Excited-Band Coherent Delocalization for Improved Optical Lattice Clock Performance

We implement coherent delocalization as a tool for improving the two primary metrics of atomic clock performance: systematic uncertainty and instability. By decreasing atomic density with coherent delocalization, we suppress cold-collision shifts and two-body losses. Atom loss attributed to Landau-Zener tunneling in the ground lattice band would compromise coherent delocalization at low trap depths for our ^{171}Yb atoms; hence, we implement for the first time delocalization in excited lattice bands. Doing so increases the spatial distribution of atoms trapped in the vertically oriented optical lattice by ∼7 times. At the same time, we observe a reduction of the cold-collision shift by 6.5(8) times, while also making inelastic two-body loss negligible. With these advantages, we measure the trap-light-induced quenching rate and natural lifetime of the ^{3}P_{0} excited state as 5.7(7)×10^{-4}  E_{r}^{-1} s^{-1} and 19(2) s, respectively.

Mesenchymal Stem Cell Therapy in Acute Intracerebral Hemorrhage: A Dose-Escalation Safety and Tolerability Trial

BACKGROUND

We conducted a preliminary phase I, dose-escalating, safety, and tolerability trial in the population of patients with acute intracerebral hemorrhage (ICH) by using human allogeneic bone marrow-derived mesenchymal stem/stromal cells.

METHODS

Eligibility criteria included nontraumatic supratentorial hematoma less than 60 mL and Glasgow Coma Scale score greater than 5. All patients were monitored in the neurosciences intensive care unit for safety and tolerability of mesenchymal stem/stromal cell infusion and adverse events. We also explored the use of cytokines as biomarkers to assess responsiveness to the cell therapy. We screened 140 patients, enrolling 9 who met eligibility criteria into three dose groups: 0.5 million cells/kg, 1 million cells/kg, and 2 million cells/kg.

RESULTS

Intravenous administration of allogeneic bone marrow-derived mesenchymal stem/stromal cells to treat patients with acute ICH is feasible and safe.

CONCLUSIONS

Future larger randomized, placebo-controlled ICH studies are necessary to validate this study and establish the effectiveness of this therapeutic approach in the treatment of patients with ICH.

Intravenous ravulizumab in mechanically ventilated patients hospitalised with severe COVID-19: a phase 3, multicentre, open-label, randomised controlled trial

BACKGROUND

The complement pathway is a potential target for the treatment of severe COVID-19. We evaluated the safety and efficacy of ravulizumab, a terminal complement C5 inhibitor, in patients hospitalised with severe COVID-19 requiring invasive or non-invasive mechanical ventilation.

METHODS

This phase 3, multicentre, open-label, randomised controlled trial (ALXN1210-COV-305) enrolled adult patients (aged ≥18 years) from 31 hospitals in France, Japan, Spain, the UK, and the USA. Eligible patients had a confirmed diagnosis of SARS-CoV-2 that required hospitalisation and either invasive or non-invasive mechanical ventilation, with severe pneumonia, acute lung injury, or acute respiratory distress syndrome confirmed by CT scan or x-ray. We randomly assigned participants (2:1) to receive intravenous ravulizumab plus best supportive care (BSC) or BSC alone using a web-based interactive response system. Randomisation was in permuted blocks of six with stratification by intubation status. Bodyweight-based intravenous doses of ravulizumab were administered on days 1, 5, 10, and 15. The primary efficacy endpoint was survival based on all-cause mortality at day 29 in the intention-to-treat (ITT) population. Safety endpoints were analysed in all randomly assigned patients in the ravulizumab plus BSC group who received at least one dose of ravulizumab, and in all randomly assigned patients in the BSC group. The trial is registered with ClinicalTrials.gov, NCT04369469, and was terminated at interim analysis due to futility.

FINDINGS

Between May 10, 2020, and Jan 13, 2021, 202 patients were enrolled in the study and randomly assigned to ravulizumab plus BSC or BSC. 201 patients were included in the ITT population (135 in the ravulizumab plus BSC group and 66 in the BSC group). The ravulizumab plus BSC group comprised 96 (71%) men and 39 (29%) women with a mean age of 63·2 years (SD 13·23); the BSC group comprised 43 (65%) men and 23 (35%) women with a mean age of 63·5 years (12·40). Most patients (113 [84%] of 135 in the ravulizumab plus BSC group and 53 [80%] of 66 in the BSC group) were on invasive mechanical ventilation at baseline. Overall survival estimates based on multiple imputation were 58% for patients receiving ravulizumab plus BSC and 60% for patients receiving BSC (Mantel-Haenszel analysis: risk difference -0·0205; 95% CI -0·1703 to 0·1293; one-sided p=0·61). In the safety population, 113 (89%) of 127 patients in the ravulizumab plus BSC group and 56 (84%) of 67 in the BSC group had a treatment-emergent adverse event. Of these events, infections and infestations (73 [57%] vs 24 [36%] patients) and vascular disorders (39 [31%] vs 12 [18%]) were observed more frequently in the ravulizumab plus BSC group than in the BSC group. Five patients had serious adverse events considered to be related to ravulizumab. These events were bacteraemia, thrombocytopenia, oesophageal haemorrhage, cryptococcal pneumonia, and pyrexia (in one patient each).

