The suggestion that multiple sclerosis represents a late stage of a process which is recognized in its acute stage as acute "myelitis" or "encephalomyelitis" of certain types dates well back into the last century.1 The scene of battle has changed somewhat and now centers less about the question whether the lesions of multiple sclerosis are progressive—it appears to be almost universally accepted that they are-than about the more specific point as to whether the disseminated foci of degeneration seen in the group of "demyelinating encephalomyelitides" or encephalomyelopathies most definitely represented by the postvaccinal and postmeasles forms represent an acute form of typical sclerotic plaques. The issue is a difficult one in itself, for it consists in attempting to compare an acute lesion with a chronic one. This difficulty is increased by the fact that several varieties of lesions may often be observed in each case of the same disease.
PUTNAM TJ. STUDIES IN MULTIPLE SCLEROSISVII. SIMILARITIES BETWEEN SOME FORMS OF "ENCEPHALOMYELITIS" AND MULTIPLE SCLEROSIS. Arch NeurPsych. 1936;35(6):1289-1308. doi:10.1001/archneurpsyc.1936.02260060131011