Lifetime cost of stroke in the United States

Advances in medical revascularisation treatments in acute ischemic stroke

Urgent reperfusion of the ischaemic brain is the aim of stroke treatment and there has been ongoing research to find a drug that can promote vessel recanalisation more completely and with less side effects. In this review article, the major studies which have validated the use and safety of tPA are discussed. The safety and efficacy of other thrombolytic and anticoagulative agents such as tenecteplase, desmoteplase, ancrod, tirofiban, abciximab, eptifibatide, and argatroban are also reviewed. Tenecteplase and desmoteplase are both plasminogen activators with higher fibrin affinity and longer half-life compared to alteplase. They have shown greater reperfusion rates and improved functional outcomes in preliminary studies. Argatroban is a direct thrombin inhibitor used as an adjunct to intravenous tPA and showed higher rates of complete recanalisation in the ARTTS study with further studies which are now ongoing. Adjuvant thrombolysis techniques using transcranial ultrasound are also being investigated and have shown higher rates of complete recanalisation, for example, in the CLOTBUST study. Overall, development in medical therapies for stroke is important due to the ease of administration compared to endovascular treatments, and the new treatments such as tenecteplase, desmoteplase, and adjuvant sonothrombolysis are showing promising results and await further large-scale clinical trials.

Impact of Disability Status on Ischemic Stroke Costs in Canada in the First Year

Background:

Longitudinal, patient-level data on resource use and costs after an ischemic stroke are lacking in Canada. The objectives of this analysis were to calculate costs for the first year post-stroke and determine the impact of disability on costs.

Methodology:

The Economic Burden of Ischemic Stroke (BURST) Study was a one-year prospective study with a cohort of ischemic stroke patients recruited at 12 Canadian stroke centres. Clinical history, disability, health preference and resource utilization information was collected at discharge, three months, six months and one year. Resources included direct medical costs (2009 CAN$) such as emergency services, hospitalizations, rehabilitation, physician services, diagnostics, medications, allied health professional services, homecare, medical/assistive devices, changes to residence and paid caregivers, as well as indirect costs. Results were stratified by disability measured at discharge using the modified Rankin Score (mRS): non-disabling stroke (mRS 0-2) and disabling stroke (mRS 3-5).

Results:

We enrolled 232 ischemic stroke patients (age 69.4 ± 15.4 years; 51.3% male) and 113 (48.7%) were disabled at hospital discharge. The average annual cost was $74,353; $107,883 for disabling strokes and $48,339 for non-disabling strokes.

Conclusions:

An average annual cost for ischemic stroke was calculated in which a disabling stroke was associated with a two-fold increase in costs compared to NDS. Costs during the hospitalization to three months phase were the highest contributor to the annual cost. A “back of the envelope” calculation using 38,000 stroke admissions and the average annual cost yields $2.8 billion as the burden of ischemic stroke.

Brain-Machine Interfaces for Motor Control: A Guide for Neuroscience Clinicians

With the growing interdependence between medicine and technology, the prospect of connecting machines to the human brain is rapidly being realized. The field of neuroprosthetics is transitioning from the proof of concept stage to the development of advanced clinical treatments. In one area of brain-machine interfaces (BMIs) related to the motor system, also termed ‘motor neuroprosthetics’, research successes with implanted microelectrodes in animals have demonstrated immense potential for restoring motor deficits. Early human trials have also begun, with some success but also highlighting several technical challenges. Here we review the concepts and anatomy underlying motor BMI designs, review their early use in clinical applications, and offer a framework to evaluate these technologies in order to predict their eventual clinical utility. Ultimately, we hope to help neuroscience clinicians understand and participate in this burgeoning field.

Glycemic variability and acute ischemic stroke: the missing link?

Hyperglycemia is commonly encountered in both diabetic and non-diabetic patients in acute ischemic stroke. Hyperglycemia in stroke has been associated with poor clinical outcome, a phenomenon that has been studied in experimental models, where hyperglycemia was shown to enhance cortical toxicity, increase infarct volumes, promote inflammation, and affect the cerebral vasculature. This has led to many trials attempting to modulate the hyperglycemic response as a therapeutic and neuroprotective strategy. Intensive glycemic control has been evaluated in stroke patients, with conflicting results. The evidence linking hyperglycemia with neurotoxicity coupled with the failure of intensive glucose control regimens to improve functional outcomes in stroke suggests that novel approaches should be devised. Recent attention has been paid to another related phenomenon, that of glycemic variability, which has been proven to be a predictor of outcome in critically ill patients; however, its the impact in stroke has not been evaluated.

Delivery of iPS-NPCs to the Stroke Cavity within a Hyaluronic Acid Matrix Promotes the Differentiation of Transplanted Cells

Stroke is the leading cause of adult disability with ~80% being ischemic. Stem cell transplantation has been shown to improve functional recovery. However, the overall survival and differentiation of these cells is still low. The infarct cavity is an ideal location for transplantation as it is directly adjacent to the highly plastic peri-infarct region. Direct transplantation of cells near the infarct cavity has resulted in low cell viability. Here we deliver neural progenitor cells derived from induce pluripotent stem cells (iPS-NPC) to the infarct cavity of stroked mice encapsulated in a hyaluronic acid hydrogel matrix to protect the cells. To improve the overall viability of transplanted cells, each step of the transplantation process was optimized. Hydrogel mechanics and cell injection parameters were investigated to determine their effects on the inflammatory response of the brain and cell viability, respectively. Using parameters that balanced the desire to keep surgery invasiveness minimal and cell viability high, iPS-NPCs were transplanted to the stroke cavity of mice encapsulated in buffer or the hydrogel. While the hydrogel did not promote stem cell survival one week post-transplantation, it did promote differentiation of the neural progenitor cells to neuroblasts.

Real-world evaluation of the effects of counseling and education in diabetes management

Background. Patient education has long been recognized as a component of effective diabetes management, but the impact of counseling and education (C/E) interventions on health care costs is not fully understood. Objectives. To identify the incidence and type of diabetes C/E received by type 2 diabetes patients and to evaluate associated economic and clinical outcomes. Methods. This retrospective cohort study used the Premier-Optum Continuum of Care database (2005-2009) to compare adult patients with type 2 diabetes receiving C/E to those not receiving C/E (control). The index date was the first C/E date or, in the control cohort, a randomly assigned date on which some care was delivered. Patients had at least 6 months' pre-index and 12 months' post-index continuous health plan coverage. Health care costs and glycemic levels were evaluated over 12 and 6 months, respectively, with adjustment for differences in baseline characteristics using propensity score matching (PSM). Results. Of 26,790 patients identified, 9.3% received at least one C/E intervention (mean age 53 years, 47% men) and 90.7% received no C/E (mean age 57 years, 54% men). Standard diabetes education was the most common form of C/E (73%). After PSM, C/E patients had some improvements in glycemic levels (among those with laboratory values available), without increased risk for hypoglycemia, and incurred $2,335 per-patient less in diabetes-related health care costs, although their total health care costs increased. Conclusions. Despite the low uptake of C/E services, C/E interventions may be associated with economic and clinical benefits at 12 months. Further analyses are needed to evaluate the long-term cost-effectiveness of such initiatives.

