Deterioration following spontaneous improvement : sonographic findings in patients with acutely resolving symptoms of cerebral ischemia

The Sky's the Limit: Expanding Nursing's Contribution to Acute Stroke Science

Stroke is the number one cause of preventable disability in adults in the United States. Significant advances have occurred in medications and technology supporting rapid stroke diagnosis and treatment during the past 30 years, along with blurring of the lines of what traditionally constituted nursing or medical research. Ischemic stroke is a disease of vascular insufficiency that mirrors myocardial infarction more than any other neurologic diagnosis. My primary program of research is focused on exploration of methods to improve intracranial blood flow in patients with hyperacute ischemic stroke who have viable, yet vulnerable, brain tissue to prevent worsening or enable improvement of stroke symptoms. I am also examining augmentation of recombinant tissue plasminogen activator treatment and stimulation of both arteriogenesis and angiogenesis with external counter-pulsation in patients with intracranial atherosclerosis. My secondary program of research focuses on methods to improve stroke systems of care, including improvement of advance practice providers' contributions to acute stroke care, use of innovative mobile stroke units, and improvement of quality core measure processes. Lessons learned along the way are highlighted, along with the value of interdisciplinary "team science" to build knowledge and enhance the care of highly vulnerable patients with acute stroke.

Predictors of early neurologic deterioration (END) following stroke thrombectomy

BACKGROUND

Early neurologic deterioration (END) following ischemic stroke is a serious event and is associated with poor outcomes. However, the incidence and predictors of END after stroke thrombectomy for emergent large vessel occlusion are largely unknown.

METHODS

The baseline characteristics of patients enrolled in the COMPASS trial (NCT02466893) were analyzed. The primary outcome was worsening of ≥4 National Institutes of Health Stroke Scale (NIHSS) points 24 hours post thrombectomy (4+ END₂₄) and the secondary outcome was deterioration of ≥2 points (2+ END₂₄).

RESULTS

Among 270 patients, 27 (10%) developed 4+ END₂₄ and 42 (16%) had 2+ END₂₄. Those with 4+ END₂₄ were older (76.4±12.9 vs 70.9±12.9 years; p=0.04), had a higher prevalence of hypertension (96% vs 69%; p=0.003), diabetes (41% vs 27%; p=0.13) and higher pretreatment systolic blood pressure (SBP) (170.4±32.6 vs 157.6±28.1 mmHg; p=0.03). More 4+ END₂₄ patients had failed reperfusion: Thrombolysis in Cerebral Infarction ≤2a (26% vs 8%; p=0.003). In unadjusted analysis, older patients and those with hypertension, diabetes, elevated SBP and failed reperfusion had higher odds of 4+ END₂₄. In adjusted analysis, age increase by 5 years led to an increase in 4+ END₂₄ of 28%, diabetes increased odds of 2.6 and failed reperfusion increased odds of 4.5. In the multivariable analysis for the secondary outcome, age (OR 1.33; 95% CI 1.109 to 1.593), diabetes (OR 2.7; 95% CI 1.247 to 5.764) and failed reperfusion (OR 7.2; 95% CI 0.055 to 0.349) were also significant predictors of 2+ END₂₄.

CONCLUSIONS

Older patients with acute ischemic stroke who have a history of diabetes or hypertension, with elevated pretreatment SBP and failed reperfusion are at a higher risk of END following stroke thrombectomy for emergent large vessel occlusion.

Rt-PA thrombolytic therapy in patients with acute posterior circulation stroke: A retrospective study

At present, recombinant tissue-type plasminogen activator (rt-PA) thrombolytic therapy is widely used in patients with acute ischemic stroke within 4.5 h following stroke onset. However, the efficacy of intravenous alteplase thrombolytic therapy for posterior circulation stroke (PCS) has been rarely described. The present study aimed to predict the outcome of patients with PCS following rt-PA thrombolytic therapy in a more efficient manner. Data were collected from patients who had suffered from posterior circulation ischemic stroke, who had been treated with rt-PA over a period of 4 years (2016-2020), and had been treated at a stroke center. All patients were treated with alteplase at a standard dose of 0.9 mg/kg. According to the onset to needle time (ONT), these patients were divided into the 0-3 and 3-4.5 h groups, and the National Institutes of Health Stroke Scale (NIHSS) score was compared before thrombolysis and at 24 h after thrombolysis. Subsequently, the patients with acute PCS whose ONT was ≤3 h were divided into the NIHSS score >3 points and NIHSS score ≤3 points groups, and the NIHSS score improvement rate was compared 24 h later. A total of 989 patients were included in the study; there were 783 patients with acute anterior circulation stroke (ACS) and 203 patients with acute PCS (of note, 2 patients had negative results from brain magnetic resonance imaging); 63 patients were treated with urokinase (UK) thrombolysis and 140 patients were treated with alteplase intravenous thrombolysis. The 140 patients that received alteplase thrombolytic therapy were divided into two groups, namely the ≤3 h group and 3-4.5 h group, which, on the basis of the ONT, no significant differences were found between the two the groups according to the NIHSS score before thrombolysis (P>0.05). The NHISS scores in the ≤3 h group were significantly lower than those in the 3-4.5 h group following thrombolysis therapy, and the differences between the two groups were statistically significant (P<0.05); the patients with acute PCS treated with rt-PA in the ≤3 h group were divided into the NIHSS score ≤3 points group and the NIHSS score >3 points group. In this ≤3 h group, the average NIHSS score improvement rate following rt-PA thrombolysis was 0.535 (53.5%) in the NIHSS score ≤3 points group and that in the NIHSS score >3 points group was 0.336 (33.6%); the difference between the two groups was statistically significant (P<0.05). The patients treated with intravenous alteplase thrombolysis within 3 h following stroke onset benefited more than those treated with thrombolysis therapy within 3 to 4.5 h after stroke onset. On the whole, the present study demonstrates that the patients with mild stroke (NIHSS score ≤3 points) who were treated at an earlier stage (received alteplase thrombolysis therapy within 3 h after stroke onset) benefited to a greater extent from the therapy.

