Harahsheh, Ehab

Introduction: Embolic stroke of undetermined source (ESUS) is a clinical paradigm that helps to classify and lead investigations into cryptogenic stroke. Diagnostic evaluation of ESUS involves investigating several potential etiologies of stroke. One such etiology includes antiphospholipid syndrome (APLS), a syndrome known to cause hypercoagulability. Clinical characteristics of primary APLS in ESUS have not been described. Methods: This is an IRB approved, retrospective study including patients from 2015-2020 who were seen at Mayo Clinic, were diagnosed with ESUS, and had APLS testing (anti-cardiolipin, beta-2 glycoprotein, or lupus anticoagulant). Baseline characteristics and radiographic features were collected and compared between patients who were and were not diagnosed with APLS, as well as between patients who were and were not APLS antibody positive. Results: Our study included 206 patients. Positive APLS antibody testing was seen in 21 (10%) patients. Of those patients, 8 (4%) received a formal diagnosis of APLS. Compared to controls, patients with positive APLS antibodies as well as those diagnosed with APLS were more likely to have a history of cancer (20 [11%] APLS antibody negative vs 7 [33%] APLS antibody positive p=0.004) (23 [12%] APLS diagnosis negative vs 4 [50%] APLS diagnosis p=0.002). Mean age in primary APLS was greater, 57 years old APLS antibody negative vs 69 years old APLS antibody positive (p<0.001) and 58 years old APLS diagnosis negative vs 75 years old APLS diagnosis (p=0.001) (Table 1). Regressions analyses examining infarct topography and rate of hemorrhagic transformation were non-significant between groups (p>0.1) Conclusion: APLS presenting as ESUS is associated with older age and history of malignancy. We speculate this finding may underscore the need to consider hypercoagulable conditions more broadly in stroke evaluations of older populations. Larger cohorts and longer follow up will be required to validate this observation.

Abstract Background Despite the increasing incidence of neuroinvasive West Nile virus (NiWNV) infection in the US, the spectrum of disease characteristics and neuroimaging findings in immunosuppressed (IS) individuals are not adequately described. We aimed to compare the clinical characteristics and outcomes of NiWNV infection in IS and immunocompetent (IC) patients. Methods We extracted relevant data from all NiWNV patients hospitalized 7/2003-10/2021 at Mayo Clinic hospitals. Cohort was inclusive of patients from the recent historic WNV outbreak in Arizona in 2021. Chi-Square or Kruskal-Wallis and logistic regression were used to compare relevant variables and determine predictors of mortality respectively. Results We included 115 patients (72 IC and 43 IS), mean age 63.5 years; neurologic syndromes included meningoencephalitis (85.2%), encephalomyelitis (8.7%) and myeloradiculitis (6.1%). Presenting symptoms were malaise (72%), fever (66%), altered mentation (64%), gastrointestinal (47%) and myalgia (35.7%). MRI brain was abnormal in 62.8% (49/78), demonstrating T2/FLAIR hyperintensities in 47.4% (brainstem, thalamus, temporal lobes), leptomeningeal enhancement (16.7%) and diffusion restriction (20.5%). Altered mental status (76.7% vs 56.9%), myalgia (44.4% vs. 20.9%), myoclonus (18.6% vs. 4.2%) and thalamic MRI T2 FLAIR abnormalities (11.4% vs 0%) were more common in IS patients. Higher CSF WBC counts were observed in IC vs IS patients (P&lt; 0.05). Immunosuppressed patients were more likely to be treated with intravenous immunoglobulin (44.2% vs 8.3% p=&lt; 0.001) and/or interferon therapy (32.6% vs 6.9%, p=0.0003) and had increased odds of 90-day mortality on multivariable analysis (Adjusted Odds Ratio, AOR 2.22; 95% CI 1.065-4.627, p=0.0334). In the IS subgroup, ICU admission, mechanical ventilation, and Glasgow coma scale of &lt; 8 were associated with reduced overall survival/increased 90-day mortality (p&lt; 0.005). Conclusion Individuals presenting in summer/fall months with the aforementioned symptoms and/or MRI abnormalities should be evaluated for NiWNV infection. Compared to the immunocompetent, immunosuppressed patients with NiWNV are at a significantly greater mortality risk. Novel and effective antiviral therapies aimed at improving outcomes are warranted. Disclosures All Authors: No reported disclosures.