Introduction The aim of this study is to evaluate computed tomography perfusion (CTP) during admission baseline period (days 0–3) in aneurysmal subarachnoid hemorrhage (A-SAH) for development of vasospasm. Methods Retrospective analysis was performed on A-SAH patients from Dec 2004 to Feb 2007 with CTP on days 0–3. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were analyzed for qualitative perfusion deficits. Quantitative analysis was performed using region-of-interest placement to obtain mean CTP values. Development of vasospasm was determined by a multistage hierarchical reference standard incorporating both imaging and clinical criteria. Student's t test and threshold analysis were performed. Results Seventy-five patients were included, 37% (28/75) were classified as vasospasm. Mean CTP values in vaso-spasm compared to no vasospasm groups were: CBF 31.90 ml/100 g/min vs. 39.88 ml/100 g/min (P<0.05), MTT 7.12 s vs. 5.03 s (P<0.01), and CBV 1.86 ml/100 g vs. 2.02 ml/100 g (P=0.058). Fifteen patients had qualitative perfusion deficits with 73% (11/15) developed vasospasm. Optimal threshold for CBF is 24–25 mL/100 g/min with 91% specificity and 50% sensitivity, MTT is 5.5 s with 70% specificity and 61% sensitivity and CBV is 1.7 mL/ 100 g with 89% specificity and 36% sensitivity. Conclusion These initial results support our hypothesis that A-SAH patients who develop vasospasm may demonstrate early alterations in cerebral perfusion, with statistically significant CBF reduction and MTT prolongation. Overall, CTP has high specificity for development of vasospasm. Future clinical implications include using CTP during the baseline period for early identification of A-SAH patients at high risk for vasospasm to prompt robust preventative measures and treatment.

Background/Objective: Severe Acute Respiratory Syndrome Coronavirus-2 (SARSCoV-2) is a novel coronavirus strain that most commonly affects the respiratory system with observational studies and case reports suggesting this virus may target the central nervous system. To date there has been one case report of COVID-19 related acute necrotizing encephalopathy.Methods: Observational study of COVID-19 patients admitted to two hospitals of a large metropolitan health maintenance organization serving over 600,000 members using retrospective electronic and radiographic medical record evaluation across 4 months (March – June of 2020) after multiple cases of acute necrotizing encephalopathy were diagnosed.Results: During this time frame 216 patients were diagnosed with COVID-19, 106 (49%) required hospitalization, 21 (20%) required admission to the intensive care unit (ICU) and 18 (17%) required intubation. Of the 18, 4 (22%) had clinicoradiologic evidence of acute necrotizing encephalopathy (ANE) diagnosed, two with associated areas of hemorrhage.Conclusions: Acute necrotizing encephalopathy (ANE) with or without hemorrhage, is a rare CNS disease, usually seen in childhood as a complication of viral infections. We identified a high percentage of COVID-19 patients with clinicoradiologic evidence of acute necrotizing encephalopathy in our cohort. To our knowledge, ANE has not been reported in patients with SARS or MERS. Understanding the pathogenesis, neurotropism and effects of the SARS-CoV-2 virus is important in developing treatments and improving morbidity and mortality.