The wonderful saints who starved themselves or lived on sacramental bread are almost a multitude. Saint Joseph, Saint Catherine of Sienna,Saint Rose of Lima, Saint Collete, Saint Peter of Alcantara are of the number. In modern and even in recent times not a few of these cases have become widely known. Margaret Weiss, about whom a book was written in 1542, is said to have done without food and drink for three years. She suffered from pains and contractures. She passed neither urine nor feces; at least, such are the accounts which have come down to us.
Sarah Jacob, the Welsh fasting girl, has shared with Louise Lateau popular and medical notoriety. When about ten years old she suffered from various hysterical and hystero-epileptic symptoms. The quantity of food she took gradually dwindled; on October 10, 1867, it was said that she ceased to take any food whatever, and so continued till the day of her death, more than two years later. She had many visitors, pilgrims from far and near, who often left money or gifts. The vicar of her neighborhood came to believe in her, and an investigation was suggested. At one investigation, not very rigidly conducted, nothing was discovered. After a time she was visited by Fowler of London, who decided that the case was one of hysteria with simulation, probably associated with the power or habit of long fasting. Trained nurses were sent from Guy's Hospital to conduct the second watching. Under the watching the girl died, starved to death. The father was afterward condemned to imprisonment and hard labor for twelve months, the mother for six months. In Brooklyn a few years since one Molly Fancher, a similar case, attracted much attention, and was written about and commented upon by the press.
BYH. C. WOOD, M.D.
BYH. C. WOOD, M.D.
INTRODUCTION.—The term neurasthenia, signifying nervous weakness, and not rarely paraphrased by nervous exhaustion, indicates by its very derivation that it denotes not a distinct disease, but a condition of the body. The relations of the nervous system to the functions of organic and animal life are so intimate that almost all forms of exhaustion might well be discussed under the present heading. A further difficulty in attempting to decide the exact limitations of this article is to be found in the fact that hysteria, insanity, chorea, and various other nervous diseases are very closely connected with nervous exhaustion. Indeed, many of the cases which are considered by authorities as instances of neurasthenia would be more appropriately classed with one or other of the especial diseases. Thus, the nervous fears discussed in such detail by George M. Beard in his work upon neurasthenia plainly belong with the monomaniacal insanities, and, although they usually are associated with nervous depression, may coexist with great physical and mental power.
Further, very many chronic diseases produce neurasthenia. It has not been many years since general debility was a common inscription upon records of diagnosis. In very many cases the general debility afflicted the diagnostic powers or zeal of the physician rather than the body of the patient, and it is to be feared that neurasthenia not rarely at present replaces it. Malarial poisoning, chronic Bright's disease, chronic diarrhœa, lithæmia, and various other affections may be readily overlooked, and patient and physician satisfied with the diagnosis of neurasthenia; indeed, in my own experience in a very considerable proportion of the cases which had been diagnosed as nervous exhaustion the patient was really suffering from definite disease.
The folly of attempting to make neurasthenia a distinct affection is strongly brought out whenever it is attempted to give sharp diagnostic differences between it and other diseases. As examples may be noted the flat contradictions which exist in the different diagnostic tables given in the elaborate work of the late George M. Beard.
It is necessary, therefore, in the outset, to recognize that neurasthenia is a bodily condition which is very frequently associated with various chronic disorders, or not rarely coexists with perverted functional activity of the nervous centres, which perverted nerve-functions may, however, exist independently of any perceptible neurasthenia, and are not simply the outcomes of the neurasthenia. Under these circumstances an apologyfor devoting an article in this work to the consideration of neurasthenia may seem necessary to readers. The justification of the present discussion is to be found in the facts that neurasthenia often exists without the presence of definite disease, and that still more frequently it is a bodily condition which dominates in its therapeutic importance the manifestations of perverted functions, so that the patient is to be treated for it rather than for the disease with which it is associated.
ETIOLOGY.—There are various chronic diseases which may lead directly to nervous exhaustion. Neurasthenia may, moreover, be the result of disease which is long past; neglected diarrhœas, bleeding piles, and other affections with exhausting discharges, when they have been cured, may leave behind them conditions whose source and nature it is most important to recognize.
Overwork, excessive mental emotion, need only to be alluded to as capable of producing a pure neurasthenia. As Samuel Jackson was accustomed to say, in his lectures at the University of Pennsylvania thirty years ago, “Whenever the expenditure of nerve-force is greater than the daily income, physical bankruptcy sooner or later results.” It is to be remembered that the nerve-capital of persons differs almost as widely as does their moneyed capital. There are numerous families many of whose members are neurasthenics from birth—i.e.who are born with less power of creating nervous energy than is necessary to meet the requirements of the ordinary duties of life. There is every grade of natural endowment between the most feeble person, scarcely able to produce more nervous energy than is necessary for breathing, eating, and drinking, and the organism that is capable of enduring incessant toil. The development of neurasthenia is therefore not so much the result of a strain which is absolutely great as of a strain which is excessive in its relations to the organism which has to bear it.
