To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Early reperfusion has the best likelihood for a favorable outcome in acute ischemic stroke (AIS) with large vessel occlusion (LVO). Our experience with mobile stroke unit (MSU) for direct to angiosuite (DTAS) transfer in AIS patients with suspected LVO is presented.
Retrospective review of prospectively collected data from November 2019 to August 2022, of patients evaluated and transferred by the University of Alberta Hospital MSU and moved to angiosuite for endovascular thrombectomy (EVT).
A total of 41 cases were included. Nine were chosen for DTAS and 32 were shifted to angiosuite after stopping for computed tomography (CT) angiography of the head and neck (no-DTAS). Stroke severity measured by NIHSS (median with interquartile range (IQR)) was higher in patients of DTAS, 22 (14–24) vs 14.5 (5–25) in no-DTAS (p = 0.001). The non-contrast CT head in MSU showed hyperdense vessels in 8 (88.88%) DTAS vs 11 (34.35%) no-DTAS patients (p = 0.003). The EVT timelines (median with IQR, 90th percentile) including “door to artery puncture time” were 31 (23–50, 49.2) vs 79 (39–264, 112.8) minutes, and “door to recanalization time” was 69 (49–110, 93.2) vs 105.5 (52–178, 159.5) minutes in DTAS vs no-DTAS group, respectively. The workflow times were significantly shorter in the DTAS group (p < 0.001). Eight (88.88%) out of 9 DTAS patients had LVO and underwent thrombectomy.
MSU for DTAS in patients with high NIHSS scores, cortical signs, and CT showing hyperdense vessel is an effective strategy to reduce the EVT workflow time.
Hyperacute treatment of acute stroke may lead to thrombolysis in stroke mimics (SM). Our aim was to determine the frequency of thrombolysis in SM in primary stroke centers (PSC) dependent on telestroke versus comprehensive stroke centers (CSC).
Retrospective review of prospectively collected data from the Quality improvement and Clinical Research (QuICR) registry, the Discharge Abstract Database (DAD), and The National Ambulatory Care Reporting System (NACRS) of consecutive patients treated with intravenous thrombolysis for acute ischemic stroke in Alberta (Canada) from April 2016 to March 2021.
A total of 2471 patients who received thrombolysis were included. Linking the QuICR registry to DAD 169 (6.83%) patients were identified as SM; however, on our review of the records, only 112 (4.53%) were actual SM. SMs were younger with a mean age of 61.66 (±16.15) vs 71.08 (±14.55) in stroke. National Institute of Health Stroke Scale was higher in stroke with a median (IQR) of 10 (5–17) vs 7 (5–10) in SM. Only one patient (0.89 %) in SM groups had a small parenchymal hemorrhage versus 155 (6.57%) stroke patients had a parenchymal hemorrhage. There was no death among patients of thrombolysed SM during hospitalization versus 276 (11.69%) in stroke. There was no significant difference in the rate of SM among thrombolysed patients between PSC 27 (5.36%) versus CSC 85 (4.3%) (P = 0.312). The most responsible diagnosis of SM was migraine/migraine equivalent, functional disorder, seizure, and delirium.
The diagnosis of SM may not always be correct when the information is extracted from databases. The rate of thrombolysis in SM via telestroke is similar to treatment in person at CSC.
Annually, 15% of patients who receive oral anticoagulation require interruption for surgery or an invasive procedure. This study evaluates the adherence of patients with atrial fibrillation with a history of stroke or transient ischemic attack to the Thrombosis Canada Perioperative guidelines for the discontinuation and reinitiation of anticoagulation treatment.
We collected data from a prospective patient survey at the Stroke Prevention Clinic in the University of Alberta hospital. Patients’ charts were reviewed from the electronic medical records, and adherence was looked at according to the Thrombosis Canada Perioperative guidelines for the interruption of anticoagulants.
