Rodney Bell

Guidelines for the Evaluation and Management of Status Epilepticus

Status epilepticus (SE) treatment strategies vary substantially from one institution to another due to the lack of data to support one treatment over another. To provide guidance for the acute treatment of SE in critically ill patients, the Neurocritical Care Society organized a writing committee to evaluate the literature and develop an evidence-based and expert consensus practice guideline. Literature searches were conducted using PubMed and studies meeting the criteria established by the writing committee were evaluated. Recommendations were developed based on the literature using standardized assessment methods from the American Heart Association and Grading of Recommendations Assessment, Development, and Evaluation systems, as well as expert opinion when sufficient data were lacking.

Efficacious Recombinant Influenza Vaccines Produced by High Yield Bacterial Expression: A Solution to Global Pandemic and Seasonal Needs

It is known that physical linkage of TLR ligands and vaccine antigens significantly enhances the immunopotency of the linked antigens. We have used this approach to generate novel influenza vaccines that fuse the globular head domain of the protective hemagglutinin (HA) antigen with the potent TLR5 ligand, flagellin. These fusion proteins are efficiently expressed in standard E. coli fermentation systems and the HA moiety can be faithfully refolded to take on the native conformation of the globular head. In mouse models of influenza infection, the vaccines elicit robust antibody responses that mitigate disease and protect mice from lethal challenge. These immunologically potent vaccines can be efficiently manufactured to support pandemic response, pre-pandemic and seasonal vaccines.

Association between hyperoxia and mortality after stroke: a multicenter cohort study.

Objective:To test the hypothesis that hyperoxia was associated with higher in-hospital mortality in ventilated stroke patients admitted to the ICU. Design:Retrospective multicenter cohort study. Setting:Primary admissions of ventilated stroke patients with acute ischemic stroke, subarachnoid hemorrhage, and intracerebral hemorrhage who had arterial blood gases within 24 hours of admission to the ICU at 84 U.S. ICUs between 2003 and 2008. Patients were divided into three exposure groups: hyperoxia was defined as PaO2 ≥300 mm Hg (39.99 kPa), hypoxia as any PaO2<60 mm Hg (7.99 kPa) or PaO2/FiO2 ratio ⩽300, and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital mortality. Participants:Two thousand eight hundred ninety-four patients. Methods:Patients were divided into three exposure groups: hyperoxia was defined as PaO2 more than or equal to 300 mm Hg (39.99 kPa), hypoxia as any PaO2 less than 60 mm Hg (7.99 kPa) or PaO2/FIO2 ratio less than or equal to 300, and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital mortality. Interventions:Exposure to hyperoxia. Results:Over the 5-year period, we identified 554 ventilated patients with acute ischemic stroke (19%), 936 ventilated patients with subarachnoid hemorrhage (32%), and 1,404 ventilated patients with intracerebral hemorrhage (49%) of whom 1,084 (38%) were normoxic, 1,316 (46%) were hypoxic, and 450 (16%) were hyperoxic. Mortality was higher in the hyperoxia group as compared with normoxia (crude odds ratio 1.7 [95% CI 1.3-2.1]; p < 0.0001) and hypoxia groups (crude odds ratio, 1.3 [95% CI, 1.1–1.7]; p < 0.01). In a multivariable analysis adjusted for admission diagnosis, other potential confounders, the probability of being exposed to hyperoxia, and hospital-specific effects, exposure to hyperoxia was independently associated with in-hospital mortality (adjusted odds ratio, 1.2 [95% CI, 1.04–1.5]). Conclusion:In ventilated stroke patients admitted to the ICU, arterial hyperoxia was independently associated with in-hospital death as compared with either normoxia or hypoxia. These data underscore the need for studies of controlled reoxygenation in ventilated critically ill stroke populations. In the absence of results from clinical trials, unnecessary oxygen delivery should be avoided in ventilated stroke patients.

