injection of them, I am unable to find any cases recorded as spinal congestion during life, and carefully examined with a due regard to sources of error after death, in which such changes were found. It is true that after strychnine- and cocaine-poisoning an intense hyperæmia[69] of the cord is found. In mammals it is of a far more pronounced character than in reptiles, and usually more marked in proportion to the existing asphyxia. That the characteristic toxic effects of these drugs is not to be sought for in their direct or indirect congesting influence is shown by the fact that exsanguinated frogs can be made to undergo strychnine tetanus when their blood is replaced by a saline solution according to the method of Salkowski. Little support, therefore, could be derived from a pretended analogy between toxic and {804} pathological hyperæmias, even if the phenomena of both were similar; which is not the case.

[Footnote 68: _Diseases of the Nervous System_, 7th ed., p. 392.]

[Footnote 69: It is true that in animals which are so organized that the congestion cannot be attributed to asphyxia, as I showed (_Hammond Prize Essay of the American Neurological Association_, 1878) in some experiments on strychnine, arterial congestion and small foci of hemorrhage were found in the upper cervical cord of frogs who had been kept in continuous strychnine tetanus for over seventy days.]

The introduction of subaqueous caissons for workmen engaged in the building of bridges, in which those employed labor under abnormal atmospheric pressure, has led to the development of a previously-unknown cerebro-spinal affection known as the caisson disease, and in which, it is generally supposed, either congestion or hemorrhage of the spinal cord occurs in consequence of sudden changes of vascular pressure resulting from sudden diminution of the barometric pressure. Clinically, this affection has been studied in England, France, and above all in America in connection with the building of the East River Bridge and the one over the Mississippi at St. Louis.[70] Experiments by Hoppe-Seyler, Bert, and I. Rosenthal have shown that a sudden diminution of pressure leads to hemorrhages in various tissues, and, according to the two first-named, a development of gas occurs in the vascular and other fluids of the body. A number of peculiar symptoms which do not specially interest us here occur in conjunction with the so-called caisson disease: these are—pain in the ear, with or without otitis sicca; peculiar pains in the joints, which occur on leaving the caisson, and are probably due to hyperæmia of the joint-surfaces and sudden increase of the intra-articular fluid; and retardation of the pulse-rate. In some cases cerebral hyperæmia is added, the patients tottering about as if drunk. The spinal symptoms consist of a paraplegiform affection. The paralysis is usually sudden; in some cases the patient a few minutes after stepping from the air-chamber falls down perfectly helpless as far as the lower half of the body is concerned. The expulsive power of the bladder is usually weakened, and there is anæsthesia to all forms of sensation in the affected limbs, as well as diminished electro-cutaneous sensibility. The patient often complains of a strange feeling, as if the lower half of his body were a foreign substance. With this the electro-muscular reactions are normal. In the majority of cases these symptoms disappear entirely in from three to ten days, but occasionally they remain longer; imperfect recovery of motion and sensation occurs, or, as happened in a few cases, one of which was carefully examined during life by Lehwess and after death by Leyden, death occurs as in myelitis. In the only case where an autopsy and careful microscopical examination were made under these circumstances[71] peculiar fissures were found in the substance of the spinal cord, surrounded by areas of reactive myelitis and filled with granule-cells. The absence of any pigmentary relics of a hemorrhage induced Leyden to assume that the lacunæ were not of hemorrhagic origin. He inclines to the view that they were due to the escape of gas from the blood-plasma, and consequent multilocular inflation of the tissue. If his observation be confirmed, it constitutes a strong objection to the hyperæmia theory of the caisson disease. There is neither permanent hyperæmia nor congestive or hemorrhagic myelitis developed, as far as the limited material thus far studied permits a conclusion.

[Footnote 70: Clark, _St. Louis Med. and Surg. Journ._, cited from Hammond, _loc. cit._]

[Footnote 71: E. Leyden, _Archiv für Psychiatrie_, ix. p. 316.]

Pure spinal hyperæmia rarely presents itself for treatment. The form due to over-exertion is recovered from by rest in a very short time; that due to suppressed discharges, by the re-establishment of the latter or by {805} the application of leeches to the lumbo-sacral and iliac region. Ergotin is recommended by Hammond in very large doses. It is a question whether this drug may not exert a bad effect in protracted cases where its use has to be continued for a long time.[72] In using it, it is well to bear in mind that imperfect nutrition of nerve-elements is perfectly compatible with an increased blood-amount.

[Footnote 72: A young physician, who for a long period took ergotin in twelve-grain doses for the relief of symptoms regarded as congestive, acquired a tolerance of the drug such as I have not seen recorded anywhere, and in addition presents some obscure signs of cerebellar disease and initial optic-nerve atrophy.]

Strychnia has been given with benefit in the caisson disease—another evidence, as this drug is theoretically contraindicated in true hyperæmia, that this disease is not, as Hammond and the majority of authors with him regard it, essentially a congestive affection. The treatment of those numerous cases in which signs of venous fulness accompany spinal exhaustion and irritation is detailed in the articles dealing with those affections.