Persistent challenges in endovascular treatment decision-making for acute ischaemic stroke

PURPOSE OF REVIEW

Although endovascular treatment (EVT) is the gold standard for treating acute stroke patients with large vessel occlusion (LVO), multiple challenges in decision-making for specific conditions persist. Recent evidence on a selection of patient subgroups will be discussed in this narrative review.

RECENT FINDINGS

Two randomized controlled trials (RCTs) have been published in EVT of basilar artery occlusion (BAO). Large single arm studies showed promising results in Patients with low Alberta stroke program early CT score (ASPECTS) and more distal vessel occlusions. Recent data confirm patients with low National Institutes of Health Stroke Scale (NIHSS) despite LVO to represent a heterogeneous and challenging patient group.

SUMMARY

The current evidence does not justify withholding EVT from BAO patients as none of the RCTs showed any signal of superiority of BMT alone vs. EVT. Patients with low ASPECTS, more distal vessel occlusions and patients with low NIHSS scores should be included into RCTs if possible. Without participation in a RCT, patients should be selected for EVT based on age, severity and type of neurological impairment, time since symptom onset, location of the ischaemic lesion and perhaps also results of advanced imaging.

Caught in Action - Evolving Emergent Large Vessel Occlusion and Collateral Failure During Alteplase Infusion for Acute Ischemic Stroke

BACKGROUND

Published reports of acute deterioration during alteplase infusion for acute ischemic stroke due to development of partial to complete large vessel occlusion and collateral failure are sparce.

MATERIALS AND METHODS

We describe an 84-year-old patient with a fluctuating clinical course due to evolving emergent large vessel occlusion of right M1 segment of the middle cerebral artery and collateral failure during alteplase infusion. Potential mechanisms of acute deterioration within 24 h after thrombolysis are discussed.

RESULTS

Urgent mechanical thrombectomy was performed with resultant partial recanalization and small volume residual infarcts at 72 h magnetic resonance imaging of brain.

CONCLUSIONS

Progression from partial to complete occlusion may occur within minutes, even during administration of intravenous thrombolytics in hyper-acute stroke. In patients who deteriorate within 24 h of stroke onset, non-contrast CT of brain, followed by CT perfusion and angiography, is the imaging protocol of choice in the mechanical thrombectomy era.

Frequency and Prognostic Significance of Clinical Fluctuations Before Hospital Arrival in Stroke

BACKGROUND AND PURPOSE

Clinical fluctuations in ischemic stroke symptoms are common, but fluctuations before hospital arrival have not been previously characterized.

METHODS

A standardized qualitative assessment of fluctuations before hospital arrival was obtained in an observational study that enrolled patients with mild ischemic stroke symptoms (National Institutes of Health Stroke Scale [NIHSS] score of 0-5) present on arrival to hospital within 4.5 hours of onset, in a subset of 100 hospitals participating in the Get With The Guidelines-Stroke quality improvement program. The number of fluctuations, direction, and the overall improvement or worsening was recorded based on reports from the patient, family, or paramedics. Baseline NIHSS on arrival and at 72 hours (or discharge if before) and final diagnosis and stroke subtype were collected. Outcomes at 90 days included the modified Rankin Scale, Barthel Index, Stroke Impact Scale 16, and European Quality of Life. Prehospital fluctuations were examined in relation to hospital NIHSS change (admission to 72 hours or discharge) and 90-day outcomes.

RESULTS

Among 1588 participants, prehospital fluctuations, consisting of improvement, worsening, or both were observed in 35.5%: 25.1% improved once, 5.3% worsened once, and 5.1% had more than 1 fluctuation. Those who improved were less likely and those who worsened were more likely to receive alteplase. Those who improved before hospital arrival had lower change in the hospital NIHSS than those who did not fluctuate. Better adjusted 90-day outcomes were noted in those with prehospital improvement compared to those without any fluctuations.

CONCLUSIONS

Fluctuations in neurological symptoms and signs are common in the prehospital setting. Prehospital improvement was associated with better 90-day outcomes, controlling for admission NIHSS and alteplase treatment.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02072681.

Evolution of the stroke paradigm: A review of delayed recanalization

While the time window for reperfusion after ischemic stroke continues to increase, many patients are not candidates for reperfusion under current guidelines that allow for reperfusion within 24 h after last known well time; however, many case studies report favorable outcomes beyond 24 h after symptom onset for both spontaneous and medically induced recanalization. Furthermore, modern imaging allows for identification of penumbra at extended time points, and reperfusion risk factors and complications are becoming better understood. Taken together, continued urgency exists to better understand the pathophysiologic mechanisms and ideal setting of delayed recanalization beyond 24 h after onset of ischemia.

