Total Transverse Lesions.—Total transverse lesions, that is, those in which the cord is completely crushed or torn across, are much more common than partial lesions, being an almost invariable accompaniment of a complete dislocation or of a fracture-dislocation of the spine. Even when the displacement of the vertebræ is only partial and temporary, the cord may be completely torn across. Similar lesions may result from stabs or bullet-wounds.
From the records of cases in which the vertebræ were injured by modern rifle bullets, even although the bony walls of the spinal canal had not been fractured and no hæmorrhage had occurred within the spinal canal, the cord in the vicinity was degenerated into a “custard-like material” incapable of any conducting power (Makins). According to Stevenson, “this must have been due to the vibratory concussion communicated to it by the passage of the bullet at a high rate of velocity.” The importance of this observation lies in the fact that in such cases no benefit can follow operative interference.
The clinical features vary with the level at which the cord is injured, and the diagnosis as to the nature and site of the lesion is to be made by a careful analysis of the symptoms. By gently passing the fingers under the patient's back as he lies recumbent, any irregularity in the spinous processes or laminæ may be detected, but movement of the patient to admit of a more direct examination of the spine is attended with considerable risk, and should be avoided. Skiagrams are indispensable, as they show the exact site and nature of the lesion.
Immediate Symptoms.—At whatever level the cord is damaged there is immediate and complete paralysis of motion and sensation (paraplegia) below the seat of injury, and the paralysed limbs at once become flaccid. On careful examination, a narrow zone of hyperæsthesia may be mapped out above the anæsthetic area, and the patient may complain of radiating pain in the lines of the nerves derived from the segments of the cord directly implicated. In complete transverse lesions the paralytic symptoms are symmetrical; any marked difference on the two sides indicates an incomplete lesion.
Retention of urine and retention or incontinence of fæces are constant symptoms. In young men priapism is common—the corpus cavernosum penis is filled with blood without actual erection. There is other evidence of vaso-motor paralysis in the form of dilatation of the subcutaneous vessels, and local elevation of temperature in the paralysed parts. The deep reflexes, including the tendon reflexes, are permanently lost.
Unless regularly emptied by the catheter, the bladder becomes distended, and there is dribbling of urine—the overflow from the full bladder. As the bladder is unable to empty itself, and its trophic nerve supply is interfered with, the use of the catheter involves considerable risk of infection, unless the most rigid precautions are adopted. Hypostatic pneumonia is liable to develop. Great care in nursing is necessary to prevent trophic sores occurring over parts subjected to pressure, such as the sacrum, the scapulæ, the heels, and the elbows.
Later symptoms are the result of descending degeneration taking place in the antero-lateral columns of the cord. There are often violent and painful jerkings of the muscles of the limbs; the muscles become rigid and the limbs flexed.
Treatment.—When the cord is completely divided, no benefit can follow operative interference, and treatment is directed towards the prevention of infective complications from cystitis and bed-sores.
Injuries of the Cord at Different Levels.—Cervical Region.—Complete lesions of the first four cervical segments—that is, above the level of the disc between the third and fourth cervical vertebræ—are always rapidly, if not instantaneously, fatal, as respiration is at once arrested by the destruction of the fibres which go to form the phrenic nerve. It is from this cause that death results in judicial hanging.
In lesions between the fifth cervical and first thoracic segments inclusive, all four limbs are paralysed. Sensation is lost below the second intercostal space. The parts above this level retain sensation, as they are supplied by the supra-clavicular nerves which are derived from the fourth cervical segment ([Fig. 205]). Recession of the eyeballs, narrowing of the palpebral fissures, and contraction of the pupils result from paralysis of the cervical sympathetic. Respiration is almost exclusively carried on by the diaphragm, and hiccup is often persistent. There is at first retention of urine, followed by dribbling from overflow, and sugar is sometimes found in the urine. Priapism is common. The pulse is slow (40 to 50) and full; and the temperature often rises very high—a symptom which is always of grave omen.