Spinal Anæmia.

Anæmia of the cord-substance proper, like hyperæmia, is practically inseparable from the corresponding condition of the membranes. The influence of a reduced blood-amount on the functional activity of the spinal cord is more susceptible of exact demonstration than the corresponding nutritive disturbance of the brain. As the functions of this segment of the nervous axis are far simpler than those of the higher organ, there is more unanimity among observers as to the interpretation of their disordered states. In Stenon's experiment, and the more elaborate modifications made by those who have followed his method, it is found that interference with the supply of arterial blood to the spinal cord is followed by abolition of the function of the gray matter; if the supply be still further diminished, the functions of the white tracts become eliminated; next the peripheral nerves, and ultimately the muscles themselves, lose their normal excitability. On the re-establishment of the circulation these various parts regain their functional capacity in the inverse order of its suspension—the muscles first, next the nerves, then the white substance, and last the gray substance of the cord. The initial symptoms of some cases of myelitis from refrigeration correspond more nearly to such a result of artificial anæmia of the cord than they do to anything that is customarily regarded as hyperæmia.[73]

[Footnote 73: I have seen distinct pallor of the spinal meninges on dipping the posterior extremities of a dog, whose cord had been exposed, into water. It is to be remarked, however, that other observers, notably Hammond, have either obtained different results or interpreted the consequences of refrigeration differently.]

No one has gone farther than Hammond in erecting a theoretical anatomical framework which elaborately provides for the accommodation of various symptoms of spinal anæmia. He describes anæmia of the posterior columns, and sharply discriminates between it and anæmia of the antero-lateral columns. It is a question whether the conducting tracts of these columns are seriously affected in their functions by anæmia as long as the centres of innervation are well nourished. Undoubtedly, it is the gray substance of the cord which is most vulnerable to the influence of {806} disturbed circulation and nutrition, as Stenon's experiment has shown; and a glance at the distribution of the blood-vessels will show that a partial anæmia or hyperæmia, limited to special cornua in any considerable length of the cord, is an exceedingly improbable occurrence. With regard to isolated anæmia of the white columns, it is to be admitted that the posterior are most vulnerable to malnutrition. But it is doubtful whether this vulnerability is so great as to allow of an exclusively posterior anæmia, or whether a protracted anæmia of this kind could exist for years as a purely symptomatic—or, as some designate it, functional—disorder.

Hammond candidly states that in specifically locating the lesions in these affections he is aware that post-mortem examinations are wanting to support them, and admits that what he calls anæmia of special parts of the cord is the spinal irritation of most authors, and in part the reflex paraplegia of others.

The most clearly-established form of cerebral anæmia is the one which is indicated by the ischæmic paraplegia of Jaccoud and the paraplegia following profuse hemorrhages. The former is produced by all causes which, by obstructing the flow of arterial blood in the abdominal or thoracic aorta, cut off the proper blood-supply to the cord, which the latter receives through the intercostal and upper lumbar arteries. Aneurism, compression by tumors, and embolism of the aorta produce this result. The consequence is paraplegia corresponding in all features of its development to the phenomena observed in Stenon's experiment. These features, already detailed, suffice to show that it is not the anæmia of the peripheral nerves and muscles that is chiefly responsible for the paraplegia, but the insufficient irrigation of the gray and white substance of the cord itself. The same is true of the paraplegia following hemorrhage which has been noted after uterine, renal, and enteric hemorrhages. Both affections are exceedingly rare.

The influence of general anæmia on the functions of the spinal cord is not susceptible of accurate study. The cerebral enlargement of the nervous axis is so much more unfavorably situated than the cord that it suffers first and most when general anæmia is present. The consequence is that the signs of cerebral anæmia mask those of spinal anæmia. It is supposed, however, by many authorities that the effect of anæmia on the cord may be regarded as an auxiliary factor in the production of hysterical and neurasthenic symptoms.

How far the spinal cord is liable to suffer from arterial spasm is as yet a matter of conjecture. It is supposable that just as a powerful psychical impression provokes a sudden spasm of the cerebral arteries, so a peripheral irritation may provoke a spasm of the spinal arteries. In this way the reflex paralyses, motor and vaso-motor, are explained by many writers.

The subject of reflex palsy has been so much confused by improper cataloguing—if it can be so called—that some of the best authorities have become sceptical as to its occurrence. Among the chief sources of error has been the attributing to irritation of the genital organs various convulsive, psychical, and paralytic disorders. Adherence of the prepuce and its excessive length were charged with being responsible for idiocy, imbecility, epilepsy, and every form of paraplegia and panplegia. It was further claimed that instances of complete cure of each of these {807} affections had followed the removal of the exuberant or adherent prepuce. I cannot find a single instance recorded where such a cure was effected in any of our large medical centres, so as to prove convincing to critical colleagues. On the contrary, L. C. Gray[74] has shown that various surgical procedures have been needlessly resorted to on this erroneous theory in cases of organic diseases of the spinal cord. I have seen two unfortunate children suffering from the worst forms of anterior poliomyelitis, one afflicted with pseudo-hypertrophic paralysis, and several hydrocephalous and microcephalous idiots, whose prepuces had been sacrificed to the theory alluded to—it is needless to add without any result, good or bad.