INTERPRETATION

Addition of ravulizumab to BSC did not improve survival or other secondary outcomes. Safety findings were consistent with the known safety profile of ravulizumab in its approved indications. Despite the lack of efficacy, the study adds value for future research into complement therapeutics in critical illnesses by showing that C5 inhibition can be accomplished in severely ill patients.

FUNDING

Alexion, AstraZeneca Rare Disease.

Balamuthia mandrillaris encephalitis presenting as a symptomatic focal hypodensity in an immunocompromised patient

We present the case of a 61-year-old woman with a history of orthotopic heart transplant who was hospitalized with new-onset headache. Brain MRI revealed T2 hyperintense signal involving the left occipital lobe with leptomeningeal enhancement and mild vasogenic edema. Initial neurologic examination was normal, however after 7 days she developed imbalance, visual disturbances, night sweats, bradyphrenia, alexia without agraphia, and right hemianopsia. Brain MRI showed enlargement of the left occipital mass and worsening edema. Stereotactic needle biopsy showed non-diagnostic necrosis. The patient continued to deteriorate despite dexamethasone. CSF suggested infection and CMV CSF PCR was positive. The patient received vancomycin, imipenem, and ganciclovir. After obtaining a positive serum Beta-D-Glucan (Fungitell), amphotericin was added. Despite best medical efforts, the patient expired. Postmortem broad-range PCR sequencing of the brain tissue was positive for rare amoeba Balamuthia mandrillaris.

Subrecoil Clock-Transition Laser Cooling Enabling Shallow Optical Lattice Clocks

Laser cooling is a key ingredient for quantum control of atomic systems in a variety of settings. In divalent atoms, two-stage Doppler cooling is typically used to bring atoms to the μK regime. Here, we implement a pulsed radial cooling scheme using the ultranarrow ^{1}S_{0}-^{3}P_{0} clock transition in ytterbium to realize subrecoil temperatures, down to tens of nK. Together with sideband cooling along the one-dimensional lattice axis, we efficiently prepare atoms in shallow lattices at an energy of 6 lattice recoils. Under these conditions key limits on lattice clock accuracy and instability are reduced, opening the door to dramatic improvements. Furthermore, tunneling shifts in the shallow lattice do not compromise clock accuracy at the 10^{-19} level.

Reintubation Summation Calculation: A Predictive Score for Extubation Failure in Critically Ill Patients

Objective

To derive and validate a multivariate risk score for the prediction of respiratory failure after extubation.

Patients and methods

We performed a retrospective cohort study of adult patients admitted to the intensive care unit from January 1, 2006, to December 31, 2015, who received mechanical ventilation for ≥48 h. Extubation failure was defined as the need for reintubation within 72 h after extubation. Multivariate logistic regression model coefficient estimates generated the Re-Intubation Summation Calculation (RISC) score.

Results

The 6,161 included patients were randomly divided into 2 sets: derivation (n = 3,080) and validation (n = 3,081). Predictors of extubation failure in the derivation set included body mass index <18.5 kg/m² [odds ratio (OR), 1.91; 95% CI, 1.12–3.26; P = 0.02], threshold of Glasgow Coma Scale of at least 10 (OR, 1.68; 95% CI, 1.31–2.16; P < 0.001), mean airway pressure at 1 min of spontaneous breathing trial <10 cmH₂O (OR, 2.11; 95% CI, 1.68–2.66; P < 0.001), fluid balance ≥1,500 mL 24 h preceding extubation (OR, 2.36; 95% CI, 1.87–2.96; P < 0.001), and total mechanical ventilation days ≥5 (OR, 3.94; 95% CI 3.04–5.11; P < 0.001). The C-index for the derivation and validation sets were 0.72 (95% CI, 0.70–0.75) and 0.72 (95% CI, 0.69–0.75). Multivariate logistic regression demonstrated that an increase of 1 in RISC score increased odds of extubation failure 1.6-fold (OR, 1.58; 95% CI, 1.47–1.69; P < 0.001).

Conclusion

RISC predicts extubation failure in mechanically ventilated patients in the intensive care unit using several clinically relevant variables available in the electronic medical record but requires a larger validation cohort before widespread clinical implementation.

Guillain-Barré Syndrome After Acute Hepatitis E Infection: A Case Report and Literature Review

INTRODUCTION

Guillain-Barré syndrome precipitated by hepatitis E virus infection is rare, yet its incidence is increasing.

