Heredity.—It is still doubtful whether hereditary influences, excluding the tu bercular and the carcinomatous, play any part in the causation of tumors of the brain.
It is probable that worry, anxiety, excessive alcoholic indulgence, cerebral congestion, and depressed states of the nervous system favor the development of cerebral growths in tubercular and syph ilitic subjects, and they favor the forma tion of cancerous growths in other por tions of the body and secondarily in the brain in certain persons, especially those who are the offspring of families in which the history of cancer is found.
ExcITING CAUSES. - There is appar ently a direct relation between injury of the brain and the development of tumor in only a few instances. It ap pears from the study of numerous cases that this relation is frequently over estimated.
Syphilis and tuberculosis are two of the most potent causes of tumors of the brain. I have no doubt that the time will come when we shall be able to at tribute the origin of many tumors of the brain to micro-organisms.
Pathology.—According to Gowers, about four-fifths of the non-syphilitic tu mors of the brain are either tubercular or sarcomatous (including the gliomatous). It is difficult to determine the frequency of syphilitic tumors of the brain, as so many cases yield temporarily or perma nently to antisyphilitic treatment, and are lost sight of by the observer. The dif ficulty is still further enhanced from the fact that many cases of non-syphilitic tu mors temporarily yield to antisyphilitic treatment, and may pass from under the physician's observations before their true nature is determined. The gliomata are found only in the central nervous system and in the retina, and occur far more fre quently in the brain than in the cord.
From a study of Starr's tables, con sisting of analysis of three hundred cases of tumor of the brain in children, in nearly one-half the tumor was found in the cerebellum, pons, and medulla, while in the same number in the adult only a little more than one-fifth were located in this portion of the brain and its stem. The cerebellum in childhood appears to be a little more than twice as often the seat of tumor as in adult life, but in adults the cortex of the cerebrum is the seat of tumors six times as often as in childhood. From a study of the loca tion of tumors it will be found that por tions of the brain inaccessible to the sur geon's knife are much more commonly the seat of growths in children than in adults.
Tubercular growths are the most frequent of brain-tumors, especially in childhood, and their most common seat is in the cerebellum or other structures in the posterior cerebral fossa. In nearly one-half the cases the growths are mul tiple, and give rise to a confusion of symptoms, especially in relation to local ization. Syphilitic growths, which are often accompanied by endarteritis or a low form of meningitis, affect the cere brum much more frequently than the cerebellum, and are found on the sur face, either at the base or on the convex surfaces of the frontal lobe and the con volutions near the fissure of Rolando. Gliomata and sarcomata are frequent forms of tumor of the brain. The former grow from the neurogliar tissue, infil trate the surrounding portions of the brain, may be of considerable size, and are often scarcely distinguishable from the adjacent brain-substance; the latter develop from the connective tissue of the membranes and vessels, and are fre quently capsulated.
Prognosis. — The tubercular in chil dren and the gummatous growths in young adults give the most favorable prognosis. In rare instances a sarcoma tous growth may become capsulated and cease to grow or even decrease in size. The duration of life in tumors of the brain varies from a few months to two or three years. In exceptional cases life
is prolonged for many years.
Treatment. — Persons suffering from tubercular or syphilitic growths should be kept as well nourished as possible, by means of a generous and nutritious diet, and general tonics, consisting of codliver oil, iron, quinine, extract of sumbul, and arsenic, together with plenty of fresh air. In tubercular tumors alcoholic stimula tion in many instances has seemed to be beneficial in my experience. The treat ment should be different in the early stages of intracranial growths from that which should be adopted after the brain has received considerable damage and the tumor attained considerable size. In the early course of the disease the pa tient should have the benefit of the doubt when syphilis cannot be excluded. The more acute and irritative the symptoms in cases of syphilis of the brain, the greater the demand for mercury pushed rapidly to its constitutional effect; the slower the growth, the more likely that potassium iodide will be more beneficial than mercury. In most cases, while in unctions of mercury are employed vig orously, potassium iodide should be pushed to the point of tolerance. If with six weeks' active antisyphilitic treat ment, carried to the point of tolerance, the symptoms do not begin to yield, it is probable that little will be accom plished by this method. It should be borne in mind that syphilitic subjects, who are emaciated and anaemic, will not respond to active antisyphilitic agents until the nutrition has been improved. In the late stages of tumor of the brain prolonged and vigorous antisyphilitic agents are, to say the least, useless, if not cruel. In such cases, if improvement is not manifest within one or two weeks, vigorous measures should cease.
Headache is lessened by keeping the bowels open freely each day, the digest ive organs in the best possible condition, and avoiding causes that are likely to increase the blood-supply to the brain. Cold to the head and a mustard plaster to the nape of the neck often relieve an annoying headache. Sometimes local abstraction of blood from the head by means of leeches to the temple or nape of the neck has been employed with benefit.
Such anodynes as cannabis Indica (Ilering's extract or Parke, Davis & Co.'s normal liquid), with one of the coal tar products, with or without codeine, should be employed before hypodermic injections of morphine are resorted to. Mustard to the neck and over the stom ach, with cold to the head, will often re lieve vomiting. Twenty to 30 grains of hydrate of chloral given by bowel in starch-water will often stop the vomit ing as well as the general convulsions. Morphine hypodermically administered may be resorted to with confidence in the intractable cases of vomiting and general convulsions.
In case the tumor is accessible to the surgeon's knife, an operation for its re moval should not be postponed if the symptoms have failed to be decidedly modified by antisyphilitic agents, vigor ously pursued for a period of from six to eight weeks. No one should think of trying to remove a carcinoma or a mel anotic sarcoma from the most accessible regions of the brain, if the diagnosis of the nature of the tumor were possible or strongly probable. In some cases of tumor of the brain, in which there is no prospect of removing the growth, in the hopes of relieving the severe and ago nizing pain a button of bone may be re moved from over the seat of pain. In two personal cases this procedure has lessened or relieved the pain for pro longed periods. Several other similar cases, equally successful, have been re ported.