Iatrogenic stroke caused by cerebral air embolism and acute reperfusion therapy using hyperbaric oxygen.

Objective: Air embolisms are mostly iatrogenic and a rare yet dreaded complication following percutaneous procedures. Intravascular entrapment of air can result in occlusion of end arteries and subsequent tissue ischemia and infarction. Cerebrovascular occlusions caused by air embolisms are time-sensitive and an uncommon cause of ischemic stroke, warranting an alternative acute management and reperfusion strategy. Methods: During a CT-guided lung biopsy, the patient developed left-sided paresis and sensory deficits prior to loss of consciousness. CT revealed air in the aorta, both ophthalmic arteries and vessels in the right parietal region. The patient was swiftly air-lifted to the nearest hyperbaric oxygen chamber for an alternate emergency reperfusion therapy. The following eight days the patient received hyperbaric oxygen therapy and gradually improved. Nine days after symptom onset he was discharged with a minor left facial palsy. Conclusions: Cerebrovascular occlusions are critical events regardless of etiology. Air embolism is rare but potentially catastrophic and can occur during both percutaneous procedures and surgeries. Vigilance and knowledge of this potential complication are needed to rapidly provide beneficial treatment. That is, high flow oxygen and correct positioning pending hyperbaric oxygen therapy.

Thrombectomy in large vessel occlusion stroke-Does age matter?

OBJECTIVES: Endovascular treatment (EVT) is the gold standard treatment for emergent large vessel occlusion (LVO). The benefit of EVT for emergent LVO in elderly patients (>80 years old) is still debated as they have been under-represented in randomized controlled trials. Elderly patients with an emergent LVO are a growing population warranting further study. MATERIALS & METHODS: We included 225 consecutive patients treated with EVT for LVO either in the anterior or posterior circulation. The clinical outcome was assessed using the National Institute of Health Stroke Scale (NIHSS). Long-term functional outcome was assessed using 90-day modified ranking scale (mRS). RESULTS: Neurological improvement: A five-year higher age predicted a 0.43 higher mean NIHSS score after EVT (p = .027). After adjusting for confounders (influencing variables), the association between age and post-interventional NIHSS was reduced and non-significant (p = .17). At discharge, a five-year higher age predicted a 0.74 higher mean NIHSS (p = .003). After adjusting for confounders this association was reduced and non-significant (p = .06). Long-term functional outcome: A five-year higher age predicted a 0.20 higher mRS at three months (p < .001). When adjusting for confounders this number was reduced to 0.16, yet still highly significant (p < .001). CONCLUSIONS: Age seems to have a minor role in predicting neurological improvement after EVT but has an impact on long-term functional outcome. The decision to perform or withhold EVT should therefore not solely be based on age.

Pressor therapy in acute ischaemic stroke: an updated systematic review.

Background: Low blood pressure (BP) in acute ischaemic stroke (AIS) is associated with poor functional outcome, death, or severe disability. Increasing BP might benefit patients with post-stroke hypotension including those with potentially salvageable ischaemic penumbra. This updated systematic review considers the present evidence regarding the use of vasopressors in AIS. Methods: We searched the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE and trial databases using a structured search strategy. We examined reference lists of relevant publications for additional studies examining BP elevation in AIS. Results: We included 27 studies involving 1886 patients. Nine studies assessed increasing BP during acute reperfusion therapy (intravenous thrombolysis, mechanical thrombectomy, intra-arterial thrombolysis or combined). Eighteen studies tested BP elevation alone. Phenylephrine was the most commonly used agent to increase BP (n = 16 studies), followed by norepinephrine (n = 6), epinephrine (n = 3) and dopamine (n = 2). Because of small patient numbers and study heterogeneity, a meta-analysis was not possible. Overall, BP elevation was feasible in patients with fluctuating or worsening neurological symptoms, large vessel occlusion with labile BP, sustained post-stroke hypotension and ineligible for intravenous thrombolysis or after acute reperfusion therapy. The effects on functional outcomes were largely unknown and close monitoring is advised if such intervention is undertaken. Conclusion: Although theoretical arguments support increasing BP to improve cerebral blood flow and sustain the ischaemic penumbra in selected AIS patients, the data are limited and results largely inconclusive. Large, randomised controlled trials are needed to identify the optimal BP target, agent, duration of treatment and effects on clinical outcomes.