SYMPTOMS.—The onset of neurasthenia is always gradual, although at times the condition appears to develop with great suddenness. Under these circumstances, however, the explosion has been preceded by a long train of more or less overlooked phenomena: thus, in a case that just now occurs to me a gentleman had long suffered from the premonitory symptoms of neurasthenia, to which he had paid but little attention until he was one day seized with violent vertigo, accompanied by such prostration of strength that he had to be taken home from the street in a carriage. The symptoms vary very much according to the portion of the nervous system which is especially affected, and also to some extent according to the etiology of the attack. Nervous exhaustion may in the beginning affect the whole of the nervous system, or it may be at first purely local and coexist with general nervous strength. Many cases of spermatorrhœa are instances of the local form of neurasthenia, the sexual centres being primarily affected; but as in these cases, sooner or later, the whole of the nervous system becomes implicated, so in other forms of the disorder the exhaustion, at first local, finally, if neglected, implicates the whole organism. There are not rarely cases of brain exhaustion in which the symptoms are at first purely local. Almost always the cause of a local neurasthenia is excessive use of the part; thus, cerebral asthenia is usually the result of mental overwork, sexual asthenia of sexual excesses, etc. When to the intellectual fatigue is added the depressing effectsof excessive anxiety or allied emotions, the symptoms usually from the first are more general. The exhaustion may affect chiefly a single function of the brain. As an instance may be cited the case of a postal clerk now under my care, who has been accustomed to distribute five to eight thousand letters every day from a general mass into three hundred pigeon-holes representing as many post-office districts scattered over a large territory. As soon as the address is read there must be an instantaneous automatic recognition of the district to which the letter goes. It is at this place where, in the case now under consideration, the symptoms manifest themselves. Reading the address fails to produce immediate recognition of the locality to which the letter is to be assigned. Asked in what district such a post-office is, the clerk answers instantly, but seeing the address himself he hesitates, and sometimes balks so that he can distribute only about one-third as many letters as when in health. As in most cases of local nerve exhaustion, in this patient some evidences of general implication exist, there being decided disturbance of the sexual organs.
Another form of local neurasthenia which is frequently associated with brain exhaustion is that of writer's cramp. I have repeatedly seen it come on as the herald of a general breakdown; but under such circumstances the symptoms have usually not been those of typical writer's cramp: there have usually been not so much marked spasms as loss of power and distress in the arm on attempting to write.
In pure brain exhaustion loss of the disposition to work is usually the first symptom, the sufferer finding that it constantly requires a more and more painful effort of the will to perform the allotted task. The basis of this difficulty is largely loss of the power of fixing the attention, and this by and by is accompanied with weakness of the memory. Disturbances of sleep are frequent. Various abnormal sensations in the head are complained of. In most cases there is not absolute headache, but a feeling of weight or fulness or an indescribable distress, usually aggravated by mental effort.
It is true that in some cases of very dangerous brain-tire cerebration is performed with extraordinary vigor and ease; the power of work is for the time markedly increased, and even the quality of the product may be raised; the patient may even glory in a wild intellectual exaltation, a sense of mental power, with an almost uncontrollable brain activity. It is probable, however, that these cases are not instances of pure neurasthenia, but that there is an active congestion of the cortical gray matter. It is certain that they are very prone to end in serious organic brain trouble. In some cases of cerebral asthenia there are disturbances of the special senses, tinnitus aurium, flashes of light, and even the seeing of visions. Under these circumstances it is again probable that active congestion of the affected centres exists.
Severe cerebral neurasthenia may be associated with good spirits, but usually there is marked depression, and this perversion of function may finally go on to decided melancholy. The will-power, as all other functional activities of the brain, is prone to be weakened; morbid fears may finally develop themselves; and at last that which was at the beginning a simple brain exhaustion may end in hypochondriasis or insanity. In my own experience such ending is very rare unless there have been from thebeginning marked symptoms of hypochondriasis or melancholy; in other words, unless there be the inborn tendency to distinct mental disorders, cerebral neurasthenia rarely produces them, but in a person who inherits such tendency the brain exhaustion may become an exciting cause of insanity.
The symptoms of brain-tire may be very largely existing in the individual who still has muscular strength and is capable of enduring much physical labor; but in most cases, sooner or later, the more general symptoms of neurasthenia manifest themselves.
Amongst the earliest of these symptoms may be disorder of the special senses. For reasons which are not very evident it is the eye which is generally affected. Although existing deafness is often greatly intensified by the coming on of nervous exhaustion, I cannot remember ever to have seen severe deafness entirely neurasthenic. The nature of the optical trouble is to be recognized by the fact that vision is at first good, but fails when the eye is steadily used for a few minutes, although the organ is physically perfect. This weakness of the eye may long be the most troublesome manifestation of the disorder.
