Dynamic Imaging of Blood Coagulation Within the Hematoma of Patients With Acute Hemorrhagic Stroke

BACKGROUND

The dynamics of blood clot (combination of Hb [hemoglobin], fibrin, and a higher concentration of aggregated red blood cells) formation within the hematoma of an intracerebral hemorrhage is not well understood. A quantitative neuroimaging method of localized coagulated blood volume/distribution within the hematoma might improve clinical decision-making.

METHODS

The deoxyhemoglobin of aggregated red blood cells within extravasated blood exhibits a higher magnetic susceptibility due to unpaired heme iron electrons. We propose that coagulated blood, with higher aggregated red blood cell content, will exhibit (1) a higher positive susceptibility than noncoagulated blood and (2) increase in fibrin polymerization-restricted localized diffusion, which can be measured noninvasively using quantitative susceptibility mapping and diffusion tensor imaging. In this serial magnetic resonance imaging study, we enrolled 24 patients with acute intracerebral hemorrhage between October 2021 to May 2022 at a stroke center. Patients were 30 to 70 years of age and had a hematoma volume >15 cm3 and National Institutes of Health Stroke Scale score >1. The patients underwent imaging 3×: within 12 to 24 (T1), 36 to 48 (T2), and 60 to 72 (T3) hours of last seen well on a 3T magnetic resonance imaging system. Three-dimensional anatomic, multigradient echo and 2-dimensional diffusion tensor images were obtained. Hematoma and edema volumes were calculated, and the distribution of coagulation was measured by dynamic changes in the susceptibilities and fractional anisotropy within the hematoma.

RESULTS

Using a coagulated blood phantom, we demonstrated a linear relationship between the percentage coagulation and susceptibility (R2=0.91) with a positive red blood cell stain of the clot. The quantitative susceptibility maps showed a significant increase in hematoma susceptibility (T1, 0.29±0.04 parts per millions; T2, 0.36±0.04 parts per millions; T3, 0.45±0.04 parts per millions; P<0.0001). A concomitant increase in fractional anisotropy was also observed with time (T1, 0.40±0.02; T2, 0.45±0.02; T3, 0.47±0.02; P<0.05).

CONCLUSIONS

This quantitative neuroimaging study of coagulation within the hematoma has the potential to improve patient management, such as safe resumption of anticoagulants, the need for reversal agents, the administration of alteplase to resolve the clot, and the need for surgery.

Young Female With Hypereosinophilia, Rash, and Gait Disturbance: A Case Report

Eosinophilia is known to be associated with a multitude of co-morbidities. However, unexplained eosinophilia poses a diagnostic challenge, and the methods used to investigate unexplained eosinophilia vary from region to region. In this case report, we describe a unique case of a young female presenting with marked eosinophilia to a tertiary hospital in the northeastern United States. Our patient presented with a few weeks of lower extremity rash, gait instability, and new onset marked eosinophilia. We further report the investigations undertaken during the hospitalization to highlight the broad differential diagnoses. Later, we provide a consolidated diagnosis of eosinophilic granulomatosis with polyangiitis (EPGA) based on the clinical context. Our patient was eventually started on a high-dose steroid taper. In the following weeks, while we noted gait improvement, we observed biomarker (eosinophilia) relapse after steroid taper. Depending on symptom progression, we planned for future remission induction with immunomodulatory agents. The report further discusses the pleomorphic presentation of EPGA cases, the natural course of disease, and currently available prognostic indices.