The Next Step in the Treatment of Stroke

Although many patients do not receive reperfusion therapy because of delayed presentation and/or severity and location of infarct, new reperfusion approaches are expanding the window of intervention. Novel application of neuroprotective agents in combination with the latest methods of reperfusion provide a path to improved stroke intervention outcomes. We examine why neuroprotective agents have failed to translate to the clinic and provide suggestions for new approaches. New developments in recanalization therapy in combination with therapeutics evaluated in parallel animal models of disease will allow for novel, intra-arterial deployment of therapeutic agents over a vastly expanded therapeutic time window and with greater likelihood success. Although the field of neuronal, endothelial, and glial protective therapies has seen numerous large trials, the application of therapies in the context of newly developed reperfusion strategies is still in its infancy. Given modern imaging developments, evaluation of the penumbra will likely play a larger role in the evolving management of stroke. Increasingly more patients will be screened with neuroimaging to identify patients with adequate collateral blood supply allowing for delayed rescue of the penumbra. These patients will be ideal candidates for therapies such as reperfusion dependent therapeutic agents that pair optimally with cutting-edge reperfusion techniques.

External Validation of the WORSEN Score for Prediction the Deterioration of Acute Ischemic Stroke in a Chinese Population

Background: Early neurological deterioration (END) has been recognized as a serious neurological complication after acute ischemic stroke. However, to date, the WORSEN score was the only one scoring system specifically developed to detect END events in acute ischemic stroke patients. The purpose of this study was to investigate the WORSEN score's utility in China, and to determine the potential predictors of END in acute stroke patients. Methods: Consecutive patients with acute ischemic stroke admitted to the Department of Neurology, Aerospace Center Hospital between March 2015 to February 2017 were recruited into the study's cohort and divided into two groups: patients with and without END. END was defined as either an increase in two or more NIHSS points, an increment of at least one point in motor power or a description of fluctuating of clinical symptoms in medical reports during the first 7 days after admission. Severe END was defined as an increase of NIHSS ≥ 4 points from baseline during the first 7 days after admission. Results: Three hundred fifty four patients with acute ischemic stroke were enrolled in the present study and 67.5% were male. END occurred in 90 of these patients and severe END occurred in 55 of these patients. Logistic regression analysis showed that an initial NIHSS score ≥8, diameter of infarction, striatocapsular infarction, and TOAST type of large arterial atherosclerosis were independent predictors for END. The area under the ROC curve (AUC) of the WORSEN score for the prediction of END was 0.80 (95%CI 0.75-0.84), with a sensitivity of 62.22%, a specificity of 88.26%, positive predictive values of 64.37% and negative predictive values of 87.27%. Meanwhile, the AUC of the WORSEN score for the prediction of severe END was 0.82 (95%CI 0.78-0.86), with a sensitivity of 70.91%, specificity of 83.95%, positive predictive values of 44.83% and negative predictive values of 94.01%. Conclusion: END is a relatively common neurological complication in patients with acute ischemic stroke. Our findings showed that the WORSEN score had a good predictive value for identifying patients with END in a Chinese population. Moving forward, multi-center studies are required for further validations.

Impact of intravenous thrombolysis on functional outcome in patients with mild ischemic stroke without large vessel occlusion or rapidly improving symptoms

BACKGROUND

Optimal treatment strategy in patients with mild ischemic stroke remains uncertain. While functional dependency or death has been reported in up to one-third of non-thrombolyzed mild ischemic stroke patients, intravenous thrombolysis is currently not recommended in this patient group. Emerging evidence suggests two risk factors-rapid early improvement and large vessel occlusion-as main associates of unfavorable outcome in mild ischemic stroke patients not undergoing intravenous thrombolysis.

AIMS

To analyze natural course as well as safety and three-month outcome of intravenous thrombolysis in mild ischemic stroke without rapid early improvement or large vessel occlusion.

METHODS

Mild ischemic stroke was defined by a National Institute of Health Stroke Scale score ≤6. We used the modified Rankin Scale (mRS) to compare three-month functional outcome in 370 consecutive mild ischemic stroke patients without early rapid improvement and without large vessel occlusion, who either underwent intravenous thrombolysis (n = 108) or received best medical treatment (n = 262).

RESULTS

Favorable outcome (mRS ≤ 1) was common in both groups (intravenous thrombolysis: 91%; no intravenous thrombolysis: 90%). Although intravenous thrombolysis use was independently associated with a higher risk of asymptomatic hemorrhagic transformation (OR = 4.62, p = 0.002), intravenous thrombolysis appeared as an independent predictor of mRS = 0 at three months (OR = 3.33, p < 0.0001).

CONCLUSIONS

Mild ischemic stroke patients without rapidly improving symptoms and without large vessel occlusion have a high chance of favorable three-month outcome, irrespective of treatment type. Patients receiving intravenous thrombolysis, however, more often achieved complete remission of symptoms, which particularly in mild ischemic stroke may constitute a meaningful endpoint.

[Reperfusion therapy in patients with minor or mild ischemic stroke]

A significant number of patients with minor or mild stroke symptoms on initial presentation subsequently develop neurological deterioration and poor clinical outcomes at hospital discharge. The presence of an underlying large vessel occlusion is a strong predictor of both clinical worsening and poor outcome. Although patients with a low baseline National Institutes of Health Stroke Scale (NIHSS) could have been included in some randomized controlled trials, the benefits of the mechanical thrombectomy for patients with a low NIHSS score are unknown. The causes of neurological deterioration in patients with underlying large vessel occlusion are heterogeneous, but include collateral failure, and no straightforward mechanisms are found in the majority of cases. Patients with internal carotid artery occlusion, but with a patent middle cerebral artery (MCA), can occasionally have good collateral circulation and develop only minor or mild stroke. These patients exhibit collateral MCA flow via the circle of Willis despite ipsilateral internal carotid artery occlusion. However, thrombus migration may cause occlusion of collateral MCA flow, leading to dramatic neurological deterioration. Careful observation and detailed assessment are required for the management of these patients. Recent studies have examined the efficacy and optimal timing of thrombolysis or mechanical thrombectomy for patients with minor or mild stroke. Herein, we review the mechanisms of neurological deterioration, and the efficacy of reperfusion therapy, for patients with minor or mild stroke.

