Migratory basal ganglia lesions in subacute sclerosing panencephalitis (SSPE): clinical implications of axonal spread.

We report a boy with subacute sclerosing panencephalitis (SSPE) who exhibited parkinsonian symptoms four months after onset. The symptoms improved after administration of levodopa. One year after onset, bilateral symmetric lesions appeared in the substantia nigra and the putamen, as observed using magnetic resonance imaging. After a one-year interval, the lesions migrated to the bilateral caudate and the cerebellar dentate nuclei. The series of migratory legions, each of which was connected by axonal pathways originating from the substantia nigra, suggests axonal spread of the SSPE virus.