The monosymptomatic (recurrent infantile hemiplegia) and the polysymptomatic forms of disseminated vasculomyelinopathy that follow various infections and antigenic challenge to the nervous system were seen in two cases. These cases emphasize the importance of vasculopathy as the initial and obligatory component of the postinfectious and postimmunization neurologic syndromes as well as the clinical and pathological variability of the secondary effects on the nervous system. Recurrent infantile hemiplegia occurred in the first patient. In the second patient, after two episodes of postinfectious myelinoclastic encephalopathy, concurrent acute hemorrhagic leukoencephalopathy and an acute Guillain-Barré syndrome following swine flu vaccination developed.