HYDROCEPHALUS, Chronic.
If the accumulation of fluid is confined to the ventricles (internal hydrocephalus), an attempt should he made to permanently drain them, but when the fluid is located in the subarachnoid and subdural space (external hydrocephalus), the drainage of the ventricles is unnecessary or futile. To differentiate between the two conditions Dandy and Black fan's method of injecting phenol-sulphonephthalein has proved valuable; this reagent is excreted in the urine, and the rate of its elimination deter mines whether the fluid is within or without the ventricles, being much retarded in the internal variety. Sharpe inserts a needle into the ven tricle and another into the lumbar subarachnoid space, and when the flow from the ventricle needle is greatly in excess of that from the lumbar puncture he judges that the ventricle is blocked. His operation aims at drainage by inserting six linen strands into the ventricles in the internal type of hydrocephalus and the same number into the sub arachnoid or subdural space in the external variety, bringing their ends out through the temporal muscle and fascia beneath the scalp. Absorp tion of the threads does not occur for several months, by the end of which time a permanent canal becomes established. Two-thirds of all his cases were successful.
Another method consists in the introduction of a fine bent tube of gold into the descending horn of the lateral ventricle, the end projecting from the ventricle being secured in its place by sutures applied to the inner aspect of the dura water, thus establishing a free communication or drainage between the interior of the ventricle and the subarachnoid space, so as to remedy the blocking of the natural drainage channel of the brain and cord.
Drugs internally are of little value except in syphilitic cases, where Mercury and Iodides should be steadily pushed, but in any case where tapping of the ventricles or lumbar puncture is to be tried these drugs should be employed simultaneously with the operative procedure, and the effect of an elastic bandage applied to the skull should be carefully watched.
The treatment of the various forms of Cephaloceles in which some portion of the cerebrum or its membranes project under the scalp through a congenital opening in the cranial bones is usually very unsatisfactory. Small meningoceles, if they have a narrow neck, may sometimes be successfully dealt with by reflecting a flap of the scalp and closing the neck of the sac by ligatures, so as to prevent the escape of cerebro-spinal fluid.