In some instances, before any loss of muscular strength is marked, vaso-motor weakness is prominent. Excessive blushing on the slightest provocation, great flushing of the face after the use of alcohol or other stomachic irritant, waves of heat passing over the body, occasional pallors provoked by exertion or apparently causeless, and cold extremities, are some of the phenomena which mark the lack of power in the centres that control the blood-vessels. Closely allied to these disturbances are those of secretion. In my own experience the most marked of these is a tendency to night-sweats, but in some cases the hands, and more rarely the palms of the feet, are perpetually bathed in perspiration, which may be greatly increased by any emotional disturbance. In some patients there is a very great tendency to serous diarrhœa, which in its turn of course increases the nervous exhaustion.
In many neurasthenics the heart as well as the vaso-motor system sympathizes in the weakness, so that palpitation and shortness of breath not rarely follow even slight exertion: a more characteristic symptom is, however, a peculiar dropping of the heart's beat, which is to the patient at first very alarming, but which is entirely independent of any lesion of the heart itself. The true nature of this cardiac intermission is to be recognized by the existence of other symptoms of neurasthenia, and by the fact that it is not constant, and that it is very prone to follow eating or gastric irritation of any kind. Not rarely it is relieved at once by the belching up of wind. When tobacco has been very freely used the cardiac symptoms of neurasthenia usually come on very early, and may be very severe. Under these circumstances it is really a mixture of neurasthenia and tobacco-poisoning with which we have to deal.
The muscular strength may finally fail almost altogether. It is almost characteristic that the patient should be capable of much exertion under excitement, and should suffer from the results of such exercise not immediately, but after one or two days.
In many cases of neurasthenia atonic dyspepsia exists, but it is always a question for careful consideration how far a nervous condition is due to the dyspepsia and how far the dyspepsia is caused by the nervous condition.
Disturbances of sensation are common in neurasthenia, these disturbances taking the form in many instances of itchings or formication or other similar minor ills. Neuralgia is often severe and its attacks frequent, but I am convinced that something more than simple nervous exhaustion is responsible for its production. I believe that there is a neuralgic diathesis or temperament which is often associated with neurasthenia, but may exist without it, and which probably has, at least on many occasions, relations to a gouty ancestry. When such temperament exists the neuralgic attacks are greatly aggravated by the coming on of neurasthenia. Hyperæsthesia and anæsthesia mark the line where simple neurasthenia passes into hysteria. The same also is true of the peculiar tenderness over the spinal processes of the vertebræ, which is especially frequent in women, and is the chief symptom of the so-called spinal irritation or spinal anæmia—an affection which I believe to be a form of neurasthenia allied to hysteria.
In neurasthenia disturbances of the sexual organs are very common; in women great pain on menstruation, ovarian irritation, the so-called irritable uterus of Hodge, are closely connected with a general nerve weakness. In not a small proportion of the cases of uterine disorders which are often locally treated I believe the local disease is largely the expression of the general condition. It is well known that masturbation and sexual excess in the male may produce an exhaustion of the nerve-centres especially implicated and also a general nervous exhaustion. This is the common history of spermatorrhœa. It is no less true that a general neurasthenia may produce a local weakness of the sexual centres, with symptoms at least resembling those of spermatorrhœa—namely, great irritability of the sexual organs, with a practical impotence due to immediate seminal discharge whenever coition is attempted. I have certainly seen this condition result from excessive intellectual labor when there has been no sexual excess, and at a time when the muscular strength was still good. Such cases may, perhaps, be distinguished by the fact that unprovoked emissions are not nearly so apt to occur as in true spermatorrhœa.
TREATMENT.—The natural cure for neurasthenia is rest, and my own experience coincides with the logical inferences to be drawn from an etiological consideration of the subject—namely, that medicines are only of limited value, and unless very judiciously administered may readily do harm. Disturbing symptoms should be met and tonics may be used, especially strychnine and arsenic, but all drugs hold a secondary position in the relief of a pure neurasthenia. In using remedies the practitioner must be guided by general principles, and I shall not engage in any detailed consideration of the subject, but employ the space at my disposal with a discussion of rest.
When nervous exhaustion has been produced by over-use of any one organ or system of organs, absolute rest of such organ is a primary necessity. Thus, when there has been sexual excess absolute avoidance of use of the sexual organs must be enjoined, and in married Americans it is often essential to insist upon man and wife occupying distinct apartments1or even to separate them by a journey.
1Because in this country man and wife habitually occupy one bed. Sexual continence under these circumstances can only be obtained at the cost of a suppressed sexual excitement worse than moderate indulgence.
Again, in cases of brain-tire it is the brain which should be rested. To rest an overwearied, excited brain is often not an easy task. In attempting it the effort should be to obtain the following results: 1st. The removal of all cares, anxieties, and all brain-work, especially those of such character as have been connected with the breakdown. 2d. The maintenance of the interest of the patient, so that the past shall for the time being be forgotten, and the present not overweighted with irksomeness. 3d. Invigoration of the physical health of the whole body, and especially of the nervous system. In order to obtain the first of these measures of relief, isolation of some sort is essential; for the second mental occupation is usually required; for the third fresh air, exercise, or some substitute is to be superadded to abundant food and rest.
