Cataleptic Symptoms Following Bilateral One-Stage Removal of Frontal Cortex in Cats

Abstract

The author wishes to present a brief report concerning a peculiar group of symptoms, in many ways suggestive of catalepsy, which has been observed in 8 cats following a one-stage operation in which both frontal lobes of the cerebral cortex were removed. These operations were done with every precaution to secure good hemostasis and prevent hemorrhage from complicating the interpretation of the subsequent observations. Careful autopsies revealed that in no instance was there any sign of hemorrhage at the base of the brain or of blood in the ventricles. The observations on animals (cats) were made on relatively acute preparations. Cats 5, 6, 7, 8, 9, 10, 11, and 12 survived for 28, 3, 19, 2, 8, 13, 6 and 15 days, respectively. Animal 9 died after a laboratory accident; animal 6 of pneumonia, and animal 8 of an infection contracted post-operatively. All others were sacrificed.

These animals all showed a remarkable plasticity of the muscles of the limbs and back. Such plastic tonus was especially well observed if the animals were placed in a supine position in a wooden trough-like structure. The limbs of these animals were usually rigidly extended when in this position. If they were passively flexed by the observer, there was considerable resistance, and the limbs remained flexed for exceptionally long periods of time, hours in many instances. When passively extended, there was likewise considerable resistance, and the limbs remained extended for very long periods. Furthermore, these animals made little or no effort to escape when in the supine position, but would lie quietly, breathing regularly. They were neither moribund or comatose. Moving objects placed before the eyes elicited a following movement of the eyes.