Efficacy and safety of nerinetide for the treatment of acute ischaemic stroke (ESCAPE-NA1): a multicentre, double-blind, randomised controlled trial

BACKGROUND

Nerinetide, an eicosapeptide that interferes with post-synaptic density protein 95, is a neuroprotectant that is effective in preclinical stroke models of ischaemia-reperfusion. In this trial, we assessed the efficacy and safety of nerinetide in human ischaemia-reperfusion that occurs with rapid endovascular thrombectomy in patients who had an acute ischaemic stroke.

METHODS

For this multicentre, double-blind, randomised, placebo-controlled study done in 48 acute care hospitals in eight countries, we enrolled patients with acute ischaemic stroke due to large vessel occlusion within a 12 h treatment window. Eligible patients were aged 18 years or older with a disabling ischaemic stroke at the time of randomisation, had been functioning independently in the community before the stroke, had an Alberta Stroke Program Early CT Score (ASPECTS) greater than 4, and vascular imaging showing moderate-to-good collateral filling, as determined by multiphase CT angiography. Patients were randomly assigned (1:1) to receive intravenous nerinetide in a single dose of 2·6 mg/kg, up to a maximum dose of 270 mg, on the basis of estimated or actual weight (if known) or saline placebo by use of a real-time, dynamic, internet-based, stratified randomised minimisation procedure. Patients were stratified by intravenous alteplase treatment and declared endovascular device choice. All trial personnel and patients were masked to sequence and treatment allocation. All patients underwent endovascular thrombectomy and received alteplase in usual care when indicated. The primary outcome was a favourable functional outcome 90 days after randomisation, defined as a modified Rankin Scale (mRS) score of 0-2. Secondary outcomes were measures of neurological disability, functional independence in activities of daily living, excellent functional outcome (mRS 0-1), and mortality. The analysis was done in the intention-to-treat population and adjusted for age, sex, baseline National Institutes of Health Stroke Scale score, ASPECTS, occlusion location, site, alteplase use, and declared first device. The safety population included all patients who received any amount of study drug. This trial is registered with ClinicalTrials.gov, NCT02930018.

FINDINGS

Between March 1, 2017, and Aug 12, 2019, 1105 patients were randomly assigned to receive nerinetide (n=549) or placebo (n=556). 337 (61·4%) of 549 patients with nerinetide and 329 (59·2%) of 556 with placebo achieved an mRS score of 0-2 at 90 days (adjusted risk ratio 1·04, 95% CI 0·96-1·14; p=0·35). Secondary outcomes were similar between groups. We observed evidence of treatment effect modification resulting in inhibition of treatment effect in patients receiving alteplase. Serious adverse events occurred equally between groups.

INTERPRETATION

Nerinetide did not improve the proportion of patients achieving good clinical outcomes after endovascular thrombectomy compared with patients receiving placebo.

FUNDING

Canadian Institutes for Health Research, Alberta Innovates, and NoNO.

Intraarterial Thrombolysis as Rescue Therapy for Large Vessel Occlusions

Background and Purpose—

Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry.

Methods—

The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT.

Results—

A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P =0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P =0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P =0.29) and mortality (42.9% versus 44.7%; P =0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P =0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P =0.02).

Conclusions—

Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.

First Pass Effect

Background and Purpose—

In acute ischemic stroke, fast and complete recanalization of the occluded vessel is associated with improved outcomes. We describe a novel measure for newer generation devices: the first pass effect (FPE). FPE is defined as achieving a complete recanalization with a single thrombectomy device pass.

Methods—

The North American Solitaire Acute Stroke Registry database was used to identify a FPE subgroup. Their baseline features and clinical outcomes were compared with non-FPE patients. Clinical outcome measures included 90-days modified Rankin Scale score, National Institutes of Health Stroke Scale score, mortality, and symptomatic intracranial hemorrhage. Multivariate analyses were performed to determine whether FPE independently resulted in improved outcomes and to identify predictors of FPE.

Results—

A total of 354 acute ischemic stroke patients underwent thrombectomy in the North American Solitaire Acute Stroke registry. FPE was achieved in 89 out of 354 (25.1%). More middle cerebral artery occlusions (64% versus 52.5%) and fewer internal carotid artery occlusions (10.1% versus 27.7%) were present in the FPE group. Balloon guide catheters were used more frequently with FPE (64.0% versus 34.7%). Median time to revascularization was significantly faster in the FPE group (median 34 versus 60 minutes; P =0.0003). FPE was an independent predictor of good clinical outcome (modified Rankin Scale score ≤2 was seen in 61.3% in FPE versus 35.3% in non-FPE cohort; P =0.013; odds ratio, 1.7; 95% confidence interval, 1.1–2.7). The independent predictors of achieving FPE were use of balloon guide catheters and non-internal carotid artery terminus occlusion.