The proper method of meeting these indications varies greatly, not only with the varying physical conditions and idiosyncrasies of patients, but also with their diverse domestic and pecuniary relations. To give detailed directions for every case is impossible, and I shall therefore limit myself first to simple cases of brain-tire in which the muscular strength is preserved; second, to cases of profound general neurasthenia.
In brain-tire travel is usually recommended, and travel affords, when properly directed, separation from old cares and thoughts, a maintenance of interest by a succession of novel sights and experiences, and the physical stimulation of fresh air and exercise. In bad cases general travel is too stimulating, and ocean-voyaging is much better. Upon the ocean is to be found nothing provocative of thought, only complete isolation, fresh air, enjoyment if the patient be fond of the sea, and a sufficient exercise, especially if the sufferer in any large measure works in the management of a sailing vessel. Hence prolonged yachting affords in many cases our best method of relief. The isolation of the North Woods or any other large primeval wilderness may be complete, the air most fresh, and the exercise to be had also boundless, but at the same time controllable; the man may, according to his will, lie in his tent and be fed by his guide or be unceasingly active. If the life be agreeable to the sufferer, and sufficient care against undue exposure be exercised, the camp-cure is most efficient. European travel may serve almost equally well, provided hard journeying, sight-seeing, and even cities are avoided. The quiet of Switzerland or the Tyrol may bring restoration when the bustle of London and Paris might complete the ruin.
To those who cannot travel extensively the seashore, mountains, or lowlands of the United States are open, and the best way of meeting the indications in any individual case must be determined by a joint consultation between doctor and patient.
There are cases of neurasthenia in which the slightest exercise does harm, and in which even the unconscious effort of company and conversation is an injury. Between the extremely exhausted and the slightly brain-tired is every grade of case, and much tact is often required in properly regulating the treatment of the individual case.
It is only the most severe forms of neurasthenia which require the use of the so-called rest-cure. For such, however, it is a very valuable method of treatment. It finds its most brilliant application undoubtedly in neurasthenic women, but, more or less modified according to circumstances, it has a wide scope in the treatment of both sexes. When the bodily condition isdeveloped by prolonged lactation, nursing, grief, overwork, acute disease, or other temporary or removable cause, the rest-cure may give permanent relief; and even when the cause of the neurasthenia is largely inherited feebleness of constitution, it is a valuable though a more temporary remedy. This method of treatment has long been used in this city, and was especially dwelt upon in its general scope by Samuel Jackson, but in its modern form it has become a very valuable method of treatment, essentially different in its details from what it was formerly, and far more potent in its influence. To S. Weir Mitchell is due a great debt of gratitude, for by him has this improvement been made.
The principles of the rest-cure are absolute rest, forced feeding, and passive exercise. Absolute rest is often prescribed by the physician without being sufficiently definite and insisted upon. When it is desired to apply it most strictly, it should be clearly explained that the patient is not to be allowed to get out of bed even to pass urine or feces, not to feed himself or herself, or perform any act of the toilet whatsoever. The rest also must be for the mind as well as for the body, and it is essential that the patient be isolated. Separation from friends should especially be insisted upon in the case of women. It may be possible to separate a man in his own house completely from his daily cares, but a woman in her own house is in the midst of her daily business, and is like a man placed in the corner of his factory. In obstinately severe cases of neurasthenia complete and absolute isolation is a sine quâ non, and especially when there is a decidedly hysterical element is it necessary to separate the patient entirely from her friends. Under these circumstances there must be a well-trained nurse who is personally agreeable to the patient. The confinement would be very irksome to any except the most exhausted patient were it not for the daily visit of those engaged in the treatment; to further provide against ennui the nurse should be a good reader, so that under the definite instructions of the physician she can occupy a certain portion of the time in reading to the patient.
In order to maintain the functions of the skin the patient should be well sponged in bed every morning after breakfast. A strong solution of salt, or, better, sea-brine, is to be preferred to simple water, and frequently it may be followed by the use of alcohol. In very feeble cases the alcohol may be employed alone. I have seen very good effects from momentarily rubbing each portion of the skin with ice just after the bathing.