Treatment of Status Epilepticus: An International Survey of Experts

BackgroundAs part of the development of the Neurocritical Care Society (NCS) Status Epilepticus (SE) Guidelines, the NCS SE Writing Committee conducted an international survey of SE experts.MethodsThe survey consisted of three patient vignettes (case 1, an adult; case 2, an adolescent; case 3, a child) and questions regarding treatment. The questions for each case focused on initial and sequential therapy as well as when to use continuous intravenous (cIV) therapy and for what duration. Responses were obtained from 60/120 (50%) of those surveyed.ResultsThis survey reveals that there is expert consensus for using intravenous lorazepam for the emergent (first-line) therapy of SE in children and adults. For urgent (second-line) therapy, the most common agents chosen were phenytoin/fosphenytoin, valproate sodium, and levetiracetam; these choices varied by the patient age in the case scenarios. Physicians who care for adult patients chose cIV therapy for RSE, especially midazolam and propofol, rather than a standard AED sooner than those who care for children; and in children, there is a reluctance to choose propofol. Pentobarbital was chosen later in the therapy for all ages.ConclusionThere is close agreement between the recently published NCS guideline for SE and this survey of experts in the treatment of SE.

Targeted temperature management after intracerebral hemorrhage (TTM-ICH): methodology of a prospective randomized clinical trial.

Rationale Intracerebral hemorrhage causes 15% of strokes annually in the United States, and there is currently no effective therapy. Aims and hypothesis This is a clinical trial designed to study the safety, feasibility, and efficacy of a protocol of targeted temperature management to moderate hypothermia in intracerebral hemorrhage patients. Methods The targeted temperature management after intracerebral hemorrhage trial is a prospective, single-center, interventional, randomized, parallel, two-arm (1:1) phase-II clinical trial with blinded end-point ascertainment. Intracerebral hemorrhage patients will be randomized within 18 h of symptom onset to either 72 h of targeted temperature management to moderate hypothermia (32–34°C) followed by a controlled rewarming at of 0·05–0·1°C per hour or 72 h of targeted temperature management to normothermia (36–37°C) using endovascular or surface cooling. Outcomes The primary outcome is the development of serious adverse events possibly and probably related to treatment. Secondary outcomes include in-hospital neurological deterioration between day 0–7, in-hospital mortality, functional outcome measured by the modified Rankin scale at discharge and 90 days, and effect of treatment allocation on cerebral edema and hematoma volume. Discussion Intracerebral hemorrhage remains the most severe form of stroke with limited options to improve survival. As the early resuscitation phase in the intensive care unit represents the greatest opportunity for impact on clinical outcome, it also appears to be the most promising window of opportunity to demonstrate a benefit when investigating aggressive treatments. Conclusion More research of novel therapies to improve outcomes after intracerebral hemorrhage is desperately needed. The results of the targeted temperature management after intracerebral hemorrhage clinical trial may provide additional information on the applicability of targeted temperature management after intracerebral hemorrhage.

Quantification of cerebral infarct size by creatine kinase BB isoenzyme.

Creatine Kinase BB isoenzyme (CKBB) has been shown to rise in the serum and CSF following acute cerebral injury. To test the hypothesis that brain infarct size could be estimated from the appearance and disappearance of CKBB in the serum and CSF, strokes of varying size were produced in twelve mongrel dogs by silastic emboli. The rate of disappearance, Kd of CKBB (-.00732 +/- 0.001 min-1 mean +/- SE, N = 8) was determined by injecting purified CKBB (25 IU) intravenously then measuring its disappearance. Following the embolic stroke, serum samples were taken hourly for 24 hours and then at intervals for up to 160 hours for measurement of CKBB by radioimmunoassay until the animals were sacrificed. The brains were then removed, fixed in formalin, cut in 2 mm sections and photographed. The area of the infarct was measured using high pad digitizer interfaced with an Apple computer. The infarct size was then calculated from the area and thickness. Using a one-compartment mathematical model, the infarct size was estimated from the amount of CKBB appearing in the serum, the Kd of CKBB, and the amount of CKBB depleted from tissue. The computed infarct size correlated well (r = 0.94) with the measured infarct size. This model may have value in testing therapeutic modalities in the intact animal.

