A fulminant case of JC virus encephalopathy supporting a novel syndrome associated with JC virus infection of cortical neurons

The JC virus ( JCV) is well known for causing progressive multifocal leukoencephalopathy (PML), a potentially fatal, demyelinating disease of the central nervous system (CNS). PML almost exclusively affects immunosuppressed patients, whereas it is rare in immunocompetent subjects. Recently, a new clinical entity, named JCV encephalopathy ( JCVE), has been observed. We present the case of a 62-year-old male, with no identifiable immunosuppression, who developed aphasia and progressive reduction in consciousness. He had a six months insidious history of psychiatric symptoms. He passed away 3 weeks after onset of symptoms. On admission, brain MRI demonstrated a prominent grey matter involvement. Serological tests and cerebrospinal fluid analysis were all negative for infectious diseases. A whole-body CT scan was negative for cancer. Several EEGs showed a diffuse anterior theta activity with bilateral parietal epileptic periodic discharges. A second MRI imaging showed a more prominent non-enhancing grey and white matter involvement, compatible with PML. Finally, CSFPCR for JCV was performed and resulted positive. To the best of our knowledge, our report is the second case of JCVE described so far. Similarly to our patient, the previous case developed symptoms consistent with a CNS disease with progressive clinical course. MRI abnormalities were initially restricted to the hemispheric grey matter and only later extended to the subcortical regions. Our case suggests that JCV infection should be considered even in immunocompetent patients presenting with unexplained cortical lesions and rapidly progressive encephalopathy. Matteo Ciocca1, Marta Pirovano1, Monica Lodi2, Antonino Romeo2, Vincenza Fetoni1