The question of feeding is one of great importance, and requires the utmost care and attention from the physician. The end to be attained is to feed the patient as much as can be digested, but not to overdo and derange the digestion. Food should be given at intervals of two or three hours, and must be both light and nutritious. It should, at least at first, largely consist of milk, except in those rare cases in which that fluid does really disagree, and not merely is thought to do so. The milk should be skimmed or given in the form of koumiss. Beef and other concentrated meat-essences are valuable as stimulants, and may be used, especially as the basis of soups. Various farinaceous articles of food may be added to them, or if an egg be broken into the concentrated bouillon or beef-essence just as it ceases boiling a nutritious, and to many persons palatable, dish is obtained. When constipation exists, oatmealporridge, Graham bread, fresh or dried fruits may be allowed if readily digested by the patient. In order to give an idea of the general plan of the dietary, the following schedule of the daily life is given. Such a schedule should always be put into the hands of the nurse, who should be required to follow it strictly. It must be altered from day to day, so as not to weary the patient with monotony. It is especially important to remember that the diet must be carefully studied for each patient, and be adapted to the individual requirements of the case. Success will in a great measure depend upon the practical skill and tact of the physician in this adaptation:
In many cases the patient at first can take very little food, and it is very frequently best to begin the treatment with an entirely liquid diet, giving milk every two hours, or using Liebig's raw-meat soup, with milk or plain farinaceous food, and only after a time gradually accustoming the patient to solid food. Not rarely a prolonged treatment by the so-called milk diet is of avail. The rest-cure is indeed largely based upon a careful regulation of the food; but a full discussion of the various dietaries to be used would require a treatise upon dietetics.
Passive exercise is to be obtained by the use of electricity and massage, the object being to get the effects of exercise upon the nutrition and circulation without the expenditure of the patient's nerve-force. By the use of electricity muscular contractions are secured which simulate those which are voluntary and more or less thoroughly replace them. By the general application of the current to the whole body we probably affect the tone of all of the minute blood-vessels, and certainly in this or some other way stimulate the general nutrition, and, as has been shown by S. Weir Mitchell, for the time being elevate the bodily temperature.
The faradic current is alone used. It is applied in two ways: first, to the individual muscles; second, to the whole body. The séances should be daily, the operator beginning at the hand or foot, and systematically faradizing each muscle of the extremities and trunk.
The slowly-interrupted current is generally preferable, but advantage is sometimes gained by varying the rapidity of the interruptions. The general rule is to select that current which produces most muscular contraction with the least pain. The poles should be applied successively to the motor points of the muscles, so as to contract each firmly and thoroughly. This process should occupy from thirty to forty minutes. The electrodes are then to be replaced by large sponges well dampened with salt water: one of these should be put at the nape of the neck and the other against the soles of the feet, and a rapidly-interrupted current, asstrong as the patient can bear, should be sent through the body for twenty minutes or half an hour. It is not necessary for the operator to remain during this time. In some cases the electrical programme may be varied so as to get a local stimulant action from the general current; thus, when digestion is enfeebled and the bowels costive for a portion of the time one of the sponges may be placed upon the epigastric region. In women when there is great abdominal and pelvic relaxation one pole may be placed high up in the vagina. I have seen old-standing prolapses cured in this way. Some electro-therapeutists claim great advantage from galvanization of the cervic sympathetic ganglia, but I do not myself believe that they ever succeeded in reaching these ganglia with the current.
Massage, like electricity, affects greatly the peripheral circulation, empties the juice-channels, and gives tone to the muscular system. It must be clearly distinguished from rubbing of the skin. It consists in manipulations of such of the muscles as are not too deep to be reached, and of the cellular tissue: in order to lessen as much as may be the skin friction by these manipulations, it is often well to anoint the surface with cocoanut or other bland oil. As sold in the drug-stores, cocoanut oil is very often rancid, and at any time it is well substituted by the cheaper cottonseed oil. In practising massage it is essential to remember that the natural course of the venous blood and the juices of the cellular tissue is toward the centre of the body; therefore, all general movements should be practised in this direction.
The manipulations are percussion, rolling, kneading, and spiral. They consist of movements made with the pulpy ends of the fingers and thumbs, and spiral movements with the whole hand so folded as to adapt its palm to the limb. In percussion the strokes should be from the wrist, and should be quick and short. It is probably not possible, even by long strong strokes, to affect deep muscles. In the rolling manipulation the effort is to roll the individual muscles beneath the pulps of the fingers. This manipulation may be varied by pinching the muscles, not the skin, and kneading. In each case it is intermittent pressure upon the muscles which is aimed at. The circular movements are to be in opposite directions with both hands simultaneously, the limb being grasped by one hand a little above the other, and a spiral sweep made up the limb, the ball of the thumb and the palm of the hand resting upon the patient, and the pulpy parts of the thumb and the fingers grasping the limb. It is especially such motions as these which affect the circulation of the flesh-juices.
The length of time the patient is to be kept in bed and treated in the manner described varies of course with the individual case, but usually less than four weeks is not sufficient, and rarely are more than six weeks required. In getting up, the patient should begin by sitting up one or two hours a day, increasing daily, but not too rapidly, the time of being out of bed and the amount of exertion made. The electrical treatment should be gradually intermitted: in many cases massage twice a week seems to be of service even after the patient is about. In the going back to ordinary daily life great care is to be exercised to proportion the amount of exertion to the newly-obtained strength, so as not to lose what has been gained. In cases of natural or of long-standing acquiredsevere neurasthenia the mode of life must be arranged to correspond with the small daily product of nervous energy.