Conclusions—

The achievement of complete revascularization from a single Solitaire thrombectomy device pass (FPE) is associated with significantly higher rates of good clinical outcome. The FPE is more frequently associated with the use of balloon guide catheters and less likely to be achieved with internal carotid artery terminus occlusion.

Clinical and Angiographic Outcomes with the Combined Local Aspiration and Retriever in the North American Solitaire Stent-Retriever Acute Stroke (NASA) Registry

Background

Various techniques are used to enhance the results of mechanical thrombectomy with stent-retrievers, including proximal arrest with balloon guide catheter (BGC), conventional large bore proximal catheter (CGC), or in combination with local aspiration through a large-bore catheter positioned at the clot interface (Aspiration-Retriever Technique for Stroke [ARTS]). We evaluated the impact of ARTS in the North American Solitaire Acute Stroke (NASA) registry.

Summary

Data on the use of the aspiration technique were available for 285 anterior circulation patients, of which 29 underwent ARTS technique, 131 CGC, and 125 BGC. Baseline demographics were comparable, except that ARTS patients are less likely to have hypertension or atrial fibrillation. The ARTS group had more ICA occlusions (41.4 vs. 22% in the BGC, p = 0.04 and 26% in CGC, p = 0.1) and less MCA/M1 occlusions (44.8 vs. 68% in BGC and 62% in CGC). Time from arterial puncture to reperfusion or end of procedure with ARTS was shorter than with CGC (54 vs. 91 min, p = 0.001) and was comparable to the BGC time (54 vs. 67, p = 0.11). Final degree of reperfusion was comparable among the groups (TICI [modified Thrombolysis in Cerebral Infarction] score 2b or higher was 72 vs. 70% for CGC vs. 78% for BGC). Procedural complications, mortality, and good clinical outcome at 90 days were similar between the groups.

Key Messages

The ARTS mechanical thrombectomy in acute ischemic stroke patients appears to yield better results as compared to the use of CGCs with no significant difference when compared to BGC. This early ARTS technique NASA registry data are limited by the earlier generation distal large bore catheters and small sample size. Future studies should focus on the comparison of ARTS and BGC techniques.

Interhospital Transfer Before Thrombectomy Is Associated With Delayed Treatment and Worse Outcome in the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke)

Supplemental Digital Content is available in the text.

Background:

Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation.

Methods:

STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0–2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass.

Results:

A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients (P<0.001). Clinical outcomes were better in the direct group, with 60.0% (299/498) achieving functional independence compared with 52.2% (213/408) in the transfer group (odds ratio, 1.38; 95% confidence interval, 1.06–1.79; P=0.02). Likewise, excellent outcome (modified Rankin Score 0–1) was achieved in 47.4% (236/498) of direct patients versus 38.0% (155/408) of transfer patients (odds ratio, 1.47; 95% confidence interval, 1.13–1.92; P=0.005). Mortality did not differ between the 2 groups (15.1% for direct, 13.7% for transfer; P=0.55). Intravenous tissue plasminogen activator did not impact outcomes. Hypothetical bypass modeling for all transferred patients suggested that intravenous tissue plasminogen activator would be delayed by 12 minutes, but MT would be performed 91 minutes sooner if patients were routed directly to endovascular-capable centers. If bypass is limited to a 20-mile radius from onset, then intravenous tissue plasminogen activator would be delayed by 7 minutes and MT performed 94 minutes earlier.

Conclusions:

In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Rescue Thrombectomy in Large Vessel Occlusion Strokes Leads to Better Outcomes than Intravenous Thrombolysis Alone: A 'Real World' Applicability of the Recent Trials

BACKGROUND

The Interventional Management of Stroke III (IMS-III) trial demonstrated no benefit for intravenous recombinant tissue plasminogen activator (IV rt-PA) followed by endovascular therapy versus IV rt-PA alone. However, IMS-III mostly included earlier generation devices. The recent thrombectomy trials have incorporated the stent-retriever technology, but their generalizability remains unknown.