[Footnote 74: _Reflex Irritation from Genital Irritation_. In this paper written communications from all or nearly all neurologists in the United States—certainly including all those of national fame and large experience—are cited, in which they testify to never having seen a case of this character cured by operations on the penis (_Annals of Anatomy and Surgery_, Jan. and Feb., 1882.)]

The possibility of a reflex paralysis occurring from genital irritation in the male cannot be denied; among the lower animals a ligature around the spermatic cords sometimes produces paraparesis, and paraplegia is a common complication of renal and vesical troubles in others. But analogous observations in man are rare, and becoming rarer with our increasing acumen in diagnosis. In females peculiar reflex disturbances are found associated with uterine and ovarian derangements. In one case of retroflexion, with possible dislocation of the ovary, referred to me by H. J. Boldt, there is a remarkable vaso-motor paralysis of the right arm during each menstrual period: this member becomes greatly enlarged, of a purplish-blue color, and cold. Equally remarkable are the reflex disturbances resulting from the presence of worms in the intestinal canal. Every form of spinal and cerebral paralysis, even aphasia, has been observed in connection with helminthiasis. Such disorders yield as rapidly as they are developed to the exhibition of vermifuges.

Special interest has been aroused by the discovery laid down in the joint treatise of J. W. Mitchell, Morehouse, and Keen of reflex paralysis following injuries, observed in the War of the Rebellion. The cases cited by them appear singular on first sight. The paralysis is often observed in parts of the body which are not only remote from the seat of injury, but have no direct connection, physiologically or otherwise, with it. The hand may be injured and the opposite leg paralyzed.

Since Mitchell, Morehouse, and Keen first announced the existence of this peculiar form of reflex paralysis a careful search has been made by military surgeons engaged in other campaigns for like results. Notably was this done in the Franco-Prussian War. A number of confirmatory instances have been collected, some of which rival in singularity those related by the discoverers of the affection. In one case a unilateral paralysis agitans followed a punctured wound of the opposite shoulder, and in another reflex aphasia followed a gunshot wound of the lumbar region.[75] A discrimination is to be made between such cases where the paralysis, anæsthesia, or neuralgia is an immediate result of the injury, and those where they follow after weeks or months. In the latter instance we have not true reflex disorders to deal with, an ascending {808} neuritis having been found in the few cases which could be carefully followed up.[76]

[Footnote 75: _Sanitäts Bericht über die deutschen Heere im Krieg gegen Frankreich_, 1870-71, vol. vii.—abstracted in _Neurologisches Centralblatt_, 1886, p. 207.]

[Footnote 76: In a case of Mollenhauer's, vesical paralysis and paresis of the right leg occurred six years ago (1880) in a veteran of our civil war who had a gunshot wound of the right hand, with signs, which are still present, of occasional exacerbation of brachial neuritis. Prodromal signs of paresis were noticed at intervals since his return from the campaign. The bladder trouble and paresis are now apparently stationary. Such a case can be accounted for only on the assumption of an organic cord-change secondary to a neuritis.]

The theory that the reflex paralysis from utero-ovarian, intestinal, and surgical affections, when acutely produced, is due to central anæmia, is as acceptable as any other would be in the absence of decisive observations.

Spinal anæmia will but rarely present itself as a subject for special and separate treatment. When not associated with an intrinsically grave condition, such as aortic obstruction, dysentery, fatal hemorrhage, or typhoid fever, it is an exceedingly benign affection, rapidly yielding to tonic and restorative measures combined with rest.

Embolism, Thrombosis, Hemorrhage, and Abscess of the Spinal Cord.

Although the spinal cord is a segment of the same central organ as the brain, nourished in a similar way, and subject to the same physiological and pathological laws, lesions of the vascular apparatus, which play so important a part in brain pathology, play a comparatively insignificant one in that of the spinal cord. Embolic, thrombic, and primary hemorrhagic lesions of the cord are so rare that their possible existence has even been denied. A primary thrombosis of the cord has not yet been satisfactorily demonstrated to occur independently of syphilitic lesions; and when it occurs the ensuing tissue-changes, as described by Heubner, Julliard, and Greiff, are usually in the background as compared to the gummatous, sclerotic, or meningitic changes which coexist. The clinical as well as the anatomical picture is accordingly either one of a myelitis or meningitis, as the cases of Charcot-Gombault, Heubner, McDowell, Wilks, Wagner, Zambaco, Homolle, Winge, Moxon, Schultze, Westphal, Julliard, and Greiff show. (See Myelitis and Spinal Meningitis.)