In dismissing this subject I desire to caution against a routine employment of this so-called rest-cure, which might readily degenerate into a species of quackery; and, again, to call attention to the widespread value of the principles which underlie it, and the importance of the physician applying those principles with endless modifications of detail.
BYHENRY M. LYMAN, A.M., M.D.
BYHENRY M. LYMAN, A.M., M.D.
The regularly-recurring incidence of natural sleep forms one of the most important subjects of physiological investigation. Occurring ordinarily at stated intervals connected with the diurnal revolution of the earth, it may for a time be postponed by an effort of the will, but an imperious necessity for repose finally overcomes all opposition, and the most untoward circumstances cannot then prevent the access of unconsciousness. Thus produced, the relation of cause and effect between weariness and sleep becomes very apparent. The refreshing influence of such repose points clearly to the restorative character of the physical processes that continue despite the suspension of consciousness; it also renders evident the final cause of that periodical interruption of activity which the brain experiences in common with every other living structure.
Careful observation of the manner in which sleep invades the body indicates that its evolution is not associated with a simultaneous suspension of every mode of nervous function. The sense of sight is the first to yield. The eyelids close and the muscles that support the head give way. The body seeks a recumbent position; quiet and seclusion are instinctively sought. The purely intellectual faculties are not yet depressed, and the reflex energies of the spinal cord are exalted. Soon, however, the other senses fail; hearing persists the longest of all. Released from the control of external impressions, the internal senses preserve their functions after a strangely-disordered fashion, dependent upon the progressive suspension of activity in the various cerebral organs. First the power of volition ceases; then the logical association of ideas comes to an end. Presently the reasoning faculties disappear, and judgment is suspended. We thus become no longer capable of surprise or astonishment at the vagaries of memory and imagination, the only mental faculties that remain in action. To their unrestrained function we owe the presentation in consciousness of the disorderly picture which we call a dream. During the early stages of this somnolent state we often remark the fact of dreaming, and an effort at attention may produce a partial awakening; but usually the subsidence of cerebral function is progressive and rapid. The fire of imagination fades; the field of consciousness becomes less and less vividly illuminated; the entire nervous apparatus yields to the advancing tide; and, finally, the dominion of sleep is fully confirmed.
During the act of awaking the order of sequences is reversed. From the end of the first hour of repose the depth of sleep, at first rapidly, then more gradually, diminishes.1Dreams disturb its quiet, mental activity increases, the power of volition revives; once more the individual is awake.
1Kohlschütter,Messungen der Festigkeit des Schlafes, Dissert., Leipzig, 1862, andZeitschr. f. Rat. Med., 1863.
Sleep, then, is that condition of physiological repose in which the molecular movements of the brain are no longer fully and clearly projected upon the field of consciousness. This condition is normal, and must, consequently, be differentiated from all pathological states which produce its counterfeit by the more or less complete abolition of consciousness. This distinction becomes the more necessary because the presence of the common factor, unconsciousness, in the result has frequently led to the mistake of supposing a community of antecedents in the changes by which the passage from sensibility and consciousness to insensibility and unconsciousness is effected. It needs no argument to show that the insensibility of artificial anæsthesia is a very different thing from the unconscious condition which obtains during natural sleep. Between the stupor of intoxication and the healthful restoration of cerebral energy which accompanies genuine sleep there can be no rational comparison. It is therefore in the phenomena of syncope that the likeness of sleep has usually been sought. The well-known fact that a copious hemorrhage can speedily develop a condition of muscular relaxation, insensibility, and unconsciousness has led certain observers to the belief that natural sleep is, after all, only a species of physiological syncope. The antecedent conditions of syncope are so different from the prodromata of sleep that it is difficult to see how either state can be properly likened to the other. The bloodless condition of the brain which occasions syncope is always the result of pathological or accidental causes, and is not identical with the comparatively insignificant reduction of blood-pressure which may be observed in the brain of the healthful sleeper. It is, moreover, worthy of note that sleep is the normal condition of the unborn child, despite the fact that the growing brain receives a richer supply of oxygenated blood than the trunk and the lower limbs—a state of the circulation quite unlike that of syncope.
Fully impressed by the force of such considerations, certain physiologists2have reasoned from the analogies suggested by the results of muscular fatigue, and have imagined an hypothesis accounting for the occurrence of sleep by a supposed loading of the cerebral tissues with the acid products of their own disassimilation during wakeful activity. The acid reaction of the brain and of the nerves after exertion suggested the probability that an excessive presence of lactic acid and its sodic compounds might be the real cause of cerebral torpor and sleep. Could the hypothesis be proved, ordinary sleep would take its place in the anæsthetic category and sodic lactate should be the very best of hypnotic agents. Unfortunately for this doctrine, the administration of the lactates has yielded only the most contradictory and unsatisfactory results. It,moreover, furnishes no explanation of intra-uterine sleep nor of the invincible stupefaction produced by cold.
