Exploration of Multiparameter Hematoma 3D Image Analysis for Predicting Outcome After Intracerebral Hemorrhage.

BACKGROUND: Rapid diagnosis and proper management of intracerebral hemorrhage (ICH) play a crucial role in the outcome. Prediction of the outcome with a high degree of accuracy based on admission data including imaging information can potentially influence clinical decision-making practice. METHODS: We conducted a retrospective multicenter study of consecutive ICH patients admitted between 2012-2017. Medical history, admission data, and initial head computed tomography (CT) scan were collected. CT scans were semiautomatically segmented for hematoma volume, hematoma density histograms, and sphericity index (SI). Discharge unfavorable outcomes were defined as death or severe disability (modified Rankin Scores 4-6). We compared (1) hematoma volume alone; (2) multiparameter imaging data including hematoma volume, location, density heterogeneity, SI, and midline shift; and (3) multiparameter imaging data with clinical information available on admission for ICH outcome prediction. Multivariate analysis and predictive modeling were used to determine the significance of hematoma characteristics on the outcome. RESULTS: We included 430 subjects in this analysis. Models using automated hematoma segmentation showed incremental predictive accuracies for in-hospital mortality using hematoma volume only: area under the curve (AUC): 0.85 [0.76-0.93], multiparameter imaging data (hematoma volume, location, CT density, SI, and midline shift): AUC: 0.91 [0.86-0.97], and multiparameter imaging data plus clinical information on admission (Glasgow Coma Scale (GCS) score and age): AUC: 0.94 [0.89-0.99]. Similarly, severe disability predictive accuracy varied from AUC: 0.84 [0.76-0.93] for volume-only model to AUC: 0.88 [0.80-0.95] for imaging data models and AUC: 0.92 [0.86-0.98] for imaging plus clinical predictors. CONCLUSIONS: Multiparameter models combining imaging and admission clinical data show high accuracy for predicting discharge unfavorable outcome after ICH.

Temporal Relationship between Hyponatremia and Development of Cerebral Vasospasm in Aneurysmal Subarachnoid Hemorrhage Patients: A Retrospective Observational Study.

BACKGROUND: Hyponatremia is a common complication after aneurysmal subarachnoid hemorrhage (aSAH). Previous studies have reported an association between hyponatremia and vasospasm, however whether hyponatremia directly contributes to the pathogenesis of cerebral vasospasm (CVS), or is a by-product is still unclear. The aim of this study was to explore an association between hyponatremia and CVS after aSAH, and evaluating the temporality of these 2 events. METHODS: A retrospective study of consecutive patients with aSAH admitted to the Baylor St. Luke's Medical center between January 2008 and December 2012 was conducted. Demographics, baseline characteristics, serum sodium levels, and evidence of vasospasm detected by transcranial Doppler, CT Angiogram, MR angiogram, and digital subtracted angiography were collected. Patients were dichotomized into a hyponatremic and a normonatremic group. CVS incidence and clinical outcome was compared between groups. Timing of CVS after initial hyponatremia episodes was recorded Results: One hundred and sixty 4 patients with aSAH were included. Hyponatremia was identified in 66 patients (40.2%) and CVS occurred in 71 subjects (43.2%). The incidence of CVS was higher in the hyponatremic group compared to the normonatremic group, 65.1 % versus 28.5%, respectively (P < .001). Hyponatremia preceded CVS by median 1.5 days suggesting a temporal trend. CONCLUSIONS: Our study shows a significant association between hyponatremia and CVS, with hyponatremia preceding CVS events. This retrospective finding denotes the need for larger prospective studies, aiming to clarify the temporal relationship of serum sodium levels and CVS.

The Role of Serum Calcium Level in Intracerebral Hemorrhage Hematoma Expansion: Is There Any?

