Sleep and Its Derangements

hich has been decomposed by mental and nervous action may be replaced by new material. There are other exciting causes than this, however, for sleep is not always induced by

r distinction between the exciting and the immediate cause. Th

urce; others again find the cause in the cessation of the motion of the cerebral fibers, or rather in a partial motion in these fibers. Here I stop, for I could not, even if I wished, mention all the theories which have prevailed relative to this subject. I wi

fluence of fatigue, the countenance becomes pale; through the actions of certain emotions, blushing takes place. When we are anxious or suffering or engaged in intense thought, the perspiration comes out in big drops on our brows; danger makes some men tremble, grief causes tears to flow. Many other examples will suggest themselves to the reader. It i

ed so long, and that even now, after the subject has been so well elucidated by exact observation, it should be the generally received opinion that during sleep the cerebral tissues are in a state approaching congestion. Thus Dr. Marshall Hall,[6]

se of sleep in order of importance is the pressure ex

t a "degree of pressure is essent

the cerebral mass, and its consequent congestion in the larger

work on Epilepsy, Dr

exuses become turgid or not, we are unable to affirm otherwise than hypothetically; the evidence is more in favor of cerebral congestion than of t

a of the smaller blood-vessels of the whole body. He does not appear to ha

ecessity for sleep is experienced, there i

eep, asserting that: "It is caused by fatigue, because one of the natural consequences of continued action is a slight conge

hat sleep is due to a determ

ring forward any further citations on this point, except the following, from a curious old black-letter book now before

: Sleepe is the rest of the pores animall, proceeding of some profitable humour moistening the braine. For here is shewed by what means sleepe is caused; that is, by vapours and fumes rising from the stomache to the head, where through coldness of the braine they being congealed, doe stop the conduites and wa

s, doubtless originated in the fact that a comatose condition may be thus induced. This fact has long been known.

ita, ut arteri? ips? choroidis ea immerg

ing due to the pressure of distended blood-vessels upon t

on. It is true, we may often arrive at a correct idea of a physiological process from determining the causes and phenomena of its pathological variations, but such a course is always liable to lead to great errors, and should be conducted with every possible precaution. In the matter under consideration it is especially of doubtful propriety, for the reason stated, that coma is not to be regarded as a modification of sleep, but as a distinct morbid conditio

ry certain that the distinction is not always made by physicians; yet the causes of the two

occurs in the healthy individual,

from sleep, while it is often imp

ay be active, in stupo

through its substance cause stupor, but do not induce sleep. For the production of the latter con

mount of blood in the brain, and induces sleep. A very large dose sometimes diminishes the power of the whole nervous system, lessens the activity of the respiratory function, and hence allows blood which has not been properly subjected to the influence of the oxygen of the atmosphere to circulate through the vessels of the brain. There is

e. The dura mater was also removed, and the brain exposed. After the effects of the chloroform had passed off-some three hours subsequent to the operation-I administered

egained its ordinary appearance. In number two the active congestion passed off in less than half an hour, and was succeeded by a condition of very decided shrinking, the surface of the brain having fallen below the surface of the skull, and become pale. As these changes supervened, the animal gradually sank into a sound sleep, from which it could easily be awakened. In number three the surface of the brain became dark, almost black, from the circulation of blood containing a superabundance of car

mbers two and three differed only in degree. That this

nd, inserting the nozzle of a bellows, began the process of artificial respiration. In both dogs the congestion of the blood-vessels of the brain disappeared. The brain became collapsed, and the animals fell into a sound sleep, from which

ed upon the subject, I proceed

lightly congested, then collapsed, and sleep ensued. The sleep was sound, but the animal was easily awakened by tickling its ear. After I had continued the process for an hour and a quarter, I removed

ed, and died one hour and a quar

shown that a small dose of opium excites the mind, because it increases the amount of blood in the brain; that a moderate dose causes sleep, because it lessens the amount of blo

rom that which exists during sleep. In the one case its vessels are loaded with da

ate cause of healthy sleep. Its exciting cause is, as we have seen, the necessity for repair. The condition of the brain which is favorable to sleep may also be induced by various other causes, such as heat, cold, narcotics, an?sthetics, int