2Obersteiner, “Zur Theorie des Schlafes,”Zeitschr. f. Psych., xxix.; Preyer, “Ueber die Ursachen des Schlafes,”Vortrag. Stuttgart, bei Enke, 1877; andCentralbl. f. d. Med. Wiss., 1875, S. 577.
Far more comprehensive is the hypothesis of Pflüger.3According to this view, the cortical tissues of the brain are recruited by the assimilation of nutrient substances derived from the blood. By this process oxygen is stored up in chemical combination, forming explosive compounds whose precise composition is not fully understood. Under the influence of the various nervous stimulations that reach the brain these unstable compounds break up into simple forms. The motion thus liberated by these explosions is, in some way at present utterly unintelligible to us, projected into the field of consciousness where the mind dwells, and we are thus brought into conscious relation with the external world. That the capacity for thus signalling across the gulf which separates matter from mind is the result of a certain perfection and complexity of material structure is rendered probable by the utter failure of the infracortical organs of man to impress the conscious intelligence by any amount of independent activity. It is also indicated by the unconscious sleep of the rudimentary fœtal brain and by the brevity of the intervals of wakefulness which mark the life of the new-born babe. That this capacity is dependent upon the mobility of the atoms of the brain is shown by the speedy cessation of intelligence which follows great reduction of temperature, as in hibernation or during exposure to severe frost. That its exercise is largely dependent upon the activity of the senses is proved by the effects of interference with their function. A recent observation, recorded by Strümpell,4is very significant in this connection: A young man had lost all power of sensation excepting through the right eye and the left ear. A bandage over the eye and a plug in the ear arrested all communication between his brain and the external world. Thus imprisoned within himself, he gave utterance to an expression of surprise, and sought in vain, by clapping his hands, to arouse the sense of hearing. At the end of two or three minutes these efforts ceased; respiration and pulsation were deepened and retarded, and removal of the bandage exhibited the patient with his eyes closed in genuine sleep.
3“Theorie des Schlafes,”Arch. f. d. Ges. Physiol., x. 468.
4“Beobachtungen ueber ausgebreitete Anästhesien und deren Folgen,”Deutsch. Arch. f. klin. Med., xxii.
The dependence of the waking state upon the presence and functional activity of a sufficient quantity of a peculiarly unstable form of protoplasm in the brain is an hypothesis which presents no great difficulty of comprehension. But how may we explain the passage from the vivacity of that waking state into the inactivity of sleep? I have elsewhere5discussed the manner in which artificial sleep is produced by impregnation of the brain with anæsthetic substances, and the same general line of argument may be extended to cover the action of every stupefying agent with which the blood may become overcharged. Could the hypothesis of Obersteiner and Preyer be accepted, it would be an easy matter to explain the advent of sleep when it gradually supervenes; but we cannot thus explain the rapid and intentional passage from wide-awakefulness into the profoundest sleep, such as becomes a matter of habitual experience with sailors and with others who have formed the habit of going at onceto sleep at regularly-recurring periods of time. Certain writers have endeavored to account for this fact by imagining a special mechanism at the base of the brain (choroid plexuses of the fourth ventricle, etc.), by means of which the current of blood through the brain may be voluntarily diminished, with a consequent arrest of conscious activity. But, still adhering to the hypothesis of Pflüger, we shall find a clearer explanation of the facts by considering the phenomena connected with the succession of impressions upon the organs of sense. It has been ascertained6that such impressions must persist for a certain measurable length of time in order to excite conscious perception. A sound must be prolonged for at least 0.14″, a ray of light must agitate the retina for 0.188″–0.2″, ordinary contact with the surface of the body must continue during 0.13″–0.18″, in order to produce any knowledge of sound and light and common sensation. For the simplest act of perception 0.02″–0.04″ are necessary. It is therefore perfectly reasonable to suppose that when the explosive material of the brain has been sufficiently reduced in quantity and quality by prolonged cerebral effort, the impression of sense may no longer suffice to excite in the cortical substance vibrations of sufficient length, or following each other in sufficiently rapid succession, to sustain the conscious state. The cortex of the brain may then be likened to the surface of a body of water into which bubbles of soluble gas are introduced from below. When the bubbles are large and succeed each other rapidly, the surface is maintained in a state of continual effervescence. But if the size of the bubbles be diminished or if the solvent capacity of the liquid be increased, its surface will become almost, if not quite, perfectly tranquil. In some such way, without any great amount of error, may we picture forth the molecular changes that determine the advent of sleep.
5Artificial Anæsthesia and Anæsthetics, pp. 15-17.
6Carpenter'sPhysiology, 8th ed., p. 852.
