SUMMARY: Autoimmune encephalitis is a relatively new category of immune-mediated disease involving the central nervous system that demonstrates a widely variable spectrum of clinical presentations, ranging from the relatively mild or insidious onset of cognitive impairment to more complex forms of encephalopathy with refractory seizure. Due to its diverse clinical features, which can mimic a variety of other pathologic processes, autoimmune encephalitis presents a diagnostic challenge to clinicians. Imaging findings in patients with these disorders can also be quite variable, but recognizing characteristic findings within limbic structures suggestive of autoimmune encephalitis can be a key step in alerting clinicians to the potential diagnosis and ensuring a prompt and appropriate clinical work-up. In this article, we review antibody-mediated encephalitis and its various subtypes with a specific emphasis on the role of neuroimaging in the diagnostic work-up. ABBREVIATIONS:

Coronavirus disease 2019 (COVID-19) is associated with a severe inflammatory response. Inflammation affects atherosclerotic plaque vulnerability and promotes a thrombogenic environment. We report a series of 6 patients with COVID-19 with acute ischemic stroke due to intraluminal carotid artery thrombus presenting during an 8-day period. Six patients were included (5 men) with a mean age of 65.8 years (range, 55-78 years). COVID-19 was diagnosed by detection of Severe Acute Respiratory Syndrome coronavirus 2 in 5 patients and was presumed due to typical clinical and imaging findings in 1 patient. All patients had vascular risk factors including diabetes (83%), hyperlipidemia (100%), and smoking (17%). Four patients presented with large infarcts with initial NIHSS scores of 24-30. During their hospitalization, all patients had elevated D-dimer and C-reactive protein levels, 5 patients had elevated lactate dehydrogenase and ferritin levels, 3 had elevated interleukin-6 levels, and 2 had elevated troponin levels. Inflammation related to COVID-19 may result in rupture of vulnerable atherosclerotic plaques, resulting in thrombosis and acute ischemic stroke.

The authors describe a dedicated therapeutic vertebroplasty technique that uses newly designed instruments, acrylic cement, and dual guidance with ultrasonography and computed tomography for pain control in patients with bone failure, and report their experience. Between 1990 and 2002, they performed 868 percutaneous cementoplasty procedures in patients with severe osteoporosis, vertebral tumors, and symptomatic hemangiomas. In patients with osteoporosis, satisfactory results were obtained in 78% of cases; in patients with vertebral tumors, satisfactory results were obtained in 83% of cases; and in patients with hemangiomas, satisfactory results were obtained in 73% of cases. In the global series of 868 cementoplasties, an epidural leak was observed in 15 cases, which caused neuralgia in only three patients without spinal cord compression. In two patients, an asymptomatic pulmonary embolism was detected. The needle of the new vertebroplasty set is designed with side wings for easier rotation and removal. The screw syringe increases the precision of injection. The risk of leak is substantially reduced. The system is safe, reduces the cement manipulation time, and allows excellent control of the injection. The authors performed 130 vertebroplasties with this system without major complications.

To the Editor:Morbidity and mortality associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are extremely visible 1 ; however, the effect of the COVID-19 pandemic on the management of other pathologies requiring complex interventions and critical care resources-the bystander effect 2 -is not well described. This is certainly true of stroke patients whose clinical outcomes are a function of early presentation, timely diagnosis, emergent intervention, and critical care management. [3][4][5] With the arrival of COVID-19 cases in the month of March in the hotspot of Michigan, we describe the bystander effect of the COVID-19 pandemic on ischemic and hemorrhagic stroke. METHODSThis is a retrospective analysis of deidentified data submitted from 11 Comprehensive Stroke Centers (CSCs) and 1 Primary Stroke Center (PSC) in Michigan and northwest Ohio. The study was approved by the University Institutional Review Board. Patient consent was not required given the retrospective nature of the study. Using Poisson regression analysis, we calculated the incidence-rate ratios (IRRs) comparing the study period of March 2020 to each of the control periods (February 2020 and March 2019). Additionally, the unpaired t-test for continuous variables and the Chi-square test for categorical variables were used as appropriate.

Four existing minimally invasive techniques for the treatment of primary and secondary bone tumors-alcoholization (ethanol ablation), cementoplasty, radio frequency ablation, and laser photocoagulation-are reviewed and discussed. Aspects of each technique, including mechanism of action, equipment, patient selection, treatment technique, and recent patient outcome are presented.