With regard to the occurrence of hemorrhage into the substance of the spinal cord (hæmato-myelia), it is so rare an occurrence that I can recall but a single case in which I entertained the diagnosis of this lesion; and in that very case I am unable to declare that it was not a hemorrhagic myelitis. Aneurismal changes of the spinal arteries are comparatively of rare occurrence, and as other predisposing causes to primary vascular rupture are rare in the cord, the probability of its occurrence is very much diminished. Hebold,[77] in a young girl who had developed severe cerebro-spinal symptoms during a period of nine months following an erysipelatous disorder, found the upper dorsal cord, on section, dotted with numerous reddish and round points. These points corresponded to {809} aneurismal dilatations of the vessels. As there were other inflammatory and vascular lesions in the same subject, the author referred their causation to a general constitutional vice, the result either of the phlegmonous or of a tuberculous disorder.

[Footnote 77: _Archiv für Psychiatrie_, xvi. 3. Rupture of miliary and other aneurisms in the meninges has been reported by Astley Cooper, Traube, and others. It is remarkable that such cases are more and more rarely recorded from year to year in inverse ratio to the accuracy of our spinal autopsies. I have never found a miliary aneurism below the uppermost cervical level of the cord. On the other hand, I have found extensive spinal hemorrhage in cases where the vessels of the cord proper were fairly healthy.]

It is claimed that suppression of the menses, over-exertion, lifting heavy weights, and concussion are causes of spinal hemorrhage. The same causes are also mentioned for acute hemorrhagic myelitis; and it is a question whether the supposed hemorrhage is an initial lesion or secondary to congestive or anæmic softening.[78]

[Footnote 78: I have never found vascular ruptures, although carefully searching for them, in the spinal cord of persons dying instantly after falls from a great height, or, as in one case which I was fortunately able to secure the cord of, where the subject had been violently thrown down. Where hemorrhages have been found under these circumstances they were, as far as I am able to learn from the cases recorded, meningeal.]

The symptoms attributed to spinal hemorrhage are the same, taking the same locality of the cord, as those of a very rapidly-developed transverse myelitis. It is unnecessary to enumerate these here in anticipation of the next section. They are described as being much more sudden. This suddenness is the only diagnostic aid on which we can rely.[79] The fate of the patient is said by Erb to be decided within a few days. If he survive the immediate consequences of the hemorrhage, he is apt to recover, as to life, altogether, with such permanent atrophies, paralyses, and anæsthesias as are entailed by the destruction of the tracts and gray substance involved in the hemorrhage. The treatment recommended for this condition consists of rest, either in the lateral or prone position, local depletion and derivation to the intestinal canal, as well as the internal use of ergotin. The local application of ice, which is also advised, is probably based on illusory views.[80] After the immediate danger is past the case is to be treated as one of myelitis—a very safe recommendation in view of the probability that it was a case of myelitis from the beginning.

[Footnote 79: And even this sign is unavailable as a distinguishing feature in supposed hemorrhage from concussion, as sudden paraplegias of motion and sensation are found in some cases of railway spine, and, although a number of cases terminating fatally have been examined, there was not always hemorrhage even in the meninges.]

[Footnote 80: Until authorities shall have agreed as to what effect the exposure of the bodily periphery to certain temperatures has on the circulation of the cord, it would be premature to make any special recommendations as to the temperature at which they should be kept. I am inclined to believe that while, as is universally accepted, a general cooling of the bodily surface tends to increase vascular fulness in the cord, as in all other internal organs, a partial cooling, as of the feet, produces local anæmia at the level of origin of the nerves supplying the cooled part. Certainly, the bilateral neural effects of unilateral cooling are in favor of this view.]

The descriptions given of the hemorrhagic foci as observed after death strengthen the view that they were in the majority of cases of myelitic origin. Usually, they are stated to extend up and down the cord in the direction of least resistance—that is, in the gray substance—resembling an ordinary apoplectic clot. But in their neighborhood there was usually considerable softening, and, to judge by the descriptions given, this softening differed in no wise from that which is the characteristic feature of acute myelitis;[81] and often the transition from a peripheral zone of white {810} softening, through an intermediate zone of red softening, to a central compact clot, is so gradual as to leave it unquestionable that the softening pre-existed, and that a vessel had broken down in the midst of the myelitic detritus. Many ancient foci of myelitis betray the hemorrhagic complication of their initial period by the presence of pigmented residue of the absorbed clot.

[Footnote 81: In the latest treatise on nervous diseases published in our language (Ross, _loc. cit._, vol. ii. p. 325) the insufficient foundation on which a whole chapter has been built up is illustrated by the admission that the usual evidence of acute central myelitis may be observed far beyond the limits of the hemorrhagic infiltration. If a large area of softening in the brain were found to contain a central or peripheral clot of blood, and histologically resembling a typical embolic or thrombic softening, no one would be in doubt as to which of the two was the primary lesion.]