During the study period (2016–2019), there were 509 patients surveyed. Anticoagulation treatment was interrupted in 150 patients with 98 interrupted for surgical or invasive procedures. The interruption was adherent to guidelines in only 29 (29.6%) of patients and inappropriate or nonadherent in 69 (70.4%) patients. There were seven ischemic strokes recorded during the period of interruption. The proportion of strokes was higher in patients whose anticoagulation interruption was longer than what the guidelines recommended (6/61 or 9.8%) when compared to those who adhered to recommended perioperative anticoagulation guidelines (1/29 or 3.4%).
Our results indicate that significant discrepancy with following the recommended perioperative anticoagulation guidelines is common in real-life practice. Delay in re-anticoagulation may increase the risk of complications.
The variable rate of infarct progression in acute ischemic stroke as assessed by various thresholds excludes a substantial proportion of patients due to time or core constraints. We evaluated 106 patients with any-type occlusion to compare these thresholds and assessed performance of hypoperfusion index (HI) for fast and slow rate of infarct progression. Seven (12.5%) were classified fast progressors and 23 (46%), 25 (50%), 12 (24%), and 33 (66%) slow progressors using different core and time criteria. In comparison, HI categorized 100% (n = 106) of cohort with optimal cutoff 0.5 for any-type occlusion (slow progressors: HI ≤ 0.5), sensitivity/specificity 100%/91%, AUC 0.94, and indicative of eligibility for reperfusion and clinical outcomes (median 90-day modified Rankin Scale; 2 for HI ≤ 0.5 versus 5). Estimation of progressors by HI seems comprehensive but needs external validation.
During the Randomized Assessment of Rapid Endovascular Treatment (EVT) of Ischemic Stroke (ESCAPE) trial, patient-level micro-costing data were collected. We report a cost-effectiveness analysis of EVT, using ESCAPE trial data and Markov simulation, from a universal, single-payer system using a societal perspective over a patient’s lifetime.
Primary data collection alongside the ESCAPE trial provided a 3-month trial-specific, non-model, based cost per quality-adjusted life year (QALY). A Markov model utilizing ongoing lifetime costs and life expectancy from the literature was built to simulate the cost per QALY adopting a lifetime horizon. Health states were defined using the modified Rankin Scale (mRS) scores. Uncertainty was explored using scenario analysis and probabilistic sensitivity analysis.
The 3-month trial-based analysis resulted in a cost per QALY of $201,243 of EVT compared to the best standard of care. In the model-based analysis, using a societal perspective and a lifetime horizon, EVT dominated the standard of care; EVT was both more effective and less costly than the standard of care (−$91). When the time horizon was shortened to 1 year, EVT remains cost savings compared to standard of care (∼$15,376 per QALY gained with EVT). However, if the estimate of clinical effectiveness is 4% less than that demonstrated in ESCAPE, EVT is no longer cost savings compared to standard of care.
Results support the adoption of EVT as a treatment option for acute ischemic stroke, as the increase in costs associated with caring for EVT patients was recouped within the first year of stroke, and continued to provide cost savings over a patient’s lifetime.
Acute ischemic stroke may affect women and men differently. We aimed to evaluate sex differences in outcomes of endovascular treatment (EVT) for ischemic stroke due to large vessel occlusion in a population-based study in Alberta, Canada.
Methods and Results:
Over a 3-year period (April 2015–March 2018), 576 patients fit the inclusion criteria of our study and constituted the EVT group of our analysis. The medical treatment group of the ESCAPE trial had 150 patients. Thus, our total sample size was 726. We captured outcomes in clinical routine using administrative data and a linked database methodology. The primary outcome of our study was home-time. Home-time refers to the number of days that the patient was back at their premorbid living situation without an increase in the level of care within 90 days of the index stroke event. In adjusted analysis, EVT was associated with an increase of 90-day home-time by an average of 6.08 (95% CI −2.74–14.89, p-value 0.177) days in women compared to an average of 11.20 (95% CI 1.94–20.46, p-value 0.018) days in men. Further analysis revealed that the association between EVT and 90-day home-time in women was confounded by age and onset-to-treatment time.
We found a nonsignificant nominal reduction of 90-day home-time gain for women compared to men in this province-wide population-based study of EVT for large vessel occlusion, which was only partially explained by confounding.
