Insomnia; and Other Disorders of Sleep

by Henry M. Lyman

The phenomena of ordinary somnambulism are manifested, like the dreams out of which they arise, during the period of sleep. But, while dreams most frequently occur during the later portion of the night, after the deepest sleep is past, somnambulism usually occurs in the earlier part of the night, during the deepest sleep. As a consequence of this fact, consciousness is seldom affected by the molecular play of the brain during the somnambulic excursion. The sleepwalker knows nothing, and remembers nothing of the incidents in which he has been an active agent; while the dreamer seems to be more nearly awake. His consciousness is partially aroused by the play of memory and of imagination, and he can remember the spectacle which constituted his dream. The phenomena of somnambulism necessitate the participation of a larger number of faculties than are needed for the production of a dream, but their activities are coördinated upon a plane, so to speak, lower than the platform upon which the elements of dreams are arranged. Consequently, though the elements of the somnambulic process may be far more numerous and various than the elements of a dream, they may be less capable of rising into the realm of consciousness. Such a process may differ from the phenomena of ordinary life only in the fact of unconsciousness; and, when concluded, it leaves no traces in the memory of the waking state. In other instances, on the contrary, so many nervous functions may be suppressed, and so great may be the intensity of the remaining cerebral processes, that the resulting phenomena scarcely differ from an ordinary dream in which consciousness is aroused, and the waking memory is durably impressed. Between these extremes lie opportunities for an indefinite number of combinations; consequently the forms and degrees of somnambulism present a very great variety of manifestation. Maury[74] reduces these to five principal forms: First, simple movement of the limbs in connection with that partial sleep of the intellectual faculties which produces ordinary dreams. Second, somniation, a state in which the patient unconsciously performs such actions as have become so far habitual that, though complicated in their character, they constitute genuine cerebral reflexes. Third, noctambulism, or sleep-walking, in which the action, though complicated in its character, and different from the ordinary waking occupations of the patient, appears to be the result of automatic processes, constituting a dream that is acted out in time and space. Fourth, somnambulism with exaltation of the faculties, producing delirium with conscious movements during the crisis. Fifth, somnambulic life, or double consciousness, in which, with the exception of certain special modifications of intelligence, the conduct of the patient during the paroxysm does not perceptibly differ from that of the waking state, so that the subject seems to experience two successive though disconnected personalities.

The exact relation between these different degrees of somnambulism has been further elucidated by MM. Ball and Chambard.[75] Starting with the proposition that normal healthy existence is a state in which the functions of organic life furnish a basis for nervous sensibility and motion, by means of which the imaginative faculties (imagination and memory), associated with the coördinative faculties (attention, judgment, volition), are sufficiently stimulated to maintain a state of consciousness, they show that the first stage of sleep consists in the suppression of bodily motion and sensibility. The second stage consists in the further suppression of the coördinative faculties. The third stage is marked by the loss of memory and imagination. In the most profound and perfect sleep the functions of organic life alone remain. The process of awaking consists in the revival of the faculties in the inverse order of their extinction. Dreams occur during the period in which motion, sensation, and the coördinative faculties are in abeyance; but somnambulism may accompany each of the stages of sleep. Its simplest form is perhaps the rarest; corresponding to Maury’s fifth variety. In this form the functions of organic life are intact; motion and sensibility seem unchanged; the intellectual faculties display their usual activity; but the ordinary consciousness is never aroused. So far as the normal life of the subject is concerned, he is active, sensible, intelligent, but unconscious; and when the paroxysm is terminated memory contains no account of its events. Such paroxysms may occur but once in the life-time of an individual, or they may be repeated at stated intervals, constituting an alternate succession of mental states without connection in consciousness. This is called the somnambulic life, or double consciousness, several examples of which will be related upon another page.