When a synonymous mutation breaks the silence in a thalassaemia patient

Synonymous mutations were considered to lack functional roles in human diseases; however, distinguishing deleterious synonymous mutations from benign ones is still a challenge. In this article, we identified a deleterious synonymous mutation β-codon 16 (C>T). HBB: c.51C>T, in compound heterozygous form with known β-thalassaemia mutation patients who clinically presented as non-transfusion-dependent thalassaemia (NTDT). A total of 9 families with 11 compound heterozygous index cases were reported. In the heterozygous state, codon 16 (C>T) mutation results in borderline HbA2 (3.18 ± 0.36%) and slightly reduced RBC indices (RBCs: 4.73 ± 0.75 × 106 /μL, Hb: 12.26 ± 2.60 g/dL, MCV: 79.48 ± 8.40 fL, MCH: 25.95 ± 4.15 pg). The compound heterozygous patients showed elevated HbA2 (5.98 ± 1.17%) and HbF (12.75 ± 7.51%) and presented clinically as NTDT with a mean Hb of 6.95 ± 1.29 g/dL. Many of them were dependent on few transfusions and had mild splenomegaly. Of the 11 patients, 5 (45.4%) were treated with hydroxyurea. This study highlights the clinical significance of synonymous mutation, when inherited with other β-thalassaemia mutations leading to the phenotype of NTDT. Thus, the study would help to improve screening protocols for β-thalassaemia carriers, which will ultimately improve the prevention programme.

Abstract WMP23: Dynamic Imaging Of Blood Coagulation Within The Hematoma Of Patients With Acute Intracerebral Hemorrhage

Objective: To serially quantify the blood coagulation within hematoma of patients with hyper-acute intracerebral hemorrhagic (ICH) stroke using non-invasive quantitative susceptibility mapping (QSM) MRI.

Introduction: A blood clot is a combination of aggregated red blood cells, fibrin, platelets, hemosiderin, and other cell debris. An accurate evaluation of clot formation within hematoma could advance the clinical management of hematoma expansion, blood pressure management, and reversal of anticoagulants. Post-ICH hemolysis changes the heme iron oxidation state from oxy to deoxyhemoglobin (deoxy-Hb) resulting in unpaired iron electrons on aggregated RBC’s deoxy-Hb inducing magnetic susceptibility (χ). Therefore, a region with a higher number of aggregated RBC deoxy-Hb molecules, the dominant component of clots, will exhibit a higher positive χ susceptibility. We hypothesized that coagulated blood within hematoma will exhibit a higher positive χ in comparison to the non-clotted which can be quantified using quantitative susceptibility mapping (QSM), which is an advanced MRI image-processing algorithm.

Methods: For proof of concept, we measured susceptibilities of 5 human blood phantoms with various percentages of the clot. Twenty-four patients with acute spontaneous ICH were enrolled and serially imaged 3 times within 12-24 (T1), 36-48 (T2), and 60-72(T3) hours of last known well (LNW). A 3D anatomical and multi-echo gradient echo images were obtained using a 3T MRI system. Hematoma and edema volumes were segmented and used as a region of interest (ROI). The rate of coagulation was assessed by measuring the change in susceptibilities within the hematoma.

Results: The blood phantom exhibited a linear relationship between the percent coagulation and χ (R 2 =0.91). The QSM maps showed a significant increased in hematoma susceptibility over time (T1=0.29 ± 0.04, T2=0.36 ± 0.04, T3= 0.45 ± 0.04 ppm, p<0.0001). The overall average rate of coagulation was 0.00290 ± 0.0029 ppm per hour. No significant change in hematoma volume (18.9 ±3.1 cc) over time. A significant edema growth over time (T1=25.3 ± 3.6, T2= 28.1 ± 3, T3= 32.37 cc, p<0.05).

Conclusion: In conclusion, we present novel surrogate imaging markers of coagulation within the hematoma of ICH.

Mobile Stroke Units: Current Evidence and Impact

PURPOSE OF REVIEW

Several approaches have been developed to optimize prehospital systems for acute stroke given poor access and significant delays to timely treatment. Specially equipped ambulances that directly initiate treatment, known as Mobile Stroke Units (MSUs), have rapidly proliferated across the world. This review provides a comprehensive summary on the efficacy of MSUs in acute stroke, its various applications beyond thrombolysis, as well as the establishment, optimal setting and cost-effectiveness of incorporating an MSU into healthcare systems.