Embolisms and embolic softenings of that part of the spinal cord which is supplied by the small spinal vessels are so rarely observed in the dead-house that our knowledge of their possible occurrence and character is almost entirely the result of experimental observations or based on analogy. The situation of these vessels, the angle at which their supply-tubes are given off from the aorta, all act as protectors of the cord against what is one of the chief dangers to which the brain is exposed. No definite symptoms have been attributed to the few doubtful cases of simple embolic occlusion of the spinal arteries found accidentally in human subjects. Even those emboli which, when once let loose in the circulation, are found distributed in nearly every organ of the body, those derived from ulcerative endocarditis and those due to the invasion of micrococci, are comparatively rare in the cord. Leyden found multiple capillary emboli in the spinal cord from the former cause. Small grayish white foci in a similar distribution were found to be due to an invasion of cocco-bacteria from a decubitus by Rovigli.[82] In this latter case an increase of pain and muscular spasm in the history of the case of sclerosis which was thus complicated was attributed to the parasitic affection.

[Footnote 82: _Rivista sperimentale di Freniatria_, 1884, x. p. 227.]

Just as simple and infectious embolic lesions are frequent in the brain and rare in the cord, so purulent inflammation or abscess is an exceptional occurrence in spinal as compared with cerebral pathology, and probably for the same reasons.

Simple Acute Myelitis.

SYNONYMS.—Spontane (primäre) acute Rückenmarkserweichung, Softening of the spinal cord, Ramollissement blanc de la moelle, Myélite aiguë.

As Leyden, whose treatise[83] may be regarded as the foundation of our knowledge on this subject, correctly avers, it is to Abercrombie and Ollivier that we owe the determination of the existence of that acute structural disease of the spinal cord, now termed myelitis, as an affection independent of meningeal changes. The anatomical descriptions given by these older writers may be accepted at the present day as models of accurate observation by the naked eye. Their statement that in acute myelitis the substance of the spinal cord is softened and changed into a puriform, yellowish, diffluent mass; that while the disorganization is sometimes more marked in the posterior, at others in the anterior, and occasionally in the lateral half, it is most pronounced in the axis of the cord, because the central gray substance is the favorite starting-point {811} of the morbid process,—requires no modification to-day. Considerable doubt existed in the minds of the contemporaries of Ollivier and Abercrombie as to whether this change was the result of a true inflammation; and one of the clearest thinkers of the day, Recamier,[84] regarded myelitic softening as a lesion peculiar to the nervous apparatus, and different from ordinary inflammation. I believe that the most profound investigators of the present day have not been able to rid themselves of a similar doubt. The discovery of Gluge's so-called inflammatory corpuscles, which was regarded as settling the question, only served to confuse the student by the confidence with which it was urged that they were infallible criteria of the inflammatory process. Under the non-committal designation of granule-cells these bodies still flourish in the annals of cerebro-spinal pathology. As we shall see, a number of products of real disease, of artifice, and of cadaverous change have passed and do pass muster under this name. The first substantial progress in our knowledge of the minute processes underlying inflammation of the spinal cord was made by Frommann and Mannkopf, but it applied altogether to the chronic inflammatory or cirrhotic affections of the cord. The difference between acute and chronic myelitis is greater than is the difference between acute and chronic inflammation in any other organ; and it must be admitted that if Recamier is to be regarded as having erred in asserting that acute myelitis is not a true inflammation, he is justified in so far as he asserted many features of the process to be altogether peculiar to the organ affected. Leyden himself attempted to throw light on the subject by provoking myelitis experimentally in dogs. He injected Fowler's solution into the spinal cords of three dogs, and in each instance produced changes which he interpreted as comparable to the myelitis of human pathology. But the inflammation thus provoked was not of the cord-substance alone; it also involved the membranes, and the inflammatory foci were in several instances purulent. Now, pus never[85] forms in ordinary myelitis. An abscess of the cord never occurs where a septic agency can be excluded. In six dogs whose spinal cords I wounded in the dorsal and lumbar regions by aseptic methods, and who survived from two to seven days, I never found purulent or indeed any active inflammatory process, as that term is ordinarily understood, but exactly such passive and necrotic or reactive changes as occur in the acute myelitis of human pathology.

[Footnote 83: _Klinik der Rückenmarkskrankheiten_, ii. p. 115.]

[Footnote 84: Cited by Leyden.]

[Footnote 85: In the textbooks and encylopædias, without an exception, the statement that pus may be a product of myelitis is made. This is true of traumatic cases and of such depending on septic and zymotic causes alone. I am unable to find a single carefully observed case of the occurrence of pus in simple myelitis in the literature.]

Owing to the advance of clinical and anatomical knowledge made within the past fifteen years many forms of spinal disease classed with the inflammations have been recognized as distinct pathological entities, no longer to be confounded with simple acute myelitis, ordinarily so called. Special forms of acute spinal paralysis, notably acute poliomyelitis anterior of children and the corresponding chronic affection among adults, have become separated in this way, and are accordingly treated of in separate parts of this volume.[86]

[Footnote 86: For other and practical reasons the traumatic and compression forms of myelitis are also assigned a separate place.]

