CEPHALOCELE.
The term cephalocele is applied to tumor of the endocranium, presenting through defects in the cranial bones, of essentially congenital origin, and containing more or less of intracranial contents. It comprises—
A. Meningocele, which means a tumor consisting of a membranous protrusion and containing cerebrospinal fluid; and,
B. Encephalocele, referring to tumors which contain also more or less of actual brain substance.
Fig. 380
Occipital cephalocele.
Such tumors of non-traumatic origin can only be explained by the existence of congenital defects which permit the escape of that which the normal bone retains within normal limits. In most instances the defect is in the middle line, at either one or the other extremity of the skull. In some instances the arches of the atlas, or even of other cervical vertebræ, are lacking. The most common cephaloceles are the occipital, which are known as inferior when below the occipital spine, or superior when above it. Those appearing anteriorly are known as sincipital, and are met with most often at the root of the nose, where they may communicate with the orbit or the nasal cavity. Other and irregular forms are laterally or unsymmetrically located ([Figs. 380], [381] and [382]).
Cephaloceles have an elastic feeling, many of them an exquisite fluctuation. Sometimes by touch alone we recognize both their fluid and solid contents. A meningocele with thin walls is translucent. By pressure they can be reduced in size, such pressure usually producing brain symptoms, often paralysis or convulsions. Many children thus affected cannot lie upon the tumor without becoming restless. When the patients cry or make violent straining efforts it becomes larger and its covering more vascular, while during quiet sleep it is usually reduced in size or tension.
Fig. 381