Cost-utility analysis of genotype-guided antiplatelet therapy in patients with moderate-to-high risk acute coronary syndrome and planned percutaneous coronary intervention

BACKGROUND

Prasugrel is recommended over clopidogrel in poor/intermediate CYP2C19 metabolizers with acute coronary syndrome (ACS) and planned percutaneous coronary intervention (PCI), reducing the risk of ischemic events. CYP2C19 genetic testing can guide antiplatelet therapy in ACS patients.

OBJECTIVE

The purpose of this study was to evaluate the cost-utility of genotype-guided treatment, compared with prasugrel or generic clopidogrel treatment without genotyping, from the US healthcare provider's perspective.

METHODS

A decision model was developed to project lifetime economic and humanistic burden associated with clinical outcomes (myocardial infarction [MI], stroke and major bleeding) for the three strategies in patients with ACS. Probabilities, costs and age-adjusted quality of life were identified through systematic literature review. Incremental cost-utility ratios (ICURs) were calculated for the treatment strategies, with quality-adjusted life years (QALYs) as the primary effectiveness outcome. Relative risk of developing myocardial infarction and stroke between patients with and without variant CYP2C19 when receiving clopidogrel were estimated to be 1.34 and 3.66, respectively. One-way and probabilistic sensitivity analyses were performed.

RESULTS

Clopidogrel cost USD19,147 and provided 10.03 QALYs versus prasugrel (USD21,425, 10.04 QALYs) and genotype-guided therapy (USD19,231, 10.05 QALYs). The ICUR of genotype-guided therapy compared with clopidogrel was USD4,200. Genotype-guided therapy provided more QALYs at lower costs compared with prasugrel. Results were sensitive to the cost of clopidogrel and relative risk of myocardial infarction and stroke between CYP2C19 variant vs. non-variant. Net monetary benefit curves showed that genotype-guided therapy had at least 70% likelihood of being the most cost-effective alternative at a willingness-to-pay of USD100,000/QALY. In comparison with clopidogrel, prasugrel therapy was more cost-effective with <21% certainty at willingness-to-pay of >USD170,000/QALY.

CONCLUSIONS

Our modeling analyses suggest that genotype-guided therapy is a cost-effective strategy in patients with acute coronary syndrome undergoing planned percutaneous coronary intervention.

Predictors of recovery of functional swallow after gastrostomy tube placement for Dysphagia in stroke patients after inpatient rehabilitation: a pilot study

OBJECTIVE

To determine predictors of early recovery of functional swallow in patients who had gastrostomy (percutaneous endoscopic gastrostomy [PEG]) placement for dysphagia and were discharged to inpatient rehabilitation (IPR) after stroke.

METHODS

A retrospective study of prospectively identified patients with acute ischemic and hemorrhagic stroke from July 2008 to August 2012 was conducted. Patients who had PEG during stroke admission and were discharged to IPR, were studied. We compared demographics, stroke characteristics, severity of dysphagia, stroke admission events and medications in patients who remained PEG-dependent after IPR with those who recovered functional swallow.

RESULTS

Patients who remained PEG dependent were significantly older (73 vs. 54 years, p=0.009). Recovery of swallow was more frequent for hemorrhagic stroke patients (80% vs. 47%, p=0.079). Age, adjusting for side of stroke (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.82-0.98; p=0.016) and left-sided strokes, adjusting for age (OR, 15.15; 95% CI, 1.32-173.34; p=0.028) were significant predictors of swallow recovery. Patients who recovered swallowing by discharge from IPR were more likely to be discharged home compared to those who remained PEG-dependent (90% vs. 42%, p=0.009).

CONCLUSION

Younger age and left-sided stroke may be predictive factors of early recovery of functional swallow in patients who received PEG. Prospective validation is important as avoidance of unnecessary procedures could reduce morbidity and healthcare costs.

Stroke outcomes among participants randomized to chlorthalidone, amlodipine or lisinopril in ALLHAT

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) was a randomized, double-blind, practice-based, active-control, comparative effectiveness trial in 33,357 high-risk hypertensive participants. ALLHAT compared cardiovascular disease outcomes in participants initially treated with an angiotensin-converting enzyme inhibitor (lisinopril), a calcium channel blocker (amlodipine), or a thiazide-type diuretic (chlorthalidone). We report stroke outcomes in 1517 participants in-trial and 1596 additional participants during post-trial passive surveillance, for a total follow-up of 8-13 years. Stroke rates were higher with lisinopril (6-year rate/100 = 6.4) than with chlorthalidone (5.8) or amlodipine (5.5) in-trial but not including post-trial (10-year rates/100 = 13.2 [chlorthalidone], 13.1[amlodipine], and 13.7 [lisinopril]). In-trial differences were driven by race (race-by-lisinopril/chlorthalidone interaction P = .005, race-by-amlodipine/lisinopril interaction P = .012) and gender (gender-by-lisinopril/amlodipine interaction P = .041), separately. No treatment differences overall, or by race or gender, were detected over the 10-year period. No differences appeared among treatment groups in adjusted risk of all-cause mortality including post-trial for participants with nonfatal in-trial strokes. Among Blacks and women, lisinopril was less effective in preventing stroke in-trial than either chlorthalidone or amlodipine, even after adjusting for differences in systolic blood pressure. These differences abated by the end of the post-trial period.

In vivo animal stroke models: a rationale for rodent and non-human primate models

On average, every four minutes an individual dies from a stroke, accounting for 1 out of every 18 deaths in the United States. Approximately 795,000 Americans have a new or recurrent stroke each year, with just over 600,000 of these being first attack [1]. There have been multiple animal models of stroke demonstrating that novel therapeutics can help improve the clinical outcome. However, these results have failed to show the same outcomes when tested in human clinical trials. This review will discuss the current in vivo animal models of stroke, advantages and limitations, and the rationale for employing these animal models to satisfy translational gating items for examination of neuroprotective, as well as neurorestorative strategies in stroke patients. An emphasis in the present discussion of therapeutics development is given to stem cell therapy for stroke.

Anticoagulant use for the prevention of stroke in patients with atrial fibrillation: findings from a multi-payer analysis

Background

Oral anticoagulation is recommended for stroke prevention in intermediate/high stroke risk atrial fibrillation (AF) patients. The objective of this study was to demonstrate the usefulness of analytic software tools for descriptive analyses of disease management in atrial AF; a secondary objective is to demonstrate patterns of potential anticoagulant undertreatment in AF.

