tured, the period of consciousness is prolonged for hours or perhaps for days. The other signs of this condition are paralysis of the side opposite the blood-clot (not necessarily of the side opposite the injury, for the artery may rupture from contre-coup on the uninjured side); this paralysis is apt at first to be localized, but it gradually and progressively widens its domain. If the clot extends toward the base, the pupil on the same side as the clot ceases to react and dilate, and if it be the left side, aphasia is noted. The pulse becomes frequent; the breathing becomes stertorous; the temperature rises, that of the paralyzed side exceeding that of the sound side; and in a compound fracture the pressure of escaping blood may force brain-matter out of the wound. (Keen).

Treatment. In treating extradural hemorrhage, localize the clot, not by the seat of the wound or contusion, but entirely by the symptoms. Trephine one and one-fourth inches back of the external angular process, at the level of the upper border of the orbit (Krönlein). If this incision does not show the clot, trephine again at the level of the upper border of the orbit and just below the parietal eminence. The first incision gives access to the trunk and to the anterior branch; the second incision exposes the posterior branch. If signs indicate that the clot is travelling to the base, the trephine should be used half an inch lower than the first indicated point. Proceed to arrest bleeding as directed on page 252, and always drain.

(2) Subdural hemorrhage is usually due to depressed fracture and rupture of the middle cerebral artery or of a number of small vessels. The symptoms are identical with those of extradural bleeding.

The treatment is trephining at the first hemorrhagic point, enlarging the opening with a rongeur upward and backward, opening the dura, turning out the clot, ligating the

bleeding point, elevating any depression of bone, draining, and stitching the dura with catgut. Hemorrhage from internal pachymeningitis requires the same treatment.

(3) Cerebral Hemorrhage. The symptoms of cerebral hemorrhage are identical with those of apoplexy. The treatment is the same as that for apoplexy, except in ingravescent cases, when the common carotid on the same side as the clot should be ligated.

Rupture of a sinus usually arises from compound fracture or during a brain-operation. The treatment, if the rupture happens from fracture, is trephining. Enlarge the opening by the rongeur, pack with one large piece of iodoform gauze, or catch the rent with hæmostatic forceps, leaving them in place for three or four days, or apply a lateral ligature. Elevate depressed bone. In rupture during an operation, control hemorrhage by packing.

Fractures of the skull may be simple, compound, depressed, non-depressed, or punctured. They are divided into fractures of the vault, usually due to direct force, and fractures of the base, due to extension of fractures of the vault, to indirect violence (a fall upon the feet, the buttocks, or the vault), to forcing of the condyles of the lower jaw against or through the base, or to foreign bodies breaking through the orbit or the roof of the nostrils. Fracture by contre-coup, which occurs on the side opposite the application of the violence, is very rare. Fractures of the skull are uncommon in early youth, but they are much more frequent in the aged. Usually the entire thickness of the bone is fractured, but either the outer or the inner table may be broken alone. In complete fractures the inner table is broken more extensively than is the outer table, because the inner table is the more brittle, because the force diffuses, and also, as Agnew taught, because the inner table is part of a smaller curve than is the outer table, and violence forces bone-elements

together at the outer table, but tears them asunder at the inner table (Figs. 129, 130).

FIG. 129.-Section of Outer and Inner Tables, with two parallel lines (after Agnew).

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FIG. 130.-Greater Yielding of the Inner

Table than of the Outer after the Application of Violence (after Agnew).

Fractures of the Vault.-A fracture of the vault of the skull may be simple and undepressed, or may be depressed, compound, or comminuted. A mere crack may exist in a bone, and if a rent exists in the soft parts, a bit of dirt or a hair may be caught in the crack. Fractures of the vault arise from direct force. A fissure may escape recognition, although in some cases percussion gives a "cracked-pot" sound. Any considerable depression can be detected. In a simple fracture occasionally the cerebro-spinal fluid collects under the scalp and forms a tumor which pulsates and becomes tense on forcible expiration. Compound fractures can be readily recognized, but Keen cautions the surgeon not to mistake a suture, a Wormian bone, or a tear in the pericranium for a fracture. A fissured fracture is marked by a dark line of blood which sponging will not remove. Fracture of the inner table alone can be suspected only (Keen). The prognosis of fractures of the vault depends upon the extent of brain-injury rather than upon the extent of bone-injury. Simple fractures unite by bone; compound fractures with loss of bone, by fibrous tissue. The dangers may be immediate (brain-injury and septic inflammation) or be distant (epilepsy, insanity, and persistent headache).

