Nimodipine-associated standard dose reductions and neurologic outcomes after aneurysmal subarachnoid hemorrhage: the era of pharmacogenomics.

Nimodipine, an L-type cerebroselective calcium channel antagonist, is the only drug approved by the US Food and Drug Administration for the neuroprotection of patients with aneurysmal subarachnoid hemorrhage (aSAH). Four randomized, placebo-controlled trials of nimodipine demonstrated clinical improvement over placebo; however, these occurred before precision medicine with pharmacogenomics was readily available. The standard enteral dose of nimodipine recommended after aSAH is 60 mg every 4 h. However, up to 78% of patients with aSAH develop systemic arterial hypotension after taking the drug at the recommended dose, which could theoretically limit its neuroprotective role and worsen cerebral perfusion pressure and cerebral blood flow, particularly when concomitant vasospasm is present. We investigated the association between nimodipine dose changes and clinical outcomes in a consecutive series of 150 patients (mean age, 56 years; 70.7% women) with acute aSAH. We describe the pharmacogenomic relationship of nimodipine dose reduction with clinical outcomes. These results have major implications for future individualized dosing of nimodipine in the era of precision medicine.

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.

Predictors of Ventriculoperitoneal shunting following Subarachnoid Hemorrhage treated with External Ventricular Drainage.

BACKGROUND/OBJECTIVES: Aneurysmal subarachnoid hemorrhage (aSAH) is commonly associated with hydrocephalus due to subarachnoid hemorrhage blood products obstructing cerebrospinal fluid outflow. Hydrocephalus after aSAH is routinely managed with temporary external ventricular drainage (EVD) followed by standard EVD weaning protocols, which determine the need for ventriculoperitoneal shunting (VPS). We sought to investigate aSAH patients who initially passed EVD weaning trials and had EVD removal, but later presented with recurrent, delayed, symptomatic hydrocephalus requiring a VPS. METHODS: We conducted a retrospective review of all patients at our tertiary care medical center who presented with aSAH, requiring an EVD. We analyzed variables associated with ultimate VPS dependency during hospitalization. RESULTS: We reviewed 489 patients with aSAH over a 6-year period (2008-2014). One hundred and thirty-eight (28.2%) developed hydrocephalus requiring a temporary EVD. Forty-four (31.9%) of these patients died or had withdrawal of care during admission, and were excluded from final analysis. Of the remaining 94 patients, 29 (30.9%) failed their clamp trial and required VPS. Sixty-five (69.1%) patients passed their clamp trial and were discharged without a VPS. However, 10 (15.4%) of these patients developed delayed hydrocephalus after discharge and ultimately required VPS [mean (range) days after discharge, 97.2 (35-188)]. Compared to early VPS, the delayed VPS group had a higher incidence of symptomatic vasospasm (90.0% vs 51.7%; P = 0.03). When comparing patients discharged from the hospital without VPS, delayed VPS patients also had higher 6- and 12-month mortality (P = 0.02) and longer EVD clamp trials (P < 0.01) than patients who never required VPS but had an EVD during hospitalization. Delayed hydrocephalus occurred in only 7.8% of patients who passed the initial EVD clamp trial, compared to 14.3% who failed the initial trial and 80.0% who failed 2 or more trials. CONCLUSION: Patients who failed their initial or subsequent EVD clamp trials had a small, but increased risk of developing delayed hydrocephalus ultimately requiring VPS. Additionally, the majority of patients who presented with delayed hydrocephalus also suffered symptomatic vasospasm. These associations should be further explored and validated in a larger prospective study.

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.

Elevated Neutrophil-Lymphocyte Ratio is Predictive of Poor Outcomes Following Aneurysmal Subarachnoid Hemorrhage.