METHODS

The North American Solitaire Acute Stroke (NASA) registry recruited patients treated with the Solitaire FR™ device between March 2012 and February 2013. The NASA-IMS-III-Like Group (NILG baseline NIHSS score ≥10 who received IV rt-PA) was compared to the IV rt-PA and IV + intra-arterial (IA)-IMS-III groups and the MR CLEAN, ESCAPE, SWIFT Prime, and REVASCAT trial controls to assess the stent-retriever treatment in the 'real-world' setting. The NILG was also compared to non-IV rt-PA NASA patients to evaluate the impact of IV rt-PA on thrombectomy.

RESULTS

A total of 136 of the 354 NASA patients fulfilled criteria for the NILG. Baseline characteristics were well balanced across groups. Time from onset to puncture was higher in NILG than IV+IA-IMS-III patients (274 ± 112 vs. 208 ± 47 min, p < 0.0001). Occlusions involving the intracranial ICA, MCA-M1, or basilar arteries were more common in NILG than IV+IA-IMS-III patients (91.2 vs. 47.2%, p < 0.00001). Modified thrombolysis in cerebral infarction ≥2b reperfusion was higher in NILG than IV+IA-IMS-III patients (74.3 vs. 39.6%, p < 0.00001). A 90-day modified Rankin Scale score ≤2 was more frequent in the NILG than IV+IA-IMS-III patients (51.9 vs. 40.8%, p = 0.03) and MR CLEAN (51.9 vs. 19.1%, p < 0.00001), ESCAPE (51.9 vs. 29.3%, p = 0.0002), SWIFT Prime (51.9 vs. 35.5%, p = 0.02), and REVASCAT (51.9 vs. 28.2%, p = 0.0003) controls. Symptomatic intracranial hemorrhage definitions varied across the different studies with rates ranging from 2.7% (ESCAPE) to 11.9% (NILG). The NILG 90-day mortality (24.4%) was higher than in SWIFT Prime but comparable to all other groups. IV rt-PA was an independent predictor of good outcome in NASA (OR = 2.3, 95% CI 1.2-4.7).

CONCLUSION

Our results support the 'real-world' applicability of the recent thrombectomy trials.

Complete reperfusion mitigates influence of treatment time on outcomes after acute stroke

BACKGROUND

Time to reperfusion following endovascular treatment (ET) predicts outcomes after acute ischemic stroke (AIS).

OBJECTIVE

To assess the time-outcome relationship within reperfusion grades in the North American Solitaire Acute Stroke registry.

METHODS

We identified patients given ET for anterior circulation ischemic stroke within 8 h from onset and in whom reperfusion was achieved. Together with clinical and outcome data, site-adjudicated modified Thrombolysis in Cerebral Ischemia (TICI) was recorded. We assessed the impact of time to reperfusion (onset to procedure completion time) on good outcome (modified Rankin Scale 0-2 at 3 months) in patients who achieved TICI 2 or higher reperfusion in multivariable models. We further assessed this relationship within strata of reperfusion grades. A p<0.05 was considered significant.

RESULTS

Independent predictors of good outcome at 3 months among those achieving TICI ≥2a reperfusion (n=188) were initial National Institutes of Health Stroke Scale score (adjusted OR=0.90, 95% CI 0.85 to 0.95), symptomatic hemorrhage (adj. OR=0.16, 95% CI 0.05 to 0.60), TICI grade (TICI 3: adj. OR=11.52, 95% CI 3.34 to 39.77; TICI 2b: adj. OR=5.14, 95% CI 1.61 to 16.39), and time to reperfusion per 30 min interval (adj. OR=0.91, 95% CI 0.82 to 0.99). There was an interaction between final TICI grade and 30 min time to reperfusion intervals (p=0.001) such that the effect of time was strongest in TICI 2a patients.

CONCLUSIONS

Time to reperfusion was a strong predictor of outcome following ET for AIS. However, the effect varied by TICI grade such that its greatest effect was in those achieving TICI 2a reperfusion.

Abstract WP3: EMS Routing for Endovascular Patients- One Health Care Systems Successful Model

Background: Annually, over 1500 stroke patients are seen within a large metropolitan health system. The health system encompasses a designated comprehensive (CSC) and multiple primary (PSC) stroke hospitals with varying capabilities to manage stroke patients, resulting in varied care delivery. While CSCs mitigate inconsistencies by establishing a standard of stroke care, one shortcoming of the CSC model is lack of regulation in transfer of patients between centers within a health system containing multiple stroke designations.

Purpose: The purpose of the project was to create a streamlined, emergency stroke work-up process across the various levels of stroke hospitals and to apply rapid routing practices for EMS when transferring stroke patients between facilities. These changes could reduce treatment times and optimize resources to facilitate transportation of stroke patients to the appropriate center.

