BY E. C. SPITZKA, M.D.
Cerebral Hyperæmia.
Up to within a few years it was a favorite mode of explaining the results of the administration of certain narcotic and stimulant drugs, and certain of the active symptoms of mental derangement, to attribute them to an increased blood-supply of the nerve-centres. This view seemed to harmonize so thoroughly with the physiological dictum that functional activity depends on the supply of oxygenated blood that the first attempts at questioning it were treated as heresies. To-day, however, few authorities can be found to adhere unreservedly to this once-popular and easy explanation. The drift of physiological and medical opinion is in the direction of regarding some subtle molecular and dynamic state of the nerve-elements as the essential factor in intoxications as well as in maniacal and other forms of insane excitement: if they be complicated by active or passive congestions, this is probably a secondary occurrence of modifying but not of intrinsic determining power. While this change in our views is the natural result of progress in experimental pharmacology and pathology, it does not justify the extreme assertion that there is no disorder of the brain functions deserving the name of congestion and hyperæmia. This assertion seems to have been provoked by the careless manner in which these terms have been employed to designate conditions which are in reality the most different in nature that can be well conceived. No one familiar with the extent to which the term “congestion of the base of the brain” has been abused in this country will marvel that the reaction provoked by it has overstepped the boundaries of cautious criticism. That there are physiological hyperæmias of the brain is now universally admitted; the most recent experimental observations, indeed, conform most closely to the claims of the older investigators. It naturally follows that pathological hyperæmias are both possible and probable, and even if the observations in the dead-house do not strongly sustain the existence of pathological hyperæmias and congestions independently of gross disease, clinical analysis and the gratifying results of appropriate treatment justify us in retaining these designations in our nomenclature with the limitation here implied.
One great difficulty in determining the precise nature of the disorders which the physician is called upon to treat on the theory of hyperæmia lies in the number of factors which may contribute to or modify its development. If, for example, the action of the heart be increased through hypertrophy, the result to the cerebral circulation will obviously be different in a plethoric and in an anæmic person; it will be also very much different in the event of the stimulation of the centres which contract the calibre of the cerebral blood-vessels from what it would be if there were a state of vascular relaxation. Should the cardiac hypertrophy be associated with renal disease, other disturbing elements may be introduced, such as arterio-fibrosis, or the presence in the blood of certain toxic substances having direct effects of their own on the nerve-elements. The picture may be still more complicated by variations in the intracranial pressure. It is impossible to prove, either by direct or indirect evidence, that there is such a pathological state as a simple cerebral hyperæmia; indeed, there is one fact which militates strongly against, if it be not fatal to, such an assumption. Were a physiological hyperæmia to become intensified to a pathological degree, we should have corresponding clinical phenomena. In other words, the culmination of the morbid process should be preceded by an exaggerated physiological excitation similar to that observed with intoxications. But this is rarely the case, and we accordingly find that the more cautious writers, like Nothnagel,1 do not commit themselves to the view that the results of mental overstrain2 are to be classed as simple cerebral hyperæmia. Similar restrictions are to be made regarding the established congestive states, such as those following sunstroke. It has been usually supposed that insolation directly produces cerebral hyperæmia, even to the degree of engorgement, and that the after symptoms in persons who recover are due to the non-return of the meningeal and cerebral blood-vessels to their normal calibre, and to other more remote results of vascular stasis. The latter half of this proposition is in part correct; the former is contradicted by numerous pathological observations. Thus, Arndt,3 who had the opportunity of studying over one hundred cases occurring in the course of a forced march of a division of infantry from Berlin to Pankow, many of which terminated fatally, found almost uniformly a pale brain, with peculiar color-changes, denoting rather structural than circulatory trouble.4 The whole list of causes of what is commonly designated cerebral hyperæmia, congestion, and engorgement may be gone through with and similar modifying statements be found to apply to them. The nearest approach to an ideal cerebral congestion is that found with acute alcoholic intoxication. This is at first accompanied by cerebral hyperæmia, which, with the comatose climax, becomes an engorgement; accordingly, many of the results of acute alcoholic intoxication are attributed to the circulatory condition alone. The congestive troubles due to alcoholism which come to the special ken of the physician, however, are those found with the chronic form, and here a more complex pathological condition is found to underlie it; the organization of the brain is altered, the vascular channels more or less diseased, and the vaso-motor mechanism continuously deranged. This disorder, as well as the apoplectiform states attributed to vascular stasis, and the active and passive hyperæmias associated with tumors, meningitic and other gross diseases of the brain, as well as with the status epilepticus, are usually included in the discussion of cerebral congestion, and serve to swell up the chapters devoted to it. They will be found discussed in more appropriate situations in this volume. In this place it is proposed to consider only those congestive states which present themselves to the physician, independently of conditions which, if associated, preponderate in clinical and therapeutic importance.5
1 Ziemssen's Cyclopædia, “Nervous System,” i. p. 39, 2d German ed.
2 It has repeatedly happened during the past decade that young persons competing for admission to higher institutions of learning in New York City through the channel of a competitive examination died with symptoms of cerebral irritation; the death certificates in several such cases assigned meningitis or cerebral congestion as the cause of death, and attributed the disorder to mental overstrain. It is not so much the intellectual effort that has proved hurtful to the pupils as the emotional excitement attending on all competitive work, the dread of failure, the fear of humiliation, and anxiety developed by the evident futility of the cramming process. Some years ago I recorded the results of some inquiries on this head in the following words: “The mental-hygiene sensationalists, who periodically enlighten the public through the columns of the press whenever an opportune moment for a crusade against our schools and colleges seems to have arrived, are evidently unaware of the existence of such a disease as delirium grave, and ignorant of the fact that the disorder which they attribute to excessive study is in truth due to a generally vitiated mental and physical state, perhaps inherited from a feeble ancestry. Our school system is responsible for a good deal of mischief, but not for meningitis” (Insanity, its Classification, Diagnosis, and Treatment). Since then I had an opportunity of obtaining an excellent description of such a case which had been attributed to the combined effects of malaria and educational overstrain, presenting opisthotonos, fulminating onset, and an eruption!
3 Virchow's Archiv, lxiv.
4 The observations of Gärntner (Medicinische Jahrbucher, 1884, 1) harmonize with this. He found that radiant heat contracts the blood-vessels of the frog's mesentery.
5 The same applies to conditions which are discussed under this head in textbooks, although they have either only a medico-legal bearing or are inconstant factors, such as the injection of the brain in death from strangulation. I need but instance the vascular condition of brains of criminals executed by hanging. In the case of one where the strangulation had been slow I found an engorgement of all the vessels and arachnoidal as well as endymal hemorrhages; in a second, where the criminal had been carried half fainting to the drop, and death ensued quickly and without signs of distress, the brain was decidedly anæmic.