Experimental Production of Bulbar Poliomyelitis

Abstract

Poliomyelitis has been experimentally produced in Macacus rhesus monkeys by injecting the virus into the ileum between clamps or subserosally in the same area. 1 Levaditi, Kling and Hornus 2 introduced the virus into the gastrointestinal tract of a Macacus cyanomolgus monkey and the animal later became ill with the disease. In the former instance, 1 the clinical picture was similar to that seen in the human being ill with spinal poliomyelitis, The animals developed palsy of muscle groups, monoplegia and paraplegia of the legs, but not the condition of quadriplegia that usually follows intrasciatic and intracerebral inoculations and intranasal instillations.

It has been shown that the virus spreads along the axis cylinders of the sympathetic thoracolumbar outflow. 3 It has also been pointed out that such a spread from the gastrointestinal tract directly to the cord by way of the afferent and efferent grey fibers has a simple and logical anatomical explanation. 4 It is an explanation that would also apply to typhoid fever, another gastrointestinal disease. 5 Although the hypothesis as to the mechanism of spread of the virus holds true in the average case of the spinal type of poliomyelitis, it cannot be used to explain the mechanism of the production of bulbar paralysis.

Histopathological examination of the autopsied material revealed findings similar to those of Harbitz and Scheel 6 in that I found marked involvement of the nuclei of the brain stem and medulla, especially in grey fibered areas, as well as increased vascular markings. One was not always fortunate enough to see cases of so-called bulbar poliomyelitis from the onset, but the histories, symptomatology and objective findings of 45 of the 440 cases admitted to Cleveland City Hospital all presented such evidence that it could be stated that the initial involvement in practically every instance was vagal in character, i. e., accompanied by vomiting, followed by dysphagia, dysarthria and aphonia with other Symptoms developing later to indicate a spread to other cranial nerves.