Methods: The system stroke steering team, in collaboration with regional EMS directors initiated 5 primary processes to reduce delays. These included 1) door in to door out times of 60 minutes, 2) loading radiology images into a cloud environment, 3) development of EMS algorithms, 4) prompt follow-up reports on stroke transfers, and 5) rapid loop-closure on gaps in the process. A reduction in door-to-therapy time and measures of patient outcome were used as indicators for effectiveness.

Results: Implementation of a streamlined ED process and new routing protocol was associated with improved door-to-door times, door-to-treatment times and EMS transport times. Additionally, risk-adjusted mortality decreased from 0.7 in 2012 to 0.3 in 2014. Similarly, thrombolytic complications in intravenous and endovascular patients decreased from 7.5% in 2012 to 1.7% in 2014, while treatment rates in both increased.

Conclusion: Within a large health system, utilizing a consistent ED process and new EMS routing protocol could contribute to improved outcomes. This raises the possibility that implementing system routing practices may improve collaboration within stroke systems of care and advance the CSC model.

Inadvertent Stent Retriever Detachment: A Multicenter Case Series and Review of Device Experience FDA Reports

Mechanical thrombectomy using retrievable stents or stent retriever devices has become the mainstay of intra-arterial therapy for acute ischemic stroke. The recent publication of a series of positive trials supporting intra-arterial therapy as standard of care for the treatment of large vessel occlusion will likely further increase stent retriever use. Rarely, premature stent detachment during thrombectomy may be encountered. In our multicenter case series, we found a rate of detachment of less than 1% (n = 7/1,067), and all were first-generation Solitaire FR devices. A review of the US Food and Drug Administration database of device experience yielded 90 individual adverse reports of detachment. There were 82, 1 and 7 detachments of Solitaire FR (first generation), Solitaire FR2 (second generation) and Trevo devices, respectively. We conclude with a brief overview of the technical and procedural considerations which may be helpful in avoiding this rare complication.

Groin complications in endovascular mechanical thrombectomy for acute ischemic stroke: a 10-year single center experience

Background

The increasing utilization of balloon guide catheters (BGCs) in thrombectomy therapy for ischemic stroke has led to concerns about large-bore sheaths causing vascular groin complications.

Objective To retrospectively assess the impact of large large-bore sheaths and vascular closure devices on groin complication rates at a comprehensive stroke center over a 10-year period.

Methods

Radiological and clinical records of patients with acute ischemic stroke who underwent mechanical endovascular therapy with an 8Fr or larger sheaths were reviewed. A groin complication was defined as the formation of a groin hematoma, retroperitoneal hematoma, femoral artery pseudoaneurysm, or the need for surgical repair. Information collected included size of sheath, type of hemostatic device, and anticoagulation status of the patient. Blood bank records were also analyzed to identify patients who may have had an undocumented blood transfusion for a groin hematoma.

Results

A total of 472 patients with acute ischemic stroke who underwent mechanical thrombectomy with a sheath and BGC sized 8Fr or larger were identified. 260 patients (55.1%) had tissue Plasminogen Activator (tPA) administered as part of stroke treatment. Vascular closure devices were used in 97.9% of cases (n=462). Two patients were identified who had definite groin complications and a further two were included as having possible complications. There was a very low rate of clinically significant groin complications (0.4–0.8%) associated with the use of large-bore sheaths.

Conclusions

These findings suggest that concerns for groin complications should not preclude the use of BGCs and large-bore sheaths in mechanical thrombectomy for acute ischemic stroke.

Abstract W P15: Decreasing Time to Treatment in Endovascular Therapy for Acute Ischemic Stroke: A Single Institution’s Experience

Background and Purpose: Time has consistently been cited as a fundamental variable to improve clinical outcomes in stroke. We identified potential to reduce ‘Door to Imaging’ and ‘Door to Groin Puncture’ times at our institution by streamlining the flow process for acute stroke management by the multidisciplinary team.

Methods: Retrospective analysis was performed over a 3-month period on all patients who underwent mechanical thrombectomy for symptomatic stroke. Time-interval metrics collected included time from patient arrival to the start of imaging, start of groin puncture and start of revascularization. We then identified weak links in the pathway of stroke care and implemented strategies for change, including early notification of the interventionist by stroke neurologists or the ‘Code Neuro’ stroke nurse, the patient being taken directly to CT on arrival to the Emergency Department if hemodynamically stable and point of care processing of blood tests. Other interventions included enhancement of pre-hospital work-up by Emergency Medical Services and a unified paging system. Following these interventions, another analysis of time-interval metrics was undertaken on a second population of patients, also over a 3-month period.

