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.