§ 2. Paraplegia.—Rarely a sudden seizure except after injury of the spine, it is but seldom dependent on cerebral disease; in both respects it stands in complete contrast to hemiplegia. As in hemiplegia, however, the power of movement is generally more affected than the sensibility : but loss of the one seldom exists without partial failure of the other. Its characteristic is that it affects both sides of the body symmetrically, although not necessarily to the same degree. Its history points out its more or less gradual development, the occurrence of some acci dent or injury to the back, or it may perhaps afford evidence of disease of the brain. It ought always to be ascertained whether there be any deviation from the normal condition of the bones of the spine, or any point at which a sudden jar or blow causes more pain than elsewhere ; we have then to consider how high the con dition of paralysis extends.
a. In its most common form, the disease has come on by slow degrees, observed first, perhaps in one leg, and soon after in the other, and still exhibited to a greater degree in the limb in which it was first felt, but extending no higher than the loins ; it has been preceded by no accident, is accompanied by no distortion, and is entirely without pain. The patient at first only feels some weakness in the knees, and very frequently in walking, experi ences a sensation as if he were treading on soft wool ; the muscu lar sense is soon lost, and he needs to look at his feet to know where he steps ; gradually the paralysis increases, and in the worst cases he is at length reduced to such a state that he hal3 no power even to move his limbs in bed except with the assistance of his hands, and yet the upper half of the body is unaffected. This is dependent on a condition of simple atrophy of the lower part of the cord ; there is no evidence of inflammation, acute or chronic, during life, no appearance of it after death : nor do the remedies which generally influence the progress of inflammation show any power over this disease.
b. The form occurring next in frequency is that dependent on injury or diseased the spine—fracture or caries of the bone, and ulceration of the intervertebral cartilage. Displacement follow ing on the,se causes may of itself give rise to paralysis ; but in chronic cases it is seldom found unaccompanied by evidence of inflammatory action: we may, therefore, for all practical purposes, include in the same case the paralysis consequent on concussion, which may result at once from the accident, and be perpetuated by inflammation, or may only supervene some time after the in jury has been received. Here the diagnosis is generally facilitated
by the history of an accident or by the evidence of displacement. But it sometimes happens that the ulceration of the intervertebral cartilage sets up inflammation in the membranes of the cord before displacement occurs ; and while the pain on movement, and stiff ness of the back, are only supposed to be rheumatic, symptoms more or less distinct of this inflammation are developed, and paralysis speedily follows. In such cases, accurate diagnosis depends upon the correct appreciation of these symptoms, espe cially with reference to the seat of previous pain and stiffness; but it must be confessed that the knowledge often comes too late to be of much service in practice.
c. Idiopathic inflammation of the cord, of itself, as we have seen, a comparatively rare disease, may give rise to symptoms of paralysis under three distinct conditions ; they may be only the evidence of further aisintegration, and the immediate approach of death ; they may remain for a lengthened period in conse quence of chronic thickening after the acute symptoms have passed by ; or they may arise without any previous acute symp toms—the inflammation from the first presenting only the cha racters of a subacute or chronic form. An exposure to cold, the occurrence of pain in the back, and the comparative suddenness of the attack, point to a condition different from what has been recognized as the consequence of atrophy. The resulting para lysis is paraplegia, but there is very generally a considerable dif ference in the degree to which the limbs on each side are palsied.
d. The pressure of a tumor on some portion of the cord may also give rise to paraplegia: when occurring in the lower region of the back, with no external evidence of its presence, it is not to be distinguished from cases of atrophy ; but when the para lysis has come on gradually, when no history of injury is ob tained, and no evidence of distortion exists, when the patient is free from pain, and the upper extremities are partially involved as well as the lower, good ground exists for suspecting the exist. ence of this form of disease; when the breathing is also inter fered with, its seat is probably at the base of the brain, and it may be expected soon to prove fatal.