Fig. 197.—Occipital Meningocele.
(From a photograph lent by Sir George T. Beatson.)
Small meningoceles may remain stationary for a long time, or may even undergo spontaneous cure. Those of larger size usually progress till they eventually burst, and death results from the escape of the cerebro-spinal fluid or from meningitis. Infection may also occur from eczema or from excoriation of the overlying skin.
Encephaloceles are much commoner than meningoceles, and usually occur in the frontal region, where they form broad-based, elastic, and pulsatile tumours, which vary greatly in size.
The hydrencephalocele is usually met with in the occipital region, and is generally so large and associated with such great cerebral deformity as to be inconsistent with life. It does not as a rule pulsate ([Fig. 198]).
Fig. 198.—Frontal Hydrencephalocele.
(From a photograph lent by Sir George T. Beatson.)
Cephaloceles have to be diagnosed from dermoid cysts, nævi ([Fig. 199]), cephal-hydrocele, and cephal-hæmatoma. Their recognition is seldom attended with difficulty. If the margins of the gap in the skull can be distinctly felt, or the gap in the bone can be shown by the X-rays, the diagnosis is greatly simplified.