Results: Data on a total of 20 patients prior to change implementation and 22 patients after change were analyzed. The results obtained are tabulated as shown:

Conclusion: This quality improvement project was able to successfully demonstrate a reduction in various time-interval metrics following a targeted, and ongoing, initiative to optimize specific response mechanisms in the acute stroke process pathway.

North American SOLITAIRE Stent-Retriever Acute Stroke Registry

Background and Purpose—

Previous work that predated the availability of the safer stent-retriever devices has suggested that general anesthesia (GA) may have a negative impact on outcomes in patients with acute ischemic stroke undergoing endovascular therapy.

Methods—

We reviewed demographic, clinical, procedural (GA versus local anesthesia [LA], etc), and site-adjudicated angiographic and clinical outcomes data from consecutive patients treated with the Solitaire FR device in the investigator-initiated North American SOLITAIRE Stent-Retriever Acute Stroke (NASA) Registry. The primary outcomes were 90-day modified Rankin Scale, mortality, and symptomatic intracranial hemorrhage.

Results—

A total of 281 patients from 18 centers were enrolled. GA was used in 69.8% (196/281) of patients. Baseline demographic and procedural factors were comparable between the LA and GA groups, except the former demonstrated longer time-to-groin puncture (395.4±254 versus 337.4±208 min; P =0.04), lower National Institutes of Health Stroke Scale (NIHSS; 16.2±5.8 versus 18.8±6.9; P =0.002), lower balloon-guide catheter usage (22.4% versus 49.2%; P =0.0001), and longer fluoroscopy times (39.5±33 versus 28±22.8 min; P =0.008). Recanalization (thrombolysis in cerebral infarction ≥2b; 72.94% versus 73.6%; P =0.9) and rate of symptomatic intracranial hemorrhage (7.1% versus 11.2%; P =0.4) were similar but modified Rankin Scale ≤2 was achieved in more LA patients, 52.6% versus 35.6% (odds ratio, 1.4 [1.1–1.8]; P =0.01). In multivariate analysis, hypertension, NIHSS, unsuccessful revascularization, and GA use (odds ratio, 3.3 [1.6–7.1]; P =0.001) were associated with death. When only anterior circulation and elective GA patients were included, there was a persistent difference in good outcomes in favor of LA patients (50.7% versus 35.5%; odds ratio, 1.3 [1.01–1.6]; P =0.04).

Conclusions—

The NASA Registry has demonstrated that clinical outcomes and survival are significantly better in patients treated with LA, without increased symptomatic intracranial hemorrhage risk. Future trials should prospectively evaluate the effect of GA on outcomes.

Balloon guide catheter improves revascularization and clinical outcomes with the Solitaire device: analysis of the North American Solitaire Acute Stroke Registry

BACKGROUND AND PURPOSE

Efficient and timely recanalization is an important goal in acute stroke endovascular therapy. Several studies demonstrated improved recanalization and clinical outcomes with the stent retriever devices compared with the Merci device. The goal of this study was to evaluate the role of the balloon guide catheter (BGC) and recanalization success in a substudy of the North American Solitaire Acute Stroke (NASA) registry.

METHODS

The investigator-initiated NASA registry recruited 24 clinical sites within North America to submit demographic, clinical, site-adjudicated angiographic, and clinical outcome data on consecutive patients treated with the Solitaire Flow Restoration device. BGC use was at the discretion of the treating physicians.

RESULTS

There were 354 patients included in the NASA registry. BGC data were reported in 338 of 354 patients in this subanalysis, of which 149 (44%) had placement of a BGC. Mean age was 67.3±15.2 years, and median National Institutes of Health Stroke Scale score was 18. Patients with BGC had more hypertension (82.4% versus 72.5%; P=0.05), atrial fibrillation (50.3% versus 32.8%; P=0.001), and were more commonly administered tissue plasminogen activator (51.6% versus 38.8%; P=0.02) compared with patients without BGC. Time from symptom onset to groin puncture and number of passes were similar between the 2 groups. Procedure time was shorter in patients with BGC (120±28.5 versus 161±35.6 minutes; P=0.02), and less adjunctive therapy was used in patients with BGC (20% versus 28.6%; P=0.05). Thrombolysis in cerebral infarction 3 reperfusion scores were higher in patients with BGC (53.7% versus 32.5%; P<0.001). Distal emboli and emboli in new territory were similar between the 2 groups. Discharge National Institutes of Health Stroke Scale score (mean, 12±14.5 versus 17.5±16; P=0.002) and good clinical outcome at 3 months were superior in patients with BGC compared with patients without (51.6% versus 35.8%; P=0.02). Multivariate analysis demonstrated that the use of BGC was an independent predictor of good clinical outcome (odds ratio, 2.5; 95% confidence interval, 1.2-4.9).