RECENT FINDINGS

MSUs speed stroke treatment into the first "golden hour" when better outcomes from thrombolysis are achieved. While evidence for the positive impact of MSUs on outcomes was previously unavailable, two recent landmark controlled trials, B_PROUD and BEST-MSU, show that MSUs result in significantly lesser disability compared to conventional ambulance care. Emerging literature prove the significant impact of MSUs. Adaptability however remains limited by significant upfront financial investment, challenges with reimbursements and pending evidence on their cost-effectiveness.

Abstract TP262: Effect Of Prehospital Blood Pressure Fluctuations On Early Neurological Changes In Acute Ischemic Stroke Patients With Large Vessel Occlusion

Introduction: Blood pressure fluctuations in the acute phase of large vessel occlusion (LVO) ischemic stroke are associated with infarct progression and poor outcomes. We evaluated the association of prehospital blood pressure variations on a Mobile Stroke Unit (MSU) with early neurological change.

Methods: Prospectively-derived data were analyzed from tPA-eligible LVO patients treated and transported on the MSU, identified by hyperdense artery on CT or arterial occlusion on CTA. Patients were categorized by change in mean arterial pressure (ΔMAP) of > 10 mm Hg vs Δ MAP < 10 mmHg from arrival of MSU on-scene to arrival to the emergency department (ED). A sub-analysis of patients with ΔMAP > 10 mm Hg compared those whose MAP decreased by > 10 mm Hg vs those whose MAP increased by > 10 mm Hg. The primary outcome was 24-hour change in NIHSS. Groups were compared using Chi-square/Fisher’s exact test for categorical variables and Wilcoxon rank sum test for continuous variables.

Results: A total of 39 tPA-eligible LVO patients were identified, 19 with ΔMAP < 10mm Hg and 20 with ΔMAP > 10mm Hg. Baseline characteristics were comparable between groups including NIHSS (18.0 [11.0, 21.0] vs 20.0 [16.8, 25.8]) (Table 1). A similar percentage from each group received tPA and thrombectomy. Upon presentation to ED, 7/19 (37%) patients with ΔMAP < 10mm Hg had a 30% improvement in NIHSS, compared to 4/20 (20%) patients with ΔMAP >10mm Hg (p=0.417). The 24-hour change in NIHSS was also similar (ΔMAP < 10mm Hg = 7.0 [3.5, 12.0] vs ΔMAP > 10 mm Hg 10.0 [4.0, 16.0], p=0.517). Among patients with ΔMAP of 10mm Hg group, those with MAP decrease by > 10 mm Hg had a 10 point [7.0, 16.0] improvement in NIHSS vs 6.0 [2.5, 15.0] point improvement in those whose MAP increased by > 10 mm Hg (p=0.169).

Conclusion: Though limited by a small sample size, prehospital blood pressure fluctuations in LVO stroke patients on a MSU were not associated with early clinical changes.

Psychophysics Experiment to Check the Temperature Impacts Over Human Fingertips for the Application of Textural Applications in Haptics Technology

Psychophysical methods in haptic technology help in comparative study and eventually be a data set to achieve realism over skin sensation. Textural based haptic applications are widely developed using tactile displays over human fingertips. The tactile displays work on open-loop admittance feedback system and are controlled with flexible parameters by ignoring the impact of noise or disturbance variables. Human skin undergoes various noise factors like temperature, humidity, sweat, and influence of alternative senses. This paper presents the newly adopted method of psychophysics to study the influence of environmental conditions over perceiving textural surfaces. The paper adopts the detection mode of psychophysics which uses perception time as an output parameter for understanding perception memory of the human skin. We have recorded the period of the perception in three environmental conditions over human subjects under a single blindfold method to study the behaviour of human skin at fingertips. The perception time of stimulus is analysed with arithmetic average roughness value (Ra) to understand the tolerance factor required during tactile based textural applications. The proposed method is simple to structure and improves in creating the dataset required to consider the noise factor for an open-loop admission feedback system.