{812} Some dispute exists as to the propriety of making a distinction between acute and chronic myelitis, since an acute myelitis, if the initial attack be recovered from with life, presents a similar condition clinically as chronic myelitis; and this quiescent or slowly-progressing condition may extend over many years. The term acute with reference to inflammation of the spinal cord refers only to the active period of the disease. Just as an embolic softening of the brain is an acute affection, but may be followed by a chronic paralysis or aphasia, so the acute myelitic process may be followed by a chronic paraplegia. It is improper to call the latter a chronic myelitis. It is merely a protracted symptomatic sequel of the acute process. The latter is distinguished from chronic myelitis both clinically (by the rapidity of its onset) and anatomically (by the early dissolution of nerve-elements in the focus of disease). Limited in this sense, acute myelitis, excluding the special clinical forms already adverted to, is rather a rare disease.

MORBID ANATOMY.—The most recognizable change noted in an acute myelitic focus is one of consistency: the spinal substance is softened. In some cases the softening is so slight that the observer may doubt whether he has a pathological or cadaveric softening to deal with, the dorsal cord, which is most apt to be the site of an acute transverse myelitis, being precisely the part which is most apt to show the latter change even in fairly well-preserved bodies. In extreme cases the softening may be so intense that the cord-substance, completely fluidified, runs out of the meningeal sac, leaving the latter a collapsed membranous cylinder to mark the place where the cord once was. Where the cord-substance is sufficiently firm to permit of sections being made through it, the normal outline of the gray and white substance is found obliterated, either presenting the appearance as if the gray and white matter had been stirred up together or of a more uniform color-change. The color may be either white, reddish, yellowish, or chocolate-like. It depends upon the participation of the blood-vessels in the change. If there be much hyperæmia, there will be developed what is known as red softening; if there be much extravasation and commingling of blood with the diffluent cord-tissue, a chocolate color will mark the diseased area; and similarly one and the same focus may present different tints in different parts according to the age and intensity of the process and the more or less advanced retrogressive metamorphosis of the extravasated fluid. As already stated, the purulent form of softening or abscess does not occur in ordinary myelitis.

There is considerable variation in the extent of the affected areas of acute myelitis. In the typical and severe transverse form the whole thickness of the cord may be disorganized, and the disorganization may extend in the length of the cord, so as to involve the level of exit of from two to five pairs of nerves. In less furibund cases the area of absolute softening is confined to the gray substance and its immediate neighborhood, the submeningeal white substance being but slightly affected or escaping. Sometimes several foci of intense softening are scattered through a short length of the cord and connected by less severely involved areas of softening or œdema. Leyden distinguishes three types of distribution—the transverse, the longitudinal, and the disseminated insular or multiple form. He includes under the {813} longitudinal type the so-called central softening of Albert, but undoubtedly many cases of syringo-myelia have passed under this designation. The submeningeal form of softening which, with Ollivier, he states to occur in association with spinal meningitis, must be a very rare affection, as it is difficult to find a well-established case recorded. The longitudinal form shows the same predilection for the gray substance which the acute myelitic process generally does, but I have seen a finely demarcated fascicular myelitis limited to the lateral column in a paretic negro. In this case the pyramid tract and the contiguous area in front of it were so intensely softened that for a length of twelve centimeters a hollow canal ran through the cord in the place previously occupied by the diseased substance. In recent cases of myelitis the diseased area is usually found surrounded by a transition zone in which, the morbid change gradually becoming less intense, the consistency is firmer, and which merges into that of the normal cord. In cases where death occurs after a few weeks a more abrupt demarcation is usually found; this is due to the reactive changes occurring in the neighborhood. The connective tissue becomes firmer, and thus the softening centre becomes surrounded by a sclerosing capsule. Ultimately, the centre undergoes complete disintegration and absorption, and a cavity is left behind filled with a clear fluid; in short, a cyst surrounded by a firm capsule represents the residua of disease. In cases where the softening at the centre of the focus does not proceed so rapidly nor reach so high a degree as to result in liquefaction, the less vulnerable elements, the blood-vessels and supporting tissues, survive the death of the ganglionic and conducting substance; the connective elements hypertrophy, and thus a firm sclerotic patch is formed, indicating the location of the previously softened field.