Temporal changes in the documentation of neurological findings among patients with acute ischaemic stroke in a single centre in Japan: a retrospective cross-sectional study

OBJECTIVE

To evaluate temporal differences in the documentation of neurological findings by the same physicians in patients with ischaemic stroke while in hospital. We also investigated differences in the rate of documentation of neurological findings in patients with stroke between internists and neurosurgeons.

DESIGN

A retrospective medical chart review.

PARTICIPANTS

Hospitalised adult patients with acute ischaemic stroke who stayed 7 or more days in our hospital. Neurosurgeons (n=8) and internists (n=19) caring for these patients (including up to 10 patients per physician).

MAIN OUTCOME MEASURES

The documentation rate of any neurological finding in the patients on each day (from day 1 to 7 and on discharge). The documentation rates of eight neurological finding components (consciousness, mental status, cranial nerves, motor function, sensory function, coordination, reflexes and gait). We included only documentation by the same physician. Fisher's exact test was used to evaluate differences in outcomes between neurosurgeons and internists.

RESULTS

During the study period, we identified 172 patients with stroke who were cared for by 27 physicians. The documentation rates of any neurological findings were 94% (day 1), 58% (day 2), 35% (day 3), 40% (day 4), 32% (day 5), 30% (day 6) and 23% (day 7). On discharge, all eight neurological finding components were documented in less than 10% of all cases. The documentation rate was significantly higher by internists than that by neurosurgeons on each day but not on discharge.

CONCLUSIONS

The documentation rate of neurological findings by physicians during usual stroke care decreased to less than 50% after the third hospital day. Given the importance of temporal changes in the neurological symptoms of patients with stroke, further study is needed to determine whether this low documentation rate after the third hospital day was due to a lack of physician interest in neurological findings or other factors.

Progression in acute ischemic stroke: Is widespread atherosclerotic background a risk factor?

OBJECTIVES

In this study, we aimed to investigate the causes and conditions related with progression and outcome of progressive acute ischemic stroke.

PATIENTS AND METHODS

In this prospective study, a total of 78 acute ischemic stroke patients (32 males, 46 females; mean age 70±12.8 years; range 34 to 95 years) were included between February 2006 and October 2010. The patients were classified into two groups as those with and without progression according to the National Institute of Health Stroke Scale (NIHSS). Risk factors for ischemic stroke, stroke subtypes, and radiological investigations and prognosis were compared between the progressive and non-progressive patients.

RESULTS

Neurological deterioration occurred in 12 patients (15%). Progressive acute ischemic stroke patients had carotid stenosis compared to non-progressive patients (50% vs 19%), and ischemic cardiac disease (33% vs 6%) more common in the patients with progression. Mortality during hospital stay and long term-outcomes were similar between the groups.

CONCLUSION

Our study results suggest that widespread atherosclerotic diseases may induce neurological progression.

Heads Up! A Novel Provocative Maneuver to Guide Acute Ischemic Stroke Management

BACKGROUND

A common dilemma in acute ischemic stroke management is whether to pursue recanalization therapy in patients with large vessel occlusions but minimal neurologic deficits. We describe and report preliminary experience with a provocative maneuver, i.e. 90-degree elevation of the head of bed for 30 min, which stresses collaterals and facilitates decision-making.

METHODS

A prospective cohort study of <7.5 h of acute anterior circulation territory ischemia patients with minimal deficits despite middle cerebral artery (MCA) or internal carotid artery (ICA) occlusive disease.

RESULTS

Five patients met the study entry criteria. Their mean age was 78.4 years (range 65-93). All presented with substantial deficits (median NIHSS score 11, range 5-22), but improved while in supine position during initial imaging to normal or near-normal (NIHSS score 0-2). MRA showed persistent M1 MCA occlusions in 4, critical ICA stenosis or occlusion in 1, and substantial perfusion-diffusion mismatch in all. To evaluate the potential for eventual collateral failure, patients were placed in a head of bed upright posture. Mean arterial pressure and heart rate were unchanged. Two showed no neurologic worsening and were treated with supportive care with excellent final outcome. Three showed worsening, including recurrent hemiparesis and aphasia at the 6th, recurrent aphasia at the 23rd, and recurrent hemineglect at the 15th upright minute. These 3 underwent endovascular recanalization therapies with successful reperfusion and excellent final outcome.

CONCLUSION

The 'Heads Up' test may be a useful, simple maneuver to assess the risk of collateral failure and guide the decision to pursue recanalization therapy in acute cerebral ischemia patients with minimal deficits despite persisting large cerebral artery occlusion.

Accuracy of National Institutes of Health Stroke Scale Score in Predicting the Site of Arterial Occlusion in Acute Stroke: A Transcranial Doppler Study

BACKGROUND

In acute stroke, it is crucial to assess for intracranial large-vessel occlusion and site of occlusion. The National Institutes of Health Stroke Scale score (NIHSSS) is the frequently used clinical tool to predict the site of arterial occlusion. In this study we aimed to determine the following: (1) if there is a correlation between the site of occlusion and the NIHSSS at presentation (bNIHSSS); and (2) if there is a bNIHSSS cutoff which can distinguish proximal occlusions (PO) from distal occlusions (DO).

