Progressive Multifocal Leukoencephalopathy
FINDINGS:
A large area of nonenhancing signal abnormality occupies
the left occipitoparietotemporal white matter, without mass effect.
DISCUSSION:
-papovavirus (JC virus) latent reactivation
-prevalence 2-7% of AIDS/immunocompromised
-progressive course to death
-non AIDS pts may have predilection for occipital
lobes
-focal T2 hyperintensities, CT hypodensities,
confluent cavitary regions
-absent mass effect and enhancement usually, may
enhance minimally
-rarely may involve both cortex and WM, simulating
infarct
-patchy asymmetric demyelination esp parietal,
progress and coalesce