Chapter M: M——, was a stout Irish woman about forty years of age. She had (28)

In reality, the hindrance to the proper functions is nearly the same, since blood which is not duly renovated and contains the products of metamorphosis of tissue in excess is worth as little for healthy nutrition as no blood at all. There is no reason to suppose that blood in {927} circulation, no matter in how great quantity, gives rise to unconsciousness. It may cause over-action or disordered action, as in mania, but not arrest of action.

The narcotic poisons also deprive the nerve-tissue of its healthy food; whether by interference with oxygenation and depuration, or by a direct action of the substance itself on the nerve-cells, it is not easy to say. The fact that the completeness and duration of the unconsciousness are not in proportion to the paralysis or anæsthesia shows that they are to some extent independent of each other; and, although it is possible to locate with some precision the lesion which abolishes motor power and conscious sensation, yet we cannot say how much or what part of the brain must be deprived of its function in order to produce that cutting off of all conscious relation with the external world and reduction of a feeling, thinking, remembering, and acting organism to the level of a mere automatic breathing-machine, which we designate as loss of consciousness.

In fact, in the present state of our knowledge as to what consciousness is, any speculation as to its seat would be a waste of time, and we must content ourselves with recognizing that experience seems to show that a large part, rather than any particular part of the brain, must be involved, not necessarily in the primary lesion, but in the resulting pressure or anæmia.

Another theory of unconsciousness is simply that it is due to shock—that the sudden irruption of blood acts like a blow, as it were, and abolishes for a time the function of the nervous structure. This is substituting something indefinite for something comparatively definite; and it is certainly not true that the more sudden the shock the more complete the unconsciousness. It may come on after the paralysis is apparent, and in fact is more commonly gradual than sudden in its onset. The classical instantaneous shock is the rare exception. In the celebrated case where a tamping-iron was driven completely through a man's skull and brain, he himself was able to give a clear description of the accident to the surgeon who first attended him. Several other instances of severe and sudden injury to the brain without loss of consciousness have been recorded.

ETIOLOGY.—As regards the greater number of cases and the most common pathology, the existence of so specific and peculiar lesion as aneurism enables us to distinguish between predisposing and exciting causes, or, in other words, the conditions which lead to the localized periarteritis with its resulting aneurisms and those which cause their rupture. Unfortunately, the aneurisms are not usually looked for, and in the collection of statistics we are obliged to group together cases the pathology of which is not always the same, and which are usually collected under the name of apoplexy.

Age, however, is well known, both on clinical and anatomical grounds, to be the most important factor. Among the predisposing causes of apoplexy, all statistics, both of recent and older date, agree in assigning the period of life beyond forty-five or fifty as that in which the liability to apoplexy is greatly increased. There is no age, however, below this, even to infancy, in which true cerebral hemorrhage may not occur, although the intracranial hemorrhage of children is more usually {928} meningeal. It is probable, however, that in many of these the rupture of the vessel does not depend upon a previous aneurism, but on other lesions. The youngest case in which aneurisms were found by Charcot and Bouchard was twenty.

If we speak of cerebral hemorrhage in general, without reference to the presence of aneurisms, as we unfortunately are obliged to do in the great majority of cases, we may often go much below this point. In youth and childhood, however, it is possible, and often almost proved, that other conditions must have been of greater importance in determining the hemorrhage than aneurism.

In our own small series we find cases of eighteen, twenty-three, twenty-five, twenty-six, twenty-seven years of age, and quite a number from thirty to forty-five. A little further examination shows many of them not to have been of the ordinary kind; thus the patient of eighteen had valvular disease of the heart and advanced parenchymatous nephritis; the one of twenty was, so far as could be seen, typical, but no search was made for aneurisms; that of twenty-five had many small hemorrhages and was a marked case of idiopathic anæmia; that of twenty-six had valvular disease of the heart, an embolus in the middle cerebral artery, which was not in the immediate neighborhood of any hemorrhage, several old hemorrhages, and hemorrhagic infarction in other organs. The case aged twenty-seven had a very large clot in one hemisphere and advanced interstitial nephritis.

Cayley[11] describes the case of a girl of eleven with a large cavity in the left middle cerebral lobe, where nothing was discovered abnormal upon the left middle cerebral artery, but when the cerebral matter was washed away with a stream of water, the walls of the vessels were found to be dotted with oil-globules, and in several places studded with round and oval nuclei. This was before miliary aneurisms were known, but the process of preparation was exactly suited to bring them to light had they been present, and they could hardly have escaped observation and mention. Other cases of boys have been reported where the hemorrhage was of the typical kind.

[Footnote 11: _Trans. Path. Soc._, vol. xx.]

Meigs and Pepper speak of nine cases of hemorrhage into the substance of the brain in children, but give none of their own. Of the two cases mentioned by West as coming within his own observation, in one the source of the blood was in the cerebral veins obstructed by the formation of clots in the longitudinal sinus.