METHODS

Up to 313 patients from CLOTBUST data bank with demonstrable intracranial arterial occlusion and having received intravenous recombinant tissue plasminogen activator (rt-PA) were included. Occlusions were classified as PO (terminal internal carotid artery, M1 segment of middle cerebral artery [M1 MCA], and basilar artery) or DO (M2 MCA, anterior cerebral artery, posterior cerebral artery, and vertebral artery).

RESULTS

By univariate analysis, bNIHSSS, thrombolysis in brain ischemia (TIBI) flow grade before rt-PA, degree of recanalization after rt-PA, and modified Rankin Scale score at 3 months were significantly different between various sites of occlusion. By univariate analysis, a higher bNIHSSS, lower TIBI flow grade, and lower ASPECTS (Alberta Stroke Program Early CT Score) differentiated PO from DO. Lower TIBI flow grade and higher bNIHSSS differentiated PO from DO by logistic regression analysis. No single NIHSSS cutoff with acceptable sensitivity and specificity could be derived to differentiate PO from DO.

CONCLUSIONS

Although NIHSSS are higher in PO, there is no satisfactory NIHSSS cutoff which differentiates PO from DO. A vascular imaging or transcranial doppler should be obtained to determine the site of arterial occlusion in acute stroke.

How temporal evolution of intracranial collaterals in acute stroke affects clinical outcomes

OBJECTIVE

We compared intracranial collaterals on pretreatment and day 2 brain CT angiograms (CTA) to assess their evolution and relationship with functional outcomes in acute ischemic stroke (AIS) patients treated with IV tissue plasminogen activator (tPA).

METHODS

Consecutive AIS patients who underwent pretreatment and day 2 CTA and received IV tPA during 2010-2013 were included. Collaterals were evaluated by 2 independent neuroradiologists using 3 predefined criteria: the Miteff system, the Maas system, and 20-point collateral scale by the Alberta Stroke Program Early CT Score methodology. We stratified our cohort by baseline pre-tPA state of their collaterals and by recanalization status of the primary vessel for analysis. Good outcomes at 3 months were defined by a modified Rankin Scale score of 0-1.

RESULTS

This study included 209 patients. Delayed collateral recruitment by any grading system was not associated with good outcomes. All 3 scoring systems showed that collateral recruitment on the follow-up CTA from a baseline poor collateral state was significantly associated with poor outcome and increased bleeding risk. When the primary vessel remained persistently occluded, collateral recruitment was significantly associated with worse outcomes. Interestingly, collateral recruitment was significantly associated with increased mortality in 2 of the 3 grading systems.

CONCLUSIONS

Not all collateral recruitment is beneficial; delayed collateral recruitment may be different from early recruitment and can result in worse outcomes and higher mortality. Prethrombolysis collateral status and recanalization are determinants of how intracranial collateral evolution affects functional outcomes.

Outcome of patients with occlusions of the internal carotid artery or the main stem of the middle cerebral artery with NIHSS score of less than 5: comparison between thrombolysed and non-thrombolysed patients

BACKGROUND AND PURPOSE

The use of thrombolysis in patients with minor neurological deficits and large vessel occlusion is controversial.

METHODS

We compared the outcome of patients with low National Institutes of Health Stroke Scale (NIHSS) scores and large vessel occlusions between thrombolysed and non-thrombolysed patients.

RESULTS

88 (1.7%) of 5312 consecutive patients with acute (within 24 h) ischaemic stroke had occlusions of the internal carotid or the main stem of the middle cerebral artery and baseline NIHSS scores ≤5.47 (53.4%) were treated without thrombolysis, and 41 (46.6%) received intravenous thrombolysis, endovascular therapy or both. Successful recanalisation on MR or CT angiography at 24 h was more often observed in thrombolysed than in non-thrombolysed patients (78.9% versus 10.5%; p<0.001). Neurological deterioration (increase of NIHSS score ≥1 compared to baseline) was observed in 22.7% of non-thrombolysed versus 10.3% of thrombolysed after 24 h (p=0.002), in 33.3% versus 12.5% at hospital discharge (p=0.015) and in 41.4% versus 15% at 3 months (p<0.001). Symptomatic intracerebral haemorrhage occurred in two (asymptomatic in five) thrombolysed and in none (asymptomatic in three) non-thrombolysed. Thrombolysis was an independent predictor of favourable outcome (p=0.030) but not survival (p=0.606) at 3 months.

CONCLUSIONS

Non-thrombolysed patients with mild deficits and large vessel occlusion deteriorated significantly more often within 3 months than thrombolysed patients. Symptomatic intracerebral haemorrhages occurred in less than 5% of patients in both groups. These data suggest that thrombolysis is safe and effective in these patients. Therefore, randomised trials in patients with large vessel occlusions and mild or rapidly improving symptoms are needed.

Magnetic Resonance Imaging in Acute Ischemic Stroke Patients with Mild Symptoms: An Opportunity to Standardize Intravenous Thrombolysis

BACKGROUND

Patients presenting with mild stroke symptoms are excluded inconsistently from intravenous (IV) thrombolysis. We aimed to compare acute magnetic resonance imaging findings in patients with mild symptoms to those with more severe deficits to identify clinically mild patients who might benefit from IV thrombolysis.