The study was conducted to test the hypothesis that nitroglycerin (NTG) increases cerebral perfusion focally and globally in acute ischemic stroke patients, using serial perfusion-weighted imaging (PWI) magnetic resonance imaging measurements.
Patients and methods:
Thirty-five patients underwent PWI immediately before and 72 h after administration of a transdermal NTG patch or no treatment. Patients with baseline mean arterial pressure (MAP) > 100 mmHg (NTG group, n = 20) were treated with transdermal NTG (0.2 mg/h) for 72 h, without a nitrate-free interval. Patients with MAP ≤ 100 mmHg (untreated group, n = 15) were not treated. The primary outcome measure was absolute cerebral blood flow (CBF) in the hypoperfused region at 72 h.
The mean baseline absolute CBF in the hypoperfused region was similar in the NTG group (33.3 ± 10.2 ml/100 g/min) and untreated (32.7 ± 8.4 ml/100 g/min, p = 0.4) groups. The median (IQR) baseline infarct volume was 10.4 (2.5–49.3) ml in the NTG group and 32.6 (8.6–96.7) ml in the untreated group (p = 0.09). MAP change in the NTG group was 1.2 ± 12.6 and 8 ± 20.7 mmHg at 2 h and 72 h, respectively. Mean absolute CBF in the hypoperfused region at 72 h was similar in the NTG (29.9 ± 12 ml/100 g/min) and untreated groups (24.1 ± 10 ml/100 g/min, p = 0.8). The median infarct volume increased in untreated (11.8 (5.7–44.2) ml) than the NTG group (3.2 (0.5–16.5) ml; p = 0.033) on univariate analysis, however, there was no difference on regression analysis.
NTG was not associated with improvement in cerebral perfusion in acute ischemic stroke patients.
The optimal timing of anticoagulation after ischemic stroke in atrial fibrillation (AF) patients is unknown. Our aim was to demonstrate the feasibility and safety of initiating dabigatran therapy within 14 days of transient ischemic attack (TIA) or minor stroke in AF patients.
Patients and Methods:
A prospective, multi-center registry (NCT02415855) in patients with AF treated with dabigatran within 14 days of acute ischemic stroke/TIA (National Institutes of Health Stroke Scale (NIHSS) ≤ 3) onset. Baseline and follow-up computed tomography (CT) scans were assessed for hemorrhagic transformation (HT) and graded by using European Cooperative Acute Stroke Study criteria.
One hundred and one patients, with a mean age of 72.4 ± 11.5 years, were enrolled. Median infarct volume was 0 ml. Median time from index event onset to dabigatran initiation was 2 days, and median baseline NIHSS was 1. Pre-treatment HT was present in seven patients. No patients developed symptomatic HT. On the day 7 CT scan, HT was present in six patients (one progressing from baseline hemorrhagic infarction type 1). Infarct volume was a predictor of incident HT (odds ratio = 1.063 [1.020–1.107], p < 0.003). All six (100%) patients with new/progressive HT were functionally independent (modified Rankin Scale (mRS) = 0–2) at 30 days, which was similar to those without HT (90%, p = 0.422). Recurrent ischemic events occurred within 30 days in four patients, two of which were associated with severe disability and death (mRS 5 and 6, respectively).
Early dabigatran treatment did not precipitate symptomatic HT after minor stroke. Asymptomatic HT was associated with larger baseline infarct volumes. Early recurrent ischemic events may be clinically more important.
Although comorbidity increases the health care and community support needs for patients, and the burden for the health care system, there are few population-based studies on comorbidity in patients with stroke. This study aims to evaluate the occurrence of important comorbidities among stroke patients in the Canadian population.
Data from the population-based 2011–2012 Canadian Community Health Survey containing responses from 124,929 participants covering about 98% of the Canadian population when weighted were examined and analyzed by means of logistic regression models.
