B48-24 When VEGF Goes Awry: Axitinib-Associated Posterior Reversible Encephalopathy Syndrome (PRES)

Abstract Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiographic diagnosis characterized by acute encephalopathy, seizures, headache, visual hallucinations, disturbances, and hypertension. MRI typically demonstrates T2 hyperintensity in the parieto-occipital regions. Axitinib, a vascular endothelial growth factor receptor (VEGFR) inhibitor used in metastatic renal cell carcinoma (RCC), can precipitate PRES through endothelial dysfunction and hypertension. Prompt recognition and withdrawal of the offending agent are critical to prevent permanent neurologic sequelae. Herein we present a case of Axitinib induced PRES. A 69-year-old male with hypertension, long standing atrial fibrillation, syndrome of inappropriate antidiuretic hormone, and metastatic RCC presented from his skilled nursing facility with progressively worsening confusion over 8 weeks and possible seizure activity prior to arrival. He had been receiving axitinib for 12 weeks, discontinued two weeks prior due to intermittent confusion, hallucinations, and functional decline. On arrival, he was stuporous, dysarthric, and oriented only to self (A/O x1). Initial MRI of the brain without and with contrast was reported as unremarkable without any metastatic lesions or intracranial pathology. Over the hospital course, he experienced waxing and waning lucidity with intermittent fevers. Extensive infectious workup including chest X-ray, CT abdomen, urinalysis, and lumbar puncture were performed. The results were nondiagnostic. CSF studies were nonspecific due to traumatic tap; bacterial cultures and viral PCR were negative. Laboratory evaluation revealed ESR (38 mm/hr) and CRP (4.82 mg/dL). He completed empiric IV ceftriaxone, acyclovir, and IV immunoglobulin without clinical improvement. Neurology review of MRI identified bilateral occipital T2 FLAIR hyperintensities consistent with PRES. With supportive care and discontinuation of axitinib, the patient’s episodic agitation gradually stabilized. He was discharged to his skilled nursing facility on hospital day 15 with family education on PRES, ED precautions, and counseling regarding the reversible nature of symptoms after withdrawal of the offending agent.PRES is frequently underdiagnosed, particularly when neuroimaging is subtle or initial findings are nonspecific. VEGFR inhibitors, including axitinib, are known triggers due to endothelial injury and hypertension. This case emphasizes the importance of careful MRI review in the context of high clinical suspicion, even when initial imaging is reported as normal. Management focuses on removal of the inciting agent, supportive care, and blood pressure control. Early recognition prevents progression to irreversible neurologic injury. This case highlights the need for heightened awareness of PRES in patients receiving VEGF-targeted therapies and demonstrates how systematic imaging review, supportive management can improve outcomes, and targeted therapy can be associated with neurotoxicity. This abstract is funded by: None