“Who e’en for change of scene wou’d seek the shades below,”
and to one unhallowed story related in “Salmonia.”
From this excess there is the stimulus of pain to move; one of the most powerful motives of human action. Cardan, if we may believe in his “Opera et Vita,” was at least a monomaniac; and he “was wont instinctively, as it were, to relieve this tendency of his mind by the excitement of bodily pain.” I may assure you that I have, during my professional studies, often witnessed (and indeed have sometimes suggested) a remedy on this knowledge: you may be aware, that a severe and painful disorder will mitigate, if not entirely dissipate, that apathetic misery which springs from a vacant or unoccupied mind.
In contrasting childhood and age, we witness these curiosities in the restless activity of youth and early manhood, for at these periods we are very constant somnambulists; not so in the passive state of old age, in which sleep-walking is very rare. Something of this we see also in the growing pains and fidgets of girls and those whose duties are sedentary. Exercise is the relief for all this.
Now when the sleep-walk has exhausted this excess of irritability or electricity (if it be so), the dreamer returns to bed and sleep. A hint is here thrown out to us, that if powerful exertion be employed previous to sleep, the night-walk might not ensue. Lethargy often terminates in somnambulism.
If I may for another moment still prose over the intricate, but deeply interesting question of the pathology of somnambulism, I will observe, that we often find it one symptom of madness or idiocy, and we know that somnambulism not seldom terminates in epilepsy.
In the brains of epileptic idiots, who are very determined somnambulists, we discover changes the most various; effusion, congestion, ossification of membranes, ramollissement, indurcissement, bony spiculæ, or points pressing the brain, tubercles, cysts. In some, the skull assumes the density of ivory. Yet in those persons who have been known to be sleep-walkers, the inspection is seldom satisfactory. Plethora of the head has often, however, preceded the sleep-walk. Signor Pozzi, physician to Benedict XIV., if he submitted not to depletion each second month, became a somnambulist; and we have known that in chorea, previous to the dance, and in some cases of somnambulism also, pain has been felt from the occiput along the course of the spinal marrow. This is from immediate excitement; but dyspepsia and other abdominal derangements may so influence the ganglia and nerves of organic life, and through them the brain and cord, as to excite sleep-walking by remote sympathy.
That injuries of the nervous matter about the nape of the neck are of the highest importance in our studies of these eccentric actions, is certain. The experiments of Flourens show that the progressive or forward motion of animals, is influenced by varied states of the cerebellum. When Majendie cut through the corpora striata, the animal darted forward; when the pons Varolii was cut, the animal rolled over sixty times in a minute.
When a soldier is struck by a ball about the cervical vertebræ, he often springs from the ground and drops dead.
It is our duty, then, not to slight the condition of the somnambulist. If simple irritation be its exciting cause, much benefit may be derived from counter-action on the surface, and other remedial means. Even if there be diseased structure, some palliation may be afforded. As preventives of the fit, we may inculcate an abstinence from late meals, exercise in the evening previous to retirement to rest, a high pillow, &c.