CLINICAL FINDINGS

A 57-year-old man was transferred from another facility with fatigue, orange urine, and progressive weakness over 4 to 6 weeks. Initial laboratory results included total bilirubin, 9.0 mg/dL; direct bilirubin, 6.4 mg/dL; aspartate aminotransferase, 1551 U/L; alanine aminotransferase, 3872 U/L; and alkaline phosphatase, 430 U/L. Immunoglobulin M and quantitative polymerase chain reaction test results were positive for hepatitis E virus. Contrast-enhanced magnetic resonance imaging of the brain and spine showed no gross abnormalities. Analysis of cerebrospinal fluid obtained by lumbar puncture revealed the following (reference values in parentheses): total white blood cell count, 15/μL (0-5/μL), with 33% neutrophils and 54% lymphocytes; protein, 0.045 g/dL (0.015-0.045 g/dL); and glucose, 95 mg/dL (within reference range). Neurological examination revealed weakness in both upper extremities, with proximal strength greater than distal strength. The patient could not elevate either lower extremity off the bed and had areflexia and reduced sensation throughout all extremities.

DIAGNOSIS

Guillain-Barré syndrome secondary to acute hepatitis E virus infection was diagnosed on the basis of clinical characteristics, serum and cerebrospinal fluid analyses, and nerve conduction studies.

CONCLUSIONS

Nurses and clinicians should obtain a thorough history and consider hepatitis E virus infection as a precipitating factor in patients with sensory and motor disturbances consistent with Guillain-Barré syndrome. The case gives insight into the diagnostic process for Guillain-Barré syndrome and highlights the vital role of bedside nurses in evaluating and treating these patients.

Outcomes of COVID-19 With the Mayo Clinic Model of Care and Research

OBJECTIVE

To report the Mayo Clinic experience with coronavirus disease 2019 (COVID-19) related to patient outcomes.

METHODS

We conducted a retrospective chart review of patients with COVID-19 diagnosed between March 1, 2020, and July 31, 2020, at any of the Mayo Clinic sites. We abstracted pertinent comorbid conditions such as age, sex, body mass index, Charlson Comorbidity Index variables, and treatments received. Factors associated with hospitalization and mortality were assessed in univariate and multivariate models.

RESULTS

A total of 7891 patients with confirmed COVID-19 infection with research authorization on file received care across the Mayo Clinic sites during the study period. Of these, 7217 patients were adults 18 years or older who were analyzed further. A total of 897 (11.4%) patients required hospitalization, and 354 (4.9%) received care in the intensive care unit (ICU). All hospitalized patients were reviewed by a COVID-19 Treatment Review Panel, and 77.5% (695 of 897) of inpatients received a COVID-19-directed therapy. Overall mortality was 1.2% (94 of 7891), with 7.1% (64 of 897) mortality in hospitalized patients and 11.3% (40 of 354) in patients requiring ICU care.

CONCLUSION

Mayo Clinic outcomes of patients with COVID-19 infection in the ICU, hospital, and community compare favorably with those reported nationally. This likely reflects the impact of interprofessional multidisciplinary team evaluation, effective leveraging of clinical trials and available treatments, deployment of remote monitoring tools, and maintenance of adequate operating capacity to not require surge adjustments. These best practices can help guide other health care systems with the continuing response to the COVID-19 pandemic.

Yield of Head Imaging in Ambulatory and Hospitalized Patients With SARS-CoV-2: A Multi-Center Study of 8675 Patients

Background and Purpose:

To describe the neurological and cerebrovascular findings in patients who tested positive for SARS-CoV-2 and underwent head imaging in ambulatory and inpatient settings.

Methods:

Consecutive patients aged ≥18 years with SARS-CoV-2 infection diagnosed or treated at Mayo Clinic sites from 3/11/2020 to 7/23/2020 with head CT or brain MRI within 30 days of SARS-CoV-2 diagnosis were included. Demographics, medical history, indication for SARS-CoV-2 testing, neurologic symptoms, indication for brain imaging, neuroimaging findings, etiology of cerebrovascular events, and hospital course were abstracted from medical records.

Results:

Of 8,675 patients with SARS-CoV-2, 180 (2.07%) had head imaging. Mean age of the entire cohort was 42 ± 18 years, whereas mean age of those with head imaging was 62 ± 19 years. Common indications for imaging were headache (34.4%), encephalopathy (33.4%), focal neurologic symptom (16.7%), and trauma (13.9%). While 86.1% of patients who underwent head imaging had normal exams, cerebrovascular events occurred in 18 patients (0.21% of the total cohort). Of patients with cerebrovascular events, 8 (44.5%) had acute infarct; 6 (33.3%), acute intracranial hemorrhage; 5 (2.8%), subacute infarct; and 1 (0.6%) posterior reversible encephalopathy syndrome. In the thirteen patients with ischemic stroke, 6 (46.2%) had cryptogenic stroke; 3 (23.1%), other defined causes; 2 (15.4%), small vessel stroke; 1 (7.7%), large vessel stroke; and 1 (7.7%) cardioembolic stroke.

