Lesions. In meningeal bleeding the clot is found outside the dura, or between the dura and arachnoid which may or may not be ruptured. A clot on the pia mater may press seriously on the cord or may cause rupture of the arachnoid. In hemorrhage of the cord, the effusion usually begins in the gray matter, though it may extend far into the white. It may be circumscribed to half an inch in diameter or affect almost the entire length of the cord. The cord may be distinctly enlarged at the point of effusion, and in exceptional cases the blood may have broken through to the membranes. If the patient survives, absorption and degenerations of the cord are inevitable.
Symptoms. In both forms there is a sudden attack, with stiffness or paralysis of given muscles and without hyperthermia. Rigidity and spasms of the muscles are more characteristic of meningeal hemorrhage, and early paralysis of the spinal. An early hyperæsthesia is also most significant of an effusion in the cord. Rapid muscular atrophy is also characteristic of this. The two conditions resemble meningitis and myelitis but come on much more suddenly and are unattended by fever.
Treatment. Such cases are not hopeful. Cold to the affected part of the spine, keeping the patient in slings to solicit the good effect of gravitation, and giving ergot or lead acetate internally are among the first indications. Later, the treatment would be practically the same as for meningitis or myelitis. In case of complete paralysis from the sudden formation of a large clot, it has even been advised to cut down on the seat of the injury and evacuate the blood, using antiseptic precautions.
SPINA BIFIDA.
This is an elastic swelling consisting of the spinal meninges enclosing a liquid, and in some cases the spinal cord as well, and protruding between the unclosed laminæ of the vertebral rings, usually in the region of the sacrum or loins. It is essentially an arrest of development on the part of the vertebræ and enveloping muscles and skin, and an extension of the cord and effusion of the meningeal and central spinal liquids, in the absence of their bony and muscular support. Hydrocephalus is no uncommon complication.
The diagnosis may be based on the presence of an elastic, somewhat transparent tumor, projecting from the vertebral spines, at birth. If it contains a segment of the cord it is usually flattened, depressed on the summit and often associated with paralysis.
As occurring in the lower animals this need not be treated. In man, careful antisepsis and evacuation followed by injection of a solution of iodine 10 grs., iodide of potassium 30 grs., and glycerine 1 oz., have, in favorable cases, secured obliteration of the sac, but even then the recovery has rarely been complete and permanent. Paralysis and death have usually supervened.
SPINAL CARIES. TUBERCULAR OR OTHER INFECTIVE DISEASE OF THE VERTEBRÆ.
Spinal caries in old horses, sprains, fractures, infections; caries often confined to articulating processes: anatomical form: Axoido-atloid caries from poll evil, concussions, fights, rachitis. Tubercle of bone and intervertebral cartilage in cattle. Symptoms: distortion, stiffness, rigidity; stands day and night, sensory and motor paralysis: localization of lesion; dyspnœa; spastic palsy back of lesion; effect on tail, sphincters. Diagnosis: progressive tenderness and stiffness of spine, distortion, localized exaltation or depression of nervous function, osteoporosis, rachitis, caries, tubercle, melanoma, abscess, infectious disease. Treatment: Sling in narrow stall, good food, pure air, sunshine, tonics, phosphates.
As seen in the human subject spinal caries is usually tubercular and is known as “Pott’s disease.” As seen in old horses it appears to be rather a result of other infections, especially purulent, and may have started in connection with traumatic or mechanical injuries to the bones and ligaments. In such cases I have seen it repeatedly in hollow backed horses in which the line of the spine descended abruptly and extremely from the withers and rose again to the sacrum. The distortion was so great that the back appeared as if it could barely sustain the weight of the animal and yet the patients were kept at work and proved useful for light driving. Post mortem examination showed extensive caries and suppuration of the vertebral bodies, confined, however, to one or two segments as if due to a mechanical lesion. In the region of the loins it is much more likely to affect the articulations of the vertebral rings, because of the manner in which these are wedged into each other when the spine is pressed downward. In the neck where the normal movement is so much freer such injuries are much less common. Caries affecting the articular surfaces of the axoido—atloid joint is by no means uncommon. It may follow poll evil, or injuries sustained when a horse runs against a wall, or in the fights of bulls or rams. Disease of the vertebræ may be of the nature of rachitis occurring in this case in early life.