A Case of Guillain-Barré Syndrome Associated With COVID-19

A novel member of human RNA coronavirus, which is an enveloped betacoronavirus, has been termed severe acute respiratory syndrome coronavirus-2 (SARS COV-2). The illness caused by SARS COV-2 is referred to as the coronavirus disease 2019 (COVID-19). It is a highly contagious disease that has resulted in a global pandemic. The clinical spectrum of COVID-19 ranges from asymptomatic illness to acute respiratory distress syndrome, septic shock, multi-organ dysfunction, and death. The most common symptoms include fever, fatigue, dry cough, dyspnea, and diarrhea. Neurological manifestations have also been reported. However, the data on the association of Guillain-Barré syndrome (GBS) with COVID-19 are scarce. We report a rare case of a COVID-19-positive 36-year-old immunocompromised male who presented with clinical features of GBS. His clinical examination showed generalized weakness and hyporeflexia. The cerebrospinal fluid (CSF) analysis showed albuminocytological dissociation. Intravenous immunoglobulin (IVIG) was administered based on the high clinical suspicion of GBS. The patient’s neurological condition worsened with progression to bulbar weakness and ultimately neuromuscular respiratory failure requiring mechanical ventilation. His nerve conduction studies were consistent with demyelinating polyneuropathy. He received five plasma exchange treatments and was successfully weaned from mechanical ventilation. A brain and cervical spine magnetic resonance imaging was obtained to rule out other causes, which was normal. COVID-19 is believed to cause a dysregulated immune system, which likely plays an important role in the neuropathogenesis of GBS.

Assessment of Right Ventricular Strain by Computed Tomography Versus Echocardiography in Acute Pulmonary Embolism

BACKGROUND

Right ventricular strain (RVS) identifies patients at risk of hemodynamic deterioration from pulmonary embolism (PE). Our hypothesis was that chest computed tomography (CT) can provide information about RVS analogous to transthoracic echocardiography (TTE) and that RVS on CT is associated with adverse outcomes after PE.

METHODS

Consecutive emergency department patients with acute PE were prospectively enrolled and clinical, biomarker, and imaging data were recorded. CTs were overread by two radiologists. We compared diagnoses of RVS on CT (defined as right ventricle:left ventricle ratio ≥ 0.9 or interventricular septal bowing) to echocardiography (defined as right ventricular hypokinesis, right ventricular dilatation, or interventricular septal bowing). We calculated the test characteristics (with 95% confidence interval) of CT and TTE for a composite outcome of severe clinical deterioration, thrombolysis/thrombectomy, or death within 5 days.

RESULTS

A total of 298 patients were enrolled; 274 had CT and 118 had formal TTE. Of the 104 patients who had both CT and TTE, the mean (±SD) age was 58 (±17) years; 50 (48%) were female and 88 (85%) were Caucasian. Forty-two (40%) had RVS by TTE and 75 (72%) had RVS by CT. CT and TTE agreed on the presence or absence of RVS in 61 (59%) cases (κ = 0.24). Using TTE as criterion standard, the test characteristics of CT for RVS were as follows: sensitivity = 88%, specificity = 39%, positive predictive value = 49%, and negative predictive value = 83%. Fourteen (13%) patients experienced severe clinical deterioration or required hospital-based intervention within 5 days. This occurred in 30% of patients with RVS on both TTE and CT, 20% of patients with RVS on TTE alone, 3% of patients with RVS on CT alone, and 4% of patients without RVS on either modality.

CONCLUSIONS

In acute PE, CT is highly sensitive but only moderately specific for RVS compared to TTE. RVS on both CT and TTE predicts more events than either modality alone. TTE confers additional positive prognostic value compared to CT in predicting post-PE clinical deterioration.