Conclusion:

In ambulatory and hospitalized patients with SARS-CoV-2 infection, the rate of head imaging is low, with common indications of encephalopathy and headache. Cerebrovascular events occurred rarely, and cryptogenic stroke was the most common stroke mechanism.

Anticoagulation in COVID-19: A Systematic Review, Meta-analysis, and Rapid Guidance From Mayo Clinic

A higher risk of thrombosis has been described as a prominent feature of coronavirus disease 2019 (COVID-19). This systematic review synthesizes current data on thrombosis risk, prognostic implications, and anticoagulation effects in COVID-19. We included 37 studies from 4070 unique citations. Meta-analysis was performed when feasible. Coagulopathy and thrombotic events were frequent among patients with COVID-19 and further increased in those with more severe forms of the disease. We also present guidance on the prevention and management of thrombosis from a multidisciplinary panel of specialists from Mayo Clinic. The current certainty of evidence is generally very low and continues to evolve.

Creation of an optic nerve sheath diameter ultrasound model for NeuroICU education

BACKGROUND

Using ultrasound to measure optic nerve sheath diameter (ONSD) is an emerging bedside technique to noninvasively assess intracranial pressure (ICP) in patients with brain injury. This technique is unique among bedside ultrasonography and is often performed by providers who have no formal ultrasound training. We sought to create a low-cost, 3D, reusable ONSD model to train neurology, neurosurgery, and critical care providers in measuring ICP.

RESULTS

We identified 253 articles, of which 15 were associated with models and 2 with simulation. One gelatin model was reported, upon which we based our initial design. We could not validate the visual findings of this model; however, after constructing multiple beta models, the design most representative of human eye anatomy was a globe made of ballistics gel and either a 3 mm, 5 mm, or 7 mm × 50 mm 3D-printed optic nerve inserted into a platform composed of ballistics gel, all of which sat inside a 3D-printed skull. This model was used to teach ONSD measurements with ultrasound at a continuing medical education event prior to training on a live human model.

CONCLUSION

A simple 3D ballistic ONSD model allows learners to practice proper hand placement and pressure, basic landmarks, and ONSD measurement prior to operating on a human eye. This model is replicable and sustainable given that the globe and platform are composed of ballistics gel.

A Combined Approach to Intracerebral Hemorrhage: Intravenous Mesenchymal Stem Cell Therapy with Minimally Invasive Hematoma Evacuation

BACKGROUND

Mesenchymal stem cells (MSCs) are multipotent stromal cells currently being tested as therapy for a variety of diseases. MSC therapy and hematoma evacuation using a minimally invasive approach are being studied separately to improve clinical outcomes after stroke. We report the first case of a patient with intracerebral hemorrhage (ICH) treated with combination MSC therapy and endoscopic hematoma evacuation.

CASE REPORT

A 36-year-old woman with a past medical history of essential chronic hypertension and right lung bronchial atresia presented to the emergency department with acute neurologic decline (National Institute of Health Stroke Scale [NIHSS] score, 22). Computed tomography showed a 4.4 × 3.5 × 3.5 cm right basal ganglia hemorrhage with intraventricular extension. An external ventricular drain was placed, and she was enrolled in a Phase I clinical trial investigating intravenous MSC therapy for acute ICH. Continued neurologic deterioration due to increased intracranial pressure led to minimally invasive hematoma evacuation using the Artemis Neuro Evacuation Device (Penumbra, Inc.) on hospital day 4. Follow-up scans showed decreased density and extent of hemorrhage. She was discharged on day 41 with improved neurologic function scores (NIHSS score, 2). At 3-month follow-up, she was walking on her own, but had residual left arm and hand weakness (modified Rankin Score, 2).

CONCLUSIONS

This case report suggests that the combination of MSC therapy and minimally invasive hematoma evacuation may be safe and well tolerated. Further larger randomized clinical trials are required to identify whether MSC therapy in combination with minimally invasive hematoma evacuation is safe, tolerable, and potentially improves outcomes than either alone.

Early Bortezomib Therapy for Refractory Anti-NMDA Receptor Encephalitis

Introduction: Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an increasingly recognized form of immune-mediated encephalitis. Here we present a case that represents the shortest hospitalization-to-bortezomib treatment timeline (42 days), and we believe that this is reflected in the patient's outcome with complete independence within a short timeframe.