Background Recent studies of patients with intracerebral hemorrhage suggest an association between peripheral blood neutrophil-lymphocyte ratio and neurologic deterioration. We aimed to study the prognostic utility of neutrophil-lymphocyte ratio in predicting inpatient mortality in aneurysmal subarachnoid hemorrhage. Methods We conducted a retrospective electronic medical record review of the clinical, laboratory, and radiographic data of patients with aneurysmal subarachnoid hemorrhage 18 years of age or older presenting to the neuroscience intensive care unit from January 1, 2011, to December 31, 2017. Patients with aneurysmal subarachnoid hemorrhage were divided into 2 groups (group 1, alive at discharge; group 2, deceased prior to discharge), and neutrophil-lymphocyte ratio laboratory mean values were recorded for each patient. Our primary outcome measure was inpatient mortality, and our secondary measure was incidence of pneumonia with hospitalization. Results We identified 403 patients with aneurysmal subarachnoid hemorrhage for the study. After exclusion criteria, 44 eligible patients were divided into the 2 groups (group 1, n = 32; group 2, n = 12). Mean neutrophil-lymphocyte ratio for group 1 was 11.53, and for group 2, 17.85 (P < .01). The mean neutrophil-lymphocyte ratio of those who developed pneumonia compared to those who did not was 15.28 versus 12.81, respectively (P = .39). A Kaplan-Meier plot demonstrated increased mortality among patients with a neutrophil-lymphocyte ratio equal to or greater than 12.5 compared to those with a neutrophil-lymphocyte ratio less than 12.5. Conclusions These preliminary data demonstrate that a neutrophil-lymphocyte ratio equal to or greater than 12.5 at admission predict higher inpatient mortality in patients with aneurysmal subarachnoid hemorrhage.

Safety and Tolerability of Concentrated Intraventricular Nicardipine for Poor-Grade Aneurysmal Subarachnoid Hemorrhage-Related Vasospasm.

Objective: To report the preliminary safety, tolerability, and cerebral spinal fluid (CSF) sampling utility of serial injections of concentrated intraventricular nicardipine (IVN) in the treatment of aneurysmal subarachnoid hemorrhage (aSAH). Methods: We report the clinical, radiographic, and laboratory safety and tolerability data of a retrospective case series from a single academic medical center. All patients with aSAH developed vasospasm despite enteral nimodipine and received serial injections of concentrated IVN (2.5 mg/mL). CSF injection safety, tolerability, and utility are defined and reported. Results: A total of 59 doses of concentrated IVN were administered to three patients with poor-grade SAH. In Case 1, a 33-year-old man with modified Fisher scale (mFS) grade 4 and Hunt-Hess scale (HH) score 4 received 26 doses; in Case 2, a 36-year-old woman with mFS grade 4 and HH score 5 received 13 doses; and in Case 3, a 70-year-old woman with mFS grade 3 and HH score 4 received 20 doses. No major safety or tolerability events occurred. Two patients were discharged to a rehabilitation facility, and one died after discharge from the hospital. Conclusions: A concentrated 4 mg IVN dose (2.5 mg/mL) in a 1.6 mL injection appears relatively safe and tolerable and potentially offers a second-line strategy for treating refractory vasospasm in poor-grade SAH without compromising intracranial pressure or cerebral perfusion pressure.

Real versus simulated galactic cosmic radiation for investigating cancer risk in the hematopoietic system - are we comparing apples to apples?

Deep space exploration missions need strategies to mitigate the potentially harmful exposure to galactic cosmic radiation. This form of radiation can cause significant damage to biological systems and organisms, which include radiation-induced carcinogenesis in the hematopoietic system. Ongoing studies investigate these effects using cell- and animal-based studies in low earth orbit. The logistic challenges and costs involved with sending biological specimens to space have prompted the development of surrogate ground-based radiation experiments to study the mechanisms of biological injury and cancer risk. However, simulating galactic cosmic radiation has proven difficult and current studies are only partially succeeding at replicating the complexity of this radiation and its downstream injury pathways. Accurate simulation of chronic, low dose galactic radiation will improve our ability to test mitigation strategies such as drug development and improved shielding materials that could be crucial and essential for successful space exploration.

