Abstract TMP60: Misdiagnosis Of Posterior Reversible Encephalopathy Syndrome And Reversible Cerebral Vasoconstriction Syndrome In The Emergency Department

Introduction: Syndromes of cerebrovascular dysregulation such as posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS) can be challenging to diagnose given their rarity and the need for advanced neuroimaging to diagnose them. We sought to measure the rate of potential PRES/RCVS misdiagnosis in the ED and identify features associated with misdiagnosis. Methods: We conducted a retrospective cohort study of patients with PRES/RCVS using deidentified administrative claims data from all nonfederal EDs and hospitals across 11 states from 2016-2018. To identify patients with PRES/RCVS, we used the previously validated ICD-10-CM codes I67.841 and I67.83. We defined patients with a probable misdiagnosis of PRES/RCVS as those with an ED visit resulting in discharge to home that occurred within the 14 days prior to their PRES/RCVS hospitalization. Only preceding ED visits where a non-specific neurological condition (e.g., headache, dizziness, numbness) was diagnosed were considered instances of probable ED misdiagnosis. Standard tests of comparison between patients with versus without probable misdiagnosis were used to identify patient-level and ED facility-level features associated with misdiagnosis. Results: We identified 4,633 patients hospitalized for PRES/RCVS; the majority (4,169; 90.0%) had PRES. A total of 210 patients (4.5%, 95% CI: 3.95-5.17) had at least one preceding ED visit with a probable misdiagnosis; these patients were younger (mean age 47.7 vs. 53.8 years; P<0.001) and more often female (80.4% vs. 69.7%: P<0.001). Misdiagnosed patients generally had fewer vascular risk factors including hypertension (46.3% vs. 84.9%; P<0.001) and more often had a history of headache (81.1% vs. 22.6%; P<0.001) and psychiatric disease (48.6% vs. 34.9%; P<0.001) as compared to patients without an ED misdiagnosis. Facility factors inversely associated with probable misdiagnosis included an ACGME-approved residency (63.4% vs. 75.3%; P<0.001) and on-site neurological services (74.9% vs. 84.7%; P<0.001). Conclusion: Probable ED misdiagnosis occurred in nearly 1 of 20 cases of PRES/RCVS in a large, multistate cohort.