Case Report: We describe a case of anti-NMDA receptor encephalitis in an 18-year-old African American female presenting with progressive, medically refractory disease. Despite two rounds of high-dose intravenous steroids, plasma exchange, immunoglobulin administration, and rituximab for B-cell depletion, the patient failed to respond by hospital day 42 and received off-label use of the proteasome inhibitor bortezomib. During the 15 days after the bortezomib administration, the patient showed dramatic neurologic recovery that allowed her transfer out of the intensive care unit. At follow-up after 1-month, the patient reported feeling normal cognitively and showed dramatic improvement in cognitive scores.

Conclusion: This case and literature review provide preliminary evidence that early treatment of anti-NMDA receptor encephalitis with the proteasome inhibitor bortezomib appears safe and tolerable. However, randomized trials are needed to show the efficacy and the long-term benefit.

Cerebrospinal meningitis: a global disease with regional variability?

INTRODUCTION

In this edition, Szymanski et al. present the results of their retrospective study of the clinical differences between patients with meningococcal meningitis and pneumococcal cerebrospinal meningitis at the Regional Specialistic Hospital in Wroclaw, Poland.

CLINICAL REFLECTIONS

The authors found that compared to patients with N. meningitidis, patients with S. pneumoniae were older, more frequently had chronic comorbidities, and had higher rates of pneumonia, longer hospitalisations, and higher mortality. Patients with N. meningitidis had higher rates of haemorrhagic rash and DIC.

CLINICAL IMPLICATIONS

These characteristics and outcomes reflect previous reports from Western Europe and the United States.

Abstract TP141: Can the Human Eye Match a Computer Algorithm in Identifying Hypoperfusion in Asymptomatic Carotid Artery Stenosis?

Background: Perfusion weighted imaging on MRI (MRP) and computerized tomography perfusion (CTP) are increasingly required to manage large vessel disease. Computerized algorithms can quantify perfusion data, but the programs are expensive and not widely used outside acute stroke evaluation. We aimed to determine how well human observers can identify asymmetries in cerebral perfusion images compared with an automated computer algorithm.

Methods: Ten clinicians experienced in treating carotid artery disease (4 vascular neurologists, 3 neuroradiologists, 1 vascular surgeon, 1 neurosurgeon, 1 interventional radiologist) were given 28 post-processed, color-coded, axial-slice MRP scans from patients in the Carotid Revascularization Endovascular versus Stenting Trial - Hemodynamics (CREST-H) study. All patients had >70%, unilateral, asymptomatic carotid artery stenosis and had varying degrees of time-to-peak (TTP) delay on the side of stenosis, ranging from 0 to 2 secs, quantified by a semi-automated system that computes quantitative perfusion maps, using deconvolution of tissue and arterial signals (Olea, Cambridge, MA). A minimum volume of 10cc was required for a given TTP delay. Clinicians were asked to determine asymmetry (y/n) and side of occlusion for each case. Number of correct responses that matched the computer output were tallied.

Results: We averaged correct responses by the 10 clinicians for cases at each increment of TTP delay; (Figure). At TTP delays ≥1.5 seconds, accuracy was ≥80%. At 1.25 sec accuracy fell to 60%, and at ≤ 1 sec, accuracy was ≤50%. For TTP=0 (no asymmetry), accuracy was 71%.

Conclusions: Visual impression of hemodynamic asymmetry among experienced clinicians was reasonably accurate for TTP delays ≥1.5 seconds, but declined with more subtle asymmetries. Depending on the clinical impact of TTP delays (for CREST-H: correlation with cognitive decline), experienced clinicians may perform as well as an automated algorithm.

Incorporation of Telestroke into Neurology Residency Training: "Time Is Brain and Education"

Background: With increasing demand for neurologists, nontraditional health care delivery mechanisms have been developed to leverage this limited resource. Introduction: Telemedicine has emerged as an effective digital solution. Over the past three decades, telemedicine use has steadily grown; however, neurologists often learn on the job, rather than as part of their medical training. The current literature regarding telestroke training during neurology training is sparse, focusing on cerebrovascular fellowship curricula. We sought to enhance telestroke training in our neurology residency by incorporating real-life application. Materials and Methods: We implemented a formal educational model for neurology residents to use telemedicine for remote acquisition of the National Institutes of Health Stroke Scale (NIHSS) for patients with suspected acute ischemic stroke (AIS) before arrival at our comprehensive stroke center. This three-phase educational model involved multidisciplinary classroom didactics, simulation exercises, and real-world experience. Training and feedback were provided by neurologists experienced in telemedicine. Results: All residents completed formal training in telemedicine prehospital NIHSS acquisition and had the opportunity to participate in additional simulation exercises. Currently, residents are gaining additional experience by performing prehospital NIHSS acquisition for patients in whom AIS is suspected. Our preliminary data indicate that resident video encounters average 10.6 min in duration, thus saving time once patients arrive at our hospital. Discussion: To our knowledge, this is the first report of a telestroke-integrated neurology residency program in a comprehensive stroke center resulting in shortened time to treatment in patients with suspected AIS. Conclusions: We present a model that can be adopted by other neurology residency programs as it provides real-world telemedicine training critical to future neurologists.

