WOUNDS AND INJURIES OF THE SPINE AND SPINAL CORD.
Injuries of the spine resemble more or less closely those of the head. Fractures of the spine generally occur in combination with dislocation, as fracture-dislocation. Thus displacement is generally present and causes a fatal compression or crushing of the cord. When the cord has once been crushed at the site of the displacement of the fracture-dislocation there is no hope of its ever healing. Therefore the lower end of the cord is never again in functional connection with the brain. These injuries are more rapidly fatal the higher up they are. If the injury is above the fourth cervical vertebra death is nearly immediate, for then even diaphragmatic breathing is impossible, and the injured person dies of asphyxia. Fracture of the odontoid process of the axis, which regularly occurs in hanging, may occur from falls on the head, etc., and is not always immediately fatal. Thus in one case[666] the person lived fifteen months and in another case sixteen months. In the latter case the fracture was due to the patient turning in bed while his head was pressed on the pillow. In some cases it may be questioned how far this injury may result from disease of the bones or ligaments. Therefore a careful examination of these parts should be made after death, which will usually enable us to answer this question, which may be brought up by the defence. It is hardly necessary for our purpose to enumerate the symptoms of fracture-dislocation of the spine. Of course the patients are almost always unable to walk and so are bed-ridden. A marked feature of fracture-dislocation of the spine is the length of time intervening between the injury and the fatal termination, and yet the injury is wholly responsible for the death of the injured person. This delay may last for months or even for years with careful treatment. But sooner or later the case generally ends fatally, though not necessarily so. Where the cord has been entirely crushed the result is almost always fatal; where the cord is not so injured recovery may and often does occur. According to Lutaud, fractures of the spine are sometimes followed by secondary paralysis coming on after healing of the fracture. At the outset we can seldom give a definite prognosis, which can only be given after watching the developments of the case. The prognosis is more favorable in fracture of the arches alone or when the injury is in the lower part of the spine and not very severe. The commonest cause of fracture-dislocation of the spine is forced flexion of the spinal column. Injuries to the spine are generally the result of falls or blows on the spine, especially in its lower part. Lutaud[667] states that after forced flexion of the spine without fracture paraplegia may sometimes occur, which is attributed to forced elongation of the cord. This paraplegia, which may seem to be grave, is completely recovered from as a rule.
Incised or punctured wounds of the spinal cord are rare, as it is so well protected except in the very highest part behind. Here between the occiput and the atlas and between the latter and the axis, and to a less extent between the axis and the third cervical vertebra, the cord is more exposed, owing to the narrowness of the laminæ. It is here that pithing is done, which is almost instantly fatal, as the medulla oblongata and upper part of the spinal cord are the parts injured, and they contain the respiratory and other vital centres. Pithing may be done with such a small needle-like instrument as to leave scarcely any trace. Only a slightly bloody streak may persist, which may appear superficial if the instrument is introduced obliquely. Such a mark in this location with no other apparent cause of death should always lead to an examination of the upper part of the cord, which will always reveal the cause of death in such cases. Pithing is practised especially in infanticide.
As with the brain, so with the spinal cord, we may have CONCUSSION due to the shock of a contusing blow. Concussion of the spinal cord, as of the brain, may be fatal without showing scarcely a mark of violence externally or internally. As the cord is so well protected from injury, it must be extremely rare to have concussion of the cord without some actual lesion of its substance. As concussion of the cord is not often the result of the injuries of which we are treating, but rather of railroad injuries and the like, it will not be considered at length in this connection. As a result of a blow or fall on the spine or communicated to it, hemorrhage may occur in the substance of the cord or around it between or outside its membranes. In very rare cases such a hemorrhage may occur spontaneously as the result of disease, of which the writer has seen one case. It may be associated with concussion or laceration of the cord. It may destroy life directly by extension or indirectly by leading to a spreading inflammation. Hemorrhage in or about the cord causes a gradual compression of the cord, and in cases of fracture of the spine often adds to the compression due to the displacement of the bones. In hemorrhage into the substance of the cord paralysis comes on early or immediately and may be complete while symptoms of irritation fail. The latter symptoms are most marked in meningeal hemorrhage in which paralysis is delayed in appearance and generally incomplete. The products of an inflammation due to an injury may compress the spinal cord in the same way that hemorrhage does.
Wounds and injuries of the varieties we are considering, affecting the spine and spinal cord, are generally accidental, less often homicidal, and almost never suicidal.