TRAUMATIC CEPHALOCELES

Many cases have been recorded in which a cephalocele developed after an injury to the skull. In such conditions it is necessary that a comminuted or fissured fracture of the vault should be present, that the underlying dura mater should be torn, and that the adjacent brain substance should be severely contused or lacerated. Cerebro-spinal fluid may alone escape through the gap in the skull to the subaponeurotic and subcutaneous regions, leading to the formation of a false traumatic meningocele. When the brain shares in the outward protrusion the condition is known as false traumatic meningo-encephalocele. This protrusion of the brain is dependent on the fact that the injury—necessarily a severe one—leads to considerable brain lesion, with subsequent œdema and localized or general increase in the intracranial pressure.

Occasionally, the external accumulation of cerebro-spinal fluid communicates with one of the horns of the lateral ventricle. A meningo-encephalocele, having such connexions, is produced in the following manner:—the protruded brain includes that part of the cerebral substance which bounds one of the horns of the lateral ventricle, usually the descending cornu. The ventricular channel becomes elongated in the outward direction, towards and through the gap in the skull, whilst the increased intraventricular tension gradually dilates up the new channel, and, in course of time, still further spreads out and thins that part of its cerebral boundary which lies external to the skull deficiency.

There can be no question that after the patient has reached the age of three years traumatic cephaloceles are of exceedingly rare occurrence. This special liability in quite young children has been ascribed to the greater elasticity of the infant skull, and to the supposed greater adherence of the dura mater. Though these factors may exercise some influence on the production of the tumour, it seems more probable that the development of a cephalocele is dependent to a greater degree on the general vitality of the child. Thus, a blow that produces in the adult a comminuted or widely fissured fracture of the skull, with laceration of the dura mater and injury to the underlying brain, frequently leads to a fatal result, whilst the child often recovers. Again, in the adult, the force required to produce such a lesion usually suffices to lacerate the integument. Consequently a compound comminuted fracture of the vault with hernia cerebri is relatively more common in the adult than in the infant.

The right side of the head is more frequently affected than the left, and, of all bones in the skull, the parietal is the one most constantly involved.

Symptoms.

During the first few days subsequent to the injury the child merely suffers from the symptoms common to all severe head-injuries—concussion and brain irritation. The osseous lesion is obscured by the presence of a well-marked cephalhæmatoma. After the lapse of a short time—usually one to two weeks—the partial resolution of the hæmatoma allows one to observe, for the first time, that a definite tumour remains. This tumour is irreducible, pulsates freely, and may be translucent. If the protruding brain substance includes the precentral region—the motor area—definite weakness or paralysis of the opposite face and extremities may be observed. Usually, however, no such symptoms are forthcoming, and the child appears but little the worse for the accident. Shortly afterwards the tumour becomes more defined in outline, and careful palpation will reveal the defined margins of an osseous deficiency. Compression of the protruded mass will often throw the child into general convulsions, or induce a state of compression with dilated pupils, slow pulse, and stertorous respiration. Compression, however, seldom results in any marked diminution in the size of the tumour. The conditions may remain stationary, but, as a general rule, the hernial protrusion slowly increases in size and the child dies in general convulsions, preceded by symptoms of brain irritation or compression.

Treatment.

Three courses are available in the treatment of this condition:—

1. Expectant treatment, combined with the application of pressure.

2. Aspiration and puncture.

3. Free exposure and further treatment according to the conditions found.

In the majority of cases the local conditions preclude any attempt at radical cure—the gap in the skull is large, the margins of the deficiency are thinned and everted, and the brain enters largely into the formation of the projecting mass. Furthermore, the dura mater is torn and in a tag-like condition. Only in the most favourable cases—when the tumour is small and the gap narrow—can radical treatment be advocated.

The application of pressure—without previous aspiration—exercises but little effect on the size of the tumour and, under such treatment, the danger of brain-compression is always present.

Aspiration with the object of removing the fluid constituents of the tumour, and thus of reducing its size, has occasionally been followed by disastrous results. Still, many cases were so treated in the pre-aseptic days, and the modern methods of cleanliness should allow of better results. One or more aspirations may be carried out, this treatment to be followed by the application of steady and uniform pressure, preferably with the aid of elastic bandages, the degree of compression depending on the size and constituents of the tumour. The patient must be watched most carefully, in order to guard against the development of symptoms pointing to cerebral compression. Irritating injections should never be used.

One must acknowledge that this mode of treatment has—except in a few isolated cases—not produced very satisfactory results. Still, since an open operation is usually out of the question, no other course remains.

The after-history of these cases is not very encouraging. In one of Weinlecher’s cases the child was living 5 years later, but pulsation was still present. In Lucas’s case the patient died 21 months later from meningitis. In Sir T. Smith’s case, pulsation was present 3 years after the accident, and in Silcock’s there was no marked change for the better after 11 years. On the other hand, a case reported by Golding Bird steadily improved, and a second case reported by the same writer gave every promise of a permanent cure. The two following cases have come under my own observation:—

1. A female child, 11 months old, was knocked down by a van, and, on admission, a large hæmatoma was seen situated over the right temporo-parietal region. The child was semi-comatose, but recovered consciousness next day. The hæmatoma softening, a gap in the bone was felt, one-third of an inch wide, and extending from the occipital bone upwards and inwards to the middle line. The swelling increased in size when the child cried. Pulsation was present and translucency was obtained. The tumour increased in size for some days, but no untoward symptoms developed. For over one month pressure was applied, but without much benefit, though the general condition of the child was good. The edges of the gap became thickened. The child was then removed from the hospital.

2. A male child fell 19 feet on to his head. He was concussed, and, on admission, presented a hæmatoma over the right fronto-parietal region, and subconjunctival hæmorrhage in the left orbit. Four days later he was apathetic and there was some paresis of the left arm and leg. As the hæmatoma became softer, pulsation was noticed over a small area, and, in this situation, the swelling increased in size on straining. A fracture was detected later, one-third of an inch in diameter, and extending across the left frontal bone to the right temporal region. Pressure was applied, the tumour steadily decreased in size, and eventually the gap was completely closed.

Synopsis of 38 cases of traumatic cephalocele.

Fractures of the skull resulting from injuries received at or shortly after birth.

In the consideration of injuries to the skull and brain in babies the following points should be noted:—

1. The bones of the skull are elastic and pliable, and consequently a blow may lead to a ‘bending-in’, either temporary or permanent. Slight depressions may exist without any associated fracture, but all major depressions are accompanied by a fracture of the bone, especially evident on examination of the internal table.

2. The fibrous tissue intervening between the component parts of the vault tends to cause a limitation of the fracture to the particular bone affected. Downward extension to the base is of infrequent occurrence, but, when that region is involved, the fracture usually follows the transbasic lines described in the section dealing with fracture of the base of the skull ([p. 82]).

3. The dura is said to be more adherent to the inner table of the skull than in adults. The relative infrequency in the young of extra-dural hæmorrhage has been ascribed to this peculiarity. It would appear, however, more probable that the rarity of such hæmorrhages results from the bending-in, without splintering, of the bone.

4. The brain of the infant is equally—if not more—liable to bruising and laceration, but the results are far less definite than in adults. There can be no question that extensive cerebral injury may exist in the child without leading to the development of any definite localizing symptoms.