as not been received with favor by any considerable number of physiologists. Before, therefore, detailing my own experience, I propose to adduce a few of the most striking pr

integument. While the young man was awake this chasm was quite superficial, but as soon as sleep ensued it became very deep. The change was due to the fact that during sleep the brain was in a collapsed condition. From a careful observation

ep is due to "a diminished s

membranes lay bare. When she was in deep sleep the brain remained motionless beneath the crest of the cranial bones; whe

he mode of operation of narcotic medicines, he conceived the idea of trying the effect of compressing the carotid arteries on the functions of the brain. The first experiment was performed on himself, by a friend, with the effect of causing immediate and deep sleep. The attempt

are at least important as physiological facts, and as throwing light on the causes of slee

he opportunity was afforded him of examining the condition of the cerebral circulation while the patient was under the influence of

operations until they were quieted by a repetition of the remedy. Then the pulsations would diminish, the cerebral surface recede within the opening of the skull, as if by collapse; the appearance of the organ becoming pale and shrunken with a cessation of the bleeding. In fact, we were convinced that diminis

tion; nor does it appear that he employed this agent unmixed with ether, in the case which he has recorded so well. He has, probably, based his remarks on this point upon the phenomena observed when the

same direction, and which will be hereafter detailed, were of prior date, I cheerfully yield all the honor which may attach to the determination of the question under consideration to this

The longer the administration of the chloroform was continued, the greater was the congestion. As the effects of this agent passed off, the animal sank into a natural sleep, and then the condition of the brain was very materially changed. Its surface became pale and sank down below the level of the bone; the veins ceased to be distended, and many which had been full of dark blood could no longer be distinguished. When the animal was roused, the surface

in the skull, and securely cemented to the edges with Canada balsam. The phenomena observed did not d

f the brain, attended with coma. This last condition he very properly separates from sleep, which is never caused by pressure from the veins. He likens

, Durham deduces the

for during sleep the veins are not distended; and when they are, symptom

ondition, and the blood in the encephalic vessels is not onl

n of the brain tissue; and, on the other hand, the condition which prevails during waking is associated with mental activity, bec

he brain during sleep is distributed

the body, tends to induce and favor sleep. Such circumstances may act primarily through the nervous or through the vascular system. Among those which act through the nervous system, may be instanced the presence or absence of im

its activity, is suggested by the recognized analogical fact that the products of ch

ep, gives his adhesion on principles of analogy to that which holds to a diminished afflux of blood. Taking

. And that if the period during which the gland reconstitutes its immediate principles corresponds to a period of reduced activity of circulatory phenomena-to a state of relative an?mia-and that when it functionates it is awakened to a state in which its capillaries are turgid with blood, it is very admissible that th

rvations relative to the immediate cause of sleep, which up to the present time have

pper, was subject to severe and frequent epileptic fits, during which I often attended him. In the course of my treatment, I soon became acquainted with the fact that, at the beginning of the comatose condition which succeeded the fits, there was invariably an elevation of that portion of the scalp covering the deficiency in the cranium. As the stupor passed away, and sleep from

n young infants the portion of scalp covering the anterior fontanell

ith the view of ascertaining the condition of the cerebral circu

r, evidently conveyed dark blood, and the whole exposed surface of the brain was of a purple color. As the an?sthetic influence passed off, the circulation of the blood in the brain became more active. The purple hue faded away, and numerous small vessels filled with red blood became visible; at the same time the volume of the brain increased, and when the animal became fully aroused, the organ protruded through the opening in the skull to such an extent that, at the most prominent part, its surface

e, and had a few minutes previously eaten a little meat and drank a small quantity of water. The brain protruded through the opening in the skull, and its surface was of a pink hue, with numerous

zation was continued, the color of the surface darkened to a deep purple, and it ceased to protrude through the opening. Finally, when a state of complete an?st

on of the brain. Had this condition existed, it would have been difficult to account for the diminution in bulk, which certainly took place. There was evidently less blood in the cerebral tissue than there

m upon the brain, when introduced into the system by inhalation. Suppuration had not yet taken place, and the parts were in good condition. The opening in the skull was completely filled by the br

below the level of the chasm in the skull. On the contrary, its protrusion was greater than before the commencement of the experiment.

