It is possible to draw conclusions as to the size of the communicat ing duct and the pressure conditions present in the interior of the skull from the difference in tension. This is a matter of importance in decid ing upon the passibility of operation.
This refers principally to anterior cephalocele; the occipital form differs in this respect, inasmuch as it. is more frequently present as a meningoeele (Fig. 4). That smaller hernias are more frequent and rarely contain brain substance is perhaps due to the fact that they emanate from the fourth ventricle with its thin covering. In the large tumors, which almost attain to the size of the rest of the skull and are broadly sessile, large parts of the primitive cerebral sac are frequently prolapsed (see Fig. 3).
The symptoms of these tumors are so distinct that they can hardly be mistaken. It is of clinical importance to know that these cerebral l•rithc, as long as they remain closed and do not approach a fissure of the cranium, often cause little disturbance in the condition of the child for a long time.
The bimanual examination—pressing upon the cyst and upon i he fontanelle—gives information as io the size of the cyst. In this con nection the variations of the pulse and respiration pre,ssu•e, which parallel those of the fontanelles, are of importance. When the tension is low the firmer parts of the contents as well as the size of the bony defects can be felt. portion of the fluid can be pushed back by pres sure upon the tumor, while the palpating finger of the other hand can feel the rising pressure of the fontanelles.
If these latter symptoms are absent, the conclusion is justified that tho communication with the cerebral cavity is only slight or obliterated. This, together with the absence of firm parts and transparency of the tumor, points to meningorek The diagnosis may therefore not be difficult. The position of the tumor, f he variations of its pulse pressure, the possibility of partly squeezing it out, the results of palpation and its location, distinguish it materially from any other tumor. A closed meningocele might be mis taken for a cystic tumor of the cranium, which, however, would not make any practical difference. These tumors are not of infrequent occurrence.
The prognosis of these malformations varies according to the extent in each case. As a general rule they have a great tendency to enlarge. The tension and thinning of the walls involve the danger of bursting and infection, quite aside from the increasing disfigurement.
The treatment can, in the light of our present knowledge, only be surgical, and consists in the removal of the hernial sac after its contents have been replaced.
An ear-shaped incision is made around the pedicle, so that skin suture will not lie over hernial suture. The pedicle is then exposed and the hernial sac is opened. After rapid inspection and reposition as far as possible of the protruding parts the hernial sac is closed. Very few punctures should be made. If 1110 pedicle is thin enough to be ligated and invaginated, this is preferable to any suture, because every needle puncture which pierces the inner surface is a canal for the exudation of the cerebrospinal fluid. This interferes with the healing of the wound and at the same time forms an open door for infection, which in any ease can only be avoided with difficulty. The closure of the osseous defect is done by the osteoplastic method. Osseous or cartilaginous tissue can be made to grow into the gap by means of grafts either from the same or from another bone, and later these can be used in conjunction with the nutrient skin flap for covering the defect. The following example may illustrate this: An eight-weeks-old child (Fig. 2) was admitted with an anterior nasofrout al encephalocystovele. There was a gap at the base of the nose measuring 2 cm. in diameter, above which was a multiple vascular tumor. Many small fibromas and cysts were attached to this tumor which were produced by disseminated remnants of blastoderms and pointed to the origin of development. The tumor was partly reducible and soft masses could be felt by palpation. As a preliminary operation the anterior half of the patella (which in the child is cartilaginous except for the osseous nucleus) of about the size of the osseous defect was removed and inserted, the freshened side outward, through a slit under neath the skin of the frontal bone in the neighborhood of the tumor.