Transverse myelitis at and above the level of origin of the phrenic nerve is almost immediately fatal, through its interference with the innervations required in respiration. In the upper part of the cervical enlargement it produces complete paraplegia of motion and sensation in the trunk and all four extremities. In the lowest part of the cervical enlargement it produces paralysis of the same parts, but the serratus magnus and scapular muscles escape. The nuclei of origin of the muscles moving the upper extremity are situated so that those which are farthest removed from the axis of the body when the arms are extended are situated lowest in the cord. The sensory paralysis is distributed in harmony with the motor paralysis; that is, when there is paralysis of motion in the hand and forearm the anæsthesia or subjective numbness is also in the hand and forearm. The same correspondence is not found in affections of the lumbar enlargement, for anæsthesia of the gluteal region accompanies paralysis of the crural muscles when the lesion is low down at the level of the lower lumbar and upper sacral nerves. The distribution of the anæsthesia, in other words, is not by segments of the limb, but by surfaces. The gluteal, posterior femoral, gastrocnemial, and outer pedal surfaces are affected together with the muscles moving the foot, while the thigh and inner side of the leg and foot become anæsthetic, with lesion of the upper part of the lumbar enlargement accompanying paralysis of the quadriceps and deep muscles. It is not difficult to understand this discrepancy when we bear in mind the different plan of distribution followed by the brachial plexus as compared with the lumbar and sacral plexuses. It is not, in my experience, found that the anæsthesia affects that surface which covers the part moved by the paralyzed muscle; which is characteristic of associated paralysis and anæsthesia from cortical disease.
One of the most dreaded occurrences in acute myelitis is the malignant bed-sore. The ordinary decubitus which results from the protracted sojourn of the patient in bed, coupled with the prominence of his trochanters and sacrum resulting from general or atrophic emaciation, is also common, but is comparatively benign and easy to prevent or to manage when established. The malignant bed-sore, on the other hand, is a spontaneous occurrence, due to the same obscure but undeniable trophic influences exerted for good by the normal and for evil by the diseased nerve-centres, which play so large a part in the symptomatology of tabes dorsalis. It cannot be avoided; it is not due to pressure alone, or, as some have claimed, to the macerating influence of the dribbling and decomposing urine. The development of this lesion is exceedingly rapid, and it may be regarded as a sort of local gangrene. The skin shows a livid color; vesicles appear, then burst; the part becomes denuded; and within a few days a deep ulcer with a dark border and base appears, discharging a sanious fluid. The subsequent history is that of a rapid extension and destruction of the neighboring tissues, even down to the bone, and if situated over the sacrum opening into the spinal canal through the necrotic arches of the sacral vertebra, thus leading either to general septicæmia or to putrid infection of the spinal meningeal sac. Occasionally, gangrenous spots coexist on other parts of the body, notably the lower extremities, where neither pressure nor maceration can be accused of playing a part, proving that the process is primarily due to the spinal affection.
Acute central myelitis, as described by Dujardin-Beaumetz, Hayem, Hallopeau, and Erb, usually runs its course very rapidly. Indeed, all of these observers speak of it as the most violent and quickly fatal variety of spinal inflammation. I have, however, seen one case with T. A. McBride at the Presbyterian Hospital in which all the characteristic symptoms of acute central myelitis were markedly developed and present in their characteristic groupings, and yet the patient had been suffering from progressing symptoms of myelitis for one year and a half before that time.100 Usually, complete anæsthesia and paralysis of the lower half of the body occur in this form. But the most characteristic feature is a rapidly progressive atrophy not only of the paralyzed muscles, but also of some which are still partially under the dominion of the will. With this there is extreme vesical and rectal trouble, the sphincters being paralyzed. As a rule, the deep and superficial reflexes are destroyed—they are always diminished—and trophic disturbances of a malignant type, such as acute decubitus, joint-changes, and œdema, are common. The paraplegia is characterized by the flaccid condition of the limbs; the contractures and spastic symptoms found with other forms of myelitis are entirely absent, and qualitative electrical changes, beginning with disappearance of farado-muscular contractility, are found in the atrophying muscles. There are marked constitutional symptoms with this form; the tendency to an ascent of the process and successive involvement of one segment after another of the gray matter is great, and a fatal issue, as far as known, is inevitable.