its, with like results. Within a short period I have in part gone over the ground

erally ensue, a state of insensibility resembling natural sleep is always the first result. Lately, I have had, through the kindness of my friend, Dr. Van Buren, the opportunity of examining a case which affords strong confirmation of the correctness of the preceding views. It was that of a lady in whom both common carotids were tied for a cirsoid aneurism, involving a great portion of the right side of

cal and natural sleep is the necessity which exists that the loss of substance which the brain has undergone, during its state of greatest activity, should be restore

There is no exception to this law, and hence we are frequently able to produce this condition at will. Several of t

in giving rise to sleep. During the prevalence of high temperatures the blood flows in increased proportion to the surface of the body and to the extremities, and consequently the quantity in the brain is diminished. Sleep accordingly results unless the irritation induced

by putting the arm or leg into hot water. The swelling of the blood-vessels is then very distinctly seen. It

This it does by reason of the determination of blood to the surface of the body which moderate cold induces in vigorous persons. T

his experience in Northern Europe that the stupor produced by severe cold would terminate in death unless resisted, urged his companions to keep in motion when they began to feel drowsy. "Whoever sits down will sleep," said he, "and whoever sleeps will rise no more." Yet he was the first to feel this irresistible desire for repose, and entreated his companions to allow him to lie down. He was roused from his stupor with great difficulty and carried to a fire, when he revived. Two black men of the party, whose organizations were not so robust as those of the whites, perished. Dr. Whiting[25] relates the case of Dr. Edward Daniel Clark, the celebrated traveler, who on

y have succumbed. As it was, I reached a rancho in time to be relieved, though several minutes elapsed before I was able to speak. The sensations experienced were rather agreeable than otherwise. There was a great desire to rest and to yield to the languor which was present, and there was a feeling of recklessness which rendered me perfectly indifferent to the consequ

ns of our senses requires that the circulation of blood in the brain shall be active. When we isolate ourselves from external things, and restrain our thoughts, we lessen the amount of blood in the brain, and sleep results. It is not, however, always easy for us to do this. The nervous system is excited, ideas follow each other in rapid succession, and we lie awake hour after hour vainly trying to forget that we exist. The more the will is brought to bear upon the subject the more rebellious is the brain, and the more it will not be forced by such means into a state o

evices, have been suggested, and have proved more or less effectual. Boerhaave[26] states that he procured sleep by placing a brass pan in such a position that the patient heard the sound of water which was made to fall into it, drop by drop. In general terms, monotony predispo

horse in a mill, the opera, Mr. Humdrum's conversations, Mr. Proser's poems, Mr. Laxative's speeches, Mr. Lengthy's sermons. I tried the device of my own childhood, and fancied that the bed rushed with me round and round. At length Morpheus reminded me of Dr. Torpedo's Divinity Lectures, where the voice, the manner, the matter, even the very atmosphere and the streamy candlelight were all alike somnifi

as doubtless replete with blood, the tension is at last removed, the blood flows out of the brain, the face becomes pale, and sleep ensues. It is thus, as Macnish[29] says, that "t

paying particular attention to the noises in the street, so as to weary the sense of hearing. It is well known that sleep may be induced by gentle frictions of various parts of the body, and doubtless th

ors and flavors, accomplish this end. In these respects, however, habit exercises great influence, and thus individuals, for instance, who are accustomed to continual loud noises, cannot sleep when the sound is inte

ld; and she sinks into a quiet slumber, which lasts fifteen or twenty minutes. In this lady the amount of blood is not sufficient for the due performance of all the operations of the economy. The digestive organs imperatively require an increased quantity, and the flow takes place from the brain; it being the

It would be exceedingly difficult to explain the fact upon any other hypothesis. I have seen many instances of somnolency due to this cause. It acts not only by dire

nished amount of blood or a depraved quality of this fluid being supplied, and hence, in old age, or under the influence of a deficient quanti

le of causing sleep, not coming within the range of ordinary