Ketamine in seizure management and future pharmacogenomic considerations

Ketamine is a noncompetitive N-methyl-_D-aspartate antagonist with emerging evidence for use in medically refractory epilepsy. We describe the novel use of low-dose intravenous (IV) ketamine transitioning to enteral formulation in a patient with drug-resistant localization-related refractory epilepsy. We performed a National Library of Medicine (NLM) literature review using search terms "ketamine", "low dose", and "seizure" for similar cases, followed by an illustrative clinical case. Our NLM search engine methodology yielded 24 hits, none of which described use of low-dose ketamine for seizures. Anesthetic doses are used for status epilepticus, but we show that in a patient with postoperative worsening of his chronic seizure burden, low-dose IV ketamine can be used to avoid oversedation and intubation. We demonstrate that IV ketamine can be transitioned to oral regimen to shorten length of stay in the intensive care unit and hospital and has future CYP2B6 pharmacogenomic considerations for further dose individualization.

Acute bacterial meningitis and stroke

INTRODUCTION

Acute bacterial meningitis remains a common disease, especially in developing countries. Although advances over the last century have improved mortality and morbidity, the neurological adverse effects remain high. Specifically, acute ischaemic stroke is a serious comorbidity that represents both disease severity and poor prognosis. This review presents the clinical connection between meningitis and stroke, and discusses the neuroinflammatory components that have direct ties between these diseases.

STATE OF THE ART

Ischaemic stroke is the direct result of the inflammatory response produced to eradicate infectious pathogens. Bacterial virulence factors and pathogen-associated molecular patterns cause direct damage to the blood-brain barrier and trigger leukocytes to react to the infection. Cytokines are released that cause further destruction of the blood-brain barrier, lead to neuronal death, and recruit the prothrombotic effects of the coagulation cascade through the complement system. Unfortunately, this inflammatory response causes vasculopathy and hypercoagulation of the cerebral blood vessels, leading to cerebral ischaemia.

CLINICAL IMPLICATIONS

Pharmacological attempts to mitigate this inflammatory response have produced both positive and negative results. On the one hand, corticosteroids have been shown to improve mortality if given early in patients with bacterial meningitis, particularly pneumococcal meningitis. On the other hand, corticosteroids have been linked to delayed cerebral infarction and other adverse effects.

FUTURE DIRECTIONS

New targets for specific inflammatory markers have shown success in rodent models, but have not yet been proven beneficial in humans. Genetic markers are on the horizon, and may serve as individualised targets for diagnosis and therapy.

Reducing Door-to-Reperfusion Time for Mechanical Thrombectomy With a Multitiered Notification System for Acute Ischemic Stroke

OBJECTIVE

To reduce door-to-angiographic reperfusion (DTR) time to 120 minutes for patients presenting with acute ischemic stroke attributed to anterior circulation large-vessel occlusion amenable to endovascular mechanical thrombectomy.

PATIENTS AND METHODS

Patients treated with mechanical thrombectomy before (April 10, 2015, through April 11, 2016) and after (April 12, 2016, through May 10, 2017) implementation of a multitiered notification system were studied. Lean process mapping was used to assess inefficiencies with multidisciplinary triage. A 3-tiered paging platform, which rapidly alerts essential personnel of the acute ischemic stroke team at advancing decision points, was introduced.

RESULTS

Sixty-two patients were analyzed before and after implementation (34 vs 28, respectively). Following intervention, DTR time was reduced by 43 minutes (mean DTR, 170 minutes vs 127 minutes; P=.02). At 90-day follow up, 5 of the 28 patients in the postintervention cohort (19%) had excellent neurologic outcomes, defined as a modified Rankin Scale score of 0, compared to 0 of 34 (0%) in the preintervention cohort (P=.89). Reductions were also seen in the length of stay on the neurocritical care service (mean, 6 vs 3 days; P=.006), and total hospital charges for combined groups (mean, $100,083 vs $161,458; P<.001).

CONCLUSION

The multitiered notification system was a feasible solution for improving DTR within our institution, resulting in reductions of overall DTR time, neurocritical care service length of stay, and total hospital charges.

Tacrolimus (FK506)-induced cerebral blindness following bone marrow transplantation

Three patients who developed acute onset of cerebral blindness within 5-47 days of BMT using tacrolimus (FK506) as primary GVHD prophylaxis are described. This syndrome has been described with the use of cyclosporin A (CsA) and FK506 in solid organ transplant recipients. CsA-induced cerebral blindness has also been noted in BMT recipients but to date there have been no reports of this complication in BMT patients receiving FK506. We have noted a striking similarity in the clinical and radiographic presentations between these patients and those with CsA-associated cerebral blindness. Reversibility within 1-2 weeks of onset and the potential for substitution of CsA for FK506 in these patients is described.