The Power of Mobile Health: The Girl With the Gadgets in Uganda.

Medical-grade ultrasound devices are now pocket sized and can be easily transported to underserved parts of the world, allowing health care providers to have the tools to optimize diagnoses, inform management plans, and improve patient outcomes in remote locations. Other great advances in technology have recently occurred, such as artificial intelligence applied to mobile health devices and cloud computing, as augmented reality instructions make these devices more user friendly and readily applicable across health care encounters. However, broader awareness of the impact of these mobile health technologies is needed among health care providers, along with training on how to use them in valid and reproducible environments, for accurate diagnosis and treatment. This article provides a summary of a Mayo International Health Program journey to Bwindi, Uganda, with a portable mobile health unit. This article shows how point-of-care ultrasonography and other technologies can benefit remote clinical diagnosis and management in underserved areas around the world.

Nimodipine-induced junctional bradycardia in an elderly patient with subarachnoid hemorrhage.

Subarachnoid hemorrhage is a devastating form of stroke with often detrimental outcomes for patients. Here we describe a patient with subarachnoid hemorrhage treated with nimodipine, which resulted in marked bradycardia with junctional atrioventricular heart block. Nimodipine is metabolized predominantly by the cytochrome P450 3A subfamily, and its use is often associated with adverse events, such as hypotension and bradycardia, which can be exacerbated by advanced age. Our patient had the CYP3A5*3/*3 genotype, possibly predisposing her to poor metabolism of this drug. Our case report demonstrates the potential for pharmacogenomics in patients with subarachnoid hemorrhage to help predict their response to nimodipine, minimize adverse drug reactions, and potentially individualize dosing to improve future clinical outcomes.

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.

Safety, Tolerability, and Efficacy of Pain Reduction by Gabapentin for Acute Headache and Meningismus After Aneurysmal Subarachnoid Hemorrhage: A Pilot Study.

Introduction: Severe, often sudden-onset headache is the principal presenting symptoms of aneurysmal subarachnoid hemorrhage (aSAH). We hypothesized that gabapentin would be safe and tolerable for aSAH-induced headaches and would reduce concurrent opioid use. Methods: We performed a single-center, double-blind, randomized, placebo-controlled trial (registered at ClinicalTrials.gov; NCT02330094) from November 24, 2014, to June 24, 2017, where aSAH patients received either dose-escalating gabapentin or oral placebo, both alongside a standard of care pain regimen. After 7 days, patients had the option to continue in an open-label period until 14 days after enrollment or until discharge from the intensive care unit. Our primary endpoint was the efficacy of gabapentin in reducing headache numeric pain scores and opioid usage in patients with aSAH compared to the placebo group. We identified 63 potential patients with aSAH for the study. After applying stringent exclusion criteria, 16 eligible patients were enrolled into one of two arms. Results: The study ended prematurely after reaching a pre-specified funding period and an unexpected drop in aSAH cases. There was a trend toward lower headache numeric pain scores and opioid use in the gabapentin treated arm; however this was not significantly different. Gabapentin was well tolerated by participants and no adverse effects were reported. Conclusions: While there was a trend toward lower pain scores and opioid requirement in the gabapentin group, the study was underpowered to detect a difference. Larger multicenter trials are required to evaluate the efficacy of gabapentin to reduce opioid requirements after aSAH.

Using Cerebral Metabolites to Guide Precision Medicine for Subarachnoid Hemorrhage: Lactate and Pyruvate.

Subarachnoid hemorrhage (SAH) is one of the deadliest types of strokes with high rates of morbidity and permanent injury. Fluctuations in the levels of cerebral metabolites following SAH can be indicators of brain injury severity. Specifically, the changes in the levels of key metabolites involved in cellular metabolism, lactate and pyruvate, can be used as a biomarker for patient prognosis and tailor treatment to an individual's needs. Here, clinical research is reviewed on the usefulness of cerebral lactate and pyruvate measurements as a predictive tool for SAH outcomes and their potential to guide a precision medicine approach to treatment.

