HYDROCEPHALUS.

Water in the Head.

External or Chronic Hydrocephalus.

Hydrocephalus, Sauv. gen. 285. Lin. 216. Boerh. 1217.

Hydrocephalum, Vog. 384.

This differs from the hydrocephalus formerly treated of at some length under the title of Apoplexia Hydrocephalica, chiefly in the water being collected in the external parts of the head, whereas the former is entirely within the skull. In the fifth volume of the Medical Observations we have an account of a very extraordinary case of this kind. The patient was a child only of a few days old, and had a tumor on his head about the size of a common tea-cup, which had the appearance of a bladder distended with water; near the apex was a small opening, through which a bloody serum was discharged. In other respects the child was healthy. No application was used but a piece of linen dipped in brandy. The tumor continued to increase for many months; at the end of which time the membrane containing the water appeared equally thick with the other part of the scalp, except at one place about the size of a shilling, which continued thin, and at times appeared as if it would burst. He remained in this situation for about 17 months, when the circumference of the head was 20 inches, the base 16½, the middle 18½, and from the base to the apex near 8½. The water was then drawn off, and the child died in two days. Almost all other cases of this temper have proved fatal; the sutures of the skull generally give way, and the whole external part of the head is equally enlarged; but in the instance just now given there was a deficiency of part of the bones. Although, however, in some instances where the head is thus enlarged to an enormous size, the water is exterior to the brain, and therefore entitled to the appellation of hydrocephalus exterior, yet much more frequently in those instances where there is a manifest separation of the bones of the cranium at the sutures, the water is still contained within the ventricles; and accordingly the disease may be much more properly distinguished into the acute and chronic hydrocephalus, than as is Hydrocephalus commonly done into the internal and external. Although the latter be much slower in its progress, sometimes subsiding even for years, yet it is equally difficult of cure with the former, and very often it proves fatal in a few days if the water be drawn off by an artificial opening, which may be very easily performed by a mere puncture with a common lancet, without either pain or any immediate hazard from the operation itself, although the water be lodged in the ventricles; for these are distended to an enormous size, and the substance of the brain almost totally destroyed, so that hardly anything is to be punctured but membrane.