Spontaneous intracerebral hemorrhage (ICH) is a devastating form of stroke, with a high rate of mortality and morbidity. Even with the best current medical or surgical interventions, outcomes remain poor. The location and initial hematoma volume are strong predictors of mortality. Hematoma expansion (HE) is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for HE have been identified, including baseline ICH volume, anticoagulation, and computed tomography angiography spot signs. Recent studies have shown the correlation of serum calcium (Ca++) levels on admission with HE. Low serum Ca++ level has been associated with larger hematoma volume at the time of presentation, HE, and worse outcome. Although the causal and mechanistic links between low serum Ca++ level and HE are not well understood, several mechanisms have been proposed including coagulopathy, platelet dysfunction, and higher blood pressure (BP) in the context of low serum Ca++ level. However, low serum Ca++ level might be only a biomarker of the adaptive response due to acute inflammatory response following acute ICH. The purpose of the current review is to discuss the evidence regarding the possible role of low serum Ca++ level on HE in acute ICH.

Real-time Noninvasive Monitoring of Intracranial Fluid Shifts During Dialysis Using Volumetric Integral Phase-Shift Spectroscopy (VIPS): A Proof-of-Concept Study.

BACKGROUND: Cerebral edema, which is associated with increased intracranial fluid, is often a complication of many acute neurological conditions. There is currently no accepted method for real-time monitoring of intracranial fluid volume at the bedside. We evaluated a novel noninvasive technique called "Volumetric Integral Phase-shift Spectroscopy (VIPS)" for detecting intracranial fluid shifts during hemodialysis. METHODS: Subjects receiving scheduled hemodialysis for end-stage renal disease and without a history of major neurological conditions were enrolled. VIPS monitoring was performed during hemodialysis. Serum osmolarity, electrolytes, and cognitive function with mini-mental state examination (MMSE) were assessed. RESULTS: Twenty-one monitoring sessions from 14 subjects (4 women), mean group age 50 (SD 12.6), were analyzed. The serum osmolarity decreased by a mean of 6.4 mOsm/L (SD 6.6) from pre- to post-dialysis and correlated with an increase in the VIPS edema index (E-Dex) of 9.7% (SD 12.9) (Pearson's correlation r = 0.46, p = 0.037). Of the individual determinants of serum osmolarity, changes in serum sodium level correlated best with the VIPS edema index (Pearson's correlation, r = 0.46, p = 0.034). MMSE scores did not change from pre- to post-dialysis. CONCLUSIONS: We detected an increase in the VIPS edema index during hemodialysis that correlated with decreased serum osmolarity, mainly reflected by changes in serum sodium suggesting shifts in intracranial fluids.

Human Albumin Use in Adults in U.S. Academic Medical Centers.

OBJECTIVE: To determine rates and predictors of albumin administration, and estimated costs in hospitalized adults in the United States. DESIGN: Cohort study of adult patients from the University HealthSystem Consortium database from 2009 to 2013. SETTING: One hundred twenty academic medical centers and 299 affiliated hospitals. PATIENTS: A total of 12,366,264 hospitalization records. INTERVENTIONS: Analysis of rates and predictors of albumin administration, and estimated costs. MEASUREMENTS AND MAIN RESULTS: Overall the proportion of admissions during which albumin was administered increased from 6.2% in 2009 to 7.5% in 2013; absolute difference 1.3% (95% CI, 1.30-1.40%; p < 0.0001). The increase was greater in surgical patients from 11.7% in 2009 to 15.1% in 2013; absolute difference 3.4% (95% CI, 3.26-3.46%; p < 0.0001). Albumin use varied geographically being lowest with no increase in hospitals in the North Eastern United States (4.9% in 2009 and 5.3% in 2013) and was more common in bigger (> 750 beds; 5.2% in 2009 and 7.3% in 2013) compared to smaller hospitals (< 250 beds; 4.4% in 2009 to 6.2% in 2013). Factors independently associated with albumin use were appropriate indication for albumin use (odds ratio, 65.220; 95% CI, 62.459-68.103); surgical admission (odds ratio, 7.942; 95% CI, 7.889-7.995); and high severity of illness (odds ratio, 8.933; 95% CI, 8.825-9.042). Total estimated albumin cost significantly increased from $325 million in 2009 to $468 million in 2013; (absolute increase of $233 million), p value less than 0.0001. CONCLUSIONS: The proportion of hospitalized adults in the United States receiving albumin has increased, with marked, and currently unexplained, geographic variability and variability by hospital size.

