Acute simple meningitis is ushered in by cerebral hyperæmia of the active form. This is not alone demonstrated by the early symptoms of this disease, but also by the fact, which I have observed in two cases, that where this form of meningitis originates on one side, as from extension of the middle-ear trouble, the opposite cerebral hemisphere exhibited intense congestion of the ideal type.
In that serious form of mental disease known variously as grave or acute delirium and typhomania (Luther Bell) a form of cerebral hyperæmia is observed which in its intensity approximates inflammatory congestion. The surface of the brain appears marbled and mottled; blood seems to exude from the gyri after the pia is removed; the cortical lamination is invisible, owing to the hyperæmic discoloration of the gray substance; and the parenchymatous elements themselves appear to be in a state of cloudy swelling. In one case I have observed transudation of a hyaline proteinaceous substance and an exudation of fibrin around the larger arterioles. In some cases of typhus fever a less intense but similar congestive hyperæmia is found. The hyperæmias of paretic dementia, of acute delirium, and of typhus fever agree in this one feature: that all districts of the brain, from the cortex and white substance of the cerebral hemispheres to the medulla oblongata, are involved nearly to the same degree. In the hyperæmia of simple meningitis of the convexity it is chiefly confined to the pia mater and the most superficial cortical strata.
Congestion of the brain from stagnation of the venous return circulation should not be confounded with active hyperæmia. With this condition, which may be due to thrombosis of the sinuses, morbid growths near the jugular foramen or in the neck around the internal jugular veins, or, finally, to certain cardiac and pulmonary disorders, there is rather a lesser than a greater amount of blood sent to the brain; and it is not infrequently found that while the surface of the brain appears congested, owing to the prominence of the cerebral veins, the deeper parts are quite anæmic; and if the injection be general, it will be found that the blood, whether in arteries or veins, has the venous character. An excellent example of this form of congestion is afforded by persons dying in the status epilepticus. In their brains the venous channels stand out, filled to their extreme capacity with blood almost black in color; and in prepared sections, particularly such as are taken from the pons and medulla oblongata, a beautiful natural injection of the vessels is found. But that rosy color which is so characteristic of active hyperæmia is absent, the tissues appearing purplish, bluish, or chocolate-colored.
SYMPTOMATOLOGY.—There are few symptoms attributable to the nervous system which have not been enumerated among the characteristics or the occasional manifestations of cerebral hyperæmia. Thus, Hammond not only follows Andral in enumerating apoplectic, convulsive, comatose, and maniacal symptoms as acute manifestations of active cerebral congestion, but assures us that aphasia may occur under the same circumstances. In the course of his work on the subject, “an absolute want of power to get correct ideas of even simple matters,” confusion of ideas, weakening of the judgment, vacillation of purpose, diminished logical power, illusions and hallucinations of every sense, delusions, morbid apprehension of impending evil, imperative, suicidal, and other impulses, suspicion, hypochondriasis, furious delirium, and the use of profane and obscene language, are enumerated among the characteristic or prominent symptoms of various forms and cases of cerebral hyperæmia.7 Not one but several of the recognized forms of insanity have yielded a fair quota of their symptoms to this long array. Among somatic signs he in like manner names neuralgic pains, numbness, spasms, paralysis, false impotence, hyperæmia of the tympanum, choked disc, abolition or perversion of the sense of smell, taste, and sight, fibrillary or fascicular twitches, various states of the urinary excretions, diplopia, and monoplegias. It is here equally evident that the initial symptoms of a considerable number of organic and clearly defined affections have been included. It is on account of the confusion engendered by this wide interpretation of the meaning of the term congestion of the brain that I have determined to limit the term as previously indicated, and to consider only the active form here.
7 A Treatise on the Diseases of the Nervous System, 7th ed., pp. 1-53. The natural inference following a perusal of this chapter, as well as the monographs to which their author refers, is that he has gathered together all states in which cerebral hyperæmia was an associated factor, as well as those in which he appears to assume its existence on theoretical grounds, and designated them as cerebral congestion. In some instances he uses the terms hypochondria and cerebral hyperæmia interchangeably (p. 50, loc. cit.).