CONCLUSIONS

Use of a BGC with the Solitaire Flow Restoration device resulted in superior revascularization results, faster procedure times, decreased need for adjunctive therapy, and improved clinical outcome.

Hemorrhagic stroke: aneurysmal subarachnoid hemorrhage

Non-traumatic subarachnoid hemorrhage (SAH) represents approximately 5-6% of all strokes. Morbidity and mortality rates remain high, but accurate diagnosis using clinical assessment and neuroimaging, critical care management, and early treatment using either surgical or interventional techniques have improved overall outcomes. This, the fifth in a Missouri Medicine series on stroke, summarizes the clinical and imaging aspects of making the diagnosis of SAH, critical care management of the patient, treatment options, and factors important in prognosis.

Is mechanical embolectomy performed in nonanesthetized patients effective?

BACKGROUND AND PURPOSE

In centers performing endovascular treatment for patients with AIS, there is variability in placing patients under general anesthesia. Nonanesthetized patients might move during the procedure leading to complications and prolonging the time to revascularization due to lack of cooperation. However, general anesthesia can lead to a delay of the procedure, an inability to assess the patient during the procedure, and fluctuations of blood pressure. Our center does not routinely either use general anesthesia or sedate patients. We report our experience with nonanesthetized patients undergoing emergent mechanical embolectomy.

MATERIALS AND METHODS

We performed a retrospective analysis of 66 consecutive patients enrolled in the MERCI Registry at our center from June 2007 to June 2009. A univariate statistical analysis was performed by using the Fisher exact test for categoric variables and the Student t test for continuous variables in comparing use of general anesthesia with nonanesthetized patient demographics, procedural times, procedural complications, good outcome, and mortality.

RESULTS

Nine patients (13.6%) were placed under general anesthesia, and 57 (86.4%) were awake. Higher baseline NIHSS scores and older age were statistically associated with general anesthesia. No significant difference occurred between groups in the time to groin puncture or procedural times. Revascularization rates were 77% for general anesthesia patients and 70% for nonanesthetized patients (P = .331). The nonanesthetized group had better outcomes, but we did not control these outcomes for other factors. Complications were much more frequent in the general anesthesia patients (22%) than in the nonanesthetized patients (3.5%) (P = .0288).

CONCLUSIONS

Performing mechanical embolectomy in nonanesthetized patients at our institution does not prolong procedure time, decrease revascularization rates, increase complication rates, or decrease good outcome. Mechanical embolectomy in nonanesthetized patients is effective and should be considered an option in the treatment of the patient with AIS.

Acutely ruptured intracranial saccular aneurysms treated with stent assisted coiling: complications and outcomes in 42 consecutive patients

BACKGROUND

Antiplatelet agents are required to prevent thromboembolic complications from recently deployed intracranial stents, yet they carry a risk of bleeding complications that may be serious in patients with recent subarachnoid hemorrhage.

METHOD

Consecutive patients at a single institution who had ruptured intracranial saccular aneurysms treated with stent assisted coiling were retrospectively reviewed. Our primary outcomes were ischemic stroke related to the stent and bleeding complications possibly related to antithrombotic therapy. Secondary outcomes included 3 month follow-up National Institute of Health Stroke Scale (NIHSS) scores and modified Rankin Scale (mRS) scores.

RESULTS

44 aneurysms in 42 patients were treated. Seven patients experienced ischemic strokes during their hospitalization. Five ischemic strokes were secondary to vasospasm; one was definitely related to thrombus formation within the stent and one was possibly related to the stent. Two patients had asymptomatic intracranial hemorrhages and one patient had a symptomatic intracranial hemorrhage. Patients with Hunt and Hess grades I-II (n=25) experienced no stent associated ischemic strokes or symptomatic intracranial hemorrhages. The two stent associated ischemic strokes and one symptomatic intracranial hemorrhage occurred in patients with Hunt and Hess grades III-V (n=17) and patients with external ventricular drains (EVDs) (n=17). Only one patient had disability at the 3 month follow-up that was possibly related to the stent (mRS score of 3 and NIHSS score of 2).