Methods

Retrospective data analyses were performed using the Anticoagulant Quality Improvement Analyzer (AQuIA), a software tool designed to analyze health plan data. Two-year data from five databases were analyzed: IMS LifeLink (IMS), MarketScan Commercial (MarketScanCommercial), MarketScan Medicare Supplemental (MarketScanMedicare), Clinformatics™ DataMart, a product of OptumInsight Life Sciences (Optum), and a Medicaid Database (Medicaid). Included patients were ≥ 18 years old with a new or existing diagnosis of AF. The first observed AF diagnosis constituted the index date, with patient outcomes assessed over a one year period. Key study measures included stroke risk level, anticoagulant use, and frequency of International Normalized Ratio (INR) monitoring.

Results

High stroke risk (CHADS₂ ≥ 2 points) was estimated in 54% (IMS), 22% (MarketScanCommercial), 64% (MarketscanMedicare), 42% (Optum) and 62% (Medicaid) of the total eligible population. Overall, 35%, 29%, 38%, 39% and 16% of all AF patients received an anticoagulant medication in IMS, MarketScanCommercial, MarketScanMedicare, Optum and Medicaid, respectively. Among patients at high risk for stroke, 19% to 51% received any anticoagulant.

Conclusions

The AQuIA provided a consistent platform for analysis across multiple AF populations with varying baseline characteristics. Analyzer results show that many high-risk AF patients in selected commercial, Medicare-eligible, and Medicaid populations do not receive appropriate thromboprophylaxis, as recommended by treatment guidelines.

Nut consumption and risk of type 2 diabetes, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies have shown inverse associations between nut consumption and diabetes, cardiovascular disease (CVD), and all-cause mortality, but results have not been consistent.

OBJECTIVE

We assessed the relation between nut intake and incidence of type 2 diabetes, CVD, and all-cause mortality.

DESIGN

We searched PubMed and EMBASE for all prospective cohort studies published up to March 2013 with RRs and 95% CIs for outcomes of interest. A random-effects model was used to pool risk estimates across studies.

RESULTS

In 31 reports from 18 prospective studies, there were 12,655 type 2 diabetes, 8862 CVD, 6623 ischemic heart disease (IHD), 6487 stroke, and 48,818 mortality cases. The RR for each incremental serving per day of nut intake was 0.80 (95% CI: 0.69, 0.94) for type 2 diabetes without adjustment for body mass index; with adjustment, the association was attenuated [RR: 1.03; 95% CI: 0.91, 1.16; NS]. In the multivariable-adjusted model, pooled RRs (95% CIs) for each serving per day of nut consumption were 0.72 (0.64, 0.81) for IHD, 0.71 (0.59, 0.85) for CVD, and 0.83 (0.76, 0.91) for all-cause mortality. Pooled RRs (95% CIs) for the comparison of extreme quantiles of nut intake were 1.00 (0.84, 1.19; NS) for type 2 diabetes, 0.66 (0.55, 0.78) for IHD, 0.70 (0.60, 0.81) for CVD, 0.91 (0.81, 1.02; NS) for stroke, and 0.85 (0.79, 0.91) for all-cause mortality.

CONCLUSIONS

Our meta-analysis indicates that nut intake is inversely associated with IHD, overall CVD, and all-cause mortality but not significantly associated with diabetes and stroke. The inverse association between the consumption of nuts and diabetes was attenuated after adjustment for body mass index. These findings support recommendations to include nuts as part of a healthy dietary pattern for the prevention of chronic diseases.

Stem cell therapy for acute cerebral injury: what do we know and what will the future bring?

PURPOSE OF REVIEW

The central nervous system has limited capacity for regeneration after acute and chronic injury. An attractive approach to stimulate neural plasticity in the brain is to transplant stem cells in order to restore function. Here, we discuss potential mechanisms of action, current knowledge and future perspectives of clinical stem cell research for stroke and traumatic brain injury.

RECENT FINDINGS

Preclinical data using various models suggest stem cell therapy to be a promising therapeutic avenue. Progress has been made in elucidating the mechanism of action of various cell types used, shifting the hypothesis from neural replacement to enhancing endogenous repair processes. Translation of these findings in clinical trials is currently being pursued with emphasis on both safety as well as efficacy.

SUMMARY

Clinical trials are currently recruiting patients in phase I and II trials to gain more insight in the therapeutic potential of stem cells in acute cerebral injury. A close interplay between results of these clinical trials and more extensive basic research is essential for future trial design, choosing the optimal transplantation strategy and selecting the right patients.

A literature review of indirect costs associated with stroke

BACKGROUND

Stroke is a leading cause of mortality and long-term disability. However, the indirect costs of stroke, such as productivity loss and costs of informal care, have not been well studied. To better understand this, we conducted a literature review of the indirect costs of stroke.

METHODS

A literature search using PubMed, MEDLINE, and EconLit, with the key words stroke, cerebrovascular disease, subarachnoid hemorrhage, intracerebral hemorrhage, cost-of-illness, productivity loss, indirect cost, economic burden, and informal caregiving was conducted. We identified original research articles published during 1990-2012 in English-language peer-reviewed journals. We summarized indirect costs by study type, cost categories, and study settings.

RESULTS

We found 31 original research articles that investigated the indirect cost of stroke. Six of these investigated indirect costs only; the other 25 studies were cost-of-illness studies that included indirect costs as a component. Of the 31 articles, 6 examined indirect costs in the United States, with 2 of these focused solely on indirect costs. Because of diverse methods, kinds of data, and definitions of cost used in the studies, the literature indicated a very wide range internationally in the proportion of the total cost of stroke that is represented by indirect costs (from 3% to 71%).

CONCLUSIONS

Most of the literature indicates that indirect costs account for a significant portion of the economic burden of stroke, and there is a pressing need to develop proper approaches to analyze these costs and to make better use of relevant data sources for such studies or establish new ones.

The one-year attributable cost of post-stroke dysphagia

With the recent emphasis on evidence-based practice and healthcare reform, understanding the cost of dysphagia management has never been more important. It is helpful for clinicians to understand and objectively report the costs associated with dysphagia when they advocate for their services in this economy. Having carefully estimated cost of illness, inputs are needed for cost-effectiveness analyses that help support the value of treatments. This study sought to address this issue by examining the 1-year cost associated with a diagnosis of dysphagia post-stroke in South Carolina. Furthermore, this study investigated whether ethnicity and residence differences exist in the cost of dysphagia post-stroke. Data on 3,200 patients in the South Carolina Medicare database from 2004 who had ICD-9 codes for ischemic stroke, 434 and 436, were retrospectively included in this study. Differences between persons with and without dysphagia post-stroke were compared with respect to age, gender, ethnicity, mortality, length of stay, comorbidity, rurality, discharge disposition, and cost to Medicare. Univariate analyses and a gamma-distributed generalized linear multivariable model with a log link function were completed. We found that the 1-year cost to Medicare for persons with dysphagia post ischemic stroke was $4,510 higher than that for persons without dysphagia post ischemic stroke when controlling for age, comorbidities, ethnicity, and proportion of time alive. Univariate analysis revealed that rurality, ethnicity, and gender were not statistically significantly different in comparisons of individuals with or without dysphagia post-stroke. Post-stroke dysphagia significantly increases post-stroke medical expenses. Understanding the expenditures associated with post-stroke dysphagia is helpful for optimal allocation and use of resources. Such information is needed to conduct cost-effectiveness studies.