Safety and Effectiveness of Factor VIII Inhibitor Bypassing Activity (FEIBA) and Fresh Frozen Plasma in Oral Anticoagulant-Associated Intracranial Hemorrhage: A Retrospective Analysis.

BACKGROUND: Oral anticoagulant (OAT)-associated intracranial hemorrhage (ICH) is a life-threatening emergency for which prothrombin complex concentrates (PCC) are considered first-line reversal agents. The only approved PCC in the USA for warfarin-associated ICH is non-activated PCC. Little data are available regarding the safety and effectiveness of factor VIII inhibitor bypassing activity (FEIBA) which is an activated prothrombin complex concentrate (aPCC). The aim of this analysis was to assess the safety and effectiveness of FEIBA compared to fresh frozen plasma (FFP) for reversal of OAT-associated ICH. METHODS: Data were retrospectively collected to compare coagulation markers and in-hospital clinical outcomes in patients who received aPCC with or without FFP versus FFP alone for the reversal of OAT-associated ICH. RESULTS: Eighty-four patients met inclusion criteria; 50 patients received FFP alone, and 34 patients received FEIBA (mean dose 20 U/kg) with or without FFP for OAT-associated ICH. The proportion of diagnosed thrombotic events during hospitalization was similar in both groups (8% in the FFP group vs. 12% in the FEIBA group; P = 0.56). Median time to INR < 1.5 was achieved faster in the FEIBA group versus the FFP group (0.5 h [IQR 0.5-1.] vs. 10 h [IQR 5-16.3], respectively; P < 0.001) reflecting a trend toward shorter median time to neurosurgical intervention. Hematoma expansion, length of stay, and all-cause mortality were similar between both groups. CONCLUSIONS: Administration of FEIBA does not appear to increase the risk of thrombotic events compared with FFP. FEIBA administration resulted in faster INR reversal with a trend toward shorter time to neurosurgical intervention. However, there was no difference in hematoma expansion, mortality or length of stay.

Application of Tauroursodeoxycholic Acid for Treatment of Neurological and Non-neurological Diseases: Is There a Potential for Treating Traumatic Brain Injury?

The objective of this review was to evaluate the potential of tauroursodeoxycholic acid (TUDCA) for neuroprotection in traumatic brain injury (TBI) patients in the neurocritical care setting. Specifically, we surveyed preclinical studies describing the neuroprotective and systemic effects of TUDCA, and the potential therapeutic application of TUDCA. Preclinical studies have provided promising data supporting its use in neurological disease characterized by apoptosis-induced neuronal loss. TUDCA inhibits multiple proteins involved in apoptosis and upregulates cell survival pathways. In addition, TUDCA exhibits anti-inflammatory effects in models of neuroinflammation and attenuates neuronal loss in chronic neurodegenerative diseases. This may be applicable to TBI, which also triggers inflammatory and apoptotic processes. Additionally, preliminary data support the use of pharmacological therapies that reduce apoptosis and inflammation associated with TBI. The anti-apoptotic and anti-inflammatory mechanisms of TUDCA could prove promising in the treatment of TBI. Currently, there are no published data supporting improvement in clinical outcomes of TBI by treatment with TUDCA, but future studies should be considered.

Neurogenic Stunned Myocardium Following Acute Subarachnoid Hemorrhage: Pathophysiology and Practical Considerations.