In vitro profiling of antimethicillin-resistant Staphylococcus aureus activity of thymoquinone against selected type and clinical strains

This study explores antimethicillin-resistant Staphylococcus aureus (MRSA) activity of a bioactive phytochemical constituent, thymoquinone obtained from the medicinal herb, Nigella sativa Linn. Based on initial assessment on crude extract of seeds of Nigella sativa Linn, the pure active constituent was employed in the study. A total of 99 MRSA strains which comprised of 40 types and 59 clinical strains were selected for the study. Minimum inhibitory concentration (MIC), bactericidal activity, postantibiotic effect (PAE) and propensity to select resistant mutants were determined using standard protocols. Results revealed that thymoquinone exhibited MIC in the range of 8-16 μg ml(-1) and MIC90 of 16 μg ml(-1) against MRSA strains. It was bactericidal to MRSA by demonstrating >3 log kill. It showed a longer PAE of 3·2 ± 0·2 h. Upon exposure to high-density inoculum of MRSA, it did not select resistant mutants. Transmission electron microscopy of thymoquinone-treated MRSA showed no lysis but damage to cell wall and cell membrane which corroborated well with the salt tolerance and bacteriolysis assays. In conclusion, MIC90 , bactericidal property, longer PAE, absence of resistant mutant selection and damages in cell membrane and cell wall imply a promising anti-MRSA activity of thymoquinone.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first detailed report on anti-MRSA activity of thymoquinone. The assessment was made with both type and clinical strains. Thymoquinone may be a potential lead compound which can be further optimized to discover novel anti-MRSA agents.

Sjogren-Larsson syndrome: A rare neurocutaneous disorder

Sjogren-Larsson syndrome is an autosomal recessive disorder characterized by defective activity of fatty aldehyde dehydrogenase. It presents as a triad of congenital ichthyosis, spastic diplegia, and mental retardation. The pathology behind this syndrome is the failure of degradation of fatty aldehydes. This case is presented for its rarity.

A rare case of glycine encephalopathy unveiled by valproate therapy

Glycine encephalopathy (GE) or nonketotic hyperglycinemia is an autosomal recessive disorder due to a primary defect in glycine cleavage enzyme system. It is characterized by elevated levels of glycine in plasma and cerebrospinal fluid usually presenting with seizures, hypotonia, and developmental delay. In our case, paradoxical increase in seizure frequency on starting sodium valproate led us to diagnose GE.

Association between electrocardiographic findings, right heart strain, and short-term adverse clinical events in patients with acute pulmonary embolism

BACKGROUND

Electrocardiographic (ECG) changes may be seen with pulmonary emboli (PE). Whether ECG is associated with short-term adverse clinical events after PE is less well established.

HYPOTHESIS

ECG findings are associated with short-term clinical deterioration after PE.

METHODS

Consecutive adult PE patients were enrolled in an academic emergency department from 2008 to 2011. The primary outcome was right heart strain (RHS) on echocardiogram or CT pulmonary angiography, or TnT ≥0.1 ng/mL. We derived an ECG (TwiST) score that is associated with RHS and short-term adverse clinical events.

RESULTS

We enrolled 298 patients with PE. On multivariate analysis, T-wave inversion in leads V(1) through V(3) (OR: 4.7, 95% confidence interval [CI]: 1.7-13.2), S wave in lead I (OR: 2.0, 95% CI: 1.1-3.5), and tachycardia (OR: 2.5, 95% CI: 1.3-4.8) were associated with RHS. A TwiST score ≤2 (n = 210, 72%) was 84% (95% CI: 77%-90%) sensitive for the absence of RHS, whereas a TwiST score ≥5 (n = 47, 16%) was 93% (95% CI: 88%-97%) specific for the presence of RHS.

CONCLUSIONS

A simple ECG (TwiST) score can identify patients likely or not likely to have RHS with >80% specificity and sensitivity and may assist in identifying patients with acute PE at risk for adverse clinical events before pursuing other advanced imaging tests.

