MENINGITIS Is the term applied to that form of inflammation of the brain which affects the serous membranes by which that organ is sui-rounded. The following definition has been given of this dieeate. It is a complex morbid state of the immediate coverings of the brain attended with more or less vascularity and opacity of the arachneel membrane, and the formation of adventitious products between the arachnold and pia-mater, and the effusion of pus or Denim In the same situation. Acute pain in the head accompanies these lesions, attended with intolerance of light and sound. There is present also watchful ness, delirium, a flushed countenance, and redness of the conjunctiva, or a heavy suffused state of the eyes. The pulse is quick, and there are frequent spasmodic, twitching; or convulsions passing into Bonnie letacy, coma, and complete relaxation of the limbs.
This disease comes on at all ages. It attacks children during the period of teething, and comes on in scarlet fever, measles', and other diseases caused by morbid poisons. It is then known under the name of acute hydrocephalus. [Iirneoceruatcs.] Adults are liable to this ,disease as the result of typhus, typhoid,and paludal fevers. [reveres.] It also comes on as the result of accidents, of intemperance, great mental anxiety, and intense heat of the sun—" coup de soleiL" There is a great difference in the course and character of meningitis, according as it appears in a state of the system in which ;scrofula is present, and one in this tendency is absent. Bence the disease ma divided by some writers into simple and tubercular meningitis.
All forms of meningitis assume with more or less constancy three stages. 1. The stage of excitement resulting from the inflammation. 2. The stage of compression which indicates that effusion has taken place. 3. A stage in which the symptoms either pass from the last tote that of health, or in Which the disease progressively terminates in death. In each stage there is a distinct set of symptoms arising from the locality of the disease. The mental, sensorial, and motorial functions are distinctly affected. In the first stage, the mental symptoms are either somnolence or wakefuluees, or tho one alternating with the other. There is delirium which is frequently of a furious character. In
the second stage tho delirium becomes quieter, or passes into coma, whilst in the third, the mental functions aro entirely lost. In the first stage the most remarkable sensorial symptqm is the intense and continuous pain in the head, which diminishes or disappears in the second stage; whilst in the third stage, complete anesthesia takes place. The material symptoms of the first stage are restlessness, twitching's, and vomiting. In the second stage convulsions aro fre quently present, but in the third stage there is absolute paralysis of all the muscles.
The duration of these stages varies. Sometimes each lasts a week. The pulse in the first stage is from 00 to 100, in the second from 1]0 to 130, and in the last stage it is scarcely to be counted.
The symptoms of tubercular meningitis differ (rein those of the eimplo form, in their being generally less active. They occur in a state of the system which indicates to a greater or less degree the condition of tuberculous cachexia.
In the adult, the symptoina of meningitis have a tendency from the beginning to assume a convulsive or apoplectic character.
The treatment of this disease must in a great measure depend on the nature of tho symptoms of the general disease with which it is asso ciated. When it arises from mechanical injuries, it requires a more antiphlogistie treatment than when associated with blood disease. [Ilennocreaboars.] Cerebritis or EnerpAalitis. —When the substance of the brain is affected independent of the surrounding membranes, the disease is called Cerebritin, or Encephalitis. This disease in its pure form is accompanied by very different symptoms from the first, the most dis tinguishing of which are the absence of headache and delirium. It consists in an Inflammatory action of the vessels which supply the substance of tho brain. It may however be combined with inflamma tion of the meninges, and then the symptoms of the attack are of a combined character. The lesions of the brain discovered after death in cerebritis, are a softening or suppuration of some part of the substance of the brain, which Is frequently attended with a dusky redness.