The question of the ossification of the calvarium is of practical importance. While it was formerly believed that the interference with the growth of the cerebrum consisted pringuily tbe premature ossifi cation of the skull (probably because of Virchow's erroneous belief that the sutures close prematurely in cretinism); it is now well known that the primary lesion is situated in the brain itself and. that failure of the fontanelle to close, abnormal persistence of the frontal suture, deficient ossification of the calvarium and even persistent separation of the sutures occurs later in life in microcephaly.
Microcephaly does not interfere with the individual's bodily de velopment. The subjects may attain the age of fifty years and over. On the other hand, microcephaly is usually' accompanied by a high degree of idiocy. Many of the children who even in infancy arouse attention by their restlessness, their inability to concentrate, total absence of any power of reasoning, absence of reaction to pain (Thie mich), are mierocephalic. Sometimes there is general muscular flaccid ity and the child cannot raise its head. Much more frequently marked muscular rigidity is the most prominent symptom. The arms are tightly pressed against the chest, the elbows bent, the, hands are flexed on the forearm and the fingers turned into the palms; the legs are in extension and extreme adduction, with a tendency to crossing. The trunk muscles may be so rigid that the child can be picked up like a piece of wood.
The abdomen is often of board-like hardness and retracted or scaphoid. 6ometirues this picture of microcephalic rigidity with idiocy (Freud, Ibrahim) is complicated by athetoid movements, dysphagia, pseudo bulbar symptoms and epileptic attacks.
Ibrahim attempted to distinguish clinically between pure micro cephaly dependent upon arrest of development and pseudomicro cephaly due to some intra-uterine diaease. Although this distinction cannot he rigidly maintained, it appears nevertheless that athetosis, bulbar symptoms and epilepsy point rather to pseudornicrocephaly while general rigidity indicates a pure mierocephaly.
The prognosis of microcephaly is extremely gloomy. Functions which are often preserved in chil dren with irreparable injuries to the cerebrum, are usually com pletely lost in microcephaly. It is practically impossible to effect any itnprovement in the child's mental state. to accustom it to eleanliness or even to get it to use its legs.
For a time the therapeutic outlook seemed more hopeful when Lamlelongue, starting out with the idea of a primary ossifi cation of the skull, attempted by chiseling out large pieces of the calvarium to give the cerebrum an opportunity to develop. Oper
ations of this kind have since been repeatedly performed, and whole sections have been removed from the circumference of the skull, so that the calvarium was connected with the lower portions of the skull only by the soft parts; but, although the children stood the operation surprisingly well, it was not followed by the desired result (L5wenstein) and the operation must /IOW be regarded as obsolete fl'ilcz).
6. CoNyenital Hydrocephalus.—The term hydrocephalus is used in pediatric neurology to designate a group of morbid conditions having as a common symptom enlargement of the skull, the result of accumula tion of fluid. The term is used with little regard to the fact that the pathology and etiology of hydrocephalus may be exceedingly variable; the one distinction made being between external hydrocephalus (effu sion between the surfaces of the brain and the calvarium) and in internal hydrocephalus (the collection of fluid in the ventricles of the brain).
Clinically the cases are divided between acute and chronic hydro cephalus. It would be well to give up this comprehensive term, which, like "cerebral infantile palsy," merely tends to the making of sympto matic, instead of etiologic diagnoses, in favor of a rational classification based on the causes of hydrocephalus.
It cannot be denied that such ft classification would be difficult in the present state of our knowledge. The follovring, which is in part copied from Leon d'Astros, may be suggested: (1) Congenital hydro cephalus. This is usually internal, rarely external, and belongs to the group of congenital diseases of the central nervous system now under discussion. (2) Acquired hydrocephalus. This may be acute or chronic. The acute form belongs among the inflammatory diseases of the menin ges. Chronic hydrocephalus may also be the expression or result of diseases of the external and internal membranes of the brain. Among these simple meningitis and ependyrnitis due to hereditary syphilis are the most important. Chronic acquired hydrocephalus is also ob served after sinus phlebitis (Marfan), in sclerotic processes affecting the brain, in brain tumor, and after severe diseases generally. In all these cases the fluid may accumulate within the ventricles or on the outside of the brain surface.