Insights into a personalized management of blood pressure in acute stroke.

PURPOSE OF REVIEW: Blood pressure management in acute stroke has long been a matter of debate. Epidemiological data show that high blood pressure is associated with death, disability and early stroke recurrence, whereas the pathophysiological rationale for ensuring elevated blood pressure in order maintain adequate cerebral perfusion remains a pertinent argument, especially in ischaemic stroke. RECENT FINDINGS: The European Stroke Organisation Guidelines on blood pressure management in acute ischaemic stroke and intracerebral haemorrhage provide recommendations for the appropriate management of blood pressure in various clinical acute stroke settings. SUMMARY: In this narrative review, we provide specific updates on blood pressure management in ICH, blood pressure management in the setting of reperfusion therapies for ischaemic stroke, and the evidence for the use of induced hypertension in patients with acute ischaemic stroke in the light of the recent guidelines.

Time-Based Decision Making for Reperfusion in Acute Ischemic Stroke.

Decision making in the extended time windows for acute ischemic stroke can be a complex and time-consuming process. The process of making the clinical decision to treat has been compounded by the availability of different imaging modalities. In the setting of acute ischemic stroke, time is of the essence and chances of a good outcome diminish by each passing minute. Navigating the plethora of advanced imaging modalities means that treatment in some cases can be inefficaciously delayed. Time delays and individually based non-programmed decision making can prove challenging for clinicians. Visual aids can assist such decision making aimed at simplifying the use of advanced imaging. Flow charts are one such visual tool that can expedite treatment in this setting. A systematic review of existing literature around imaging modalities based on site of occlusion and time from onset can be used to aid decision making; a more program-based thought process. The use of an acute reperfusion flow chart helping navigate the myriad of imaging modalities can aid the effective treatment of patients.

Multiple simultaneous embolic cerebral infarctions 11 months after COVID-19.

BACKGROUND: The coronavirus disease (COVID-19) pandemic has led to an unprecedented worldwide burden of disease. However, little is known of the longer-term implications and consequences of COVID-19. One of these may be a COVID-19 associated coagulopathy that can present as a venous thromboembolism (VTE) and further, as multiple paradoxical cerebral emboli. CASE PRESENTATION: A 51 year old man presented to the emergency department with multiple simultaneous embolic cerebral infarctions 11 months after mild COVID-19. In the subacute phase of the COVID-19 illness the patient developed increasing shortness of breath and was found to have an elevated D-dimer and multiple bilateral segmental pulmonary emboli. He was subsequently treated with 3 months of anticoagulation for a provoked VTE. The patient then presented 11 months after the initial COVID-19 diagnosis with multiple simultaneous cerebral infarctions where no traditional underlying stroke etiology was determined. A patent foramen ovale (PFO) and an elevated D-dimer were found suggesting a paradoxical thromboembolic event due to an underlying coagulopathy. CONCLUSIONS: This case report highlights the one of the potentially more serious complications of long-term COVID-19 where VTE due to a persistent coagulopathy is seen almost a year after the initial illness. Due to the highly prevalent nature of PFO in the general population, VTE due to COVID-19 associated coagulopathy could lead to ischemic stroke. This case report highlights the possibility for an underlying COVID-19 associated coagulopathy which may persist for many months and beyond the initial illness.

Reversed Robin Hood syndrome visualized by CT perfusion.