It seems to be generally admitted, with Hayem, that the blood found exuded in the hemorrhagic form of myelitis does not necessarily indicate an active determination, but is rather, like some forms of so-called red softening of the brain, the result of capillary rupture or necrosis in the midst of the disintegrated tissue, now rendered incapable of supporting the vessels. The existence of a purely white form of myelitic softening shows that a textural change is the primary occurrence, and that the participation of hyperæmia or congestion is not an essential feature of myelitis. The assumption of an initial inflammatory congestion is made rather on theoretical grounds than on the basis of observation. It is simply incredible that, as Ross[87] claims, white softening should be a third stage, preceded by red and yellow softening as a first and a second stage! How the extravasated blood, which pathologists generally allow to leave long-lasting traces, manages to disappear, and how blood-vessels in the midst of necrotic or œdematous surroundings suddenly acquire such contractile energy as to produce a total emptying of their contents while the perishable nerve-elements remain behind, are problems which should be solved before attempting to assign to a condition which is often found to be a primary phase of myelitis the position of a late and regressive stage. Erb admits that red softening, to which he also assigns the position of a first stage, is very rarely seen, only traumatic and rapidly fatal cases of central myelitis offering opportunities of examining it. None of the {814} various forms of exudation claimed to occur at this period under the names of vitreous, colloid, or hyaline deposit have been confirmed in any recently well-studied case.[88] The great mass of authorities, however, still agree in regarding the minute changes of the initial stage of myelitis to correspond to those of ordinary inflammation. The vessels are described as injected, the adventitial spaces as crowded with the formed elements of the blood, and the vascular walls and the neuroglia infiltrated with granule-cells and fatty granular matter. By some, inflammatory changes of the neuroglia are described, but I am unable to find a single case in which these were determined in early fatal cases. As far as our observation goes, the hypertrophy of the neuroglia is a later occurrence.

[Footnote 87: _A Treatise on Diseases of the Nervous System_, 1882, vol. ii. p. 280. The author states no authority, nor does he advance his own observations in support of this statement.]

[Footnote 88: Baumgarten's case of hyaline exudation, _Archiv der Heilkunde_, vol. xvii. 276, was an infectious myelitis and associated with anthrax.]

As to the nervous elements themselves, they are always found affected. The nerve-cells appear inflated, their processes fragile, sometimes suddenly swollen in their course, at others very thin and brittle. Multiplication of the nuclei of the large multipolar cells has been described. It must be an unusual occurrence, as it has been confirmed by but a few of the numerous observers who have examined into this question. The protoplasm of the nervous elements loses its normal striation and fine molecular granulation; it becomes either coarsely granular or hyaline. The axis-cylinders, both in their intracinereal and their intramyelinic course, show changes similar to those of the cell-processes in the gray matter. Particularly frequent are swellings in their course, the diameter of the cylinder being so much increased as to almost equal that of the myelin tube. This increase in diameter is regarded as an inflammatory swelling by some, as secondary to disturbed nutrition by others; it precedes disintegration: the substance becomes granular, fragile, and in the end dissolves. In the mean time the myelin loses its continuity, irregular segments of it fusing into round and oval masses.[89]

[Footnote 89: Many of the bodies represented as granule and colloidal cells are in reality round spheres of myelin, whose resemblance to a nucleated cell is sometimes heightened by their occasional inclusion of a fragment of an axis-cylinder which has not yet lost its power of imbibing carmine and other dyes. Where softening has proceeded farthest, there the spherical and other forms of myelin are found crowding the field, and mingled with them are blood-corpuscles, fragments of blood-pigment, granular detritus, and bodies known as fatty granular cells. A number of bodies of very different origin have received this name, some of them, like the fragments of myelin alluded to, not even meriting the name of cells. Others, however, are veritable formed histological elements, either leucocytes or cellular ingredients of the neuroglia, which, having fed on the products of myelin disintegration, have become enlarged and coarsely granular. The longer the duration of the process the more numerous are these bodies, showing that they are not the coarse and essential factor of the inflammation, but an accompaniment, subserving some conservative process, inasmuch as they either remove effete material or contribute to the permanent organization of the cicatricial or atrophic tissue.]

The period now reached by the morbid process may be regarded as a sort of interregnum. The necrotic tissues have not yet disappeared on the one hand, the products of inflammation have not yet organized themselves on the other. It is in this period that the ganglionic elements are described as undergoing certain changes in outline and in appearance. Above all, one change has interested observers, which, consisting in the development of what appear to be spherical vacuoles in the interior of the cell, is termed vacuolization. I can compare it to nothing so nearly as to {815} the appearance which is produced by the formation of gas-bubbles in a putrefying albumen or other semifluid substance.

This vacuolization of ganglion-cells is now regarded as a cadaveric change. It is not agreed, as yet, whether its occurrence in myelitis is so frequent as to suggest its ante-mortem occurrence as a veritable feature of the disease. I have been struck by this change in the neighborhood of wounds artificially produced in dogs, even in the fresh specimen. It must be remembered, however, that under these circumstances, the nutrition of the cell being destroyed and exposure to the macerating effect of the cerebro-spinal and pathologically exuded fluids occurring, a cadaveric change may take place intra vitam.

The influence of phosphorus and alkaloid as well as metallic poisons on the cord has been experimentally studied by a number of observers. Unfortunately, Popow, Tschisch, and Danillo—who described as characteristic a resulting change in the staining reaction of the cells, the development of vacuoli in them, and an atrophy of their processes—had not made a sufficient number of examinations of normal cords under like methods of preparation to recognize which of these deviations is without the physiological confines. Kreyssig[90] demonstrated the existence of all these conditions in the cords of perfectly healthy animals preserved in chromic acid;[91] and Schultze confirms him, and expresses a surprise, which must be shared by all reflecting investigators, that poisons of so widely different a character should have an identical effect on the cord-substance, as is claimed by the writers named.

