Rituximab-Associated Inflammatory Progressive Multifocal Leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a rare disease of the immunosuppression that results from neurotropic invasion of the JC virus which leads to demyelination of oligodendrocytes. Immune reconstitution inflammatory syndrome (IRIS), on the other hand, is a condition of inflammation that develops as the immune system reconstitutes. This case report describes a case of a 35-year-old HIV-negative male who presented with three weeks of right lower extremity paresthesias as well as right upper extremity apraxia. He was diagnosed with PML complicated by IRIS secondary to Rituximab, which he had completed four months prior to presentation. Despite the condition's poor prognosis, the patient recovered with only minor deficits.