Reversed Robin Hood Syndrome (RRHS) was first described in 2007 as a cause of worsening neurological deficit in the setting of an acute ischemic event. RRHS is the shunting of cerebral blood flow to nonstenotic vascular territories due to impaired vasodilation bought on by hypercapnia. A 77 year old lady presented with acute onset left hemiparesis and an exacerbation of her underlying chronic obstructive pulmonary disease (COPD). CT angiography and perfusion visualized RRHS and appropriate treatment was initiated. Treatment strategies for RRHS differ considerably to those for acute ischemic stroke. Choosing the correct treatment strategy is decisive for good clinical outcome.

Endovascular thrombectomy at low-volume centres: A Bayesian solution.

PURPOSE: Endovascular treatment (EVT) is traditionally performed by neurointerventional radiologists at tertiary medical centres imposing long transport ways to large vessel occlusion (LVO) stroke patients in rural areas. The purpose of this study is to evaluate the technical and clinical results over time at Stavanger University Hospital, a hospital without neurointerventional expertise, where trained general interventional radiologist performs EVT. METHODS: All patients with LVO stroke treated with EVT from May 2009 to December 2018 were included in the analysis. Technical outcome was measured by the modified treatment in cerebral ischaemia (mTICI) score, functional outcome by the modified Rankin Scale (mRS), complications registered. RESULTS: A total of 235 patients were treated with EVT. An angiographically good result (mTICI 2b or 3) could be seen in 66.7% of the patients treated the first year. In 2011, the year EVT with stent retrievers was introduced, the recanalization rate rose to 81.8%, and from 2014 onwards, it was stable around 80%. After introduction of aspiration together with stent retrievers in 2012, a good functional outcome (mRS 0-2) was obtained in >40% of the treated patients. In 2018, 61.1% of the patients got a good functional outcome. CONCLUSIONS: Endovascular treatment of LVO stroke performed by general vascular interventional radiologist in close collaboration with diagnostic neuroradiologists and stroke neurologists can achieve technical revascularization results and clinical patient outcomes in line with international recommendations, and the randomized controlled studies performed. This approach may help to introduce EVT in geographical areas where this service is lacking due to the absence of neurointerventional specialists.

Reducing door-to-needle times in stroke thrombolysis to 13 min through protocol revision and simulation training: a quality improvement project in a Norwegian stroke centre.

BACKGROUND: In eligible patients with acute ischaemic stroke, rapid revascularisation is crucial for good outcome. At our treatment centre, we had achieved and sustained a median door-to-needle time of under 30 min. We hypothesised that further improvement could be achieved through implementing a revised treatment protocol and in situ simulation-based team training sessions. This report describes a quality improvement project aiming to reduce door-to-needle times in stroke thrombolysis. METHODS: All members of the acute stroke treatment team were surveyed to tailor the interventions to local conditions. Through a review of responses and available literature, the improvement team suggested changes to streamline the protocol and designed in situ simulation-based team training sessions. Implementation of interventions started in February 2017. We completed 14 simulation sessions from February to June 2017 and an additional 12 sessions from November 2017 to March 2018. Applying Kirkpatrick's four-level training evaluation model, participant reactions, clinical behaviour and patient outcomes were measured. Statistical process control charts were used to demonstrate changes in treatment times and patient outcomes. RESULTS: A total of 650 consecutive patients, including a 3-year baseline, treated with intravenous thrombolysis were assessed. Median door to needle times were significantly reduced from 27 to 13 min and remained consistent after 13 months. Risk-adjusted cumulative sum charts indicate a reduced proportion of patients deceased or bedridden after 90 days. There was no significant change in balancing measures (stroke mimics, fatal intracranial haemorrhage and prehospital times). CONCLUSIONS: Implementing a revised treatment protocol in combination with in situ simulation-based team training sessions for stroke thrombolysis was followed by a considerable reduction in door-to-needle times and improved patient outcomes. Additional work is needed to assess sustainability and generalisability of the interventions.

Endovascular Thrombectomy in the Elderly: Do Radiological and Clinical Outcomes Differ from Those in Younger Patients? A Prospective Single-Center Experience.