There was a statistically significant association between stroke history and multiple comorbid risk factors. Stroke prevalence increased in individuals with heart disease (odds ratio (OR): 3.80, 95% confidence interval (CI): 3.77–3.84), hypertension (OR: 1.97, 95% CI: 1.95–1.99), diabetes (OR: 1.74, 95% CI: 1.72–1.75), mood disorder (OR: 2.14, 95% CI: 2.12–2.17), and chronic obstructive pulmonary disease (COPD) (OR: 1.46, 95% CI: 1.44–1.48) compared to others without the condition. Of 2067 participants with stroke, 1680 (81.3%) had one or more comorbid conditions (heart disease, hypertension, diabetes, mood disorder, or COPD) that coexist with stroke and 48% had two or more. Comorbidity increased with age, and two-thirds of stroke patients with comorbid medical conditions were 60 years of age or older.
This population-based study provides evidence of comorbidity between stroke and other conditions that include heart disease, hypertension, diabetes, mood disorder, and COPD. Canadian individuals with stroke have a high burden of comorbidity. Health care systems need to recognize and respond to the strong association of comorbidity and stroke occurrence. This key factor should be considered when allocating resources.
Thrombolysis in acute ischemic stroke is usually performed in comprehensive stroke centres. Lack of stroke expertise in remote small hospitals may preclude thrombolysis. Telemedicine allows such management opportunities in distant hospitals.
We report our experience in managing acute stroke over a two-year time period with telestroke. The University of Alberta Hospital acted as the ‘hub’ and seven remote hospitals as ‘spoke’. The neurologist at the ‘hub’ provided stroke expertise to the local physician using either a two-way video link or telephone. Cranial CT scans were transmitted to ‘hub’. Education sessions were held before the initiation of the program.
Of 210 patients 44 (21%) received thrombolysis at the ‘spoke’ sites. In 34/44 (77%) two-way video link was available while in 10/44 (23%) telephone was used. Five (11.4%) patients experienced intracranial hemorrhage after thrombolysis, 2 (4.5%) were symptomatic. Favorable (mRS=0-1) outcome at three months was 16/40 (40%) and mortality was 9/40 (22.5%). Four patients were lost to follow-up. There was no significant three months outcome difference between two-way video link and telephone consultation (P = 0.689). Over two years the number of acute stroke transfers decreased from 144 to 15 at one of the ‘spoke’ sites, a 92.5% decline.
It is possible to successfully treat patients with acute ischemic stroke at remote sites through videoconferencing or telephone consultation. Telestroke can also lead to a significant reduction in the number of patients requiring transfer to a tertiary care centre.
Statins have been shown to increase endothelial progenitor cells (EPCs) in patients with cardiovascular disease. However, there is no similar study that has been done on the patients recovering from cerebrovascular disease. We present the largest prospective study of statin therapy on EPC levels of patients recovering from stroke.
Our study subjects were treated with rosuvastatin (10 mg/day) over a period of 12 weeks. Blood was collected from these patients periodically and EPC levels were measured along with other biochemical parameters.
Results and Conclusions:
Our study shows that rosuvastatin treatment significantly reduces the low density lipoprotein (LDL) levels in the patients over the 12 weeks. However, we did not find any corresponding changes in the EPC levels during this time period. Earlier reports indicated that statin use could increase EPC proliferation. Our research, however, indicates that the in-vivo effects of rosuvastatin are not similar to those of previous reports. There may be several reasons for this lack of congruence between these two studies, including age of the study population, predominantly low high density lipoprotein (HDL) levels in our subjects and effects from other concomitant medications.
Intra-cerebral hemorrhage is an unusual and often fatal complication of endarterectomy (CEA). Previous cerebral infarction, intra-operative or post operative hypertension, and the use of anti-coagulants are some of the defined major risk factors. Hemorrhage usually occurs early after CEA, and a second hemorrhage has only once been reported. We wish to report a patient who developed three separate hemorrhages following CEA. This patient had a long history of poorly controlled hypertension. We believe that poorly controlled hypertension, in addition to other reported factors, may be an important separate risk factor for post-CEA hemorrhage.