Neurogenic stunned myocardium (NSM) is a triad of transient left ventricular dysfunction, electrocardiogram changes, and elevation in cardiac enzymes, often mimicking a myocardial infarction. It has been described following acute brain injury. The purported mechanism is catecholamine excess resulting in cardiac dysfunction. From the clinical standpoint, the most frequently encountered electrocardiographic changes are QTc prolongation and ST-T changes, with modest elevations in troponin levels. Basal and mid-ventricular segments of the left ventricle are most commonly involved. NSM poses therapeutic challenges when it occurs secondary to aneurysmal subarachnoid hemorrhage, particularly in the setting of coexisting vasospasm. Overall, NSM carries good prognosis if recognized early, with appropriate management of hemodynamic and cardiopulmonary parameters.

Predictors of nosocomial pneumonia in intracerebral hemorrhage patients: a multi-center observational study.

BACKGROUND: Nosocomial pneumonia (NP) is a frequent complication among spontaneous intracerebral hemorrhage (sICH) patients. This study was aimed at identifying in-hospital risk factors that predispose sICH patients to NP. METHODS: We identified 591 consecutive sICH subjects admitted to six tertiary care hospitals between 2008 and 2012. Information regarding patients' demographics, admission data, laboratory tests, medical history, diagnostic imaging, in-hospital treatments, complications, and outcomes were collected. Using a competing risks analysis, we assessed risk factors associated with NP. RESULTS: Mean age of the subjects was 68 years; 51 % were female and 76 % were white. One-hundred sixteen (19.6 %) of the sICH patients had NP. In the univariate analysis, variables including age, non-white race, early hospital admission (<6 h after onset), larger hematoma volume, basal ganglia or intraventricular hemorrhage, multisite hemorrhage, in-hospital aspiration, intubation, nasogastric tube placement, hematoma evacuation, high ICH score, ventricular drainage, and tracheostomy had a positive association with NP. However, in the multivariate analysis, only early hospital admission, in-hospital aspiration, intubation, and tracheostomy remained statistically significant predictors (p < 0.05). For patients who survived hospitalization, the median length-of-stay (LOS) with or without NP was 20.0 and 4.0 days, respectively (p < 0.0001). For patients who did not survive to discharge, the median LOS with or without NP was 10.5 and 2.0 days, respectively (p < 0.001). CONCLUSIONS: Independent predictors of NP included early hospital admission, in-hospital aspiration, intubation, and tracheostomy. NP was associated with prolonged hospital LOS.

Multidisciplinary protocol for rapid head computed tomography turnaround time in acute stroke patients.

BACKGROUND: The door-to-computed tomography (CT) head reporting time is an essential step to determining eligibility for thrombolysis in acute stroke patients, but the specific components of the process have not been reported in detail. METHODS: We performed a retrospective cross-sectional analysis of the prospectively collected Get-With-The-Guidelines database in our comprehensive stroke center to evaluate the effect of a structured multidisciplinary protocol on head CT times in acute stroke patients under consideration for thrombolysis. RESULTS: The median CT turnaround time in the first 6-month period was 27 (interquartile range [IQR], 27) and decreased in all subsequent periods after implementation of a formal protocol to 18 (IQR, 12; range, 17-20 minutes; P < .0001 for all pairwise comparisons). The median CT turnaround time was 18 (IQR, 12) versus 20 (IQR, 14) minutes for patients with admission diagnosis of stroke (n = 1123) versus nonstroke (n = 685; P < .0001), respectively. CONCLUSIONS: A structured multidisciplinary protocol for obtaining acute stroke protocol head CT scan was associated with reduced CT turnaround time over the study period. Prospective studies should be done to determine if implementation in other stroke centers confirms the effectiveness of our protocol.

Marked olfactory impairment in idiopathic intracranial hypertension.