OBJECTIVES: Endovascular treatment (EVT) has emerged as the gold standard therapy for stroke due to large vessel occlusion (LVO). There is however limited evidence to suggest that similar efficacy can be expected in elderly patients. We aimed to assess the efficacy and safety of EVT in elderly patients (aged > 80), comparing outcomes to younger patients (aged < 80). MATERIAL AND METHODS: A total of 195 patients with LVO stroke treated with EVT were included and dichotomized by age. We compared neurological improvement, clinical 90 day outcome, technical recanalization rates, procedure-related complications, and mortality in between the groups. RESULTS: Both groups showed equally marked neurological improvement. A favorable outcome modified Rankin Scale (mRS < 2) was seen in 28% of the elderly patients compared to 46% of the younger patients (p = 0.01). mRS 0-3 was seen in 46% of the elderly patients and 58% of the younger patients (p = 0.09). The rates of successful technical recanalization did not differ between the groups and there were no differences in procedural complication rates or incidence of symptomatic intracranial bleeding. Three-month mortality rates were however higher in the elderly group. CONCLUSIONS: EVT in the elderly resulted in equally notable neurological improvement as compared to younger patients. Although the elderly had a higher mortality rate and fewer favorable clinical outcomes at 3 month follow-up, a strict upper age limit for EVT seems unjustified.

Kynurenine Pathway Metabolites in Alzheimer's Disease.

BACKGROUND: Metabolites of tryptophan, produced via the kynurenine pathway (kynurenines), have been linked to Alzheimer's disease (AD) in small cohorts with conflicting results. OBJECTIVE: To compare differences in plasma kynurenine levels between AD and controls and identify potential associations with cognition. METHODS: The study included 65 histopathologically-confirmed AD patients and 65 cognitively-screened controls from the Oxford Project to Investigate Memory and Ageing (OPTIMA) cohort. Cognition was assessed using the Cambridge Cognitive Examination (CamCog). Tryptophan, kynurenines, neopterin, and vitamin B6 forms were measured in plasma by liquid chromatography-tandem mass spectrometry. Non-parametric statistics, logistic regression and standardized robust regressions were applied with a false discovery rate of 0.05. RESULTS: Tryptophan, xanthurenic acid, 3-hydroxyanthranilic acid, and quinolinic acid were lower in AD (Odds ratios (ORs) 0.24 -0.47; p-values <0.001 -0.01). Pyridoxal 5'phosphate did not differ between AD and controls. Kynurenine, anthranilic acid, quinolinic acid, and markers of immune activation (neopterin, kynurenine/tryptophan ratio, and the PAr index (Pyridoxic acid/(Pyridoxal 5'phosphate + Pyridoxal)) increased with age (ß 0.31 -0.51; p-values <0.001 -0.006). Xanthurenic acid decreased with age (ß: -0.42, p < 0.001). Elderly AD patients with high quinolinic acid performed worse on the CamCog test, indicated by a significant age*quinolinic acid interaction (ß 0.21, p < 0.001). CONCLUSION: Plasma concentrations of several kynurenines were lower in patients with AD compared to controls. Low xanthurenic acid occurred in both AD and with aging. Inflammation-related markers were associated with age, but not AD. However, elevated QA was associated with poor cognition in older AD patients.

The golden hour of acute ischemic stroke.

