Depression of the bone is more or less serious, according to the depth of depression, and the spi culx into which the bone has been broken. Our guide in the treatment of depressed bone should be the symptoms of compression of the brain, for there are numerous cases on record in the works of Wise man, Platner, Turner, Desault, IIill, J. Bell, Aber nethy, Hennen, and Thomson, where patients have recovered without the operation of trepan, especially among young people. As long, therefore, as there are no urgent symptoms of compressed brain, so long there can be no necessity for trephining, but merely strict and active anriphlogistic treatment, and by which mode of delay, the aggravation at tendant on the operation is avoided.—" Si nulla mala indicia stint, modioli usus supervacuus est." " It is remarked, that in times of war and trouble, when men are not allowed to take care of their wounds, those who are least cared for are soonest cured; and a man who is forced to wrap a clout about his head and ride for his life, is safer than one who is chambered np, dieted, and dressed, and perhaps tre panned by the surgeon." Cases have occurred where the trephine was about to he applied to a depressed bone, when the patient has awoke from the stun of the blow. The depression frequently extends only to the inner table of the skull. There are some ex ceptions, however, to this general rule of the non employment of the trephine; thus, for example, when the bone is injured with a sharp-pointed in strument, as a mason's chisel or a spike of an iron railing, the spicula project in such a manner in wards upon the brain, as to require a large crown of a trephine to encircle and remove the whole : this is termed the punctured fracture. Secondly, if the bone be so indented as to afford every reason to believe there are spiculx projecting inwards, it is also proper. Thirdly, the application of the trephine is also considered by some indispensable in compound fracture, and in the camerated frac ture of the ancients, but unless spicul2e are supposed to be formed, there are no just grounds for such an operation; since the antiphlogistic treatment is suf ficient. When the trephine is used in depressed bone, the centre pin of the instrument must rest on the sound portion of the cranium, while a little less than the half of the circle includes the depressed portion : previously however to its application, a -tripod incision of the scalp is made, and the dissected back from the pericranium, the latter of which being easily cut with the teeth of the saw, forms no impediment to its operation. Having re 0 moved a portion of the sound cranium with the tre phine, the elevator is inserted beneath the depress ed portion, and steadily elevated. From this it will at once appear evident, that the trephine should be applied to that portion of the sound cranium oppo site to the most depressed and loose portion. Hey's saw, depicted in Fig. 19 of Plate DXV. is oftener employed to remove a sound part of the bone, so as to allow the elevator to be used, because a smaller portion can be taken away with it, and it can even be applied to the depressed portion; all spiculx or fragments must be carefully picked away. The remaining steps of this operation have been already detailed. In some instances of depressed bone, even Hey's saw is not necessary, there being sufficient space to use the elevator. A case is related by Sir A. Cooper, of a man who remained comatose for thirteen months, in consequence of depressed bone, and who was then trephined and recovered.
When symptoms of compression of the brain are produced by extravasion of blood, there is generally an interval of sense between the receipt of the in jury and the insensibility occasioned by the effusion of the blood, and commonly some degree of swell ing of the scalp; but in other cases, the individual lies in a state of stupor from the first, and there is no mark or trace where the effusion has taken place, or whether he be not in a state of concussion; while in others again, only one or more symptoms of com pression present themselves. Sometimes the blood vessels of the dura water are ruptured, at other times those of the brain; hence, the effusion of the blood may either he between the cranium and dura mater; the dura mater and arachnoid membrane; the arachnoid membrane and pia mater; in the me dullary substance of the brain, or in the ventricles. The first of these is more or less circumscribed; and when it occurs at the basis of the cranium is gen erally fatal. When between the dura mater and arachnoid membrane, the blood is extensively dif fused, so that unless the quantity be great, there is no marked degree of pressure. It is also widely ex travasated when situated between the arachnoid membrane and pia mate'', one of its most common seats, and does not produce much pressure, unless the quantity be considerable. When effused in the
medullary substance of the ventricles, it is circum scribed, and resembles that effused in apoplexy. In some rare cases, blood has been extravasated at once in all of these places. In the treatment of this affection, when the blow has been severe, and the patient lies in a state of stupor from the beginning, we can only use the lancet, and watch the progress of the symptoms, and if these continue clearly indi cating compression, apply the trephine. IC the blow has not stunned the patient, bloodletting neverthe less should he had recourse to, as it may check the further effusion of blood, and prevent inflammation succeeding. If the patient recovers from the insen sibility which is occasioned by the blow, and again relapses into stupor, the trephine should be in stantly applied. If there be no tumefaction of the scalp to denote the scat of the injury, the instru ment must be applied in the region of one of the meningeal arteries, where it imprints the anterior inferior angle of the parietal bone, being there com monly encased in a bony canal, and consequently very liable to be ruptured either from the unyield ing nature of the bone, or from fracture of this deli cate osseous channel. If no extravasated blood be found on the side we have trephined, there is no other alternative than the applying of the instru ment to the opposite side; and even then the blood may be effused in the basis of the cranium. If no blood be found between the bone and dura mater, but the latter appears purplish, it is probable the fluid is effused between the arachnoid membrane and pia mater, and in such an event we appear jus tified in puncturing these membranes, in order to give exit to the blood, although it is commonly so extensively diffused, that it either proves fatal by compression, or by inducing inflammation. Cases are on record where both sides of the cranium re quired to be trephined, the first operation removing only one clot of extravasation, and symptoms of compression still continuing until the opposite was removed. No reliance should be placed on the condition of the bone, as inculcated by some wri ters; it is of no moment whether the bone be dry or bleed, for its circulation may be carried on for a time by the vessels of the diploe.
Concussion is that state of the brain which re sults from a fall or blow, wherein its particles are so agitated, and its minute vessels so injured, that symptoms of compression are more or less evi denced; for if the violence of the concussion pro duce lesion of the medullary fibres or globules, and extravasion of blood, as was observed in dissections by Sir A. Cooper, the same train of symptoms must take place in concussion as in compression. Pott, Desault, and Bichat assert, that concussion and com pression are frequently evinced by the same symp toms. In the majority of cases, the patient lies coma tose, but still feels when his skin is pinched; the pulse is slow and intermitting; the breathing labori ous without stertor; the pupils in some degree dila ted; and the extremities cold. if not attended to, he remains for some time in this state, and either falls a victim, or becomes paralytic, or is attacked with in flammation of the brain, which may be said in such a case to be beyond the power of art. Inflamma tion is the most frequent consequence, and there often occurs a longer or shorter interval between the state of oppression, and that of excitement, which have been divided by Mr. Abernethy into three stages, hut such a division is seldom verified in nature, and has led to erroneous practice. The treatment of concussion is by active and strict anti phlogistic means from the very beginning; copious bloodletting at this early period is supported by Sir A. Cooper's dissections, and by his own scientific practice, and also by that of Putt, Boyer, J. Bell, Abernethy, and Mennen. Broomfield, B. Bell, and Allan recommend cordials. The most character istic symptom of concussion, is that degree of sen sibility even in a comatose state, and which resem bles somnambulism, some extraordinary and divert ing cases of which are related by Sir A. Cooper. Concussion occasionally co-exists with extravasion of blood, the former preceding tbd latter; and so also do compression and concussion. The symp toms set down as indicating either of these condi tions of the brain, are far from being conclusive, as is candidly acknowledged by many experienced sur geons. Convulsions and paralysis are frequently consequent on these affections of the brain.