OBJECTIVE: Many long-duration astronauts develop signs of elevated intracranial pressure and have neuro-ophthalmological findings similar to idiopathic intracranial hypertension (IIH) patients. Some also present with nasal congestion and subjective olfactory impairment. We prospectively evaluated olfactory function in IIH patients and the effect of 6° head-down tilt, which simulates the headward fluid shifting in microgravity, as spaceflight analogues. DESIGN: Olfaction was tested for all subjects in upright and 6° head-down tilt positions using two different measures: University of Pennsylvania Smell Identification Test and Olfactory Threshold Sniffin' Sticks with phenylethyl alcohol. RESULTS: IIH patients (n=19) had significant impairment on both olfactory measures compared with matched controls (n=19). The olfactory threshold dilution levels were 9.07 (95% CI 1.85 to 5.81) and 3.83 (95% CI 7.04 to 11.10), p=0.001, and smell identification scores were 35.61 (95% CI 34.03 to 37.18) and 32.47 (95% CI 30.85 to 34.09), p=0.008, for control and IIH subjects, respectively. The threshold detection was mildly impaired in head-down tilt compared with upright position in the combined subjects (6.05 (95% CI 4.58 to 7.51) vs 6.85 (95% CI 5.43 to 8.27), p=0.004). CONCLUSIONS: We demonstrated that IIH patients have marked impairment in olfactory threshold levels, out of proportion to smell identification impairment. There was also impairment in olfactory threshold in head-down tilt compared with upright positioning, but not for smell identification. The underlying mechanisms for olfactory threshold dysfunction in IIH patients need further exploration.

Human albumin administration in subarachnoid hemorrhage: results of an international survey.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a devastating disease. Nimodipine is the only medical treatment shown to improve outcome of SAH patients. Human albumin (ALB) may exert neuroprotection in SAH. However, current usage of ALB in SAH is not known. We conducted an international survey of clinicians involved in the care of SAH patients to determine current practice of ALB administration in SAH. METHODS: We constructed a 27-question survey. Our sampling frame consisted of neurointensivists, general intensivists, neurocritical care nurses, critical care pharmacists, and neurosurgeons. The survey was available from 11/15/2012 to 12/15/2012. We performed mostly descriptive statistical analysis. RESULTS: We obtained 362 responses from a diverse range of world regions. Most respondents were intensivist physicians (88 %), who worked in academic institutions (73.5 %) with a bed capacity >500 (64.1 %) and an established institutional management protocol for SAH patients (70.2 %). Most respondents (83.5 %) indicated that their institutions do not incorporate ALB in their protocol, but half of them (45.9 %) indicated using ALB outside it. ALB administration is influenced by several factors: geographic variation (more common among US respondents); institutions with a dedicated neuroICU; and availability of SAH management protocol. Most respondents (75 %) indicated that a clinical trial to test the efficacy of ALB in SAH is needed. CONCLUSIONS: In this survey we found that ALB administration in SAH patients is common and influenced by several factors. Majority of respondents support a randomized clinical trial to determine the safety and efficacy of ALB administration in SAH patients.

Multimodal Neurologic Monitoring in Patients Undergoing Extracorporeal Membrane Oxygenation.

Introduction Extracorporeal membrane oxygenation (ECMO) is associated with a high rate of neurologic complications. Multimodal neurologic monitoring (MNM) has the potential for early detection and intervention. We examined the safety and feasibility of noninvasive MNM during ECMO. We hypothesized that survivors and non-survivors would have meaningful differences in transcranial Doppler (TCD) sonography and electroencephalographic (EEG) characteristics, which we aimed to identify. We also investigated adverse neurologic events and attempted to identify differences in EEG and TCD characteristics among patients based on the type of ECMO and the occurrence of these events. Material and methods We performed an observational study on all patients undergoing ECMO at Baylor St. Luke's Medical Center's critical care unit in Houston, Texas, United States, from January 2017 to February 2019. All patients underwent a noninvasive MNM protocol. Results NM was completed in 75% of patients; all patients received at least one component of the monitoring protocol. No adverse events were noted, showing the feasibility and safety of the protocol. The 60.4% of patients who did not survive tended to be older, had lower ejection fractions, and had lower median right middle cerebral artery (MCA) pulsatility and resistivity indexes. Patients undergoing venoarterial (VA)-ECMO had lower median left and right MCA velocities and lower right Lindegaard ratios than patients who underwent venovenous-ECMO. In VA-ECMO patients, EEG less often showed sleep architecture, while other findings were similar between groups. Adverse neurologic events occurred in 24.7% of patients, all undergoing VA-ECMO. Acute ischemic stroke occurred in 22% of patients, intraparenchymal hemorrhage in 4.9%, hypoxic-ischemic encephalopathy in 3.7%, subarachnoid hemorrhage in 2.5%, and subdural hematoma in 1.2%. Conclusion Our results suggest that MNM is safe and feasible for patients undergoing ECMO. Certain EEG and TCD findings could aid in the early detection of neurologic deterioration. MNM may not just be used in monitoring patients undergoing ECMO but also in prognostication and aiding clinical decision-making.

