Chenrui Song, Yanqun Liu, Xiaoying Bi, Shi Wang
Progressive multifocal leukoencephalopathy (PML) is a rare fatal central nervous system demyelinating disease caused by John Cunningham virus (JCV). Immunodeficiency induces JCV reactivation, resulting in oligodendrocyte lysis, demyelination, and astrocytic dysfunction. We reported a 54-year-old male presenting with mild motor aphasia and cognitive decline. He was initially misdiagnosed with cirrhotic hepatic encephalopathy, with no response to ammonia-lowering treatment. Routine cerebrospinal fluid tests were unremarkable, while Matagenomics Capture (MetaCAP), a high-throughput sequencing technology identified 226 JCV sequences, confirming PML. PML has heterogeneous manifestations and is easily underdiagnosed in cirrhotic patients. Early differential diagnosis, CSF JCV detection, or brain biopsy is essential.