The constant and urgent request of the patient for relief, at all risks, from his distressing condition, induced the doctors to attempt the fourth operation; and when this was unsuccessful even to the extent of revealing the abnormal conditions, to the fifth operation, which was without anesthetics and which is the one chiefly interesting from the psychological point of view.
This fifth operation was performed March 26, 1907. The bone flap was for the fifth time reflected; the dura was incised some distance outside the largest previous incision; an incision was made into the gyrus centralis posterior, which appeared somewhat flattened and yellowish in color; and about one centimeter below the surface the top of a thin-walled cyst came into view. By enlarging the incision until it measured 5 centimeters this cyst was removed; but below it a still larger cyst was disclosed, which was "in turn shelled out of its bed by pushing the brain away from it, and was in this way removed unruptured." The entire procedure lasted about three hours.
But what about the mental condition of the patient during this long-continued and extensive exploration and cutting and pulling of the brain and its integuments? We are informed that he was "interested," asking questions and conversing with the doctors most of the time. Although perfectly conscious, he "experienced no sensory impressions whatever, even when the dura was incised." The only discomfort, not to say pain, given to him by these extensive explorations of his brain, was when the edge of the incision of the dura was caught in a clamp and the membrane dragged upon. The patient himself called the attention of the surgeons to an otherwise unnoticed phenomenon which consisted of a slight twitching of the muscles of the left side and shoulder.
In his report Dr. Cushing expresses his regret that this rare opportunity was not seized in order to test the effects of stimulating the posterior and post-central convolutions upon the experience of conscious sensation. In a subsequent case of cerebral surgery without anesthetics, however, these convolutions were stimulated and distinct impressions of sensations were obtained which were localized by the subject in the extremities and not at all in the cortex itself. No such sensory impressions were obtained by stimulating the pre-central area, or "motor strip," although the customary motor results were obtained. Further details of the second case were not at my disposal at the time of writing this paper.
The following remarks upon these surgical results as viewed from the psychological point of standing are intended as suggestions rather than as definitely established conclusions.
- Still more recently, as I have learned in conversation, in a third case of cerebral surgery without anesthetics, the same operator obtained similar results of conscious sensations by faradizing the same region of the cerebral surface.