Progressive Multifocal Leukoencephalopathy in a Case Without Clear Evidence of Immunodeficiency

Introduction: Progressive Multifocal Leukoencephalopathy(PML) is a rare demyelinating disease of the central nervous system due to reactivation of a latent infection with JC papovavirus. PML predominantly occurs in severely immunosupressed patients, mostly as a late complication of acquired immunodeficiency syndrome and lymphoproliferative disorders. Clinically it is manifested by motor and sensory deficits, ataxia, cognitive impairment and dementia, corresponding to central nervous system (CNS) lesions. It is difficult to distinguish PML clinically from immune-mediated diseases of the CNS, such as multiple sclerosis, neuropsychiatric sistemic lupus erythematosus and CNS vasculitis.Case Report: A 19-year-old woman presented with ataxia and slurred speech rapidly progressing to quadriparesis and confusion. The diagnosis of PML was made by detecting the JC virus in the cerebrospinal fluid by polymerase chain reaction.Discussion: PML predominantly occurs in severely immunosupressed patients. However, it must also be kept in mind in patients without an apparent immunodeficiency when the clinical and radiological features are typical.