Case Presentation: A 28-year-old female with a PMH of SLE nephritis on mycophenolate and prednisone, ESRD, and HTN was admitted after a witnessed seizure at home. She was intubated for airway protection and admitted to the MICU. Her blood pressure on admission was 188/117 mm Hg. A brain MRI without contrast showed extensive areas of T2 hyperintensity at the gray-white junction within the cerebral hemispheres bilaterally as well as small patchy areas of increased T2 signal within the cerebellar hemispheres. The patient’s mycophenolate was held and the patient was started on methylprednisolone. The main differential diagnosis was Lupus Cerebritis but this diagnosis was less likely given the unremarkable anti-double stranded DNA level, and normal C3 and C4 serum levels. The patient was started on phenytoin, however a video EEG did not reveal any seizure activity. She was extubated after two days and transferred to the general medicine floors. Her systolic blood pressure was repeatedly elevated above 170 mm Hg, but was eventually controlled with titration of labetalol. A repeat brain MRI 6 days later showed a marked interval improvement of the multiple areas of cortical-subcortical edema and swelling. The patient was started on a steroid taper. She was to continue with phenytoin upon discharge, and mycophenolate was not be to resumed. The patient remained seizure free throughout her hospital course and was discharged home as hemodynamically stable after eight days.
Discussion: Posterior Reversible Encephalopathy Syndrome (PRES) is a neurological disorder that presents with various symptoms and triggers. The most common presenting symptoms appear to be seizures, visual disturbances, headache, and altered mental status. A large percentage of these patients are also hypertensive. There are two main theories that PRES is a result of severe hypertension that causes an interruption in brain autoregulation which leads to cerebral hyperperfusion, and may cause vascular leakage and vasogenic edema; or it is a result of systemic inflammatory processes such as an autoimmune disease due to circulating endogenous or exogenous toxins which leads to vascular endothelial dysfunction. PRES is often observed during treatment regimens with immunosuppressive agents, as these medications are sources of exogenous toxins which have the ability to induce endothelial dysfunction, vascular leakage, edema formation and blood pressure elevation.
Conclusions: Hospitalists must be aware of this link between the use of immunosuppressive agents and the development of PRES. PRES presents with numerous symptoms, many of which hospitalists treat on a daily basis. But, symptom treatment is not sufficient when PRES is caused by a drug. Drug cessation is a crucial part of the management. Lupus, an autoimmune disorder, likely served as a predisposing factor to the development of PRES in our patient. The use of mycophenolate further increased that risk. Eventually, our patient did develop PRES, which manifested as seizures that resolved with cessation of mycophenolate.