A feeling of head-pressure, associated with a more or less severe dull pain, aggravated by mental exertion, by stooping down, by straining at stool, or when out of breath, and accompanied by a subjective sense of mental dulness, is the most constant feature of the ordinary cases. There is usually a vertiginous sensation, and an irritability of the eye and ear not unlike that described in the article on Cerebral Anæmia. Sleep is at first disturbed by vivid and sometimes frightful dreams; later, it becomes interrupted, and ultimately complete insomnia may develop. The action of the heart is accelerated and exaggerated in some cases; in that event increased pulsation of the carotids, flushing of the face, injection of the conjunctiva, and a subjective sense of heat in the head and face are experienced. Hammond, in accord with Hasse and Krishaber, believes that febrile symptoms may develop under these circumstances; most authorities, however, deny this for the uncomplicated form. I have never found an objective rise of the general temperature.
Such a condition as that described is usually slowly produced, several weeks, or even months, being occupied in its development. At first the unpleasant symptoms occur only at certain hours of the day, with temporary exacerbations and remissions. It may be arrested with comparative ease at any time; if neglected, the mental faculties become affected, not in the grave sense in which Hammond and the older authors describe it, so as to carry the patient into actual dementia or delusional insanity, but rather in the way of diminished working-power. It is more difficult to fix attention, to recollect words, names, and figures, or to keep up a protracted mental effort, than in health, but the formal judgment does not suffer. I have known patients to be in this condition for many months, and several for more than one year, without any grave deterioration. It is true that in the prodromal periods of some forms of insanity, such as acute mania, there is a condition very similar to that of these patients; and this has led to regarding mania as a possible phase of cerebral hyperæmia. But the very fact that, typically, mania is preceded by such a stage—which is always of brief duration—that maniacal excitement is a constant and unavoidable consequence upon it, while, as far as known, the condition here described may last for years without leading to a true psychosis, should prevent one regarding the two conditions as identical, however similar they may be for the time being.
In sufferers from cerebral hyperæmia who pass into the chronic state of this disorder the disturbance of sleep and of the digestive organs becomes very prominent, and continually reinforces the acting causes of the disorder. In a large number of cases the head-sensations become more or less localized; that is, while the general feeling of pressure or dull ache may continue, a special area, which can be covered by the palm of one hand, either in the middle part or to one side—usually the left—of that part of the vertex, is the seat of a more severe pain, complained of as a hot pressure. The patients frequently claim that the temperature is higher at this spot, and, contrary to what might be anticipated on a priori grounds, the statement will be confirmed, not alone by the coarse method of using the hand, but by the surface thermometer. The locality where this occasional rise of temperature and the more common sense of pressure are experienced corresponds to that part of the longitudinal sinus where the largest cerebral veins enter. It is a noteworthy fact that nearly all the important admunctories of this sinus empty into it within the short space of two inches at this point.
Not all sufferers from cerebral hyperæmia give a history of a gradual development of their symptoms. A few date their trouble from some single intellectual, physical, or emotional strain. In one case, complicated by marked evidences of cerebro-spinal exhaustion, the patient, a lady, had during an illness of her husband, being deserted by her servants, and the water-supply having been cut off, carried all the water required for the invalid and domestic as well as sanitary purposes up three flights of stairs for two unusually hot days in July. In two others, strikingly similar in many details of their cases, both being cornet-players, both attributing their illness to an extra call upon their instrument, it was brought on in the older patient within a few hours after playing on a hot day at the State Camp at Peekskill, and in the second at Narragansett Pier as he left the sultry concert-room and became exposed to a draught. In both these cases, as in a large number since examined, some stomach trouble could be positively determined to have antedated these symptoms. I mention this because it is only in such cases that I have found the nausea or vomiting which some writers regard as an occasional occurrence of, and due to, the lighter form of cerebral hyperæmia.
There are no ophthalmoscopic evidences of cerebral hyperæmia of this form. I have never found the optic disc presenting variations in tint beyond those found within normal limits, except in a case of saturnine encephalopathy with predominant signs of cerebral congestion. I believe that the statement of Hammond8 as to the existence of choked disc in cerebral hyperæmia is generally regarded as due to the interpretation of organic diseases as congestive states. It is not confirmed by authorities.