Two cases of disseminated vasculomyelinopathy (one of acute disseminated encephalomyelitis (ADEM), the other of acute transverse myelitis), are reported because of the persistence, 3 years and 5 months respectively, of abnormalities of magnetic resonance imaging (MRI). These abnormalities remained although in the first case the disease had been essentially asymptomatic from the onset except for one seizure, the patient remaining neurologically intact, whereas in the second case, the patient had made a complete recovery from very serious neurologic dysfunction. The first case illustrates the fact that ADEM may rarely occur without any symptoms, even in the presence of severe imaging abnormalities in both CT and MRI. Neither the persistence of a blood-brain barrier permeability alteration nor gliosis can satisfactorily explain the MRI changes, and thus the pathological significance of areas of increased signal intensity in MRI remains poorly understood and a matter of uncertainty. This report emphasizes the futility of attempting to correlate any kind of clinical observation, laboratory parameter, or effect of therapeutic regimens with changes, or lack thereof, in the MRI in multiple sclerosis and disseminated vasculomyelinopathy.