Teaching NeuroImages: epilepsia partialis continua revealing PML after allogenic stem cell transplantation.

A 54-year-old man, 15 months after allogenic peripheral blood stem cell transplantation (ASCT) for myelodysplasia, developed continuous right foot involuntary twitching. The EEG was suggestive of epilepsia partialis continua (EPC) (figure 1). Brain MRI showed increased signal in the left rolandic white matter (figure 2). Blood assessment found 3,400 leukocytes, 500 lymphocytes, and CSF PCR JC virus was positive (250 copies/mL) with normal cyto-biochemical assessment. This case fits diagnostic criteria of progressive multifocal leukoencephalopathy (PML). PML is exceptionally revealed by EPC and constitutes a rare complication of ASCT.