Cerebral Arteriovenous Malformations: Evaluation and Management

There has been increased detection of incidental AVMs as result of the frequent use of advanced imaging techniques. The natural history of AVM is poorly understood and its management is controversial. This review provides an overview of the epidemiology, pathophysiology, natural history, clinical presentation, diagnosis, and management of AVMs. The authors discussed the imaging techniques available for detecting AVMs with regard to the advantages and disadvantages of each imaging modality. Furthermore, this review paper discusses the factors that must be considered for the most appropriate management strategy (based on the current evidence in the literature) and the risks and benefits of each management option.

The methylphenidate‐induced stereotypy in the awake rat Local cerebral metabolism

The local cerebral metabolic rate for glucose (1 = CMRg) was computed in rats with methylphenidate-induced stereotypy using the quantitative 14C-2-deoxyglucose (2-DG) technique. Four rats received methylphenidate 15 mg per kilogram IP. Compared to five control animals, treated rats showed statistically significant (p≤ 0.05) increases in 1-CMRg in globus pallidus, ventral lateral nucleus of the thalamus, subthalamic nucleus, red nucleus, substantia nigra, entopeduncular nucleus, inferior olivary nucleus, and the lateral cerebellar cortex. Significantly, 1-CMRg decreased in area 4 of the motor cortex. The auditory system showed no change in 1-CMRg, demonstrating the specific action of methylphenidate in the rat brain. This technique allows evaluation of the functional anatomy of the entire central nervous system and may be helpful in understanding the mechanisms of methylphenidate-induced stereotypy.

Unruptured Cerebral Aneurysms: Evaluation and Management

The evolution of imaging techniques and their increased use in clinical practice have led to a higher detection rate of unruptured intracranial aneurysms. The diagnosis of an unruptured intracranial aneurysm is a source of significant stress to the patient because of the concerns for aneurysmal rupture, which is associated with substantial rates of morbidity and mortality. Therefore, it is important that decisions regarding optimum management are made based on the comparison of the risk of aneurysmal rupture with the risk associated with intervention. This review provides a comprehensive overview of the epidemiology, pathophysiology, natural history, clinical presentation, diagnosis, and management options for unruptured intracranial aneurysms based on the current evidence in the literature. Furthermore, the authors discuss the genetic abnormalities associated with intracranial aneurysm and current guidelines for screening in patients with a family history of intracranial aneurysms. Since there is significant controversy in the optimum management of small unruptured intracranial aneurysms, we provided a systematic approach to their management based on patient and aneurysm characteristics as well as the risks and benefits of intervention.

A rationally designed form of the TLR5 agonist, flagellin, supports superior immunogenicity of Influenza B globular head vaccines

Previously, we demonstrated that for H1N1 and H5N1 influenza strains, the globular head of the hemagglutinin (HA) antigen fused to flagellin of Salmonella typhimurium fljB (STF2) is highly immunogenic in preclinical models and man (Song et al. (2008) [13]; Song et al. (2009) [14]; Taylor et al. (2012) [12]). Further we showed that the vaccine format, or point of attachment of the vaccine antigen to flagellin, can dramatically affect the immunogenicity and safety profile of the vaccine. However, Influenza B vaccines based on these formats are poor triggers of TLR5 and consequently are poorly immunogenic. Through rational design, here we show that we have identified a fusion position within domain 3 of flagellin that improves TLR5 signaling and consequently, immunogenicity of multiple influenza B vaccines. Our results demonstrate that, similar to influenza A strains, the protective subunit of the influenza B HA can be fused to flagellin and produced in a standard prokaryotic expression system thereby allowing for cost and time efficient production of multivalent seasonal influenza vaccines.