Early flexion routine. An alternative method of continuous passive motion

One hundred knees that underwent primary total knee arthroplasties were divided into 2 groups: the first 50 consecutive knees were assigned retrospectively to Group I (control), and the following 50 knees were assigned prospectively to Group II (early flexion). All procedures were cementless meniscal-bearing total knee arthroplasties and were performed by the same surgeon. Maximum early flexion (Group II) resulted in decreased length of stay, decreased hospital costs, and increased range of motion at 1 year. In light of current government interest in hospital cost reduction, this method should be considered as an attractive alternative to continuous passive motion.

The paranasal sinuses of patients with acute graft-versus-host disease

PURPOSE

To determine whether patients who have acute graft-versus-host disease (AGVHD), are more likely to have radiographically abnormal paranasal sinuses after bone marrow transplantation than patients without AGVHD.

METHODS

This retrospective case-control study population comprised 45 adult allogeneic or matched unrelated donor patients who underwent bone marrow transplantation. Twenty-eight patients had AGVHD, and 17 patients did not. All patients had paranasal sinus imaging with either CT or plain films for evaluation of possible sinusitis after bone marrow transplantation. The severity of radiographic changes was measured with an objective scoring system based on mucosal findings.

RESULTS

An odds ratio revealed no association between AGVHD and the presence of radiographically abnormal sinuses.

CONCLUSION

The diagnosis of AGVHD should not complicate the radiographic evaluation of acute sinusitis after bone marrow transplantation.

An anatomical variation of the palmar cutaneous branch of the median nerve

A case is presented of an anomalous course of the palmar cutaneous branch of the median nerve. Wide and meticulous exposure is necessary to avoid injury to all variations of this nerve and the use of a "safe" incision will not always avoid risk of injury.

Validity and reliability of the Neurobehavioral Assessment Scale

The Neurobehavioral Assessment Scale (NAS) was developed to measure the full range of behavioral functioning from fully alert to deep coma. This investigator-rated scale was evaluated in 60 patients undergoing conscious sedation for maxillofacial procedures. The results obtained on the NAS were reliable, as evidenced by high correlations between the rating of the two raters. The scale is also valid as determined by high correlations between the NAS and a standard scale, the Glasgow Coma Scale (criterion validity) and between the NAS and the Digit Symbol Substitution Test (behavioral validity). The NAS clearly distinguished between two levels of sedation (heavy and light). Furthermore, the NAS appears to be better able to discriminate among the different degrees of sedation in lightly sedated patients than the Glasgow Coma Scale.

Femoral instrumentation using the anterosuperior iliac spine as a landmark in total knee arthroplasty. An anatomic study

Twenty-six adult cadavers were utilized in an anatomic study designed to measure intramedullary femoral alignment in relation to the anterosuperior iliac spine. Fifty femurs were measured to determine the reliability of the anterosuperior iliac spine as an accurate landmark for distal femoral resection in total knee arthroplasty (TKA). A precision machined stainless steel U-shaped parallel alignment guide was fabricated and inserted into the femoral canals of intact adult cadavers. The guide's relationship to the anterosuperior iliac spine was measured and recorded. All hips were maintained in neutral alignment. Independent variables recorded included gender, knee alignment, and side of lower extremity. The range for medial deviation was 1-28 mm for the right femur and 2-25 mm for the left femur (average, 8.5 mm). The range for lateral deviation was 3-14 mm for the right femur and 2-17 mm for the left femur (average, 10.3 mm). There was no statistical correlation between the independent variables of side measured, gender, and measured offset at the anterosuperior iliac spine. Based on this highly variable pattern of alignment, utilizing simulated intraoperative technique, use of the anterosuperior iliac spine does not provide a landmark accurate enough to repeatedly produce a distal femoral resection within 2 degrees-3 degrees of ideal. Use of the anterosuperior iliac spine may lead to less than ideal femoral resection and malpositioning of total knee components.

Acute injuries of the distal radioulnar joint

Acute injuries of the distal radioulnar joint are common. They often are not treated aggressively owing to a failure to diagnose or the misconception that there is little functional impairment if left untreated. Early aggressive treatment with restoration of anatomic alignment and stability will yield optimum results. Acute treatment usually produces a better functional outcome than late reconstructive procedures.

