Posterior Reversible Encephalopathy Syndrome (PRES) in a Patient With Primary Myelofibrosis on Ruxolitinib

Posterior reversible encephalopathy syndrome (PRES) is a reversible neurological syndrome characterized by headache, seizures, altered mental status, and visual abnormalities, in association with the characteristic bilateral white matter abnormalities in the posterior cerebral hemispheres. As the name suggests, it is typically reversible with clinical recovery within a few days, while the magnetic resonance imaging (MRI) abnormalities resolve much more slowly. We present a 78-year-old female with a known diagnosis of primary myelofibrosis (PMF), on ruxolitinib, a Janus kinase (JAK) 1 and 2 inhibitor, presenting with altered mental status. On presentation, she was hypertensive and with possible sepsis, secondary to urinary tract infection (UTI). She was intubated because of her low Glasgow Coma Scale (GCS), to secure her airways. Computed tomography (CT) of the brain did not reveal any acute ischemic changes. MRI of the brain exhibited findings suggestive of PRES. Ruxolitinib was held and the patient was treated with antihypertensives, anticonvulsants, and antibiotics. Within 24 hours of hospitalization, the patient had a complete neurological recovery, which is diagnostic of PRES. She was extubated successfully and was discharged with a resolution of her symptoms. Although several chemotherapeutic and immunosuppressant drugs are reported to be associated with PRES, the association between ruxolitinib and PRES has not been well established. Thus, case reporting is important to highlight the possible association between ruxolitinib and PRES.