and an electric forehead-light are required. Long strips of

gauze must be ready for packing in case of hemorrhage. The patient is placed recumbent, with head turned to the opposite side. A large osteoplastic flap is formed in front of the ear (Fig. 162), and is broken down. Hemorrhage is arrested. It may be found that the meningeal artery has been ruptured. If this accident has happened, and the vessel lies in a bony canal, plug with Horsley's wax. If the vessel is bleeding upon the dura, ligate by passing suture ligatures around it. If it is torn off at the foramen spinosum, pack with iodoform gauze, and postpone the rest of the operation for forty-eight hours. It may be necessary at any stage

FIG. 162.-Hartley's osteoplastic flap in removal of Gasserian ganglion (Tiffany).

FIG. 163.-Removal of Gasserian ganglion (Krause): A, middle meningeal artery: 11, ophthalmic division; III, submaxillary division; G, ganglion.

of this formidable operation to pack the wound and postpone completion for two days. The next step is to lift up the dura and with it the brain (Fig. 163). Find the inferior maxillary

nerve and clamp it with hemostatic forceps. Find the superior maxillary nerve and clamp it. Loosen the nerves from their beds with a dry dissector. Twist the clamp-forceps so as to reel up the nerves. This pulls out the ganglion intact with the motor root and the root of origin, as far back as the pons (Krause's method). Arrest bleeding; close the flap; sew the lids of the affected side together; and cover the eye with a watch-crystal.

XXIII. DISEASES AND INJURIES OF THE HEAD.

I. DISEASES OF THE HEAD.

In approaching cases of brain disorder, first endeavor to locate the seat of the trouble; next, ascertain the nature of the lesion; and finally, determine the best plan of treatment, operative or otherwise. In all operations upon the brain the surgeon must be able to determine accurately the situations of certain fissures and convolutions, the finding of the situations of these convolutions and fissures comprising the science of craniocerebral topography.

The regional terms used in craniocerebral topography are derived from Broca (Fig. 165). The middle meningeal artery

FIG. 164. The meningeal artery exposed by trephining (after Esmarch).

is found at the pterion, one and one-quarter inches posterior to the external angular process, on a level with the roof of the orbit (Fig. 164). The fissures and convolutions of the brain are shown in Figs. 166, 167, and 168. The fissure of Bichat is marked by a line on each side drawn from the inion to the external auditory process. A line from the glabella to the inion overlies the median fissure and the superior longitudinal sinus. The fissure of Rolando is very important, as

B

marking the motor region of the brain. It begins in the median line, half an inch posterior to the middle of the distance between the inion and glabella (Keen). This fissure runs downward and forward at an angle of 67.5° for a distance of three and three-eighths inches. Chiene finds the fissure of Rolando by the following method: he takes a square piece

Ob

FIG. 165.-Skull showing the points named by Broca: As, asterion (junction of the occipital, parietal, and temporal bones); basion, middle of anterior wall of foramen magnum; B, bregma (junction of the sagittal and coronal sutures); G, ophryon (on a level with the superior border of the eyebrows, and corresponding nearly to the glabella, the smooth swelling between the eyebrows); g, gonion (angle of the lower jaw); I, inion (external occipital protuberance); L, lambda (junction of sagittal and lambdoidal sutures); N, nasion (junction of the nasal and frontal); Ob, obelion (the sagittal suture between the parietal foramina); P, pterion (point of junction of great wing of sphenoid and the frontal, parietal, and squamous bones. This may be H-shaped or K-shaped, or "retourné," in which the frontal and temporal just touch); S, stephanion (or, better, the superior stephanion, intersection of ridge for temporal fascia and coronal suture); S, inferior stephanion (intersection of ridge for temporal muscle and coronal suture).

ip

FIG. 166.-View of the brain from above (Ecker).

of paper and folds it into a triangle (Fig. 170, 1); the angle BAC of this triangle is 45°; the edge D A is folded back on the dotted line A E; the angle D A E equals half of 45°, or 22.5°, and the angle CAE equals the same (Fig. 170, 2); unfold the paper in the line CA; in the figure thus formed BA C=45° and EAC 22.5; EAB=67.5°, which is the angle desired. Place the point A in the mid-line of the head, over the point of origin of the Rolandic fissure; the side AB is laid along the middle line of the head, and the line AE corresponds to the fissure of Rolando.' Fig. 169 shows Chiene's scheme for locating various points upon the brain. Horsley determines the situation of the Rolandic fissure by the use

1 American Text-book of Surgery.

of his metal cyrtometer (Fig. 171). He places the point marked zero over the inioglabellar line and midway between the inion and the glabella. To find the fissure of

S'

FIG. 167.-Outer surface of the left hemisphere of the brain (Ecker).

The

Sylvius (Fig. 167, S, s', s''), draw a line from the external angular process to the occipital protuberance. fissure of Sylvius begins on this line one and one-eighth

FIG. 168.-Inner surface of the right hemisphere of the brain (Ecker).

inches behind the external angular process; the main branch of the fissure runs toward the parietal eminence; the ascending branch of the fissure corresponds to the squamoso-sphenoidal suture, and continues upward in the

same line half an inch above the suture. The precentral sulcus (Fig. 167, F) limits anteriorly the ascending frontal convolution; it runs parallel with and just behind the

FIG. 169.-Chiene's lines for localizing brain-areas: MDCA, Rolandic or motor area; A, anterior branch of middle meningeal and bifurcation of fissure of Sylvius; AC, horizontal part of Sylvian fissure; the highest part of the lateral sinus touches PS at R; MA, precentral suicus; 1, beginning of inferior frontal sulcus; K, beginning of superior frontal sulcus; MBC contains the supramarginal convolution; B, angular gyrus.

coronal suture, and a finger's breadth in front of the fissure of Rolando. The intraparietal fissure (Figs. 166, 167, ip) limits the motor region posteriorly. It begins opposite the junction of the lower and middle thirds of the fissure of

44

FIG. 170.-Chiene's method of fixing position of the Rolandic fissure (Am. Text-book of Surgery).

Rolando, passes upward in a line parallel with the longitudinal fissure and midway between the Rolandic fissure and the parietal eminence, passes by the parieto-occipital fis