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CRANIAL

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Originally appearing in Volume V25, Page 202 of the 1911 Encyclopedia Britannica.
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CRANIAL See also:

SURGERY Surgery of the See also:Skull.—Fractures of the vault of the skull may occur without the See also:bone being driven in to compress the See also:brain, and in such cases their existence may be revealed only after See also:death. But if there is also a severe See also:scalp See also:wound the See also:line of fracture may be traced in the See also:bare bone as a thin red crack. " Think lightly," said the old physician, " of no injury to the See also:head." The patient with a suspected fracture of the skull is put to See also:bed in a dark, quiet See also:room, and he is watched. It may be that the crack has extended across a bony groove in which an artery is See also:running, and, the artery being torn, See also:haemorrhage may take See also:place within the skull and the symptoms of See also:compression of the brain may supervene. Experiments upon the See also:lower animals have taught the surgeon how to recognize the exact spot at which the compression is situated. One set of muscles after another being thrown out of See also:work in See also:regular See also:order, he knows exactly where the bleeding is going on, so, having made a hole in the skull by trephining, he turns out the See also:clot and secures the leaking See also:vessel. Compression of the brain may be the See also:direct and immediate result of a head-injury, a piece of the vault of the skull being driven in, and a See also:local or a See also:general See also:paralysis of muscles being at once observed. In addition to the See also:muscular paralysis, which may enable the surgeon to localize the spot at which there is pressure upon the brain, there is the See also:grave symptom of See also:coma or insensibility. And, as in deep See also:sleep, there is often loud snoring, due to the vibration of the paralysed soft-See also:palate. The See also:heart being loaded with imperfectly aerated See also:blood, the See also:face is dusky or livid, and the See also:pulse is slow and full. No See also:notice is taken by the See also:man of a loud shout into his See also:ear, and on the surgeon raising his eyelids the pupils are found dilated and fixed, which signifies that the reflex to See also:light is lost—a very grave sign. There may be See also:complete paralysis of one See also:side or of both sides of the See also:body.

Not only may the pressure of a blood-clot, an See also:

abscess, a See also:foreign body (such as a See also:bullet) or a depressed piece of the skull-See also:wall give rise to coma, but so may a syphilitic, a See also:malignant or an See also:innocent See also:tumour, and in cases in which the See also:administration of iodide of See also:potassium fails to afford See also:relief, the operation of trephining may perhaps be resorted to, as giving the only See also:chance of recovery. As regards treatment—short of trephining—it may be advisable to relieve the heart by bleeding. Inasmuch as the reflex actions are in See also:abeyance, it will be necessary to have the See also:bladder regularly emptied. The man should be placed on his side in bed, so that his See also:tongue may not fall back and choke him, and if it is thought inadvisable to bleed him, a full dose of See also:calomel should be administered. For the operation of trephining, the head is shaved and the skin rendered aseptic, a large See also:horse-See also:shoe flap is then turned down and the skull laid bare. With an See also:instrument on the principle of a centre-See also:bit, a disk of bone of the See also:size of a florin, a See also:crown or a napkin-ring—or even larger—is then taken out of the skull wall, and the dura mater is opened up if the cause of the compression is beneath it; otherwise, on the disk of bone being removed, the particular See also:condition is dealt with without opening the dura mater. When the clot or the tumour, or whatever it is, has been removed, the disk of bone which, during the operation, has been kept in a warm liquid, is cut up into pieces which are put back into the opening and the skull flap is brought up into its proper position. Fractures of the See also:base of the skull are always serious, in that they may run across important nerves and large blood-vessels; passing through the roof of the See also:nose, or the ear, they may be compound—that is to say, they may communicate with See also:air-cavities from which pathogenic germs may readily enter the injured tissues. Thus, the dangers of See also:sepsis are added to those of concussion or compression of the brain. Fractures of the base of the skull are often associated with bleeding from the nose, mouth or ear, or with extravasation of blood over the eyeball. Facial paralysis is the result of the line of fracture passing across the bony channel in which the seventh or facial See also:nerve is running. When the fracture passes across the temporal bone and the See also:middle ear, and ruptures the membrane of the tympanum, not only blood may See also:escape from the ear, but an apparently unlimited amount of cerebro-See also:spinal fluid.

In all cases the ear should be made surgically clean, and See also:

watch and guard kept against the entrance of septic micro-organisms. When the fracture extends through the anterior See also:part of the base of the skull this same clear fluid may escape from the nose. In both cases its See also:appearance implies that the dura mater has been lacerated and the sub-dural space opened. Concussion of the brain (stunning) may result from a See also:blow upon the head or from a fall from a height. The symptoms may be those of a See also:mere giddiness, and a feeling of stupidity, which may quickly pass off, or they may be those of severe See also:shock (see SHOCK). The See also:person may See also:die from the concussion, or he may slowly or quickly recover. The insensibility may be for a See also:time complete. The pulse maybe small, See also:quick and imperceptible, and, no blood being pumped up by the enfeebled heart, the face will be See also:pale and the See also:surface of the body See also:cold. The See also:respiratory movements are likely to be sighing and shallow, or scarcely perceptible. As a See also:rule, the pupils react to light, contracting as the lids are raised. This shows that the light-reflex is not lost, and is a See also:good See also:omen. One of the first signs of returning consciousness is that the person vomits, and after this he gradually comes See also:round.