Potential modulation on P-glycoprotein and CYP3A by soymilk and miso: in vivo and ex-vivo studies

P-glycoprotein (P-gp) and CYP3A4 both play very important roles in drug bioavailability, resistance and interactions. Our in vitro studies indicated that P-gp function was activated by many isoflavones. This study investigated the in vivo effects of soymilk and miso, isoflavone-rich soy foods, on P-gp and CYP3A by tracing the pharmacokinetics of cyclosporine (CSP), a probe drug of P-gp. Rats were orally administered CSP with and without soymilk or miso. A specific monoclonal fluorescence polarisation immunoassay was used to determine the blood concentration of CSP. The results showed that soymilk and miso significantly decreased the C(max) of CSP by 64.5% and 78.3%, and reduced the AUC(0-540) by 64.9% and 78.3%, respectively. Mechanism studies revealed that the activities of P-gp and CYP3A4 were induced by soymilk and miso. In conclusion, ingestion of soymilk and miso significantly activated the functions of P-gp and CYP3A.

Association between the Pulmonary Embolism Severity Index (PESI) and short-term clinical deterioration

The Pulmonary Embolism Severity Index (PESI) has been shown to predict 30 and 90 day mortality after PE. However, whether the PESI predicts patients who will be free of clinically adverse outcomes during a typical hospitalisation is not known. Retrospective analysis of Emergency Department patients with PE from May 2006 to April 2008. We compiled demographics, data to calculate the PESI and a composite outcome. Patients were considered to have a negative PESI if they were in category I or II (≤85 points). Patients were considered to have the composite outcome if, within five days of diagnosis, they: A) had recurrent PE; B) developed a new cardiac dysrhythmia; C) required advanced cardiac life support; D) required respiratory support; E) required vasopressors; F) received thrombolysis; G) had major bleeding; H) returned to the ED; I) died. We enrolled 245 patients with PE. Of these, 115 (47%) were male, 204 (83%) were white. The mean age was 57 ± 17 years. The PESI identified 109 (44%) as low risk and 136 (56%) as high risk. Sixty-one (26%) patients had the outcome, of whom nine (14%) were characterised as low risk by the PESI. Test characteristics were: sensitivity 86% (95% confidence interval [CI]: 75%-93%), specificity 55% (95% CI: 47%-62%), NPV 63% (95% CI: 55%-70%), PPV 40% (95% CI: 31%-49%), LR(+) 1.9 (95% CI: 1.57-2.30) and LR(-) 0.26 (95% CI: 0.14-0.48). Of the patients who had an adverse clinical event or required a hospital-based intervention within the first five days after PE diagnosis, 14% were categorised by the PESI as safe for discharge [corrected] .

HIFU procedures at moderate intensities—effect of large blood vessels

A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams.

Four-photon interferometry for secure quantum key distribution

We introduce a quantum key distribution scheme based on four-photon coincidence measurements. This scheme offers a much higher degree of security than current quantum key distribution methods and minimizes problems due to photon losses and dark counts.

Achromatic phase-shifting for white-light interferometry

The geometric (Pancharatnam) phase provides a method of introducing a variable phase shift that is almost independent of the wavelength and opens up new possibilities in broadband interferometry.

Interferometric testing of high-numerical-aperture convex surfaces

Interferometric tests of convex surfaces for large-N.A. lens systems often present problems. We show how such surfaces can be tested with a reference surface having a much smaller N.A. by making use of the aplanatic imaging properties of a spherical surface.

Phase-shifting errors in interferometric tests with high-numerical-aperture reference surfaces

The errors introduced by moving a spherical reference surface to generate a phase shift between the beams in a Fizeau interferometer are discussed.

Rehalogenating bleaches for photographic phase holograms. 3: Mechanism of material transfer

Rehalogenating bleaches produce a phase hologram by material transfer from the exposed areas to neighboring unexposed areas. Efficient material transfer requires the bath to contain an excess of bromide, suggesting that a process similar to Ostwald ripening is involved.