The other class of cases who are likely to start at night in their sleep are those who do not get out into the air enough during the day or who sleep in rooms insufficiently ventilated. At the beginning of the night the lack of ventilation makes the sleep light and easily disturbed. After a certain number of hours have been spent in a badly ventilated room the patient sinks into a rather deep sleep, which is likely to be dreamy, however, and then he is rather hard to waken, but wakes not feeling rested, but on the contrary often heavier and more tired than on retiring. In these cases an investigation of the amount of air the patient is allowing to enter his sleeping room or that his circumstances provide him with is extremely important. As for those who do not get out enough during the day, it is easy to understand that their sleep may be light. To them, as a rule, it will be a surprise to find how much depth is added to their sleep by an additional hour or two in the air. Commonly, people who do not get out much during the day are shivery and [{666}] suffer from cold, especially in the winter time, and so they are likely to keep their rooms rather tightly closed. In this case they have two reasons for a tendency to be wakeful, which is emphasized if there are noises near them or if there is anything that disturbs their sleep.
In young children, of course, it must not be forgotten that starting in sleep may be due to the twitching pains of a beginning tuberculous joint disease. At times the children are so young, or the symptoms so vague and the tenderness, if there is any, so deep, that the real significance of this may not be recognized. The most successful treatment for these starting pains in children that has thus far been found, forms a striking commentary on what we have just been saying with regard to fitful sleep when ventilation is insufficient or when the patient has not been out of doors enough during the day. The children from the New York hospitals who in recent years were taken down to Sea Breeze during the autumn and winter and made to live in wards, the windows of which were constantly open so that the temperature was often below fifty, so that doctors and nurses had to wrap themselves up warmly and sometimes cover their heads and their hands, had all been sufferers from these starting pains before this experience, but gradually they lessened in frequency until after a few months the crying of a child at night because of these pains was extremely rare. The lesson is evident, and abundance of air not only cures tuberculous conditions, but also makes the nervous system so much less irritable that starting pains do not so easily affect it.
Noise.—Slight noises often make it impossible for nervous people to sleep. This is much more a question of personal sensitiveness and anxious expectancy and over-irritability than anything else. One distinguished physician whom I knew was extremely sensitive to noise and would be awake for hours if wakened up early in the night by the slamming of a door or a call in the street or anything of the kind. He suffered from insomnia to a noteworthy degree and found to his surprise that he could sleep better on a train than anywhere else. After he had lost two or three nights of sleep he actually used to make arrangements to take a berth on an express train going out of his city, ride until the morning and then come back. He usually slept well amidst all the noise and jar of the train, though he would be quite sleepless at home as the result of even slight noises. I have known people suffering from insomnia who took a long ocean trip on a slow vessel and who slept well amidst all the noises of shipboard, but were light sleepers after landing, and felt that they missed the noise and bustle. Of course, in these cases the rocking movements sometimes predispose to sleep. It is not the custom now to rock infants to sleep and a very definite agreement seems to have been come to among pediatrists to forbid the practice as harmful. It is probable, however, that the instinct of the race in the matter was not at fault. Rocking seems to relax a certain tension of muscles that of itself prevents the brain anemia which is the physiological basis of sleep. It is extremely difficult for nervous people to relax themselves completely, and the rocking movements, by tending to help them in this matter, are excellent predisposing factors. A rocking chair or a hammock furnish abundant proof of this.
Noise in general, as regards its relation to sleep, is an extremely individual matter. Habit plays the largest role in the matter. We all know the [{667}] stories of men who have gone to great expense in order to build noise-proof rooms and yet have found afterwards that they did not sleep well. The rustle of the bedclothes as their thoraxes rose and fell in respiration was enough to disturb them when they allowed themselves to become over-sensitive about noise. We all know how impossible sleep becomes with a rustle of a mouse in the wastepaper basket, or the scratching of one on the wainscoting. On the other hand, anyone who has lived in a large city where past hundreds of thousands of homes the elevated trains thunder every few minutes all during the night, or the trolley goes rolling by within a few feet of the bed, knows, too, that a great many people become accustomed to noises so as to be utterly undisturbed by them, though at the beginning any such insensitiveness to noise seemed out of the question.
I remember having a patient who insisted that he could not sleep so near the elevated. At the end of a week he had lost so many nights of sleep that he was almost in despair. If he did get sound asleep he said he used to hear the thunder of the elevated train coming toward him in his dreams and he would begin to pull his feet up so as to get them out of the way of the train, yet always with the feeling that he could not get them quite far enough, until his knees were almost to his chin. Under the influence of a little bromides, two hours more of outdoor air than he had been accustomed to before, and some reassurance that noise need not disturb sleep at all if taken philosophically, he learned in the course of two weeks to sleep quite peacefully and now has lived for ten years where the elevated passes within ten feet of his window, which is wide open for seven months in the year and always at least slightly open, except in the most stormy weather. It is a question, then, of the individual much more than his surroundings. The problem is to predispose the mind to sleep and then the senses will not disturb it except under special circumstances.
