Abstracts

Progressive multifocal leukoencephalopathy (PML) is a rare fatal demyelinating disease of central nervous system (CNS) due to JC virus (JCV) infection, which occurs almost exclusively in immunocompromised patients. We report a case of immunocompetent child patient with pathologically-proven PML and survives over 2 year after diagnosis. Serial follow up of neuroimaging study including brain MRI, PET, SPECT, and MR spectroscopy was obtained.
An 8 years old boy who had been healthy before symptom onset admitted due to mild and slowly progressive cognitive dysfunction for 3 months. Seizure attack was accompanied 1 month after the symptom onset. Progressive gait difficulty developed with lethargic state and left hemiparesis and myoclonic status epilepticus were prominent on admission. Initial brain MRI revealed diffuse and severe increased signal intensity in white matter of right temporoparietal area in diffusion WI, T2WI, FLAIR image. EEG showed high amplitude repetitive slow spike and wave complexes with or without coincidence of myoclonic jerking movement. Brain biopsy revealed multifocal demyelinations, mononuclear cell infiltration, bizarre astrocytes and intranuclear inclusions in oligodendrocyte. Electron microscopy proved Papova viral particles in nucleus of oligodendrocytes. He did not have any clinical history of immunodeficiency and laboratory test including T-cell, B-cell, and NK cell didn[rsquo]t show any dysfunction. Anti-viral therapy with acyclovir did not improve symptom and myoclonic status was very intractable with multiple antiepileptic drugs including midazolam infusion. Progressive quadriparesis and deterioration of cognitive function were compatible with contralateral hemispheric involvement of follow up imaging study. Serial follow up of neuroimaging studies including brain SPECT and PET were done.
Neurological condition was gradually stabilized and fixed with active physical exercise. Myoclonic status was controlled with minimum evidence of visible slow frequency jerking movement. Minimal improvement of cognitive function at the point of 24 months follow up since initial symptom onset. Serial follow up of neuroimaging study with multiple modality showed gradual progression to contralateral hemisphere, which was consistent with clinical aggravation with severe atrophy finally.
Longterm survival and serial follow up of neuroimaging studies in this case could be helpful to understand the natural history of PML. This case suggest PML could be occurred in none immunocompromised condition and the fatality might be related to underlying immunocompromised state rather than the Papova viral infection in itself. The serial follow up of neuroimaging shows progressive nature and severe diffuse cortical atrophy of the brain in final.