METHODS

We retrospectively studied consecutive stroke patients presenting with perfusion deficit who underwent time-of-flight magnetic resonance angiography within 24 hours of time last seen normal. Two raters measured the lesion volumes on diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) with mismatch (MM) calculated as PWI minus DWI. Occlusion site was categorized as "proximal," "distal," or "magnetic resonance angiography-negative" by consensus review. Stroke with mild symptoms was defined as admit National Institutes of Health Stroke Scale score of 4 or less. Values were reported as n (%).

RESULTS

Ninety-one patients were included; 56 (61.5%) with nonmild and 35 (38.5%) with mild symptoms. After stratifying for occlusion site, there were no differences in PWI and MM lesion volumes for the nonmild versus mild patients (P = .34-.98 and P = .54-1, respectively). Furthermore, there was a trend for thrombolyzed mild stroke patients (88%, n = 7 of 8) to more likely have a favorable clinical outcome (discharge modified Rankin score ≤ 2) versus untreated patients (70%, n = 16 of 23).

CONCLUSIONS

When present, conspicuous vessel occlusions in clinically mild stroke patients are concomitant with similar perfusion deficit and MM volumes in more clinically severe stroke patients. Coupled with a trend toward better outcomes in mild stroke patients who were treated with IV tissue plasminogen activator (t-PA), this could indicate that advanced imaging may be used in standardizing the way these patients are selected for IV t-PA therapy.

Incidence, causes and predictors of neurological deterioration occurring within 24 h following acute ischaemic stroke: a systematic review with pathophysiological implications

Early neurological deterioration (END) following ischaemic stroke is a serious event with manageable causes in only a fraction of patients. The incidence, causes and predictors of END occurring within 24 h of acute ischaemic stroke (END24) have not been systematically reviewed. We systematically reviewed Medline and Embase from January 1990 to April 2013 for all studies on END24 following acute ischaemic stroke (<8 h from onset). We recorded the incidence and presumed causes of and factors associated with END24. Thirty-six studies were included. Depending on the definition used, the incidence of END24 markedly varied among studies. Using the most widely used change in National Institutes of Health Stroke Scale ≥4 definition, the pooled incidence was 13.8% following thrombolysis, ascribed to intracranial haemorrhage and malignant oedema each in ∼20% of these. As other mechanisms were rarely reported, in the majority no clear cause was identified. Few data on END24 occurring in non-thrombolysed patients were available. Across thrombolysed and non-thrombolysed samples, the strongest and most consistent admission predictors were hyperglycaemia, no prior aspirin use, prior transient ischaemic attacks, proximal arterial occlusion and presence of early CT changes, and the most consistent 24 h follow-up associated factors were no recanalisation/reocclusion, large infarcts and intracranial haemorrhage. Finally, END24 was strongly predictive of poor outcome. The above findings are discussed with emphasis on END without a clear mechanism. Data on incidence and predictors of the latter subtype is scarce, and future studies using systematic imaging protocols should address its underlying pathophysiology. This may in turn lead to rational preventative and therapeutic measures for this ominous event.

Historic Stroke Motor Severity Score Predicts Progression in TIA/Minor Stroke

Background:

transient ischemic attack (tIA) and minor stroke have a high risk of early neurological deterioration, and patients who experience early improvement are at risk of deterioration. We generated a score for quantifying the worst reported motor and speech deficits and assessed whether this predicted outcome.

Methods:

510 tIA or minor stroke (NIHSS>4) patients were included. the Historical Stroke Severity Score (HSSS) prospectively quantified the patient's description of the worst motor or speech deficits. the HSSS was rated at the time of first assessment with more severe deficits scoring higher. Motor HSSS included assessments of arm and leg motor power (score total 0-5). Speech HSSS assessed severity of dysarthria and aphasia (total 0-3). the association between motor and speech HSSS and symptom progression was assessed during the 90-day follow-up period.

Results:

the proportion of patients in each category of the motor HSSS was 0: 43% (216/510), 1: 22%(110/510), 2: 17% (89/510), 3: 7% (37/510), 4: 5% (28/510) and 5: 6% (30/510). Motor HSSS was associated with symptom progression (p=0.004) but not recurrent stroke. Speech HSSS was not associated with either progression or recurrent stroke. Motor HSSS predicted disability (p=0.002) and intracranial occlusion (p=0.012). Disability increased with increasing motor HSSS.

Conclusions:

taking a detailed history about the severity of motor deficits, but not speech, predicted outcome in tIA and minor stroke patients. A score based on the patient's description of the severity of motor symptoms predicted symptom progression, intracranial occlusion and functional outcome, but not recurrent stroke in a tIA and minor stroke population.

Neurofluctuation in patients with subcortical ischemic stroke

OBJECTIVE

The purpose of this study was to assess the incidence of deterioration, fluctuation, and associated risk of poor outcome in patients with subcortical stroke (SCS).

METHODS

We conducted a prospective observational study, enrolling patients admitted with SCS based on their clinical examination and imaging studies. An NIH Stroke Scale evaluation was performed daily and whenever deterioration in examination was detected. Neurologic deterioration was defined as a motor score increase of at least 1 on the NIH Stroke Scale. Modified Rankin Scale scores at discharge were used to assess outcome.

