CYTOTOXIC EDEMA IN CHEMOTHERAPY-ASSOCIATED POSTERIOR REVERSIBLE ENCEPHALOPATHY SYNDROME

Abstract

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Posterior reversible encephalopathy syndrome (PRES) is a clinical radiographic syndrome characterized by seizures, visual disturbances and altered mental status. MRI of the brain exhibits vasogenic edema. Failure of autoregulation of cerebral arteries and disruption of the endothelium of the blood-brain-barrier are the two mechanisms underlying vasogenic edema. PRES has many triggers, including the use of chemotherapeutic agents. We present the case of a patient on treatment with paclitaxel/carboplatin, diagnosed with PRES, with radiographic evidence of both vasogenic and cytotoxic edema. CASE PRESENTATION: A 61-year-old male diagnosed with squamous cell carcinoma of the lung, recently started on Carboplatin and Paclitaxel, presented to the hospital with altered mental status. He was afebrile, blood pressure 117/77 mmHg, pulse 105 and respiratory rate 24. Physical exam revealed an unresponsive male in respiratory distress. Initial CT brain and blood investigations were unremarkable. He was admitted to the ICU and intubated for failure to protect his airway. MRI brain, revealed hyperintensities on T2-weighted and FLAIR imaging with patchy restricted diffusion involving bilateral fronto-parieto-occipital cortex typical of vasogenic edema and PRES. During further workup, he was found to have a left atrial thrombus from tumor invasion. He was started on anticoagulation and loaded with levetiracetam. He was noted to have dense hemiparesis two days later and underwent CT angiography of the brain which confirmed vasogenic with cytotoxic edema and diffusely increased vascularity as a consequence of decreased cerebral autoregulation. He regained consciousness and tolerated extubation, with complete resolution of hemiparesis. Following extubation, he was found to have visual disturbances which resolved and he was discharged with no neurological deficits. DISCUSSION: PRES with both vasogenic and cytotoxic edema is rare. Our patient had a recent MRI brain and PET/CT for tumor staging, which was negative for brain metastasis. There was a lack of evidence supporting an alternative cause for development of cytotoxic edema making PRES the most likely cause. Several studies have reported cytotoxic edema in PRES. In them, endothelial dysfunction seems to cause both vasogenic and cytotoxic edema occurs in PRES, with areas surrounding marked vasogenic edema usually progressing to cytotoxic edema. CONCLUSIONS: There is increasing evidence for development of PRES with several chemotherapy agents like carboplatin/paclitaxel. It may be characterized by vasogenic as well as cytotoxic edema. Cytotoxic edema is probably related to local decreased perfusion and arteriolopathy. Further research is warranted to understand the pathophysiologic mechanisms involved. It is important to recognize symptoms early and have a high clinical suspicion in spite of radiological evidence of cytotoxic edema, as PRES generally has an excellent prognosis with complete resolution. Reference #1: Janjua, T. K., Hassan, M., Afridi, H. K., & Zahid, N. A. (2017). Oxaliplatin-induced posterior reversible encephalopathy syndrome (PRES). BMJ case reports, 2017, bcr2017221571. https://doi.org/10.1136/bcr-2017-221571 Reference #2: Roth, C., & Ferbert, A. (2011). The posterior reversible encephalopathy syndrome: what's certain, what's new?. Practical neurology, 11(3), 136 -144. https://doi.org/10.1136/practneurol-2011-000010 Reference #3: Gao, B., Yu, B. X., Li, R. S., Zhang, G., Xie, H. Z., Liu, F. L., & Lv, C. (2015). Cytotoxic Edema in Posterior Reversible Encephalopathy Syndrome: Correlation of MRI Features with Serum Albumin Levels. AJNR. American journal of neuroradiology, 36(10), 1884 -1889. https://doi.org/10.3174/ajnr.A4379 DISCLOSURES: No relevant relationships by Bilal Bangash, source=Web Response No relevant relationships by Michael Buscher, source=Web Response No relevant relationships by Jay Parekh, source=Web Response No relevant relationships by Prachi Pednekar, source=Web Response No relevant relationships by Pranav Sharma, source=Web Response