Mesenchymal stem cells for hemorrhagic stroke: status of preclinical and clinical research.

Significant progress has been made during the past few decades in stem cell therapy research for various diseases and injury states; however this has not been overwhelmingly translated into approved therapies, despite much public attention and the rise in unregulated 'regenerative clinics'. In the last decade, preclinical research focusing on mesenchymal stem/stromal cell (MSC) therapy in experimental animal models of hemorrhagic stroke has gained momentum and has led to the development of a small number of human trials. Here we review the current studies focusing on MSC therapy for hemorrhagic stroke in an effort to summarize the status of preclinical and clinical research. Preliminary evidence indicates that MSCs are both safe and tolerable in patients, however future randomized controlled trials are required to translate the promising preclinical research into an effective therapy for hopeful patients.

Downregulation of SNX27 expression does not exacerbate amyloidogenesis in the APP/PS1 Alzheimer's disease mouse model.

There is in vitro evidence that sorting nexin family member 27 (SNX27), a member of the retromer complex, changes the distribution of the amyloid-beta (Aß) precursor protein (APP) to promote its recycling and thereby prevent the production of Aß, the toxic protein associated with Alzheimer's disease (AD). In this study, we analyzed the phenotype of the familial AD APP/PS mouse strain lacking one copy of the SNX27 gene. The reduction in SNX27 expression had no significant effect on the in vivo accumulation of soluble, total, or plaque-deposited Aß, which is overproduced by the familial APP/PS transgenes. Hippocampal structure and cholinergic basal forebrain neuronal health were also unaffected. Nonetheless, mild positive and negative effects of age and/or genotype on spatial navigation performance were observed in SNX27+/- and SNX27+/-APP/PS mice, respectively. These data suggest that downregulation of SNX27 alone does not have long-term negative consequences on spatial memory, but that cognitive dysfunction in the context of high Aß deposition is exacerbated by the cellular or molecular changes induced by reduced SNX27 function.

Pharmacogenomics of Cytochrome P450 of Nimodipine Metabolism After Aneurysmal Subarachnoid Hemorrhage.

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (aSAH) is a type of stroke that is life threatening with high rates of mortality, and many survivors are left with permanent neurologic deficits. Nimodipine is the treatment of choice for aSAH with the goal of reduction of delayed cerebral ischemia. It is the only evidence-based medication that has been shown to have improved outcomes for delayed cerebral ischemia; therefore, it is important for neuroscience nurses to be knowledgeable of the pharmacology and pharmacogenomics properties of this medication, including cytochrome P450 (CYP450) enzymes. METHODS AND RESULTS: This article reviews the CYP450 enzyme system including a review of the pharmacotherapy and pharmacogenomics of nimodipine for patients with aSAH illustrated with case study of a patient with abnormal drug metabolism. CONCLUSION: CYP450 enzymes can be inhibited or induced by multiple medications resulting in clinically significant differences in drug metabolism. Food and Drug Administration-approved medication nimodipine is the only medication shown to improve outcomes in patients with aSAH. Hence, it is important to have awareness of potential drug-to-drug interactions and pharmacogenomics of nimodipine when caring for critically ill patients with aSAH.

Burnout and attrition: Expanding the gender gap in neurology?

Neurology faces an increasing shortage of neurologists in the United States due to a growing demand for neurologic services. A 7% increase in the supply of neurologists is predicted from 2012 to 2025, whereas the demand will rise by 16%. An increase in the neurology workforce is critical to meet the demands, and a significant gender gap remains within the workforce that must be addressed to further ease the discrepancy between supply and demand. Individual, institutional, and societal factors contribute to this gender discrepancy and potentially result in the burnout or soft attrition of women from neurology. These factors, including earning disparity between male and female neurologists, one of the largest gaps in pay for any medical specialty, and the lack of representation at higher academic levels with only 12% (14 of 113) of neurology department chairs at academic medical centers being women, could lead to increased attrition of women from neurology. Identifying and mitigating these factors may help narrow the gender gap and increase the supply of neurologists to better meet future demand.