RESULTS

Among 90 enrolled patients, 37 (41%) deteriorated, 75% of them in the first 24 hours after enrollment. Administration of tissue plasminogen activator was significantly associated with deterioration (hazard ratio 2.25; 95% confidence interval [CI]: 1.13-4.49) even after controlling for the association of deterioration with the early poststroke period. Deterioration conferred an increased risk of poor outcome (modified Rankin Scale scores 3-6) at discharge (relative risk: 1.80; 95% CI: 1.71-1.93). Reversion back to predeterioration deficits occurred in 38% of patients, and was associated with reduced risk of poor outcome at discharge (relative risk: 0.12; 95% CI: 0.02-0.83). Treatment with tissue plasminogen activator conferred better chances of spontaneous recovery to predeterioration deficits after initial deterioration (hazard ratio: 4.36; 95% CI: 1.36-14.01).

CONCLUSION

More than 40% of patients with SCS deteriorate neurologically. Deterioration tends to occur early after stroke, spontaneously reverses in approximately one-third of cases, and poses an increased risk of poor outcome. Therapies are needed to prevent, arrest, or reverse deterioration in patients with SCS.

Platelet-oriented inhibition in new TIA and minor ischemic stroke (POINT) trial: rationale and design

BACKGROUND

Ischemic stroke and other vascular outcomes occur in 10-20% of patients in the three-months following a transient ischemic attack or minor ischemic stroke, and many are disabling. The highest risk period for these outcomes is the early hours and days immediately following the ischemic event. Aspirin is the most common antithrombotic treatment used for these patients.

AIM

The aim of POINT is to determine whether clopidogrel plus aspirin taken <12 h after transient ischemic attack or minor ischemic stroke symptom onset is more effective in preventing major ischemic vascular events at 90 days in the high-risk, and acceptably safe, compared with aspirin alone.

DESIGN

POINT is a prospective, randomized, double-blind, multicenter trial in patients with transient ischemic attack or minor ischemic stroke. Subjects are randomized to clopidogrel (600 mg loading dose followed by 75 mg/day) or matching placebo, and all will receive open-label aspirin 50-325 mg/day, with a dose of 162 mg daily for five-days followed by 81 mg daily strongly recommended.

STUDY OUTCOMES

The primary efficacy outcome is the composite of new ischemic vascular events - ischemic stroke, myocardial infarction, or ischemic vascular death - by 90 days. The primary safety outcome is major hemorrhage, which includes symptomatic intracranial hemorrhage.

DISCUSSION

Aspirin is the most common antithrombotic given to patients with a stroke or transient ischemic attack, as it reduces the risk of subsequent stroke. This trial expects to determine whether more aggressive antithrombotic therapy with clopidogrel plus aspirin, initiated acutely, is more effective than aspirin alone.

Collateral therapeutics for cerebral ischemia

Current therapeutic strategies for acute ischemic stroke focus on vessel recanalization or penumbral neuroprotection without consideration of collaterals. Collateral circulation defines the extent of the ischemic penumbra, providing blood flow to tissues at risk of infarction downstream from an occluded artery. Therefore, leptomeningeal collaterals are a principal delivery route for oxygen, nutrients and potential therapeutic agents. Understanding of collateral anatomy and physiology is essential for the development of effective stroke treatments. Diagnostic imaging modalities may illustrate the penumbra from the collateral perspective, defining regions of relative ischemic vulnerability. Although specific collateral therapeutics are unrealized, insight may be gleaned from subtle details of prior stroke studies. Future advances will result from nascent research in therapeutic arteriogenesis and gene therapy adapted to the specific features of the cerebral circulation.

Review, historical context, and clarifications of the NINDS rt-PA stroke trials exclusion criteria: Part 1: rapidly improving stroke symptoms

BACKGROUND AND PURPOSE

Since Food and Drug Administration approval of intravenous tissue-type plasminogen activator (tPA) for treatment of acute ischemic stroke in 1996, it has become clear that several criteria used for exclusion from therapy were not based on actual data or operationally defined for use in clinical practice. All eligibility criteria from the National Institute of Neurological Disorders and Stroke (NINDS) recombinant tPA Stroke Study were adopted within the alteplase package insert as contraindications/warnings. Many clinicians have expressed the need for clarification and better definition of these treatment criteria.

METHODS

A group of investigators who also practice as stroke physicians convened a collaborative endeavor to work toward developing more clinically meaningful and consensus-driven exclusion criteria for intravenous tPA. The first of these exclusion criteria chosen was rapidly improving stroke symptoms (RISS). We reviewed and clarified the historical context and intention with the original investigators, held e-mail discussions, convened an in-person RISS Summit, and obtained the understanding of experienced stroke physicians broadly.

RESULTS

Historically, the intent of this exclusion criterion within the NINDS recombinant tPA Stroke Trial was to avoid treatment of transient ischemic attacks-who would have recovered completely without treatment. There was unanimous consensus that, in the absence of other contraindications, patients who experience improvement of any degree, but have a persisting neurological deficit that is potentially disabling, should be treated with intravenous tPA. This statement is supported from the methods established for the original NINDS trial, on the basis of detailed discussions and interviews with the former NINDS trialists. It was agreed that improvement should only be monitored for the extent of time needed to prepare and administer the intravenous tPA bolus/infusion. An explicit operational definition of RISS was developed by consensus to guide future decision making in acute stroke. There was unanimous agreement that all neurological deficits present at the time of the treatment decision should be considered in the context of individual risk and benefit, as well as the patient's baseline functional status.

CONCLUSIONS

A structured framework and quantitative approach toward defining RISS emerged through expert opinion and consensus. The term, RISS, should be reserved for those who improve to a mild deficit, specifically one which is perceived to be nondisabling. This is recommended to guide decision making on intravenous tPA eligibility going forward, including the design of future studies. An additional study of patients with rapid improvement to nonmild deficits is not justified because these patients should be treated.

