A demonstration of the effects of some lesions of the nervous system

Abstract

The effects of the lesions were shown in cinematograph films of three different animals. A rabbit which was brought into the laboratory some months ago presented constant marked torsion of the head to the left. There was no nystagmus, but merely a constant deviation of the eyes. The animal could move about on rough surfaces if it went slowly and carefully, or if its left side was supported by the side of the cage. If put on a smooth surface with the left side unsupported, any attempt on the part of the animal to move was followed by rolling movements to the left, about the long axis of the body. If no obstacle was placed in its way, the animal might roll for several yards before regaining its upright position. The animal was said to be about eight months old at the time it was brought into the laboratory, and to have been in the same condition from birth. The only gross changes visible at autopsy were in the left otic labyrinth. The nature of these changes was not determined by inspection. The histological report will be presented later. One interesting point in the deportment of the rabbit was its lack of compensation for the loss of the labyrinth, as compared with the deportment of cats or dogs after loss of one labyrinth.

Two cats were subjected to experimental ablation of the vermis and left lateral lobe of the cerebellum. The eye movements were different from those following labyrinthine lesions. One marked motor defect was the trembling and uncertainty of movement of the head when attempting to take food. Two different stages in recovery from the effects of the cerebellar lesion were shown, in one of the cats, with the gradual amelioration of the symptoms in the second stage taken at an interval of about one month after the first.