fever is a specific inflammation of the membranes cover ing the brain and cord. The malady is no mere local disorder, but a blood disease, of which the inflammatory affection of the meninges is the anatomical expression. It usually prevails in epidemics, and outbreaks of the disease have been noted in various countries widely differing in climatic and other conditions.
' Causation. —The epidemics of cerebro-spinal fever generally occur dur ing the winter months ; but isolated cases are often noticed for some time before the disease becomes more generally diffused.. Thus, before the epi demic which prevailed in Ireland in 1867, sporadic cases had been observed in the country for some years. The disease appears to be mildly infectious. It fastens upon old and young, rich and poor, but males appear to be more liable to suffer from it than females. In 1846 some cases occurred in the Dublin and Bray Workhouses, and shortly afterwards in the Belfast Work house. In these cases the sole victims were boys under the age of twelve. The girls and adults escaped. In all epidemics children are largely affected, for unlike typhus, of which cerebro-spinal fever was at one time supposed to be merely a variety, the disease readily attacks young subjects, and is most fatal in early life. Although not generated, like typhus, by insanitary conditions, the onset of the fever seems to be favoured by them ; and foul air, bad food (especially ergotized grain, according to Dr. Richardson), exposure to cold and damp, and physical fatigue, no doubt tend to encotumge the spread of this fatal malady.
Morbid Anatomy.—The vessels of the pia matey, both of the brain and cord, are congested, and lymph is exuded into the subarachnoid tissue. Sometimes it is also seen in the ventricles. It usually consists of opaque purulent matter of a greenish-yellow color. The amount varies. It may occur only in patches, or may be more general. The lymph is especially abundant at, or is confined to, the base of the brain—usually the posterior portion, the surface of the medulla oblongata, and the upper part of the spinal cord. There is often congestion of the substance of the brain, and there may be serous effusion or actual extravasation of blood. The choroid plexus is much congested, and the cervical part of the cord may be cov ered with a thick layer of bright-red vessels. In the worst cases of the disease the blood is very dark in colour and unusually liquid.
The exudation appears to be thrown out with great rapidity, for it may be found in cases where death occurred within a few hours of the child being attacked. Ebert and others have found micrococci in the purulent
effusion of the meninges, and according to some observers the disease is essentially due to micro-organisms.
Of the other organs: the spleen is generally unaltered, although sometimes it, as well as the other viscera, may be congested. There may be signs of pleurisy, and scattered patches of hepatization may be seen in the lungs. It is said that the agminated and solitary glands of the intestine have been found in some cases to be swollen.
Symptoms.—The disease generally begins suddenly during sleep, hav ing been preceded by few or no premonitory symptoms. In certain cases —usually the milder ones—the child may complain, if old enough to do so, of wandering pains, and may seem poorly for a clay or two before the out break ; but there is seldom anything to fix the attention before the first violent symptoms of the disease make their appearance. In rare cases there may be headache, vomiting, and general tenderness for some days previous to the actual beginning of the illness.
As a rule, the first noticeable feature is a rigour or a fit of convulsions ; and the younger the child, the more likely is the attack to begin with a convulsive seizure. Sometimes severe headache and vomiting may usher in the disease. If the patient, as is often the case, seems heavy and stupid after the fit, lie still shows by his restlessness, his moans and cries, and by frequently carrying the hand to the head, that he is suffering se vere pain. The pupils are contracted ; the pulse is quick, seldom lowered in frequency ; the temperature (which should always be taken in the rec tum) is 101-2° ; and the breathing is hurried. An early symptom is re traction of the head upon the shoulders. It has been suggested that this position is at first partly voluntary, to relieve the pain (which we know, from the case of the adult, to be of a very severe character) shooting down the back ; but it soon becomes involuntary from spasmoclic contraction of the muscles of the nucha. It may occur within a few hours of the onset of the illness, and is rarely delayed beyond twenty-four hours. The tetanic spasm of the muscles of the neck may extend to the whole back, the jaws, or even the limbs, and may be varied by clonic convulsive movements. In a short time the cries and manifestations of pain cease as the senses be come duller and the stupor increases. If consciousness is lost early and does not return, the symptom is a very graVe one.