BACKGROUND: Acute Ischemic Stroke (AIS) treatment has been revolutionised in the last two decades with the increasing use of Intravenous Thrombolysis (IVT) and with the advent of Endovascular therapy (EVT). AIS treatment and outcome are time dependant and time saving measures are being implemented at every step of the treatment chain. These changes have resulted in lower treatment times in-hospital, but it is unclear if this translates into more patients being treated within 60 min of symptom onset - the Golden Hour. The clinical outcome of IVT therapy in this patient group was our secondary outcome. METHODS: From 2009 onwards, systematic changes were made to the AIS treatment chain leading to a dramatic decrease in Door-to-Needle (DTN) time. Analyses were performed on the number of these treatments year on year and their clinical outcomes within the Golden Hour at Stavanger University Hospital (SUS). RESULTS: Six-hundred and thirteen patients were included; seventy-three were treated within the Golden Hour. The percentage of total IVT treatments occurring in the Golden Hour rose from 2.2% in 2009 to 14.5% in 2015 (p = 0.006) with a high of 18.3% in 2012 (p < 0.001). All of these patients had a Median NIHSS of 0 at discharge, irrespective of age and pre-existing comorbidity. There was no incidence of any ICH and in-hospital mortality was only 2.7% in this group. DISCUSSION: The time from AIS symptom onset to treatment is filled with delays. Despite the inherence of some delays,significant efforts on the part of the pre- and in- hospital treatment chain have made IVT therapy within 60 min a possibility. The allocation and use of resources in the setting of rapid AIS treatment is warrantedand yields unprecedented results. CONCLUSIONS: Our study shows that improved treatment routines led to an increase in the number of patients treated within the Golden Hour. Treatment in the Golden Hour leads to excellent outcomes in all patients, irrespective of age and pre-existing comorbidity.

Endovascular stroke treatment in a small-volume stroke center.

INTRODUCTION: Our purpose was to evaluate the safety and efficacy of endovascular treatment (EVT) of stroke caused by large vessel occlusions (LVO) performed by general interventional radiologists in cooperation with stroke neurologists and neuroradiologists at a center with a limited annual number of procedures. We aimed to compare our results with those previously reported from larger stroke centers. PATIENTS AND METHODS: A total of 108 patients with acute stroke due to LVO treated with EVT were included. Outcome was measured using the modified Rankin scale (mRS) at 90 days. Efficacy was classified according to the modified thrombolysis in cerebral infarction (mTICI) scoring system. Safety was evaluated according to the incidence of procedural complications and symptomatic intracranial hemorrhage (sICH). RESULTS: Mean age of the patients was 67.5 years. The median National Institutes of Health Stroke Scale (NIHSS) on hospital admission was 17. Successful revascularization was achieved in 76%. 39.4% experienced a good clinical outcome (mRS<3). Intraprocedural complications were seen in 7.4%. 7.4% suffered a sICH. 21.3% died within 3 months after EVT. DISCUSSION: The use of general interventional radiologists in EVT of LVO may be a possible approach for improving EVT coverage where availability of specialized neurointerventionalists is challenging. EVT for LVO stroke performed by general interventional radiologists in close cooperation with diagnostic neuroradiologists and stroke neurologists can be safe and efficacious despite the low number of annual procedures.

Mass Media Intervention in Western Norway Aimed at Improving Public Recognition of Stroke, Emergency Response, and Acute Treatment.

BACKGROUND: This study evaluates the effect of a mass media intervention (MMI) on the number of admissions to the emergency room (ER) with a suspected acute-onset stroke and on the number of patients treated with intravenous thrombolysis (IVT). The MMI was run for 1 month, with a precampaign month, priming the treatment chain and raising in-hospital awareness. METHODS: This study conducted a prospective analysis of all patients admitted to the ER before, during, and after the MMI to assess changes in admission rate and IVT treatment rate. The primary end point was to assess any change in the IVT treatment rate, and the secondary end point was to determine the number of acute stroke admissions to the ER within 4.5 hours of symptom onset. RESULTS: The MMI resulted in an increased IVT treatment rate from 7.3 to 11.3 patients per month, an increment of 54% (P = .002). This also resulted in IVT treatment percentages as high as 42%. The number of suspected acute stroke admissions to the ER increased from 37.3 to 72.8 patients per month, a 97% increase (P < .0001). The Epinion interviews showed that stroke symptom recognition increased from 66% to 75%. CONCLUSION: The MMI produced a significant increase in IVT treatment rate. This increased treatment rate is largely due to the increase in the number of acute stroke admissions to the ER. Targeting the treatment chain before the MMI led to unprecedented IVT treatment percentages. The effect of our MMI lasted for approximately 6 months before tapering off; repeated campaigns are a prerequisite for sustained IVT treatment rates.

