In the cranium itself the bones of the vertex separate, and instead of sutures there is a tightly stretched membrane. There is also congenital or acquired aplasia—i. e., absolute defect of bone between the dura and pericranium. All these changes give to hydrocephalic heads a distinctive appearance. Other developmental defects—hare-lip, club-foot, etc.—are common in these patients. Many infants thus affected die during delivery unless skilful help is at hand. The resulting disproportion between the enlarged head and the small face is most distinctive. Children in this condition suffer from disturbed digestion, are emaciated, with rachitic curvatures of the long bones; special senses are seldom developed perfectly; strabismus and nystagmus are frequent, while cramps and stupor are by no means infrequent.
Prognosis.
—While spontaneous recovery is possible, as already stated, the tendency is always toward fatality.
Treatment.
—Treatment by compression of the enlarging skull, with elastic bandages or their equivalent, is an abandoned method since compression which can be effective is too great to be tolerated. Treatment by mere aspiration is also useless. Tapping is an old operation long discontinued, recently revived, but again proved disappointing. The establishment of permanent drainage is a more recent suggestion. It depends upon the demonstration of the fact that the tension of the cerebrospinal fluid and of the blood in the cerebellar veins is the same, and that intracranial pressure forces fluid into the veins and away from the skull. Thus subdural or autodrainage was suggested. Sutherland and Cheyne, in 1898, were the first to operate in this manner. They opened the dura near the lower angle of the anterior fontanelle, through the opening carried a strand of catgut into the ventricle, and passed the outer end beneath the dura; but the method again proved disappointing. Mikulicz passed a gold tube into the right ventricle, leaving its outer end in the subcutaneous tissues about 5 Cm. from the middle line. After being three weeks in this position it ceased to drain, and was then inserted into the other ventricle. The child died, unbenefited, in six weeks. In another case he used a glass-wool drain, making it subdural rather than subcutaneous. This case seemed to be benefited. Senn has modified the method by making a large pocket in the subcutaneous tissues of the cervical region, inserting one end of a rubber tube into it and carrying the other into the ventricle between the temporal and frontal bones. Even this proved disappointing. I have twice tried conducting fluid by a small rubber tube from the ventricle into the cellular tissue in the neck, passing the tube beneath the skin by suitably curved forceps. This method, however, showed no advantage over the others mentioned above. Taylor has endeavored to make a permanent fistula between the ventricles and the subdural space by passing chromicized catgut into the ventricle and letting it drain into the latter. His results, however, were not encouraging, in spite of the plausibility of the theory upon which they were based. Drainage through the spinal canal into the abdominal cavity has also been practised by a very few surgeons. The ingenuity and theory of the method are most attractive, though but very few little patients are in condition to bear the abdominal section which is necessitated for the purpose.[43]
[43] In March, 1906, Cushing informed me that his present routine in effecting such drainage was to make a laminectomy and expose the spinal canal from the rear, then to do a laparotomy, and, exposing the bodies of the vertebræ, pass through from in front backward a silver tube, whose end should reach into the spinal canal, draining it into the abdominal cavity, the posterior wound being always snugly closed. The spinal canal is thus exposed in order to ensure the accurate performance of the other part of the operation.
Permanent drainage, then, has been a most disappointing procedure, although there need be no hesitation in tapping the lateral ventricles when there is indication for it. This can easily be done at any time by an opening about 3 Cm. behind the external auditory meatus and the same distance above the base-line of the skull. By directing the puncturing instrument to a point on the opposite side, 6 Cm. above the meatus, the lateral ventricle will be entered. (This same general direction will serve for opening an abscess in the temporosphenoidal lobe.) The best results in hydrocephalus seem to have been obtained by lumbar puncture, as first suggested by Quincke, the method being the same as that now in general use for intraspinal cocainization. As directions for entering the spinal canal with the aspirating instrument would be identical with those mentioned in the chapter on Anesthesia, when describing intraspinal cocainization, the reader is referred to that section for further direction ([p. 208]). The only case of well-marked hydrocephalus which I have ever apparently cured was one repeatedly tapped in this fashion, a considerable amount of fluid being withdrawn at each little operation.
SURGICAL TREATMENT OF DEFECTS OF INTRACRANIAL DEVELOPMENT.
There are numerous causes which produce imbecility and kindred conditions in the young. Some are in effect congenital, some are postnatal. Within the past few years a number of these cases have been subjected to surgical operation, in many instances with more or less success. Mental defect may occur from injuries at the period of birth—mainly hemorrhages, more commonly cortical, though sometimes deep. In either case the clots thus formed frequently undergo cystic alterations. The term porencephalon is modern, and applied to changes comprising disappearance of real nerve tissue with partial substitution by connective tissue, often with other degenerations, the result being atrophic alterations which apparently permit of no remedy. In a case of true porencephalon the outlook for operation is not at all encouraging, nor is it in any cases which are accompanied or caused by a genuine arrest of cerebral development. On the other hand, when the mental condition can be ascribed to the result of injuries, to hemorrhages, to meningeal irritation, to premature ossification, or too early closure of the fontanelles, or when it is accompanied by evidence of meningeal irritation or symptoms which point to a definite area of the brain as being the site of the principal disturbance, operation as a legitimate experiment may be conscientiously suggested and performed.
Fig. 383