As a matter of fact, noises usually disturb people very little at night. The most surprising things can happen between 12 and 3 o'clock and attract no attention. Burglars calmly blow up a safe in a hotel confident that if there is no one awake when the explosion occurs there will be no investigation, because even though people wake up at the noise, they will wait for its repetition in order to see what it means, will not get up to investigate, especially in cold weather, and usually promptly go to sleep again.
Lying Awake.—There are many people to whom lying awake carries with it a sense of discouragement and dread. They seem to forget that lying awake and occupation with pleasant thoughts may be made a very agreeable pastime by those who are not over-anxious to sleep and who let the pleasant thoughts that may be suggested by the environment or the noises that are heard flow through consciousness. Everyone knows how pleasant it is or may be to listen to the rain patter on the roof of a country house, or to hear the murmur of the ocean or of the wind through the trees when there is not too much anxiety about to-morrow and to-morrow's occupations and the necessity for sleep to be ready for them. Stewart Edward White, in his series of essays on "The Forest," has a chapter on Lying Awake at Night that can well be recommended to the attention of those who complain bitterly of an hour of sleeplessness. Of course, in his case the lying awake is in the midst of the forest with all the witchery of wind in the trees and the [{668}] unusual sounds of forest life, while ordinary lying awake is in the rather monotonous environment at home, but still there is much that can be said for his insistence that in peaceful brooding, faculties revive while soft velvet fingers are laid on the drowsy imagination and you feel that in their caressing vaster spaces of thought are opened up. The impatience that comes to so many almost at once if they fail to go to sleep promptly only serves to keep them awake just that much more surely.
Very often, as suggested by Mr. White, this wakefulness occurs just when a good night's rest is surely expected. There is sometimes even a preliminary period of drowsiness. Then some little noise that ordinarily would not be noticed at all floats into the consciousness with a vigor that indicates that one sense is thoroughly awake. The very surprise of it wakes up the other senses with a start and then comes the thought that there is to be no sleep for some time. If this is resented, the period of wakefulness will be all the longer. If, when it has proved to be inevitable, one sits up quietly, reads a book for a time, plays a quiet game of solitaire, it may be on a board kept beside the bed for such purposes, or in some quiet way succeeds in bothering away the thought of insomnia, then almost surely sleep will come after a time, quietly and restfully, and the lost period will not prove harmful. If nature does not want to sleep she must not be forced into it, but gently led and after a time the wakefulness will disappear.
Night Terrors.—One of the troubles of sleep that is more often called to the attention of the physician than almost any other, is the so-called "night terrors" of children. Little ones wake with a scream, sit up in bed, evidently terrified, usually trembling, and ready to seek refuge from something that has seriously disturbed them. Under Dreams we have called attention to the fact that usually these terrors are due to a dream. Sometimes the dreams are the ordinary experience of supposed falling in sleep, from which the patients wake very much startled, or they are repetitions of exciting scenes through which they have passed, or of stories that they have heard, or, above all, plays that they have seen. Ghost stories, for instance, told shortly before they go to bed will often disturb children. Fairy stories and the ordinary myths of childhood, usually with a happy ending and without any serious terrors in them, are not so likely to disturb them. Melodramatic theatrical performances to which children lend themselves and their attention with great concentration of mind, have nearly as much effect on them as if they passed through the actual scenes. Every physician knows how much a fright is likely to disturb a child and cause it to wake many a night afterwards in a state of terror.
Respiratory Interference.—It is particularly important to remember that any interference with breathing will almost surely wake the child in a seriously startled condition. Adults are often affected by this same sort of dream, due very often to some pathological condition in the throat around which a series of dream ideas collect with somewhat poignant results. I have known a man suffering from elongated uvula wake up thinking that he was suffocating because, as he thought, he had nearly swallowed his tongue, or at least had been trying to do so. The sensation was so startling that it brought him to his feet at once. I have known a patient traveling a long five-days' railroad journey and suffering severely from train catarrh, come to the [{669}] persuasion that he might suffocate during sleep because his nose was completely stopped up and he had not the habit of sleeping with his mouth open. As a result his sleep was as much disturbed by his mind as his breathing. If these affect adults so strongly, it is easy to understand why children should be so frightened by them. Children who are mouth-breathers from adenoids or nasal obstruction, and still more those whose nasal breathing apparatus is not completely stopped up, but who are frequent intermittent mouth-breathers, are especially likely to be troubled in this way. The neurosis known as nervous croup, due to a spasm of the vocal cords, occurs oftenest in this class of children and is an associated phenomenon to that of night terrors.