Thrombolysis for acute ischemic stroke in patients with cancer: a population study.

BACKGROUND AND PURPOSE: The safety of thrombolysis for acute stroke in patients with cancer is not well established. Our aim is to study the outcomes after thrombolysis in patients with stroke with cancer. METHODS: Patients with acute ischemic stroke who received thrombolysis were identified from the 2009 and 2010 Nationwide Inpatient Sample. Patients with cancer-associated strokes and noncancer strokes were compared based on demographics, comorbidities, and outcomes. RESULTS: Of the 32 576 strokes treated with thrombolysis, cancer-associated strokes had significantly higher comorbidity indices overall, but fewer vascular risk factors than noncancer strokes. There was no difference in the rates of home discharge and in-hospital mortality, after adjusting for confounders. Subgroup analysis showed that compared with liquid cancers, patients with solid tumors had worse home discharge (odds ratio, 0.178; 95% confidence interval, 0.109-0.290; P<0.001) and higher in-hospital mortality (odds ratio, 3.018; 95% confidence interval, 1.37-6.646; P=0.006) after thrombolysis. Metastatic cancers had poorest outcomes, but intracerebral hemorrhage rates were similar. CONCLUSIONS: Thrombolytic therapy for acute stroke in patients with cancer is not associated with increased risk of intracerebral hemorrhage or in-hospital mortality. However, careful consideration of the cancer subtype may help delineate the subset of patients with poor response to thrombolysis. Prospective confirmation is warranted.

Stroke-associated pneumonia: major advances and obstacles.

BACKGROUND: Stroke-associated pneumonia (SAP) has been implicated in the morbidity, mortality and increased medical cost after acute ischemic stroke. The annual cost of SAP during hospitalization in the United States approaches USD 459 million. The incidence and prognosis of SAP among intensive care unit (ICU) patients have not been thoroughly investigated. We reviewed the pathophysiology, microbiology, incidence, risk factors, outcomes and prophylaxis of SAP with special attention to ICU studies. METHODS: To determine the incidence, risk factors and prognosis of acute SAP, PubMed was searched using the terms 'pneumonia' AND 'neurology intensive unit' and the MeSH terms 'stroke' AND 'pneumonia'. Non-English literature, case reports and chronic SAP studies were excluded. Studies were classified into 5 categories according to the setting they were performed in: neurological intensive care units (NICUs), medical intensive care units (MICUs), stroke units, mixed studies combining more than one setting or when the settings were not specified and rehabilitation studies. RESULTS: The incidences of SAP in the following settings were: NICUs 4.1-56.6%, MICUs 17-50%, stroke units 3.9-44%, mixed studies 3.9-23.8% and rehabilitation 3.2-11%. The majority of NICU and MICU studies were heterogeneous including different neurovascular diseases, which partly explains the wide range of SAP incidence. The higher incidence in the majority of ICU studies compared to stroke units or acute floor studies is likely explained by the presence of mechanical ventilation, higher stroke severity causing higher rates of aspiration and stroke-induced immunodepression among ICU patients. The short-term mortality of SAP was increased among the mixed and stroke unit studies ranging between 10.1 and 37.3%. SAP was associated with worse functional outcome in the majority of stroke unit and floor studies. Mortality was less consistent among NICU and MICU studies. This difference could be due to the heterogeneity of ICU studies and the effect of small sample size or other independent risk factors for mortality such as the larger neurological deficit, mechanical ventilation, and age, which may simultaneously increase the risk of SAP and mortality confounding the outcomes of SAP itself. The pathophysiology of SAP is likely explained by aspiration combined with stroke-induced immunodepression through complex humeral and neural pathways that include the hypothalamic-pituitary-adrenal axis, parasympathetic and sympathetic systems. CONCLUSIONS: A unified definition of SAP, strict inclusion criteria, and the presence of a long-term follow-up need to be applied to the future prospective studies to better identify the incidence and prognosis of SAP, especially among ICU patients.