Retrospective cost-effectiveness analysis of treatments for aphasia: an approach using experimental data

PURPOSE

Evidence supports the effectiveness of speech-language treatment for individuals with aphasia, yet less is known about the cost-effectiveness of such treatments. The purpose of this study was to examine the incremental cost and cost-effectiveness of aphasia treatment using previously published data.

METHOD

The authors completed a retrospective cost-effectiveness analysis using experimental data that they extracted from 19 previously published aphasia treatment studies. Average and incremental cost-effectiveness ratios were calculated based on participants' pre- and posttreatment proficiency scores.

RESULTS

The average cost-effectiveness ratio for all sessions was $9.54 for each 1% increase in the outcome of interest. Measures of incremental cost-effectiveness indicated that aphasia treatments resulted in statistically significant improvements up to and including 17 treatment sessions. Increases in proficiency occurred at a cost of approximately $7.00 per 1% increase for the first 3 sessions to more than $20.00 in the 14th session; the ratio was either not statistically significant or dominated (more costly and less effective) in later sessions.

CONCLUSIONS

This cost-effectiveness analysis demonstrated that initial aphasia treatment sessions resulted in relatively larger and more cost-effective benefits than did later aphasia treatment sessions. The findings reported here are preliminary and have limitations. Prospective studies are needed to examine the cost-effectiveness of speech-language treatment for individuals with aphasia.

Generalized versus patient-specific inflow boundary conditions in computational fluid dynamics simulations of cerebral aneurysmal hemodynamics

BACKGROUND AND PURPOSE

Attempts have been made to associate intracranial aneurysmal hemodynamics with aneurysm growth and rupture status. Hemodynamics in aneurysms is traditionally determined with computational fluid dynamics by using generalized inflow boundary conditions in a parent artery. Recently, patient-specific inflow boundary conditions are being implemented more frequently. Our purpose was to compare intracranial aneurysm hemodynamics based on generalized versus patient-specific inflow boundary conditions.

MATERIALS AND METHODS

For 36 patients, geometric models of aneurysms were determined by using 3D rotational angiography. 2D phase-contrast MR imaging velocity measurements of the parent artery were performed. Computational fluid dynamics simulations were performed twice: once by using patient-specific phase-contrast MR imaging velocity profiles and once by using generalized Womersley profiles as inflow boundary conditions. Resulting mean and maximum wall shear stress and oscillatory shear index values were analyzed, and hemodynamic characteristics were qualitatively compared.

RESULTS

Quantitative analysis showed statistically significant differences for mean and maximum wall shear stress values between both inflow boundary conditions (P < .001). Qualitative assessment of hemodynamic characteristics showed differences in 21 cases: high wall shear stress location (n = 8), deflection location (n = 3), lobulation wall shear stress (n = 12), and/or vortex and inflow jet stability (n = 9). The latter showed more instability for the generalized inflow boundary conditions in 7 of 9 patients.

CONCLUSIONS

Using generalized and patient-specific inflow boundary conditions for computational fluid dynamics results in different wall shear stress magnitudes and hemodynamic characteristics. Generalized inflow boundary conditions result in more vortices and inflow jet instabilities. This study emphasizes the necessity of patient-specific inflow boundary conditions for calculation of hemodynamics in cerebral aneurysms by using computational fluid dynamics techniques.

Machine learning for outcome prediction of acute ischemic stroke post intra-arterial therapy

Introduction

Stroke is a major cause of death and disability. Accurately predicting stroke outcome from a set of predictive variables may identify high-risk patients and guide treatment approaches, leading to decreased morbidity. Logistic regression models allow for the identification and validation of predictive variables. However, advanced machine learning algorithms offer an alternative, in particular, for large-scale multi-institutional data, with the advantage of easily incorporating newly available data to improve prediction performance. Our aim was to design and compare different machine learning methods, capable of predicting the outcome of endovascular intervention in acute anterior circulation ischaemic stroke.

Method

We conducted a retrospective study of a prospectively collected database of acute ischaemic stroke treated by endovascular intervention. Using SPSS®, MATLAB®, and Rapidminer®, classical statistics as well as artificial neural network and support vector algorithms were applied to design a supervised machine capable of classifying these predictors into potential good and poor outcomes. These algorithms were trained, validated and tested using randomly divided data.

Results

We included 107 consecutive acute anterior circulation ischaemic stroke patients treated by endovascular technique. Sixty-six were male and the mean age of 65.3. All the available demographic, procedural and clinical factors were included into the models. The final confusion matrix of the neural network, demonstrated an overall congruency of ∼80% between the target and output classes, with favourable receiving operative characteristics. However, after optimisation, the support vector machine had a relatively better performance, with a root mean squared error of 2.064 (SD: ±0.408).

Discussion

We showed promising accuracy of outcome prediction, using supervised machine learning algorithms, with potential for incorporation of larger multicenter datasets, likely further improving prediction. Finally, we propose that a robust machine learning system can potentially optimise the selection process for endovascular versus medical treatment in the management of acute stroke.

Incidence, prevalence, costs, and impact on disability of common conditions requiring rehabilitation in the United States: stroke, spinal cord injury, traumatic brain injury, multiple sclerosis, osteoarthritis, rheumatoid arthritis, limb loss, and back pain

OBJECTIVE

To determine the relative incidence, prevalence, costs, and impact on disability of 8 common conditions treated by rehabilitation professionals.

DATA SOURCES

Comprehensive bibliographic searches using MEDLINE, Google Scholar, and UpToDate, (June, 2013).

DATA EXTRACTION

Two review authors independently screened the search results and performed data extraction. Eighty-two articles were identified that had relevant data on the following conditions: Stroke, Spinal Cord Injury, Traumatic Brain Injury, Multiple Sclerosis, Osteoarthritis, Rheumatoid Arthritis, Limb Loss, and Back Pain.

DATA SYNTHESIS

Back pain and arthritis (osteoarthritis, rheumatoid arthritis) are the most common and costly conditions we analyzed, affecting more than 100 million individuals and costing greater than $200 billion per year. Traumatic brain injury, while less common than arthritis and back pain, carries enormous per capita direct and indirect costs, mostly because of the young age of those involved and the severe disability that it may cause. Finally, stroke, which is often listed as the most common cause of disability, is likely second to both arthritis and back pain in its impact on functional limitations.

