Posterior reversible encephalopathy syndrome as a multiple sclerosis relapse mimic during interferon therapy

• Published in: Clinical neurology and neurosurgery Vol. 249; p. 108666
• Main Authors: Dias da Costa, Mariana, Leal Rato, Miguel, Ferreira, João, de Sá, João, Santos, Mónica
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2025; Elsevier; Elsevier Limited
• Subjects: Blood pressure; Blood-brain barrier; Brain - pathology; Diagnosis, Differential; Edema; Editing; Encephalopathy; Humans; Hypertension; Interferon; Interferon-beta - adverse effects; Interferon-beta - therapeutic use; Intracranial stenosis; Magnetic Resonance Imaging; Male; Middle Aged; Multiple sclerosis; Multiple Sclerosis, Relapsing-Remitting - diagnosis; Multiple Sclerosis, Relapsing-Remitting - drug therapy; Neurology; Neurosurgery; Patients; Posterior Leukoencephalopathy Syndrome - chemically induced; Posterior Leukoencephalopathy Syndrome - diagnosis; Posterior Leukoencephalopathy Syndrome - pathology; PRES; Recurrence; Spinal cord; Steroids; Substantia alba; Supervision; Multiple sclerosis; Interferon; PRES; Intracranial stenosis
• ISSN: 0303-8467; 1872-6968; 1872-6968
• DOI: 10.1016/j.clineuro.2024.108666

Posterior reversible encephalopathy syndrome is a rare syndrome involving the subcortical cerebral white matter. We describe the case of a 63-year-old male patient with relapsing remitting multiple sclerosis under interferon beta therapy and acute onset of atypical unilateral posterior reversible encephalopathy syndrome mimicking a relapse. This case highlights the importance of clinical suspicion for multiple sclerosis mimics, namely in older patients, which may need disease modifying treatment suspension and directed treatment in order to achieve better clinical prognosis. •Multiple sclerosis mimics include other disorders that affect the white matter, such as PRES.•Diagnosing MS mimics is of utmost importance to guarantee adequate treatment.•PRES has been previously associated with disease modifying treatments in MS, such as interferon beta.