CONCLUSION

These data suggest that higher grade hemorrhage patients, especially those with EVDs, are at greater risk for ischemic stroke and/or bleeding complications than lower grade patients. However, the complications had a small impact on mid-term disability outcomes in this cohort.

Risk factors for in-stent restenosis after vertebral ostium stenting

PURPOSE

To determine whether vascular risk factors, underlying vessel diameter, and/or the type of stent affect restenosis rates for vertebral ostium stents.

METHODS

A single-center retrospective analysis was conducted of 44 patients (31 men; mean age 61 years, range 32-81) who underwent stenting of 48 ostial lesions in the vertebral arteries between 1999 and 2005. Only patients who underwent angiographic follow-up were included in the analysis. Cox regression analysis was utilized for risk factor association with binary restenosis (> or =50% versus <50%). Stent types and stent categories were compared for differences in binary restenosis rates and lumen gain at follow-up angiography.

RESULTS

Twenty-three (48%) of 48 lesions had > or =50% stenosis at a mean follow-up of 7.7 months. Cigarette smoking was associated with higher binary restenosis rates (p=0.025), while hypertension, diabetes, hyperlipidemia, history of neck radiation, and known coronary artery and/or peripheral vascular disease were not. Reduced binary restenosis rates and improved lumen gain were seen in cobalt chromium balloon-expandable stents compared to non-cobalt chromium stents (p=0.002 and p=0.002, respectively), stainless steel balloon-expandable stents (p=0.005 and p=0.005), and the S670 stent (p=0.069 and p=0.069). The size of stent used was not associated with risk of restenosis (p=0.756).

CONCLUSIONS

Cobalt chromium stents were associated with reduced restenosis, while smoking was associated with increased restenosis risk.

Improving prediction of outcome in "good grade" subarachnoid hemorrhage

OBJECTIVE

We hypothesize that subtle neurological signs at baseline could be present in some "good grade" subarachnoid hemorrhage (SAH) patients and that they would have negative prognostic implications.

METHODS

We analyzed data from 1000 patients randomized to the Intraoperative Hypothermia for Aneurysm Surgery Trial (World Federation of Neurological Societies Grades I, II, and III). Nine hundred and forty-four patients had a complete National Institutes of Health Stroke Scale (NIHSS) examination performed at baseline. We analyzed the relationship between baseline NIHSS scores and Glasgow Outcome Scale scores at 3 months. Using stepwise logistic regression, we identified the individual NIHSS items that independently predicted outcome to construct a useful shorter version of the scale for SAH.

RESULTS

The NIHSS was abnormal at baseline in 23% of the Grade I patients and 82% of the Grade II patients. Baseline NIHSS scores strongly predicted 3-month outcomes (P < 0.001). The NIHSS items that were relevant to predict outcome were level of consciousness, dysarthria, visual fields, and worst motor score for the arms. Baseline NIHSS-SAH scores also independently predicted 3-month outcomes (P < 0.001).

CONCLUSION

Subtle neurological signs at baseline are common in World Federation of Neurological Societies Grades I and II patients and are associated with a worse outcome at 3 months. These signs are not detected by the World Federation of Neurological Societies classification. A better stratification of "good grade" SAH patients to predict long-term outcomes may be desirable for clinical trials and practice. Either using the full NIHSS or a shortened version testing level of consciousness, visual fields, dysarthria and worst arm motor score will help to better stratify "good-grade" SAH patients.

The effects of vagus nerve stimulation on decision-making

Subcortical and brainstem structures are increasingly becoming recognized as important contributors to higher cognitive functioning. Decision-making is one such function, particularly as viewed within the framework of the somatic marker hypothesis (SMH). The SMH views the participation in decision-making by the body proper as integral to emotional biasing and hence key to choosing in an advantageous manner. This study focuses on the vagus nerves as a possible conduit for somatic afferent signals pertinent to decision-making. We tested eight epileptic patients with implanted left vagus nerve stimulators. To assess decision-making we used the gambling task, which is sensitive to real-life decision-making deficits. Using a counterbalanced design, each participant performed the gambling task under a condition in which low-level vagus nerve stimulation (VNS) was covertly delivered, and another condition in which no VNS was delivered. Participants showed improved performance, that is, made more advantageous choices, in the stimulated relative to the unstimulated condition. Although these results should be viewed as preliminary, they suggest that the vagus nerve is a conduit for afferent somatic signals that can influence decision-making.

