The Biological Significance of the Lesions of Multiple Sclerosis

Abstract

There is considerable evidence to show that multiple sclerosis and the "disseminated encephalo-myelitis" often following vaccinia or infectious diseases are different stages of the same process. Lesions resembling those seen in both types have been produced experimentally by the injections of toxins and by the obstruction of cerebral venules. There is also other evidence that certain types of anoxemia or passive congestion may produce loss of myelin in a rather specific manner. It appears likely, therefore, that a step in the formation of sclerotic plaques is a venular thrombosis. There is evidence of an abnormal lability of coagulation in the blood in patients with multiple sclerosis, and there are reasons why thrombosis might be expected to occur in the white matter of the nervous system rather than elsewhere. Loss of myelin does not destroy the function of the affected fibers.