100 At the time the patient had undergone such a profound change in appearance that I failed to remember him, and it was only by accident I learned that I had seen him in private consultation with his family attendent, F. A. McGuire, a year previous. On the latter occasion I had made the diagnosis of subacute myelitis chiefly limited to the posterior columns; there were ataxia, both static and locomotor, slight incontinence, belt sensation, and ocular symptoms, with abolition of the deep reflexes in the lower limbs.
DIAGNOSIS.—The principles governing the determination of the affected region of the cord in acute myelitis are exactly the same as those detailed in the later sections on Chronic Myelitis or Sclerosis, the acuteness of the onset, and the relapses which sometimes occur, and the predominance of irritative spasms—which, however, is an inconstant criterion—serving to distinguish between the acute and chronic form of spinal inflammation. In the present state of our knowledge it is impossible to always differentiate between acute central myelitis and syringo-myelus—a condition in which the formation of a periendymal neoplasm, and its subsequent breaking down in the axis of the cord, lead to the formation of a tubular cavity.101 The neoplasm in this instance is classified among the gliomatous new formations. The symptoms depend, exactly as do those of myelitis, on the distribution of the destructive lesion. In some cases the posterior cornua and columns are chiefly involved, and extreme anæsthesia is found; in others the anterior columns are affected, and the symptoms of a poliomyelitis or an imperfect transverse myelitis may be imitated.102
101 This cavity, unlike that of hydro-myelus, is not a dilatation of the central canal, but, lying to one side of it, is excavated in the cord-substance.
102 Repeated fractures have been noted in cases marked by profound analgesia. It is believed that they are not always due to trophic changes, but may be the result of muscular action, exaggerated on account of the patient's inability to gauge his efforts. Still, in the majority of cases the presence of positive trophic disturbances of the skin seems to indicate the probability of some textural change facilitating the fracture.
As a rule, the sensory disturbance in syringo-myelus is out of proportion to the muscular atrophy developed; that is, it involves a far more extensive province. It is usually of a peculiar character: some forms of sensation are involved but slightly, or even escape, and others may be nearly destroyed. Commonly, it is the pain and temperature-sense which suffer most, while the cutaneous space and pressure, as well as the muscular sense, are not materially disturbed. These peculiarities are not commonly found in cases of myelitis, and when present, and particularly when the paralytic or sensory affections involve all four extremities alike, they suggest the existence of syringo-myelus. As yet we are unable to make more than a probable diagnosis between the two diseases.
DURATION AND PROGNOSIS.—The duration of the disease varies. Cases of the apoplectiform variety are mentioned, in which the process reached its height in a few minutes, or where the patient, having retired in good health the night before, awoke finding himself paralyzed in the lower half of his body. Death may terminate such a case in a few days or weeks. In another class of cases, complicated by serious involvement of the bladder, the fatal termination is often precipitated by putrid cystitis, pyelitis, or uræmic poisoning, and even in cases which have passed the dangers of the early period in safety these ominous complications may develop with the usual result many years after the beginning of the illness. In a number of cases the first period, that in which the morbid process becomes developed, is followed by one of comparative quiescence, in which the paralyses of sensation and motion then established remain stationary for months and years. A number of authors, Erb, Leyden, Strümpell, and Ross, speak of such a case as one in which chronic myelitis has followed an acute myelitis. It seems improper to use the terms acute or chronic in this way. As it is generally understood that the term acute applies to myelitis in which disintegration of the nerve-elements predominates over interstitial proliferation, and in which the secondary sclerosis is rather like the cicatrix of an acute inflammation and necrosis, it should not be confounded at any period, no matter how similar the clinical signs may be, with a process which is essentially an interstitial one from the start. If chronic amaurosis results from an acute glaucoma, we do not change the latter designation to chronic glaucoma.
In cases where the symptoms at the acme indicate rather an involvement of the peripheral than the central paths of the cord, and in which an incomplete motor and sensory paralysis develops, the patients often regain a considerable amount of motor power and sensation, so that they may reach a good age, suffering at most from a paresis of some one muscle or muscular group, occasional bladder trouble, and pains. It has been laid down as a rule that where paraplegia and other signs remain stationary for years, there is no hope of even partial recovery. The following remarkable and well-attested case proves that this rule is not without exceptions: