Abstract
Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder that can affect all age groups. It appears to have a higher incidence in the female population. Some common risk factors include hypertension, electrolyte abnormalities, sepsis, and chemotherapeutic medications such as Obinutuzumab. Our patient, who had chronic lymphocytic leukemia (CLL), presented with altered mental status. She was recently started on Obinutuzumab less than a week before this presentation. MRI findings were consistent with PRES, including diffuse vasogenic cerebral edema predominately throughout the bilateral parietal and occipital lobes associated with some edematous extension into the posterior part of bilateral frontal lobes. This case aims to highlight the importance of early diagnosis by appropriately identifying the MRI features of PRES to improve patient quality of life and decrease morbidity and mortality.