CHNONIC HYDROCEPHALUS. WATER IN THE BRAIN.
An accumulation of serous fluid in the investing membranes of the brain, between the brain substance and the outer and firm covering, the dura mater. The fluid is secreted by the middle or serous covering, the arachnoid membrane, and accumulates be neath the arachnoid, in the arachnoid sac or space, and even in the ventricles of the brain. The disease may progress with very little disturbance of the bodily functions until the bead has at tained an enormous size, the yielding bones giving way before it. The disease occurs in young children of strunious or scrofulous taint, and in the end is usually fatal. Latterly surgical art has been the means of saving life in some instances of it.
Thickening of the Dura Mater and Degeneration.
The dura mater is subject to a form of disease in which it be comes unduly firm and thickened in structure. In persons who are given to partake freely of alcoholic drinks, this thickening is very common. Some years ago, by the kindness of several pro fessional friends, I was able to make an inquiry into the condition of the brain in that form of disease which has yet to be described as general paralysis. In every instance I found the dura mater thickened, firm, and dense, and often adherent to the membranes beneath it at one or more points. The resistance exerted by the membrane, as thus changed, tends greatly to the production of the paralysis, and I am of opinion that it is, in some instances, the cause of it.
The dura mater is also subject to various degenerative changes. It is sometimes affected with calcareous and osseous degeneration, so that it is transformed, in parts, into a bony structure. In one instance I observed a projection of bony matter of needle-shaped character, which passed an inch into the substance of the brain itself, and was probably the cause of epileptic seizures, from which the person in whom it was found suffered, and in one of which seizures he died.