Neuro-ophthalmic findings in the visual variant of Alzheimer's disease

PURPOSE

To describe the clinical features of a visual variant Alzheimer's disease, a disorder that might be seen by the ophthalmologist with visual symptoms and signs.

DESIGN

Retrospective case series.

PARTICIPANTS

Eight patients with Alzheimer's disease presenting with predominantly visual complaints.

METHODS

A retrospective review of patients at a tertiary care academic center seen by the authors from 1999 to 2001 with Alzheimer's disease and predominantly visual complaints.

RESULTS

Eight patients with the visual variant of Alzheimer's disease were reviewed. All had seen eye care providers before referral to the neuro-ophthalmology clinic for visual complaints but without a diagnosis. Four patients had homonymous visual field loss, and two had presumed cortical visual impairment. Neuroimaging showed either normal brain (1 patient) or atrophy of the parietal or occipital areas but no structural lesions (7 patients). Fluoro-18-deoxyglucose positron emission tomography scans were performed in five of the cases, and all showed hypoperfusion in the parietooccipital areas. Neuropsychologic testing revealed visuospatial deficits in all 5 patients tested.

CONCLUSIONS

Visual symptoms might be the presenting (or rarely only) manifestation of Alzheimer's disease. Clinicians should be aware of the visual variant of Alzheimer's disease. Neuropsychological testing and magnetic resonance imaging (MRI) provide supporting evidence for the diagnosis. Positron emission tomography scans might be helpful in selected cases, especially those with a normal MRI.

Neurological aspects of biological and chemical terrorism: a review for neurologists

The Centers for Disease Control and Prevention urge physicians to become familiar with chemical and biological weapons. Preparedness among neurologists is especially important because several of these agents affect the nervous system. This article reviews 4 agents that have a history of military or terrorist use: cyanide poisons, organophosphate poisons, botulinum toxin, and anthrax. Cyanide and organophosphate poisons are characterized by dose-dependent impairment of neurological function with nonspecific symptoms such as headache or dizziness at one end of the spectrum and convulsions and coma at the other. Neurological examinations help clinicians to differentiate these agents from other intoxications. Botulinum toxin has a delayed onset of action and results in descending paralysis and prominent cranial nerve palsies. Anthrax frequently causes fulminating hemorrhagic meningitis. Early recognition of these chemical and biological weapons is key to instituting specific therapy and preventing casualties within the health care team and the community at large.

Pathological laughter and crying: a link to the cerebellum

Patients with pathological laughter and crying (PLC) are subject to relatively uncontrollable episodes of laughter, crying or both. The episodes occur either without an apparent triggering stimulus or following a stimulus that would not have led the subject to laugh or cry prior to the onset of the condition. PLC is a disorder of emotional expression rather than a primary disturbance of feelings, and is thus distinct from mood disorders in which laughter and crying are associated with feelings of happiness or sadness. The traditional and currently accepted view is that PLC is due to the damage of pathways that arise in the motor areas of the cerebral cortex and descend to the brainstem to inhibit a putative centre for laughter and crying. In that view, the lesions 'disinhibit' or 'release' the laughter and crying centre. The neuroanatomical findings in a recently studied patient with PLC, along with new knowledge on the neurobiology of emotion and feeling, gave us an opportunity to revisit the traditional view and propose an alternative. Here we suggest that the critical PLC lesions occur in the cerebro-ponto-cerebellar pathways and that, as a consequence, the cerebellar structures that automatically adjust the execution of laughter or crying to the cognitive and situational context of a potential stimulus, operate on the basis of incomplete information about that context, resulting in inadequate and even chaotic behaviour.

Trypsin and chymotrypsin inhibitor of Vigna unguiculata seeds--involvement of tyrosyls in its interaction with proteases

When trypsin and chymotrypsin inhibitor of Vigna unguiculata seeds (black-eyed pea trypsin and chymotrypsin inhibitor, BTCI) combines with beta-trysin, 4.0, 4.5, 5.0, 5.8, and 6.6 tyrosyl residues are shielded from reaction with N-acetylimidazole, at reagent/protein molar ratios of 60, 120, 200, 350 and 500, respectively. This may result from the presence of tyrosyl residues in the zone of contact between enzyme and inhibitor. In the interaction of BTCI and alpha-chymotrypsin, only 0.6 tyrosyl residues are shielded from the reaction with N-acetylimidazole, at a 500-fold reagent molar excess.