[Footnote 90: _Virchow's Archiv_, cii.]

[Footnote 91: He attributes the remarkable difference in staining of nerve-cells of the same ganglionic group and in the same section to the sudden transferral of the hardened specimens to strong alcohol, which seems to be the custom in some German laboratories. He claims that uniformity in staining is effected if the specimen be transferred from the chromic preparation to weak alcohol, then to stronger, and thus by gradual increase of the strength to strong spirit. Possibly, instead of approximating the real structural indications by this method, Kreyssig may obliterate them. In specimens which alcohol is not permitted to touch before staining is completed, very deeply and very lightly stained cells will be found almost side by side. The shorter the hardening process, the more perfect the staining method, the more likely are these differences to be found. It is reasonable to assume that the difference in dye-absorbing power indicates slight differences in the cell-protoplasm, marking the nutritive state of the latter and occurring within physiological limits.]

If life be prolonged and the conservative processes assert themselves, the disintegrated material disappears, and as the white color of the greater area of the cord was due to the myelin, and the latter has now become destroyed within the diseased area, the latter presents a grayish color. This phase is often termed gray softening. The consistency is, however, much firmer than in the previous stage. Trabeculæ of connective tissue form, enclosing in their meshes a large number of neuroglia-nuclei and sometimes spaces filled with fluid. According as condensation and retraction or rarefication preponderate the process will terminate either in the formation of a sclerotic focus or of a cyst. Occasionally an irregular spongy tissue containing several small cysts results.

Charcot claims that a restitution of anatomical continuity, and therefore of physiological potentiality, may occur in a myelitic cicatrix. But the experiments of Kahler[92] and Homén[93] prove that when a nerve-tract {816} is once destroyed within the spinal cord all hope of restoring that tract in structure, and thus to restore its functions, is at an end. Unlike the fibres of the peripheral nerves, those of the spinal cord and brain do not seem capable of regeneration.[94] If a restoration of function is to occur at all, it must occur through other channels than those destroyed—in other words, by vicarious action.

[Footnote 92: _Prager medizinische Wochenschrift_, 1884, No. 31.]

[Footnote 93: _Contribution expérimentale à la Pathologie et à l'Anatomie pathologique de la moelle épinière_, Helsingfors, 1885, abstracted in _Centralblatt für die medizinisches Wochenschriften_, 1886, No. 16.]

[Footnote 94: According to the first observer, this is probably due to structural differences. The extramedullary fibres have a sheath and annular constrictions which are absent in the intramedullary.]

In a large number of cases myelitis is a limited affection; that is, its ravages remain confined to the area originally involved. But occasionally the morbid process involves the next segments above or below, extending with specially great rapidity through the anterior gray horns. Exceptionally, the entire cord may thus become the site of a generalized myelitis. There is one segment of the cord which may be regarded as possessing an acquired vulnerability when a myelitic focus is in its neighborhood, and that is the lower end. It seems that while the results of a transverse myelitis in the middle dorsal cord may remain stationary for ten or more years, those of a transverse myelitis at the upper lumbar level do not; on the contrary, the entire cord below the lesion appears to be doomed to undergo the same degeneration by contiguity. This is the only occurrence which seems to deserve the name of a descending myelitis: an ascending extension is more frequently noted in other parts of the cord, but the frequency of both the so-called ascending and descending types has been unduly magnified by the inclusion of the secondary degenerations, which are constant sequelæ of all complete destructive transverse lesions of the cord, but which are rather passive phenomena, and probably influence the clinical progress of the case but little, except under such conditions as are potent in that chronic form of myelitis which underlies tabes dorsalis.

CLINICAL HISTORY.—The symptoms of acute myelitis usually correspond to those of any more or less completely transverse lesion of the cord, and accordingly vary with the altitude of the upper level of the lesion. In a general way, they may be stated as consisting of—

First, paralysis of movement in the parts supplied from the nerves given off below the level of the lesion. The reason for this can be easily recognized in those cases where the pyramid tract, which conveys voluntary impulses centrifugally, is interrupted by the softening.

Second, paralysis of sensation in the parts supplied by the same nerves. This is equally explained by the pathological interruption of the centripetal impressions normally conveyed brainward.

Third, alterations in the nutrition of the parts supplied by the nerves arising in the affected level.

Fourth, abolition of those reflexes which are translated in the level of the lesion.

Speaking crudely, then, the symptoms of a transverse myelitis fall into two natural groups. The one which includes the first and second categories enumerated are symptoms due to interruption of cerebral functions; the other, which comprises the last two categories, being due to abolition or perversion of spinal functions. There is a third group comprising certain constitutional symptoms.