The second form of somnambulism results from the abolition of consciousness and the more or less complete suppression of the coördinative faculties of the mind. Memory and imagination, released in great measure from the control of the higher intellectual faculties, and excited by such vestiges of sensation as still persist, create a species of delirium in which mutilated sensations, half formed thoughts and disproportioned volitions combine to produce a variety of actions. In this condition the patient dreams, and acts out his dream. He is a somnambulic dreamer.

In the third degree of somnambulism, consciousness and the entire range of intellectual faculties have disappeared. The individual resembles a creature from which the cerebral hemispheres have been removed. He is little better than a living automaton, guided only by impressions received from without. In this condition the movements of the body may become wholly responsive to the will of another—a prominent characteristic of artificial somnambulism or hypnotism.

A fourth degree of somnambulism is marked by the disappearance of consciousness, intellect, sensibility, and the power of motion. Only the lower functions of organic life remain. The patient merely lives, he neither thinks nor acts. This constitutes the state of somnambulic lethargy, a condition which differs from deep sleep only in the fact that under the influence of external impulses or of partial awaking it may easily pass into the second form of the affection, the somnambulic dream.

Such is the classification of MM. Ball and Chambard. It possesses the merit of great precision and clearness. If the warning which its authors themselves utter against its too literal acceptance be respected, it will be found to afford a very convenient explanation of the manner in which the various degrees of somnambulism are reached. But it must be remembered that between these pronounced and definite forms exist a great number of intermediate degrees. Partial revivals and temporary resurrections of the higher faculties of the mind may intrude themselves among the activities which depend upon lower functions; as, for example, when the ordinary unconsciousness of lethargy is briefly interrupted by an event which may remain permanently fixed in memory after waking, even though all other concurrent incidents were unnoticed and left no trace behind. Keeping this caution in mind, the following diagram will be found useful:

The close parallel between this diagram and the one on [page 4], which illustrates the course of sleep, will be at once remarked. The difference between the two states cannot be thus diagrammatically expressed. It is the difference between sleep in a healthy, normal subject, and sleep as modified by the somnambulistic temperament. This may be either the result of disease or of congenital defect of cerebral organization. What the particular structural difference may be, it must be impossible to decide, until it shall become possible to state the reason why one brain shall behave only in a normal manner, while another presents all the vagaries of hysteria, somnambulism,—perhaps even of insanity. That the affection is hereditary is a matter of common observation. One of my patients who is somnambulistic—walking in his sleep, climbing over the roof of his house, etc.—is the son of a father who was also a noctambulist, and who once fractured his leg by falling from a step as he was walking down stairs in his sleep. A grand-daughter is both a somniloquist and a somnambulist.

Returning now to the classification adopted by Ball and Chambard, it will be found interesting to consider a few illustrative examples of the different forms and degrees of the affection under consideration.

Somnambulic Lethargy.—This condition represents the form which outwardly resembles profound sleep. It may occur as a paroxysm without relation to other forms of the affection, or, according to my own observation, more frequently associated with other forms of somnambulism. Thus, one of my patients, a lady about thirty-five years of age, having accidentally fallen into the hands of a noted empiric, by whom, for a slight attack of tonsillitis, she was vigorously dosed with atropia, digitalis and calabar bean, finally passed into a somnambulic state corresponding to the somnambulic life of the preceding table. This continued about five weeks, when she became completely lethargic, and was transferred to my care. In this condition she remained unconscious, almost perfectly insensible, with pupils somewhat contracted and sluggish before the light, with a feeble and slightly accelerated pulse, a moderately elevated temperature, bowels and bladder insensible to their contents, mouth and throat filled with an offensive mucous secretion. By great urgency she could be sufficiently roused to open her mouth, so as to permit cleansing the cavity, and to swallow liquid food. Swallowing was effected very slowly, and only after the liquid had remained for some time in the fauces. At the end of about three weeks the patient began to exhibit more vitality. She could be more easily aroused, began to dream and to have hallucinations that were finally prolonged out of sleep into wakefulness. In the course of a few hours she was fully herself again, after eight weeks of unconsciousness.