Hospital records of thirty patients with methanol poisoning were studied. Neurologic manifestations at presentation including coma, seizures and decreased visual acuity were seen in nineteen patients. The mean blood pH at presentation was significantly lower in the patients with these neurologic signs and symptoms than in the eleven patients without them (p < 0.05). Methanol levels at presentation tended to be higher in patients with neurologic manifestations at presentation and these patients tended to present later after methanol ingestion than those patients without neurologic manifestations. Fifteen patients with methanol poisoning developed serious neurologic sequelae or died. The mean blood pH was significantly lower in this patient group than in those who survived without neurologic sequelae (p < 0.05). Methanol levels at presentation were not different in the patients who developed neurologic sequelae or died as compared to those who did not. The time from ingestion of methanol to presentation at the hospital was however significantly longer in those patients who developed neurologic sequelae or died (p < 0.05). Initiation of treatment within eight hours of ingestion of methanol was associated with a better clinical outcome.
In rodents damage from repetitive transient cerebral ischemia is more severe than that seen with a single ischemic insult of similar duration. Mild hypothermia has been shown to be very effective in protecting the brain during single ischemic insults. We tested the protective effects of hypothermia in repetitive ischemic insults. We used the gerbil model of repetitive ischemia (three minutes ischemia repeated at one hourly intervals three times) and histological evaluation was done using the silver staining technique. Our study reveals that a decrease in body and scalp temperature by 1-2 degrees Celsius can significantly reduce neuronal damage in the cerebral cortex, CA1 region of the hippocampus and substantia nigra reticulata during repetitive ischemia. As the hypothermia was induced after the initial insult, we believe this offers an opportunity for intervention in the clinical settings.
Four patients with Multicore Myopathy, a rare morphologically distinct myopathy, are described. Although previously considered to be a non-progressive or only slowly progressive myopathy, progression to significant disability was seen in three of our cases. The association of cardiac disease with Multicore Myopathy has not been previously emphasised. All four patients in this study had a cardiomyopathy, and heart disease was the cause of death in two of the patients. Multicore Myopathy is not always a benign entity. Cardiac involvement, when present, adversely affects prognosis.
We report the experience at a large teaching hospital over a 10 year period with Miller Fisher Syndrome, facial diplegia, and multiple cranial nerve palsies. In these patients, absence of drowsiness on examination, normal cranial CT scans, albumino-cytological dissociation on CSF examination and slowing of nerve conduction, all suggest that a peripheral nerve dysfunction is the underlying mechanism. Pertinent literature is reviewed, in an attempt to separate these probable variants of Guillain-Barré Syndrome from brainstem encephalitis, with which they may be confused.
Most patients with brainstem hemorrhage have a poor prognosis. There are occasional reports of a favorable outcome with hematomas restricted to the mid-brain region. We report two patients with hematomas within the lower brainstem (pons and medulla) who made a good recovery. Diagnosis was unsuspected until the cranial CT scan was done. Angiography was normal in both cases. Recovery was excellent in one and fair in the second patient. Patients with medullary hemorrhage are at risk for aspiration and may suddenly develop respiratory arrest and therefore should be carefully observed. Our review of the literature suggests that with some small brain-stem hemorrhages recovery is good to excellent and recurrences are rare.
In recent years there has been a tendency to abandon repeat cerebral angiography in patients with subarachnoid hemorrhage (SAH) if the initial angiogram is normal because prognosis is said to be excellent. Our experience does not support such a conclusion. We report our experiences in 25 patients with SAH, who had a normal initial angiogram. Aneurysms were seen in five of 20 cases when angiography was repeated. On subsequent review of the initial angiograms, the aneurysm was apparent in four of the five cases. When these four initial angiograms were shown to a second observer, unaware of the results of the second study, three of the four aneurysms were correctly identified. We suggest that if, under strong clinical suspicion of SAH, the angiogram is reported as normal the study should be reviewed by a second neuro-radiologist before proceeding to repeat angiography.
Mitral valve prolapse has been associated with an increased risk of transient or lasting ischemic events. Recurrence is uncommon after initiation of antiplatelet or anticoagulant therapy. In this communication we report two patients, both female, who had mitral valve prolapse as the major risk factor for cerebrovascular disease and who developed cerebral infarction despite anticoagulation. The cerebral infarctions were bilateral and extensive in one patient and led to the patient's death. In the second case, three infarctions resulted in moderate disability.