The case to be reported is that of a child who died of acute diffuse nonsuppurative encephalitis characterized pathologically by extensive and massive destruction of the Purkinje cells of the cerebellum. The entire cerebellum was involved, and it is roughly estimated that more than half of the Purkinje cells were necrotic or in the process of being phagocytosed, while an inestimable number of those remaining were injured more or less profoundly. Although other parts of the brain showed diffuse inflammation, with extensive retrogressive changes in the ganglion cells, the cell-destroying process was confined almost entirely to the cerebellum. The spinal cord showed little or no abnormality.
We have found no description of a similar pathologic picture in any type of human encephalitis, and though no specific inclusions were recognized, the general features of the disease from a cytopathologic standpoint suggest the activity of an unknown virus as the inciting agent.