Although poliomyelitis (infantile paralysis) is a general systemic disease, the virus attacks the motor cells of the anterior horns of the spinal cord in a specific manner. As a rule these nerve cells suffer damage out of all proportion to any other cells in the body. This remarkable specificity has never been satisfactorily explained. The suggestion that the changes in the anterior horn cells are secondary to thrombosis of the anterior spinal artery (Batten, 1902) has been discredited, but it is not yet generally accepted that the change is a direct effect of the virus or its toxin, and is not secondary to the inflammatory reaction in the vessels and supporting tissue of the cord.
From a study of fifteen cases, Blanton1 (1917) stated that the anterior horn cells suffer from the onset of the disease in the cord. He concluded that the mechanical factors of edema, congestion, compression