Dropsy of the Brain is also called chronic hydrocephalus or chronic water in the head. (For acute hydrocephalus see previous page.) Its most common forms occur in childhood. The child may be born with the disease, as shown by the very large head, which often hinders delivery, or the disease may arise after birth, generally before the child is six months old. It is due to an increased amount of fluid in the cavities—ventricles—of the brain (see p. 135). Sometimes the disease takes the form of a tumour, attached to the back of the head generally. The cavity of the tumour cates with the cavities of the brain, and may contain part of the membranes and fluid, or even part of the brain itself. The communica. tion is usually by a small opening in the occi pital bone (p. 59).
In the commoner forms there is simply an increasing quantity of fluid in the cavities of the brain. As the fluid increases the head enlarges, specially at the sides and upper parts. The bones of the skull separate from one another, the intervals between them being at first only covered by the scalp. The bead may increase enormously so that the child cannot keep it up without supporting it with its hands, the forehead, sides, and back all protruding, and the top being flattened. The skin is thinned by stretching, and the blue veins are seen through it. The eyeballs seem to protrude
owing to the stretching upwards of the eye brows and lids, while the face is very small and thin in proportion to the large head, and the body is small and badly developed. The child is liable to convulsions, loss of sight and hearing, and intelligence, while it may become fretful and passionate. Occasionally, however, intelligence remains good. Such children fre quently die at birth; they may survive to the second year or later, and die of convulsions or other disease. They may even live to a good age. If they survive, bone forms slowly to fill up the gaps left owing to the separation of the usual cranial bones. In a few cases the disease ceases, and leaves the child with large head and small face, and development otherwise diminished to a greater or less extent.
No treatment is of any avail. Strapping the head to prevent it growing, piercing it in safe places to withdraw some of the excess of fluid, and all such practices have been abundantly proved useless. Medicines, too, fail, iodide of potassium, iodide of iron, and mercury, those that might be supposed useful, among the num ber. Probably simple attention to the child's diet, and to the state of its bowels, and the use of cod-liver oil or iron tonics, is as good treatment as any.