As to depth and number the former may only be learned by studying the nature and location of the signal symptoms, the presence and order of appearance of the same, presence or absence of headache, and local changes in temperature. Tumors occurring in tuberculous individuals are probably multiple. When different centres or systems are involved multiple lesions are usually present.
It has been held that the three cardinal symptoms of brain tumor are optic neuritis, headache, and vomiting; and while each of these is significant, and all of them are corroborative, they are not necessarily present nor does their absence exclude possibility of tumor. Other signs indicating the presence of tumor, it is a mistake to wait for the development of these three. The most distinctive feature of intracranial neoplasms is the progressive character of such symptoms as are present.
There is but one form of brain tumor which is amenable to internal treatment—namely, syphilitic gumma; and in case of doubt it may be justifiable to keep the patient actively under the influence of iodides for a reasonable length of time. This, however, need never be prolonged beyond six weeks, after which time, should no improvement occur, operation should not be delayed.
Operation.
—Brain tumors are operated for two purposes: First, for relief of pain and other distressing symptoms in incurable cases; second, for radical cure. Operation is justifiable in any case when pressure symptoms become severe, particularly so when pain is localized to a reasonable extent. Choking of the optic disks is not infrequently relieved and threatened disability postponed. The complete operation consists in the exposure of the tumor and in its removal.
The osteoplastic method should be used in exposing the tumor, by which a bone flap is raised, along with the overlying scalp, from which it is not detached. The centre of this flap is supposed to be calculated to overlie the centre of the deep lesion which it is proposed to attack. In many instances the operation should be divided into two distinct procedures, the first consisting in removal of the bone and exposure of the dura; this exposure should be ample, including the whole lateral region if necessary, as Horsley has shown; the second, a week or two later, comprising the balance of that which is to be done. But comparatively little shock attends removal of the tumor in the second stage of such a divided operation. After removal of the growth its cavity is best packed with a gauze tampon, after prompt ligation of all bleeding vessels within the field of operation, although it is usually required merely on account of venous oozing, as it is often possible to cut to the depth of an inch in the brain without a single artery spurting except those in the pin. The tampon is of value if allowed to remain for forty-eight hours, as preventing filling of the cavity with clot or excessive bleeding during the vomiting which may follow the administration of the anesthetic. The vasoconstricting properties of adrenalin may prove of great service here; it should be used in the standard 1 to 1000 solution, diluted 1 to 3. I have no hesitation in spraying this upon the brain or in saturating tampons with it, which may be left in situ so long as necessary. A number of the old-fashioned small serrefines, properly sterilized, can also be resorted to, if needed, for securing vessels, which may not be easily tied. They can be left in place along with the tampon and all may be removed together.
Next to the danger from hemorrhage is that of rapid edema of the brain, which may result from increased tension in the arteries or through venous stasis, which later produces lymph stasis, by which fluid collection in the tissues is still further facilitated. Another reason for using tampons is to prevent such relaxation of veins as may predispose to this edema. In most respects the operations for removal of brain tumors differ slightly from those whose general principles are elsewhere mentioned in this work. I am greatly in favor of using secondary sutures (i. e., those tied with bow-knots), which may be loosened on the second or third day, permitting the raising of the flap, removal of tampon, etc., and I employ them largely after all sorts of operations upon the cranium. If we desire to prevent any attempt at union of wound margins we may employ the green silk protective introduced by Lister, which should have been previously carefully sterilized by boiling.
The operative treatment of cerebellar tumors is made doubly difficult by their protected position and the large sinuses with which this part of the brain is surrounded. The cavity is restricted in size, intradural tension is greater than above the tentorium, and there is no room for easy displacement or retraction of parts. The occipital bone varies much in thickness and at points is somewhat thin. Operation which is begun either as an exploration or with a fixed purpose may prove palliative, even should the original purpose fail of accomplishment, as relief may be afforded by reducing tension, such relief consisting perhaps in freedom from headache, vomiting, and vertigo. Incision should extend from the tip of the mastoid process, a little above the superior curved line, to beyond the median line, with a vertical median incision by which a flap sufficiently large may be reflected downward. It is best to reflect the periosteum with the other soft tissues in order to expose the bone. The bone should be bitten away with forceps or removed with a reliable engine as rapidly as possible, hemorrhage being controlled with Horsley’s wax.
The operation may be divided into two stages, confining the first stage to the exposure of the cerebellar surface, or the operator may attempt all at one time.
The second stage consists in raising a dural flap, by which the cerebellar surface is exposed for inspection. It will protrude promptly through the opening, so that, with the finger, it may be possible to detect a tumor by the sense of touch. If no tumor appear on or near the surface deeper exploration should be made, with the aid of a retractor and by removal of a portion of the cerebellar hemisphere. This may require further exposure of the lateral region of the skull. Tumors situated deeply or at the junction of the cerebellum and pons require all the room that can be afforded from the outside, and are better approached from the lateral region than from above or below. It is comforting to realize what considerable portions of the cerebellum can be removed without serious or extensive disturbance, but as the medulla and pons are approached there is need of great care. The opening may be extended across the middle line, and either the lateral or the longitudinal sinus, or both, may be doubly ligated and divided. The tentorium may also be divided nearly to the petrous portion, after the lateral sinus has been thus divided, and so better access given to the deep location.