Optic disc edema during strict 6° head-down tilt bed rest is related to one-carbon metabolism pathway genetics and optic cup volume.

Some astronauts on International Space Station missions experience neuroophthalmological pathologies as part of spaceflight associated neuro-ocular syndrome (SANS). Strict head-down tilt bed rest (HDTBR) is a spaceflight analog that replicates SANS findings and those who had 3-4 risk alleles (G and C alleles from the methionine synthase reductase [MTRR] A66G and serine hydroxymethyltransferase [SHMT1] C1420T, respectively) as compared to 1-2 risk alleles, had a greater increase in total retinal thickness (TRT). The objective of this study was to identify factors that contribute to the individual variability of the development of SANS in a 60 d HDTBR at the German Aerospace Center's:envihab facility, Cologne Germany. 22 of 24 subjects who participated in the HDTBR study provided blood samples for genetic analysis. Total retinal thickness and optic cup volume were measured before and after bed rest. Subjects with 3-4 versus 0-2 risk alleles had greater ΔTRT during and after bed rest, and the model improved with the addition of baseline optic cup volume. This bed rest study confirms that variants of MTRR and SHMT1 are associated with ocular pathologies. Subjects with more risk alleles had the greatest HDTBR-induced ΔTRT, reaffirming that genetics predispose some individuals to developing SANS. Preflight optic cup volume and genetics better predict ΔTRT than either one alone. Whether nutritional supplements can override the genetic influences on biochemistry, physiology, and pathophysiology remains to be tested. These findings have significant implications for both aerospace and terrestrial medicine.

The Albumin in Subarachnoid Hemorrhage (ALISAH) multicenter pilot clinical trial: safety and neurologic outcomes.

BACKGROUND AND PURPOSE: Human albumin has been shown to exert neuroprotective effects in animal models of cerebral ischemia and humans with various intracranial pathologies. We investigated the safety and tolerability of 25% human albumin in patients with subarachnoid hemorrhage. METHODS: The Albumin in Subarachnoid Hemorrhage (ALISAH) Pilot Clinical Trial was an open-label, dose-escalation study. We intended to study 4 different dosages of albumin of increasing magnitude (0.625 g/kg: Tier 1; 1.25 g/kg: Tier 2; 1.875 g/kg: Tier 3; and 2.5 g/kg: Tier 4). Each dosage was to be given to 20 adult patients. Treatment was administered daily for 7 days. We investigated the maximum tolerated dose of albumin based on the rate of severe-to-life-threatening heart failure and anaphylactic reaction and functional outcome at 3 months. RESULTS: We treated 47 adult subjects: 20 in Tier 1; 20 in Tier 2; and 7 in Tier 3. We found that doses ranging up to 1.25 g/kg/day×7 days were tolerated by patients without major dose-limiting complications. We also found that outcomes trended toward better responses in those subjects enrolled in Tier 2 compared with Tier 1 (OR, 3.0513; CI, 0.6586-14.1367) and with the International Intraoperative Hypothermia for Aneurysm Surgery Trial cohort (OR, 3.1462; CI, 0.9158-10.8089). CONCLUSIONS: Albumin in doses ranging up to 1.25 g/kg/day×7 days was tolerated by patients with subarachnoid hemorrhage without major complications and may be neuroprotective. Based on these results, planning of the ALISAH II, a Phase III, randomized, placebo-controlled trial to test the efficacy of albumin, is underway. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov. Unique identifier: NCT00283400.