Treatment. A simple fracture without depression and

without brain-symptoms is treated expectantly (by rest, quiet, low diet, purgation, moderate elevation of and cold to the head, and arterial sedatives). A simple fracture with moderate depression and without cerebral symptoms is treated expectantly, and so also is a simple fracture in which symptoms existed but are abating. Simple fracture with marked depression requires immediate trephining, even when brainsymptoms are absent. Trephining in these cases often prevents disastrous consequences, and is known as "preventive trephining" (Agnew, Keen, White, Horsley, Macewen). In all compound fractures, shave and asepticize the entire scalp, enlarge the incision, and explore the bone. If a fissure exists, it must be asepticized, and if a hair or other foreign body is found in it, in order to effect removal and secure asepsis the outer table of the skull must be cut away with a chisel, the fissure being thus converted into a broad groove. compound fracture with much depression, trephine, elevate, and irrigate. In any fracture, trephine if distinct symptoms exist. In punctured wounds of the brain (punctured fractures), always trephine, open the dura, and disinfect (Keen). In any case of fracture of the vault where trephining has been performed, do not hesitate, if it seems expedient, to open the dura and examine the brain.

In a

Fractures of the Base.-A fracture of the base of the skull may exist in only one of the three fossæ, in two of them, or it may involve all. The middle fossa is oftenest involved. Fracture of the posterior fossa is the most fatal. These fractures may be due to direct violence, to indirect force, and to extension of a fracture of the vault. Extension from the vault is always by the shortest route. Fracture by direct violence may arise from the penetration of the nasal roof, the orbital roof, or the pharyngeal roof by a foreign body. The posterior fossa may suffer from a fracture by direct violence applied to the neck. Fractures by indirect

force may arise from blows upon the frontal bone (the orbital portion of the frontal or the cribriform process of the ethmoid breaking), from falls upon the chin (the condyle of the jaw breaking the middle fossa), or from falls upon the buttocks, the knees, or the feet (fracture occurring in the posterior fossa). The base is very rarely broken by contre-coup (Treves).

Symptoms.-In fractures of the base of the skull blood and cerebro-spinal fluid are apt to flow externally. In fractures of the anterior fossa blood may run from the nose, its source being the laceration of the mucous membrane or the vessels of the dura, the fracture being compound. Cerebrospinal fluid only appears when the mucous membrane, the dura, and the arachnoid are each lacerated (Treves). In fractures of the anterior fossa blood is apt to flow into the orbit, producing subconjunctival ecchymosis, and some blood is often swallowed and vomited. In fractures of the middle fossa blood flows from the ear through a tear in the tympanum, its source being the vessels of the tympanum, the meningeal vessels, or a sinus. Blood may flow through the Eustachian tube and come from the nose, may be spit up, or may be swallowed and vomited. In many cases a quantity of cerebro-spinal fluid flows from the ear, the discharge being increased by expiratory effort and a position which favors gravity. The cerebro-spinal fluid must not be confused with either blood-serum or liquor Cotunnii. The cerebrospinal fluid is always present in large amount; the liquor Cotunnii can only be present in minute amount. Blood-serum is highly albuminous; cerebro-spinal fluid is a serous fluid of very low specific gravity, never shows more than a trace of albumin, and contains considerable chloride of sodium and in some instances sugar, which, when present, reacts to Trommer's and to Moore's test, but does not reflect polarized light nor ferment with yeast (Keetley, from Collins). Treves