Acute Down-regulation of BDNF Signaling Does Not Replicate Exacerbated Amyloid-ß Levels and Cognitive Impairment Induced by Cholinergic Basal Forebrain Lesion.

Degeneration of basal forebrain cholinergic neurons (BFCNs) precedes hippocampal degeneration and pathological amyloid-beta (Aß) accumulation, and underpins the development of cognitive dysfunction in sporadic Alzheimer's disease (AD). We hypothesized that degeneration of BFCNs causes a decrease in neurotrophin levels in innervated brain areas, which in turn promotes the development of Aß pathology and cognitive impairment. Here we show that lesion of septo-hippocampal BFCNs in a pre-symptomatic transgenic amyloid AD mouse model (APP/PS1 mice) increases soluble Aß levels in the hippocampus, and induces cognitive deficits in a spatial memory task that are not seen in either unlesioned APP/PS1 or non-transgenic littermate control mice. Furthermore, the BFCN lesion results in decreased levels of brain-derived neurotrophic factor (BDNF). However, viral knockdown of neuronal BDNF in the hippocampus of APP/PS1 mice (in the absence of BFCN loss) neither increased the level of Aß nor caused cognitive deficits. These results suggest that the cognitive decline and Aß pathology induced by BFCN loss occur independent of dysfunctional neuronal BDNF signaling, and may therefore be directly underpinned by reduced cholinergic neurotransmission.

Cholinergic basal forebrain neurons regulate fear extinction consolidation through p75 neurotrophin receptor signaling.

Cholinergic basal forebrain (cBF)-derived neurotransmission plays a crucial role in regulating neuronal function throughout the cortex, yet the mechanisms controlling cholinergic innervation to downstream targets have not been elucidated. Here we report that removing the p75 neurotrophin receptor (p75NTR) from cBF neurons induces a significant impairment in fear extinction consolidation. We demonstrate that this is achieved through alterations in synaptic connectivity and functional activity within the medial prefrontal cortex. These deficits revert back to wild-type levels upon re-expression of the active domain of p75NTR in adult animals. These findings demonstrate a novel role for cholinergic neurons in fear extinction consolidation and suggest that neurotrophic signaling is a key regulator of cholinergic-cortical innervation and function.

Cholinergic Basal Forebrain Lesion Decreases Neurotrophin Signaling without Affecting Tau Hyperphosphorylation in Genetically Susceptible Mice.

Alzheimer's disease (AD) is a progressive, irreversible neurodegenerative disease that destroys memory and cognitive function. Aggregates of hyperphosphorylated tau protein are a prominent feature in the brain of patients with AD, and are a major contributor to neuronal toxicity and disease progression. However, the factors that initiate the toxic cascade that results in tau hyperphosphorylation in sporadic AD are unknown. Here we investigated whether degeneration of basal forebrain cholinergic neurons (BFCNs) and/or a resultant decrease in neurotrophin signaling cause aberrant tau hyperphosphorylation. Our results reveal that the loss of BFCNs in pre-symptomatic pR5 (P301L) tau transgenic mice results in a decrease in hippocampal brain-derived neurotrophic factor levels and reduced TrkB receptor activation. However, there was no exacerbation of the levels of phosphorylated tau or its aggregation in the hippocampus of susceptible mice. Furthermore the animals' performance in a hippocampal-dependent learning and memory task was unaltered, and no changes in hippocampal synaptic markers were observed. This suggests that tau pathology is likely to be regulated independently of BFCN degeneration and the corresponding decrease in hippocampal neurotrophin levels, although these features may still contribute to disease etiology.