As a result of the injury, however, he may remain irritable, and liable to severe headaches or to lapses of memory. Surgery of the Brain.—Abscess of the brain is most likely to be the result of See also:

extension inwards of septic inflammation from the middle ear, or of a fracture of the skull which passes across the aural, nasal or pharyngeal air-space, giving the opportunity for. the entrance of the germs of suppuration. As the collection of pus forms, persistent headache is complained of together with, perhaps, localized See also:pain or tenderness. A See also:constant feature of See also:intra-cranial pressure, whether the result of tumour or of abscess, is the presence of headache and of vomiting. Later the patient becomes drowsy. On looking into the back of the eyeball by the ophthalmoscope, it is noticed that the optic nerve is congested (" choked "), the result of the increased intra-cranial pressure. The pulse becomes strangely slow, and is See also:apt to drop a See also:beat now and then. The temperature is high. The patient may have attacks of giddiness, and he is subject to fits of an epileptic nature; growing steadily worse, he may be found paralysed on one side, or on both sides, and, becoming insensible, may pass away in the deep sleep known as coma. The symptoms of tumour of the brain are much like those of abscess, though they come on more slowly and steadily; and inasmuch as the disease is not septic, the temperature may be undisturbed, or but little raised above normal. In the See also:case of the abscess or the tumour being on the See also:left side of the brain, and involving the speech centre (See also:Broca's convolution), the patient becomes aphasic. Tumours of the brain are likely to be sarcumatous(see See also:CANCER), but they may occur as the result of tuberculous or syphilitic See also:deposit, or of infection by the ova of the See also:dog's tape-wormhydatid cyst.

In cases of suspected cerebral tumours in which there is even a bare possibility of the patient having been the subject of syphilis, iodide of potassium is prescribed in large doses. Indeed, whilst waiting the development of further symptoms in any obscure case, it is usual to try the effect of this See also:

drug, the good See also:influence of which is by no means confined to cases of syphilis. If in spite of the administration of the iodide the symptoms are increasing, the question of opening the skull and exploring the region may arise. Before the days of anaesthetics and of See also:antiseptics such a See also:procedure could scarcely have been considered, but now the operation can be undertaken in suitable cases with a good See also:hope of success. If the case be one of abscess secondary to disease of the middle ear, the skull will probably be opened in the continuation of the operation by which the septic disease in the temporal bone was cleared away, the See also:aperture having been enlarged by the use of the trephine, See also:gouge or See also:chisel. The side of the head is shaved and rendered aseptic before the operation is begun, and when the dura mater has been incised See also:search is made for pus by the use of a grooved director. Pus having been found, the cavity is treated by See also:gentle See also:irrigation and drainage. When the operation is undertaken for a cerebral tumour the whole of the head is shaved and the skin duly prepared, so that the operation may be carried out with the least possible See also:risk of the occurrence of sepsis. A large horse-shoe incision having been made, the flap of skin and muscle is turned down, and a disk of the skull-wall, about 2 in. in See also:diameter, is removed by a trephine, worked by See also:electricity or by the See also:hand. The thick covering of the brain, the dura mater, is thus exposed, and if the presence of a tumour (or an abscess) has caused an excess of intra-cranial pressure, the membrane will bulge into the opening. The dura mater is then incised and turned down, and if the tumour is upon the cortex of the brain, and not too extensive, it is taken away. It may be necessary, however, to enlarge the opening made in the skull, and to break through a considerable See also:mass of brain-See also:tissue before the tumour can be removed.

Bleeding having been arrested by pressure with a See also:

firm plug of See also:gauze, a soft drainage See also:tube is introduced and the dura mater is stitched in position. The disk of bone (which, since its removal, has been kept in some salted warm See also:water) may be replaced before the horse-shoe flap is stitched in position, a notch having been cut in its border to allow for the drainage. In some cases the large horse-shoe flap is so made as to include a part of the bony wall of the skull. The flap of bone is shaped by See also:wire saws and then forcibly broken out by See also:elevators. The general result of operations for the removai of tumours of the brain is far from being satisfactory. But it must be remembered that without operation the outlook is without hope. Inasmuch as many of the tumours are destitute of a limiting wall, a considerable mass of brain-tissue has to be traversed in order to remove the growth, and the ultimate result, so far as the impairment of functions is concerned, is a serious disappointment. If, however, the tumour is found to be encapsuled, its removal is sometimes quite easily effected, and perfect recovery is then likely to be the result. (E.

End of Article: CRANIAL

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