Optic nerve sheath diameter and spaceflight: defining shortcomings and future directions.

Neuro-ocular changes during long-duration space flight are known as spaceflight-associated neuro-ocular syndrome (SANS). The ability to detect, monitor, and prevent SANS is a priority of current space medicine research efforts. Optic nerve sheath diameter (ONSD) measurement has been used both terrestrially and in microgravity as a proxy for measurements of elevated intracranial pressure. ONSD shows promise as a potential method of identifying and quantitating neuro-ocular changes during space flight. This review examines 13 studies measuring ONSD and its relationship to microgravity exposure or ground-based analogs, including head-down tilt, dry immersion, or animal models. The goal of this correspondence is to describe heterogeneity in the use of ONSD in the current SANS literature and make recommendations to reduce heterogeneity in future studies through standardization of imaging modalities, measurement techniques, and other aspects of study design.

MRI-based quantification of posterior ocular globe flattening during 60 days of strict 6° head-down tilt bed rest with and without daily centrifugation.

Spaceflight associated neuro-ocular syndrome (SANS) is associated with acquired optic disc edema, hyperopia, and posterior globe flattening in some astronauts during long-duration spaceflight possibly due to the headward fluid redistribution in microgravity. The goal of this study was to assess whether strict head-down tilt (HDT) bed rest as a spaceflight analog would produce globe flattening and whether centrifugation could prevent these changes. Twenty-four healthy subjects separated into three groups underwent 60 days of strict 6° HDT bed rest: one control group with no countermeasure (n = 8) and two countermeasure groups exposed to 30 min daily of short-arm centrifugation as a means of artificial gravity (AG), either intermittent (iAG, n = 8) or continuous (cAG, n = 8). Magnetic resonance images (MRI) were collected at baseline, HDT-day 14, HDT-day 52, and 3 days after bed rest. An automated method was applied to quantify posterior globe volume displacement compared with baseline scans. On average, subjects showed an increasing degree of globe volume displacement with bed rest duration (means ± SE: 1.41 ± 1.01 mm3 on HDT14 and 4.04 ± 1.19 mm3 on HDT52) that persisted post-bed rest (5.51 ± 1.26 mm3). Application of 30 min daily AG did not have a significant impact on globe volume displacement (P = 0.42 for cAG and P = 0.93 for iAG compared with control). These results indicate that strict 6° HDT bed rest produced displacement of the posterior globe with a trend of increasing displacement with longer duration that was not prevented by daily 30 min exposure to AG.NEW & NOTEWORTHY Head-down tilt (HDT) bed rest is commonly used as a spaceflight analog for investigating spaceflight associated neuro-ocular syndrome (SANS). Posterior ocular globe flattening has been identified in astronauts with SANS but until now has not been investigated during HDT bed rest. In this study, posterior ocular globe volume displacement was quantified before, during, and after HDT bed rest and countermeasures were tested for their potential to reduce the degree of globe flattening.

Exosome based analysis for Space Associated Neuro-Ocular Syndrome and health risks in space exploration.

Molecular profiling to characterize the effects of environmental exposures is important from the human health and performance as well as the occupational medicine perspective in space exploration. We have developed a novel exosome-based platform that allows profiling of biological processes in the body from a variety of body fluids. The technology is suitable for diagnostic applications as well as studying the pathophysiology of the Space Associated Neuro-Ocular Syndrome in astronauts and monitoring patients with chronically impaired cerebrospinal fluid drainage or elevated intracranial pressure. In this proof-of-concept, we demonstrate that: (a) exosomes from different biofluids contain a specific population of RNA transcripts; (b) urine collection hardware aboard the ISS is compatible with exosome gene expression technology; (c) cDNA libraries from exosomal RNA can be stored in dry form and at room temperature, representing an interesting option for the creation of longitudinal molecular catalogs that can be stored as a repository for retrospective analysis.