CONCLUSIONS

Of the common rehabilitation diagnoses we studied, musculoskeletal conditions such as back pain and arthritis likely have the most impact on the health care system because of their high prevalence and impact on disability.

Treatment patterns associated with stroke prevention in patients with atrial fibrillation in three major cities in the People's Republic of china

BACKGROUND

Atrial fibrillation (AF) is associated with an increased risk of stroke. This study assessed treatment patterns associated with stroke prevention among patients with AF in three major cities of the People's Republic of China.

METHODS

A random sample of 2,862 medical charts for patients with AF at six tertiary hospitals located in Beijing, Shanghai, and Guangzhou between 2003 and 2008 were reviewed. Patient demographics, clinical characteristics, and treatment patterns were extracted from medical charts. Antithrombotic regimens included antiplatelets, anticoagulants, and a combination of both. Descriptive analyses were performed to summarize basic antithrombotic patterns. A logistic regression model examined demographic and clinical factors associated with antithrombotic treatment patterns.

RESULTS

Of the patient sample, 55% were male, the average age was 72 years (49% ≥75 years), 15% had valvular AF, 78% had nonvalvular AF, and the remainder had unspecified AF. CHADS2 scores ≥2 were reported for 53% of patients. Antithrombotic treatment was not received by 17% of patients during hospitalization, and 66% did not receive warfarin. Among patients with valvular or nonvalvular AF, 33%, 30%, and 20% received antiplatelet, anticoagulation, and antiplatelet plus anticoagulation treatments, respectively. For patients with CHADS2 scores of 0, 1, 2, 3, and ≥4, 52%, 42%, 28%, 21%, and 21%, respectively, were treated with warfarin. Predictors of no antithrombotic treatment included age and hospital location.

CONCLUSION

Anticoagulation therapy was underused in Chinese patients with AF. Antithrombotic treatment was not associated with stroke risk. Further studies need to examine the clinical consequences of various antithrombotic treatment patterns in Chinese patients with AF.

Statins and aspirin for chemoprevention in Barrett's esophagus: results of a cost-effectiveness analysis

Data suggest that aspirin, statins, or a combination of the two drugs may lower the progression of Barrett's esophagus to esophageal adenocarcinoma. However, aspirin is associated with potential complications such as gastrointestinal bleeding and hemorrhagic stroke, and statins are associated with myopathy. We developed a simulation disease model to study the effectiveness and cost effectiveness of aspirin and statin chemoprevention against esophageal adenocarcinoma. A decision analytic Markov model was constructed to compare four strategies for Barrett's esophagus management; all regimens included standard endoscopic surveillance regimens: (i) endoscopic surveillance alone, (ii) aspirin therapy, (iii) statin therapy, and (iv) combination therapy of aspirin and statin. Endpoints evaluated were life expectancy, quality-adjusted life years (QALY), costs, and incremental cost-effectiveness ratios (ICER). Sensitivity analysis was performed to determine the impact of model input uncertainty on results. Assuming an annual progression rate of 0.33% per year from Barrett's esophagus to esophageal adenocarcinoma, aspirin therapy was more effective and cost less than (dominated) endoscopic surveillance alone. When combination therapy was compared with aspirin therapy, the ICER was $158,000/QALY, which was above our willingness-to-pay threshold of $100,000/QALY. Statin therapy was dominated by combination therapy. When higher annual cancer progression rates were assumed in the model (0.5% per year), combination therapy was cost-effective compared with aspirin therapy, producing an ICER of $96,000/QALY. In conclusion, aspirin chemoprevention was both more effective and cost less than endoscopic surveillance alone. Combination therapy using both aspirin and statin is expensive but could be cost-effective in patients at higher risk of progression to esophageal adenocarcinoma.

Neuropathologic analysis of hematomas evacuated from patients with spontaneous intracerebral hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is a devastating cause of morbidity and mortality. Intraparenchymal hematomas are often surgically evacuated. This generates fragments of perihematoma brain tissue that may elucidate their etiology. The goal of this study is to analyze the value of these specimens in providing a possible etiology for spontaneous ICH as well as the utility of using immunohistochemical markers to identify amyloid angiopathy. Surgically resected hematomas from 20 individuals with spontaneous ICH were examined with light microscopy. Hemorrhage locations included 11 lobar and nine basal ganglia hemorrhages. Aβ immunohistochemistry and Congo red stains were used to confirm the presence of amyloid angiopathy, when this was suspected. Evidence of cerebral amyloid angiopathy (CAA) was observed in eight of the 20 specimens, each of which came from lobar locations. Immunohistochemistry confirmed CAA in the brain fragments from these eight individuals. Patients with immunohistochemically confirmed CAA were older than patients without CAA, and more likely to have lobar hemorrhages (OR 3.0 and 3.7, respectively). Evidence of CAA was not found in any of the basal ganglia specimens. One specimen showed evidence of CAA-associated angiitis, with formation of a microaneurysm in an inflamed segment of a CAA-affected arteriole, surrounded by acute hemorrhage. In another specimen, Aβ immunohistochemistry showed the presence of senile plaques suggesting concomitant Alzheimer's disease (AD) changes. Surgically evacuated hematomas from patients with spontaneous ICH should be carefully examined, paying special attention to any fragments of included brain parenchyma. These fragments can provide evidence of the etiology of the hemorrhage. Markers such as Aβ 1-40 can help to identify underlying CAA, and should be utilized when microangiopathy is suspected. Given the association of (Aβ) CAA with AD, careful examination of entrapped brain fragments may also provide evidence of AD in a given patient.

Delayed neurological deterioration after subarachnoid haemorrhage

Subarachnoid haemorrhage (SAH) causes early brain injury (EBI) that is mediated by effects of transient cerebral ischaemia during bleeding plus effects of the subarachnoid blood. Secondary effects of SAH include increased intracranial pressure, destruction of brain tissue by intracerebral haemorrhage, brain shift, and herniation, all of which contribute to pathology. Many patients survive these phenomena, but deteriorate days later from delayed cerebral ischaemia (DCI), which causes poor outcome or death in up to 30% of patients with SAH. DCI is thought to be caused by the combined effects of angiographic vasospasm, arteriolar constriction and thrombosis, cortical spreading ischaemia, and processes triggered by EBI. Treatment for DCI includes prophylactic administration of nimodipine, and current neurointensive care. Prompt recognition of DCI and immediate treatment by means of induced hypertension and balloon or pharmacological angioplasty are considered important by many physicians, although the evidence to support such approaches is limited. This Review summarizes the pathophysiology of DCI after SAH and discusses established treatments for this condition. Novel strategies--including drugs such as statins, sodium nitrite, albumin, dantrolene, cilostazol, and intracranial delivery of nimodipine or magnesium--are also discussed.

