Progressive Multifocal Leukoencephalopathy (PML) is a rare and serious brain infection caused by the John Cunningham virus (JCV). It primarily affects individuals with weakened immune systems, such as those with HIV/AIDS, certain cancers, or those taking immunosuppressive medications. PML leads to the destruction of myelin, the protective covering of nerve fibers, resulting in neurological symptoms. Symptoms of PML can include confusion, weakness, vision problems, and difficulty with coordination. The disease progresses rapidly, and there is currently no specific treatment. Management focuses on improving the immune response and addressing underlying conditions to help slow the progression of the disease.