Are the current MRI criteria using the DWI-FLAIR mismatch concept for selection of patients with wake-up stroke to thrombolysis excluding too many patients?

BACKGROUND: Up to 25% of stroke patients wake up with a neurological deficit, so called wake-up stroke (WUS). Different imaging approaches that may aid in the selection of patients likely to benefit from reperfusion therapy are currently under investigation. The magnetic resonance imaging (MRI) diffusion weighted imaging - fluid attenuated inversion recovery (DWI-FLAIR) mismatch concept is one proposed method for identifying patients presenting within 4.5 hours of the ischemic event. PURPOSE: To report our experience with the DWI-FLAIR mismatch concept for selection of wake-up stroke patients to be thrombolysed at our centre. MATERIAL AND METHODS: Patients treated with off label intravenous thrombolysis (IVT) for WUS at our centre during a 6.5-month period were included. We performed MRI including DWI and FLAIR in all patients at admission. Each MRI examination was rated as either DWI-FLAIR mismatch or match. National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale were used to measure clinical outcome. Cerebral computed tomography (CT) or MRI was performed within 24 hours after thrombolysis to determine the presence of any intracranial haemorrhage (ICH). RESULTS: Ten patients treated with IVT for WUS were included. Four patients had a DWI-FLAIR mismatch and after IVT treatment the mean reduction in NIHSS in the DWI-FLAIR mismatch group was 4.0. In the DWI-FLAIR match group the mean reduction in NIHSS after IVT therapy was 4.8. None of the ten patients had any signs of ICH on follow-up imaging. CONCLUSIONS: In this small series DWI-FLAIR mismatch was not associated with worse outcome or ICH. This suggests that selecting WUS patients using DWI-FLAIR mismatch in clinical trials may exclude a large group of patients who might benefit.

Evaluation of the implementation of a rapid response treatment protocol for patients with acute onset stroke: can we increase the number of patients treated and shorten the time needed?

AIMS: This study aims to evaluate the implementation of a rapid response treatment protocol for patients presenting with acute onset ischemic stroke. Improvements of routines surrounding the admission and treatment of patients with intravenous thrombolysis (IVT), such as door-to-needle (DTN) times, and increasing the numbers of patients treated are discussed. METHODS: We conducted a retrospective analysis of all patients (n = 320) treated with IVT for acute onset ischemic stroke at the Stavanger University Hospital, Norway, between 2003 and 2012. In 2009, a succession of changes to pre- and intra-hospital routines were made as well as an improvement in the education of primary health care physicians, nurses and paramedics involved in the treatment of acute onset stroke patients (rapid response treatment protocol). Analyses of DTN times, onset-to-needle times and the number of patients treated per year were carried out to ascertain the effect of the changes made. The primary aim was to analyze DTN times to look for any changes, and the secondary aim was to analyze changes in the number of patients treated per year. RESULTS: In the years after the implementation of the rapid treatment protocol, we saw an improvement in the median DTN time with a decrease from 73 to 50 min in the first year (p = 0.03), a decrease of 45 min in the second year (p = 0.01) and a decrease of 31 min in the third year (p < 0.001). Similarly, an improvement in the number of patients treated per year was seen after enhancements in the treatment chain were made. A significant, 27-fold increase was shown when the number of patients treated in 2012 was compared with all patients treated in all years prior to the implementation of the rapid treatment protocol. CONCLUSIONS: The implementation of the rapid treatment protocol for acute onset ischemic stroke patients led to a significant decrease in the DTN time at our center. These improvements also produced an increase in the number of patients treated per year. The extension of the therapeutic window from 3 to 4.5 h for the use of intravenous recombinant tissue plasminogen activator also played a role in the increased treatment numbers.