[Direct hospital cost of stroke in Parakou in northern Benin]

Introduction

Les accidents vasculaires cérébraux constituent un véritable problème de santé publique en Afrique avec une charge importante. Les données fiables sur sa réelle charge économique sont rares en Afrique. L'objectif de cette étude était d’évaluer le coût direct hospitalier des AVC à Parakou au Bénin.

Méthodes

Il s'agissait d'une étude transversale économique ayant inclus des patients hospitalisés pour un AVC à l'hôpital de Parakou entre le 1^er Juin 2010 au 31Mai 2011. Les données concernant les différents postes de consommation ont été collectées selon la méthode dite bottom-up. Le coût était envisagé du point de vue de la société et du patient. L'unité du coût était le franc CFA (valeur en 2011). Une régression linéaire multiple était utilisée pour déterminer les meilleurs prédicteurs du coût.

Résultats

Ils étaient 78 patients dont 52 hommes, âgés en moyenne de 57 ans ± 10.9. Le NIHSS moyen était de 14,4. Le taux de mortalité était de 20,5%. Le coût direct moyen était de 316.810,3 (±230.774,8) F CFA (environ 704 ± 512 Euros). Les grands postes de consommation étaient les explorations paracliniques (34.3%) les soins et médicaments (28.4%) et les frais d'hospitalisation (17.9%). Les meilleurs prédicteurs du coût élevé étaient un AVC hémorragique, un NIHSS élevé à l'admission et une longue durée d'hospitalisation.

Conclusion

Cette étude suggère un coût élevé de la prise en charge actuelle des AVC à Parakou.

Marginal costing methods highlight the contributing cost of comorbid conditions in Medicare patients: a quasi-experimental case-control study of ischemic stroke costs

BACKGROUND

Cost of illness studies are needed to provide estimates for input into cost-effectiveness studies and as information drivers to resource allocation. However, these studies often do not differentiate costs associated with the disease of interest and costs of co-morbidities. The goal of this study was to identify the 1-year cost of ischemic stroke compared to the annual cost of care for a comparable non-stroke group of South Carolina (SC) Medicare beneficiaries resulting in a marginal cost estimate.

METHODS

SC data for 2004 and 2005 were used to estimate the mean 12 month cost of stroke for 2,976 Medicare beneficiaries hospitalized for Ischemic Stroke in 2004. Using nearest neighbor propensity score matching, a control group of non-stroke beneficiaries were matched on age, gender, race, risk factors, and Charlson comorbidity index and their costs were calculated. Marginal cost attributable to ischemic stroke was calculated as the difference between these two adjusted cost estimates.

RESULTS

The total cost estimated for SC stroke patients for 1 year (2004) was $81.3 million. The cost for the matched comparison group without stroke was $54.4 million. Thus, the 2004 marginal costs to Medicare due to Ischemic stroke in SC are estimated to be $26.9 million.

CONCLUSIONS

Accurate estimates of cost of care for conditions, such as stroke, that are common in older patients with a high rate of comorbid conditions require the use of a marginal costing approach. Over estimation of cost of care for stroke may lead to prediction of larger savings than realizable from important stroke treatment and prevention programs, which may damage the credibility of program advocates, and jeopardize long term funding support. Additionally, correct cost estimates are needed as inputs for valid cost-effectiveness studies. Thus, it is important to use marginal costing for stroke, especially with the increasing public focus on evidence-based economic decision making to be expected with healthcare reform.

The Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study protocol

BACKGROUND AND PURPOSE

Epidemiological studies of intracerebral hemorrhage (ICH) have consistently demonstrated variation in incidence, location, age at presentation, and outcomes among non-Hispanic white, black, and Hispanic populations. We report here the design and methods for this large, prospective, multi-center case-control study of ICH.

METHODS

The Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study is a multi-center, prospective case-control study of ICH. Cases are identified by hot-pursuit and enrolled using standard phenotype and risk factor information and include neuroimaging and blood sample collection. Controls are centrally identified by random digit dialing to match cases by age (±5 years), race, ethnicity, sex, and metropolitan region.

RESULTS

As of March 22, 2013, 1655 cases of ICH had been recruited into the study, which is 101.5% of the target for that date, and 851 controls had been recruited, which is 67.2% of the target for that date (1267 controls) for a total of 2506 subjects, which is 86.5% of the target for that date (2897 subjects). Of the 1655 cases enrolled, 1640 cases had the case interview entered into the database, of which 628 (38%) were non-Hispanic black, 458 (28%) were non-Hispanic white, and 554 (34%) were Hispanic. Of the 1197 cases with imaging submitted, 876 (73.2%) had a 24 hour follow-up CT available. In addition to CT imaging, 607 cases have had MRI evaluation.

CONCLUSIONS

The ERICH study is a large, case-control study of ICH with particular emphasis on recruitment of minority populations for the identification of genetic and epidemiological risk factors for ICH and outcomes after ICH.

Lifetime direct medical costs of treating type 2 diabetes and diabetic complications

BACKGROUND

Lifetime direct medical cost of treating type 2 diabetes and diabetic complications in the U.S. is unknown.

PURPOSE

This study provides nationally representative estimates of lifetime direct medical costs of treating type 2 diabetes and diabetic complications in people newly diagnosed with type 2 diabetes, by gender and by age at diagnosis.

METHODS

A type 2 diabetes simulation model was used to simulate the disease progression and direct medical costs among a cohort of newly diagnosed type 2 diabetes patients. The study sample used for the simulation was based on data from the 2009-2010 National Health and Nutritional Examination Survey. The costs of treating type 2 diabetes and diabetic complications were derived from published literature. Annual medical costs were accumulated over the life span of type 2 diabetes to determine the lifetime medical costs. All costs were calculated from a healthcare system perspective, and expressed in 2012 dollars.

RESULTS

In men diagnosed with type 2 diabetes at ages 25-44 years, 45-54 years, 55-64 years, and ≥ 65 years, the lifetime direct medical costs of treating type 2 diabetes and diabetic complications were $124,700, $106,200, $84,000, and $54,700, respectively. In women, the costs were $130,800, $110,400, $85,500, and $56,600, respectively. The age-gender weighted average of the lifetime medical costs was $85,200, of which 53% was due to treating diabetic complications. The cost of managing macrovascular complications accounted for 57% of the total complication cost.

CONCLUSIONS

Over the lifetime, type 2 diabetes imposes a substantial economic burden on healthcare systems. Effective interventions that prevent or delay type 2 diabetes and diabetic complications might result in substantial long-term savings in healthcare costs.