Returning now to the subject of the rapid induction of sleep, we find that it usually occurs among people who lead an active life in the open air, like children and laborers, and are perhaps compelled to endure frequent interruptions of their rest. The sailor who is trained to sleep and to work in rapidly-successive periods of time—four hours on deck and four hours below—has virtually become transformed by this habit into a denizen of a planet where the days and the nights are each but four hours long. His functions become accommodated to this condition; his nervous organs store up in sleep a supply of protoplasm sufficient only for an active period of four or five hours, so that when his watch on deck is ended he is in a state as well qualified for sleep as that of a laborer on shore at the end of a day of twelve or fifteen hours. Moreover, the majority of those who manifest the ability thus to fall asleep are individuals whose waking life is almost entirely sustained by their external perceptions. So soon, therefore, as such excitants are shut out by closing the eyes and by securing shelter against the sounds and impressions of the air, comparatively little remains for the production of ordinary consciousness, and sleep readily supervenes, especially if the excitable matter of the brain has been already depleted by active exertion.
It is well known that a predisposition to sleep may be very quickly induced by extraordinary expenditures of force; witness the effect of the venereal act and the consequences of an epileptic fit. That analogouspredispositions may indeed be very rapidly developed by modifications of cerebral circulation is shown by the sudden reduction of cerebral excitability during the act of fainting. But this does not prove that cerebral anæmia should be elevated to the rank of the principal cause of natural sleep. In all such cases the nervous process is the primary factor and the direct cause of change in the circulation.7The character of these changes has been admirably illustrated by the observations of Mosso.8By the aid of the plethysmograph this experimenter was enabled to compare the state of the circulation in the human brain, laid bare by erosion of the cranial bones, with the movement of the blood in other portions of the body. The occurrence of sleep caused a diminution in the number of respirations and a fall of six or eight beats in the pulse. The volume of the brain and its temperature were at the same time slightly reduced through the diversion of a portion of the blood-current to other regions of the body. If during sleep a ray of light was allowed to fall upon the eyelids, or if any organ of sense was moderately excited without waking the patient, his respiration was at once accelerated, the heart began to beat more frequently, and the blood flowed more copiously into the brain. Similar incidents accompanied the act of dreaming. The renewal of complete consciousness was followed by an immediate increase in the activity of the intracranial circulation.
7W. T. Belfield, “Ueber depressorische Reflexe erzeugt durch Schleimhautreizung,”Du-Bois Reymond's Archiv, 1882, p. 298.
8Ueber den Kreislauf des Blutes im menschlichen Gehirn, Leipzig, 1881.
In all these variations it is worthy of note that the nervous impression was the primary event. The changes of blood-pressure and circulation were invariably secondary to the excitement of nerve-tissue. Sleep, therefore, is the cause, rather than the consequence, of the so-called cerebral anæmia which obtains in the substance of the brain during repose. This condition of anæmia is nothing more than the relatively lower state of circulation which may be discovered in every organ of the body during periods of inactivity. Every impression upon the sensory structures of the brain occasions a corresponding liberation of motion in those structures. The movement thus initiated arouses the vaso-dilator nerves of the cerebral vessels and excites the vaso-constrictor nerves of all other portions of the vascular apparatus. Hence the superior vascularity of the brain so long as the organs of sense are fresh and receptive; hence the diminishing vascularity of the brain as its tissues become exhausted and unexcitable; hence the unequal and variable vascularity of different departments of the brain as sleep becomes more or less profound. These modifications of the brain and of its circulation are well illustrated by the effects of a moderate degree of cold applied to the cutaneous nerves of the body, as not infrequently happens when the night air grows cool toward morning. Such moderate refrigeration of the skin excites its sensitive nerves, which transmit their irritation to the brain. The excitement of this organ causes dilatation of its vessels, with increased irritability of the cortex, vigorous projection into the field of consciousness, and the consequent occurrence of dreams denoting imperfect slumber or even complete awakening. The remedy consists in the application of gentle heat to the surface of the body. By this means the transmission of peripheral irritation is checked; the brain becomes tranquil; sleepsupervenes. A similar wakefulness is in like manner produced by unusual heat. The remedy here consists in the employment of measures calculated to reduce the temperature of the skin to the normal degree. Sometimes wakefulness is maintained by some less general irritant. The feet alone may be cold, either because of previous refrigeration or because of local hyperæmia occurring elsewhere in an anæmic subject. There, again, equalization of the circulation—that is, the removal of cerebro-spinal irritation—may be all-sufficient to procure sleep. Noteworthy also is the tranquillizing effect of foot-baths or of the wet sheet in many cases of cerebral excitement and wakefulness. In like manner, that form of sleeplessness which often follows intense mental activity may generally be obviated by a light supper just before going to bed. Activity of the stomach is thus substituted for activity of the brain, and the consequent diversion of blood is sufficient to reduce the production of excitable matter in the brain to a point that permits the occurrence of sleep. A morbid exaggeration of this process is sometimes witnessed in the soperose condition that accompanies digestion in patients whose blood has been reduced by hemorrhage or by disease. In such cases the nutrition of the brain proceeds at so slow and imperfect a rate that any considerable diversion of blood toward other organs produces a syncopal slumber which resembles normal sleep only by the fact of unconsciousness. If, however, food be taken in excessive quantity or of irritable quality, the consequent indigestion will produce nervous excitement, reaching perhaps to the brain, and preventing sleep.