Pulmonary diffusing capacity in left ventricular dysfunction

The purpose of this study was to determine whether there are any consistent spirometric or Dsb findings in patients with LV dysfunction characterized by a clinical diagnosis of CHF and an EF less than 40 percent. We performed spirometry and Dsb in 34 patients, and found that EF correlated only with Dsb. When we separated the patients into those with rales and those without, Dsb correlated strongly with EF only in those with rales. There was no correlation with other spirometric values. Mean Dsb percent predicted was significantly lower in patients with rales despite similar mean EF. Only two of 23 patients without rales had a reduced Dsb while only one of 11 with rales had a normal Dsb. We conclude that Dsb is a good predictor of clinically evident heart failure. When rales are absent, Dsb should be normal in patients with LV dysfunction; when present, Dsb will be diminished in proportion to the EF.

Validity and reliability of the Observer's Assessment of Alertness/Sedation Scale: study with intravenous midazolam

The Observer's Assessment of Alertness/Sedation (OAA/S) Scale was developed to measure the level of alertness in subjects who are sedated. This scale was tested in 18 subjects in a three-period crossover study to assess its reliability and its criterion, behavioral, and construct validity. After receiving either placebo or a titrated dose of midazolam to produce light or heavy sedation, each subject was administered two sedation scales (OAA/S Scale and a Visual Analogue Scale) and two performances tests (Digit Symbol Substitution Test and Serial Sevens Subtraction). Two raters individually evaluated the subject's level of alertness on each of the two sedation scales. The results obtained on the OAA/S Scale were reliable and valid as measured by high correlations between the two raters and high correlations between the OAA/S Scale and two of the three standard tests used in this study. The OAA/S Scale was sensitive to the level of midazolam administered; all pairwise comparisons were significant (p less than 0.05) for all three treatment levels at both test periods.

Granulomatous Pneumocystis carinii pneumonia in three patients with the acquired immune deficiency syndrome

Pneumocystis carinii pneumonia is a frequent manifestation of the acquired immune deficiency syndrome (AIDS). It usually presents radiologically as diffuse bilateral infiltrates and histologically as a foamy, eosinophilic intra-alveolar exudate containing the organisms' cysts. We recently studied two rare cases of P carinii pneumonia presenting as pulmonary nodules on chest x-ray films in two patients with AIDS. The corresponding histologies were a combination of the usual intra-alveolar pattern, with an alveolar and interstitial granulomatous appearance. Pneumocystis carinii was present in both areas and was the only organism found in the tissues examined. A third case presented with the more common radiographic appearance but also had a granulomatous histology. We conclude that P carinii pneumonia should be considered in the differential diagnosis of pulmonary nodules in immunocompromised patients and that pathologists should be aware of the possibility of a granulomatous reaction to this organism.

Immunochemistry of the Streptococcus mutans BHT cell membrane: detection of determinants cross-reactive with human heart tissue

Cell membranes of Streptococcus mutans BHT serotype b were prepared after glass bead disruption or mutanolysin digestion of whole cells. Immunoblot analyses of BHT membrane extracts revealed major polypeptides of 42,000, 46,000, 62,000, and 82,000 daltons, as well as several minor bands, to be reactive with rabbit anti-human heart immunoglobulins. Heart cross-reactive antigens have been reported in the cell walls and culture fluids of several S. mutans serotypes. This represents the first report of cell membrane-localized heart cross-reactive antigens in this oral pathogen. Positive enzyme-linked immunosorbent assay and immunoblot reactions were also obtained with heart tissue antigen and anti-BHT sera, indicating mutual cross-reactivity. The major cross-reactive component detected by immunoblotting of human heart extracts was a 69,000-dalton polypeptide.

Mutanolysin-induced spheroplasts of Streptococcus mutants are true protoplasts

A method is described for the preparation of protoplasts of Streptococcus mutans BHT. The muralytic enzyme mutanolysin was prepared free of contaminating proteinases and shown to completely dissolve cell walls of this strain. Whole cells were converted to stabilizable protoplasts by using the enzyme in an isotonic medium containing 40% raffinose. Experiments using [3H]thymidine and [14C]leucine as cytoplasmic pool markers revealed only minimal (10%) leakage during a 1-h incubation. Examination by electron microscopy revealed the apparent absence of structural cell wall on the enlarged spherical bodies. Quantitative chemical analyses of membranes prepared by lysing protoplasts demonstrated only very small amounts of rhamnose and trace amounts of galactose. These sugars are the principal components of the BHT cell wall polysaccharide. Also, there were only small amounts of peptidoglycan components (e.g., N-acetylglucosamine) in the purified membranes obtained by this method.

Effects of diazepam on operant behavior in man

The effects of diazepam (10 mg orally) on the responding of normal human volunteers was studied in a procedure that involved the maintenance of operant behavior by monetary reinforcement and its suppression by monetary loss (punishment). Diazepam produced an antipunishment effect as shown by an increase in behavior suppressed by monetary loss. An analogy to animal procedures that selectively detect antianxiety drugs is apparent.