Recovery and quality of life in patients with ruptured cerebral aneurysms

PURPOSE

Subarachnoid hemorrhage (SAH) secondary to ruptured cerebral aneurysm is a common and frequently devastating condition with a high mortality and morbidity among survivors. The purpose of this study was to conduct a long-term follow-up of SAH patients, assess the changes in functional outcomes, describe quality of life (QOL), and determine its predictors 3.6 years after the hemorrhage.

DESIGN

The study design is an exploratory, descriptive correlational design.

METHODS

Results were collected from a sample of 113 SAH survivors treated in our institution over a 2-year period (January 2006 until December 2007). We collected data on early and long-term functional outcomes and compared the differences. The health-related QOL was measured using the Polish version of The Short Form - 36 Health Survey Questionnaire (SF-36v2). Multivariable logistic regression was derived to define independent predictors of the QOL.

FINDINGS

The mean follow-up time was 3.6 years. Sixty-six percent of patients had improvement in functional outcomes and among previously employed people 56% returned to work. QOL deteriorated in 24% of patients with the most affected dimension of Physical Role. Factors that predict good QOL are male gender, younger age, good economic/professional status, lack of physical handicaps, rehabilitation in a professional center, subjective improvement in health status, and absence of headaches or physical decline.

CONCLUSIONS AND CLINICAL RELEVANCE

Recovery process in SAH patients is dynamic and progresses over time. Since physical handicaps and low economic status significantly reduce the quality of life, an effort should be made to provide intensive rehabilitation and to encourage SAH survivors to return to work.

Trends in stroke survival incidence rates in older Australians in the new millennium and forecasts into the future

AIMS

The objective of this study is (i) to evaluate trends in the incidence rates of stroke survivors aged 60 years and older over a 11-year period in the Australian Capital Territory (ACT) and (ii) to forecast future trends in Australia until 2051.

METHODS

Analysis of age- and sex-specific standardized incidence rates of older first-ever stroke survivors in ACT from 1999-2000 to 2009-2010 and projections of number of stroke survivors (NSS) in 2021 and 2051 using 2 models based only on (i) demographic changes and (ii) assuming changing of both incidence rates and demography.

RESULTS

In the ACT in the first decade of the 21st century, the absolute numbers and age-adjusted standardized incidence rates of stroke survivors (measured as a function of age and period) increased among both men and women aged 60 years or older. The trend toward increased survival rates in both sexes was driven mainly by population aging, whereas the effect of stroke year was more pronounced in men compared with women. The absolute NSS (and the financial burden to the society) in Australia is predicted to increase by 35.5%-59.3% in 2021 compared with 2011 and by 1.6- to 4.6-fold in 2051 if current only demographic (first number) or both demographic and incidence trends (second number) continue.

CONCLUSIONS

Our study demonstrates favorable trends in stroke survivor rates in Australia in the first decade of the new millennium and projects in the foreseeable future significant increases in the absolute numbers of older stroke survivors, especially among those aged 70 years or older and men.

Selective activation of the human tibial and common peroneal nerves with a flat interface nerve electrode

OBJECTIVE

Electrical stimulation has been shown effective in restoring basic lower extremity motor function in individuals with paralysis. We tested the hypothesis that a flat interface nerve electrode (FINE) placed around the human tibial or common peroneal nerve above the knee can selectively activate each of the most important muscles these nerves innervate for use in a neuroprosthesis to control ankle motion.

APPROACH

During intraoperative trials involving three subjects, an eight-contact FINE was placed around the tibial and/or common peroneal nerve, proximal to the popliteal fossa. The FINE's ability to selectively recruit muscles innervated by these nerves was assessed. Data were used to estimate the potential to restore active plantarflexion or dorsiflexion while balancing inversion and eversion using a biomechanical simulation.

MAIN RESULTS

With minimal spillover to non-targets, at least three of the four targets in the tibial nerve, including two of the three muscles constituting the triceps surae, were independently and selectively recruited in all subjects. As acceptable levels of spillover increased, recruitment of the target muscles increased. Selective activation of muscles innervated by the peroneal nerve was more challenging.

SIGNIFICANCE

Estimated joint moments suggest that plantarflexion sufficient for propulsion during stance phase of gait and dorsiflexion sufficient to prevent foot drop during swing can be achieved, accompanied by a small but tolerable inversion or eversion moment.

The effects of heat stress and its effect modifiers on stroke hospitalizations in Allegheny County, Pennsylvania

PURPOSE

Heat has been known to increase the risk of many health endpoints. However, few studies have examined its effects on stroke. The objective of this case-crossover study is to investigate the effects of high heat and its effect modifiers on the risk of stroke hospitalization in Allegheny County, Pennsylvania.

METHODS

We obtained data on first stroke hospitalizations among adults ages 65 and older and daily meteorological information during warm seasons (May-September) from 1994 to 2000 in Allegheny County, Pennsylvania. Using conditional multiple logistic regressions, the effects of heat days (any day with a temperature greater than the 95th percentile) and heat wave days (at least two continuous heat days) on the risk of stroke hospitalization were investigated. The potential interactions between high heat and age, type of stroke, and gender were also examined.

RESULTS

Heat day and heat wave at lag-2 day were significantly associated with an increased risk for stroke hospitalization (OR 1.121, 95 % CI 1.013-1.242; OR 1.173, 95 % CI 1.047-1.315, respectively) after adjusting for important covariates. In addition, having two or more heat wave days within the 4 day window prior to the event was also significantly associated with an increased risk (OR 1.119, 95 % CI 1.004, 1.246) compared to having no heat wave days during the period. The effect of high heat on stroke was more significant for ischemic stroke, men, and subjects ages 80 years or older.

CONCLUSIONS

Our study suggests that high heat may have adverse effects on stroke and that some subgroups may be particularly susceptible to heat.

Antithrombotic therapy in patients with heart valve prostheses

Heart valve prostheses carry a risk for thrombosis and require an antithrombotic strategy to prevent stroke, systemic embolism, and prosthetic valve thrombosis. Contemporary randomized trials to guide the clinician on the optimal anticoagulant treatment are scarce, and the validity of the historical data for current recommendations can be questioned in view of the changes in valve prostheses, the patient population, and antithrombotic therapies. This limited evidence from clinical trials translates into divergent recommendations from the different scientific societies on the optimal intensity of oral anticoagulation and on the indication for antiplatelet therapy. The availability of new antithrombotic agents and the unclear thrombotic risk of the currently used prostheses underscore the need to redefine antithrombotic treatment in patients with heart valve prostheses.

