BROWNING.] Where the latter is at a.11 voluminous, in almost any part of the brain we see vomiting, often severe and even some what prolonged. Its occurrence depends upon the volume of the effusion, the speed with which it is poured out, and to some extent upon its location. In the slower, or ingravescent, forms, even though they finally reach a large size, there is less tendency to emesis. It is where we find other evidence of an apoplectic seizure that this symptom ac quires value; then it also assists mate rially in differentiating the nature of the brain-process.
Nearly always some other plausible explanation is proffered: the person has just eaten overheartily, been lying in a cramped position, had an hypodermic.
taken medicine that upset the stomach, or been suffering from gastric catarrh. The diagnostician must, of course, be able to discount such suggestions.
Yawning and Sighing. — These are very frequent and striking symptoms in hminorrhage, and are often more marked if the patient is in a sitting position. There is a slight parallelism between them and the vomiting. But as they are also common in cases of thrombosis and may occur in embolism while there is a badly damaged heart, they have only a limited diagnostic value. In cases of lnernorrhage these manifestations sug gest that the focus has already reached a sufficient size to produce some degree of brain-anmmia.
Coma and Other Disturbances of Con sciousness.—These are of great impor tance for both the positive and the dif ferential diagnosis. But at the same time they are matters most difficult to describe or define with exactness and in accordance with the facts.
Coma is a state of profound uncon sciousness not due to sleep, syncope, or drugs. But in practice we meet all kinds and degrees of disturbance of conscious ness. The eyes may be open and staring, yet the person fail to make any responses to our interrogations and evidently fail to have any understanding of language or surroundings. Afore often there is a condition of stupor that admits of but partial and temporary recognition. We can then conveniently distinguish coma, stupor (a partial coma: "semicoma tose"), and dazed conditions.
The duration of these states is next in importance. They may be of such tran sitory nature as to pass unnoticed,or they may last several hours or days, the lighter degrees being, of course, as a rule, of shorter duration. The time in the attack- when coma supervenes is also to lie noted; if at the start it may be partly a direct shock-effect; if later and more gradual it indicates that the ef fusion has reached a large volume.
The size of the output requisite to produce this symptom varies much with its location. A small clot in the pons, for instance, will produce a much deeper impression on consciousness than one of far-greater size in the pallinm. Wer nicke and others have sought to explain this by the smaller size of the vessels, their indirect course, and hence slower leakage in the hemispheres. But this view is negated by several facts, ever well it may explain the favorite sites of hremorrhage.
[A competent medical friend offers the following more scholarly definition: "Coma is a condition of profound un consciothiness. the result of injury, dis ease, or some form of intoxication." But the sleep of chloral or morphine is not termed coma, while, on the other band, that of alcoholism often Is. Neither is true coma always so profound. In fact.. there seems to be a considerable latitude in the use of this term.
Perhaps the above definition might be modified as follows: C'onta is a state of unconsciousness due to some other cause than sleep or syneope. The effects of in toxications, soporifics, or amesthetics i,hould only be called coma when the person can no longer be roused to con sciousness. AV. BriowNING.] The comparison of a large number of these cases shows that involvement of the sensory tracts has little or no influ ence on consciousness, while other cases with equal-sized foci involving certain parts of the motor path show, as a rule, very marked impairment of conscious ness. From a psychological stand-point this seemingly anomalous fact agrees with conclusions based on other evi dence. But it is cited here to prove that much depends on the part involved as to the effect on consciousness.