Review of transcranial direct current stimulation in poststroke recovery

Motor impairment, dysphagia, aphasia, and visual impairment are common disabling residual deficits experienced by stroke survivors. Recently, many novel rehabilitative modalities have been investigated for their potential to ameliorate such deficits and to improve functional outcomes. Noninvasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), have emerged as a promising tool to facilitate stroke recovery. tDCS can alter cortical excitability to induce brain plasticity by modulating the lesioned, contralesional, or bilateral hemispheres with various stimulation modalities. Along with peripheral therapies, tDCS can lead to subsequent sustained behavioral and clinical gains in patients with stroke. In this review, we summarize characteristics of tDCS (method of stimulation, safety profile, and mechanism) and its application in the treatment of various stroke-related deficits, and we highlight future directions for tDCS in this capacity.

Safety and feasibility of an early mobilization program for patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

Survivors of aneurysmal subarachnoid hemorrhage (SAH) are faced with a complicated recovery, which typically includes surgery, prolonged monitoring in the intensive care unit, and treatment focusing on the prevention of complications.

OBJECTIVE

The purpose of this study was to determine the safety and feasibility of an early mobilization program for patients with aneurysmal SAH.

DESIGN

This study was a retrospective analysis.

METHODS

Twenty-five patients received early mobilization by a physical therapist or an occupational therapist, or both, which focused on functional training and therapeutic exercise in more progressively upright positions. Participation criteria focused on neurologic and physiologic stability prior to the initiation of early mobilization program sessions.

RESULTS

Patients met the criteria for participation in 86.1% of the early mobilization program sessions attempted. Patients did not meet criteria for the following reasons: Lindegaard ratio >3.0 or middle cerebral artery (MCA) mean flow velocity (MFV) >120 cm/s (8.1%), mean arterial pressure (MAP) <80 mm Hg (1.8%), intracranial pressure (ICP) >15 mm Hg (1.8%), unable to open eyes in response to voice (0.9%), respiratory rate >40 breaths/min (0.6%), MAP >110 mm Hg (0.3%), and heart rate <40 bpm (0.3%). Adverse events occurred in 5.9% of early mobilization program sessions for the following reasons: MAP <70 mm Hg (3.1%) or >120 mm Hg (2.4%) and heart rate >130 bpm (0.3%). The 30-day mortality rate for all patients was 0%. Participation in the early mobilization program began a mean of 3.2 days (SD=1.3) after aneurysmal SAH, and patients received an average of 11.4 sessions (SD=4.3). Patients required a mean of 5.4 days (SD=4.2) to participate in out-of-bed activity and a mean of 10.7 days (SD=6.2) to walk ≥15.24 m (50 ft).

CONCLUSIONS

The results of this study suggest that an early mobilization program for patients with aneurysmal SAH is safe and feasible.

A primer on brain-machine interfaces, concepts, and technology: a key element in the future of functional neurorestoration

Conventionally, the practice of neurosurgery has been characterized by the removal of pathology, congenital or acquired. The emerging complement to the removal of pathology is surgery for the specific purpose of restoration of function. Advents in neuroscience, technology, and the understanding of neural circuitry are creating opportunities to intervene in disease processes in a reparative manner, thereby advancing toward the long-sought-after concept of neurorestoration. Approaching the issue of neurorestoration from a biomedical engineering perspective is the rapidly growing arena of implantable devices. Implantable devices are becoming more common in medicine and are making significant advancements to improve a patient's functional outcome. Devices such as deep brain stimulators, vagus nerve stimulators, and spinal cord stimulators are now becoming more commonplace in neurosurgery as we utilize our understanding of the nervous system to interpret neural activity and restore function. One of the most exciting prospects in neurosurgery is the technologically driven field of brain-machine interface, also known as brain-computer interface, or neuroprosthetics. The successful development of this technology will have far-reaching implications for patients suffering from a great number of diseases, including but not limited to spinal cord injury, paralysis, stroke, or loss of limb. This article provides an overview of the issues related to neurorestoration using implantable devices with a specific focus on brain-machine interface technology.

SAHIT Investigators--on the outcome of some subarachnoid hemorrhage clinical trials

Outcome of patients with aneurysmal subarachnoid hemorrhage (SAH) has improved over the last decades. Yet, case fatality remains nearly 40% and survivors often have permanent neurological, cognitive and/or behavioural sequelae. Other than nimodipine drug or clinical trials have not consistently improved outcome. We formed a collaboration of SAH investigators to create a resource for prognostic analysis and for studies aimed at optimizing the design and analysis of phase 3 trials in aneurysmal SAH. We identified investigators with data from randomized, clinical trials of patients with aneurysmal SAH or prospectively collected single- or multicentre databases of aneurysmal SAH patients. Data are being collected and proposals to use the data and to design future phase 3 clinical trials are being discussed. This paper reviews some issues discussed at the first meeting of the SAH international trialists (SAHIT) repository meeting. Investigators contributed or have agreed to contribute data from several phase 3 trials including the tirilazad trials, intraoperative hypothermia for aneurysmal SAH trial, nicardipine clinical trials, international subarachnoid aneurysm trial, intravenous magnesium sulphate for aneurysmal SAH, magnesium for aneurysmal SAH and from prospectively-collected data from four institutions. The number of patients should reach 15,000. Some industry investigators refused to provide data and others reported that their institutional research ethics boards would not permit even deidentified or anonymized data to be included. Others reported conflict of interest that prevented them from submitting data. The problems with merging data were related to lack of common definitions and coding of variables, differences in outcome scales used, and times of assessment. Some questions for investigation that arose are discussed. SAHIT demonstrates the possibility of SAH investigators to contribute data for collaborative research. The problems are similar to those already documented in other similar collaborative efforts such as in head injury research. We encourage clinical trial and registry investigators to contact us and participate in SAHIT. Key issues moving forward will be to use common definitions (common data elements), outcomes analysis, and to prioritize research questions, among others.

Subarachnoid Hemorrhage International Trialists data repository (SAHIT)

The outcome of patients with aneurysmal subarachnoid hemorrhage (SAH) has improved slowly over the past 25 years. This improvement may be due to early aneurysm repair by endovascular or open means, use of nimodipine, and better critical care management. Despite this improvement, mortality remains at about 40%, and many survivors have permanent neurologic, cognitive, and neuropsychologic deficits. Randomized clinical trials have tested pharmacologic therapies, but few have been successful. There are numerous explanations for the failure of these trials, including ineffective interventions, inadequate sample size, treatment side effects, and insensitive or inappropriate outcome measures. Outcome often is evaluated on a good-bad dichotomous scale that was developed for traumatic brain injury 40 years ago. To address these issues, we established the Subarachnoid Hemorrhage International Trialists (SAHIT) data repository. The primary aim of the SAHIT data repository is to provide a unique resource for prognostic analysis and for studies aimed at optimizing the design and analysis of phase III trials in aneurysmal SAH. With this aim in mind, we convened a multinational investigator meeting to explore merging individual patient data from multiple clinical trials and observational databases of patients with SAH and to create an agreement under which such a group of investigators could submit data and collaborate. We welcome collaboration with other investigators.