Ischemic stroke presenting as fluctuating focal weakness in an otherwise healthy young man

A 32-year-old man presented to our emergency department (ED) with no complaints after paramedics responded to a fall. Medics noted left-sided weakness on scene. Symptoms were initially absent in the ED, although later recurred, and included dramatically waxing and waning focal weakness. An acute middle cerebral artery ischemic stroke was diagnosed, and tissue plasminogen activator was administered. Despite a fluctuating course of symptoms, our patient ultimately achieved a complete recovery.

Oral intake 6 months after acute ischemic stroke

OBJECTIVE

It remains unclear which patients with acute stroke need percutaneous endoscopic gastrostomy (PEG) placement and when it should be performed. The aim of this study was to identify the predictors for oral intake 6 months after onset in stroke patients.

METHODS

Data were obtained from a prospectively registered database of 738 acute ischemic stroke patients both with and without a history of stroke. Patients who survived for 6 months and replied to a questionnaire were divided into two groups: those with oral intake 6 months after onset and those without. Predictors for oral intake 6 months after onset were analyzed.

RESULTS

Forty-five patients died during their hospital stay, 145 did not reply to the questionnaire, and 23 died during follow-up. Of the residual 525 patients, 485 (92.4%) had oral intake after 6 months. On multivariate analysis, modified Rankin Scale score 0 before admission (OR 2.70, 95% CI 1.10-6.61) and National Institutes of Health Stroke Scale (NIHSS) score ≤9 on day 10 (OR 21.12, 95% CI 5.04-88.39) were independent predictors for oral intake after 6 months, while NIHSS score on admission was not.

CONCLUSION

Clinicians should be cautious about PEG placement for stroke patients who were independent prior to their stroke and whose stroke severity decreases 10 days after admission, because their swallowing dysfunction may improve within a brief period.

Ischemic stroke: emergencies and management

The past 40 years have seen the evolution of acute ischemic stroke management from unproven therapies du jour, such as steroids, heparin for stroke in evolution, and hypervolemic-hemodilution, to more of a scientific basis for our decision-making process. This evolution is directly related to the advancements in imaging of stroke. It is also related to carefully designed, controlled clinical trials of potential therapies, which have led to the recognition of the benefits of thrombolytic therapy in the acute setting but have also caused confusion and frustration over the lack of benefit for potential neuroprotective agents that once seemed promising.

A novel emergency department dysphagia screen for patients presenting with acute stroke

OBJECTIVES

Dysphagia is a common complication for emergency department (ED) patients presenting with acute stroke (AS). Recent stroke recommendations have suggested that EDs screen patients with AS for dysphagia prior to administering anything by mouth. This study sought to develop and test a novel ED dysphagia screen to be used in this population.

METHODS

A multidisciplinary approach was used to create a novel dysphagia screen performed by ED nurses during the initial evaluation of patients with suspected AS. The screen consists of five questions of which any single affirmative answer signified possible dysphagia. A prospective cohort study was conducted to evaluate the performance of this screen in detecting dysphagia after AS. Patients were followed for 30 days, and true dysphagia was determined if the patient had an abnormal modified barium swallow study (MBS), had placement of a feeding tube, or was placed on a dysphagia diet after assessment by a speech pathologist. The authors performed a substudy to determine agreement using a blinded kappa (κ) assessment with a convenience sample of 40 patients.

RESULTS

Over a 21-month period, 283 patients met eligibility for analysis. The rate of cerebral infarction in this cohort was 245 (87%). The rates for true dysphagia, pneumonia, and death were 91 (32%), 26 (9%), and 18 (6%), respectively. The dysphagia screen had a sensitivity of 95% (95% confidence [CI] = 88% to 98%) and a negative likelihood ratio of 0.1 (95% CI = 0.04 to 0.2). The inter-rater agreement assessed by kappa was substantial (0.69, 95% CI = 0.55 to 0.83).

CONCLUSIONS

These data suggest that this dysphagia screen may be a valuable tool for detecting dysphagia in ED patients presenting with AS. The simple screen can be performed by nursing personnel and appears to perform well with good agreement. Given the overall rate of dysphagia in one-third of AS patients, the use of an ED dysphagia screen appears warranted.

Computed tomography and computed tomography angiography findings predict functional impairment in patients with minor stroke and transient ischaemic attack

INTRODUCTION

Abnormalities on acute magnetic resonance imaging predict outcome in minor stroke and transient ischaemic attack patients. We hypothesised that noncontrast computed tomography and computed tomography angiography findings in minor stroke and transient ischaemic attack patients would also predict functional outcome.

METHODS

We analysed consecutive patients with a transient ischaemic attack or a minor stroke with an National Institute of Health Stroke Scale <or=3 who were assessed with a noncontrast computed tomography and CT angiography of the circle of Willis and neck within 24 h of symptom onset. We assessed the association between clinical or imaging features and functional impairment on the modified Rankin Scale (mRS >or=2 ) at 90 days.

RESULTS

Among 457 patients, the median baseline National Institute of Health Stroke Scale score was 1. Median time from symptom onset to noncontrast computed tomography was 278 min (interquartile range 151-505) and median delay from noncontrast computed tomography to CT angiography was 3 min (interquartile range 0-13). At 90 days, 57 patients (12.5%) had a mRS >or=2. Clinical factors that were associated with functional impairment were age >or=60 years (RR 2.05 CI(95) 1.16-3.64) and baseline National Institute of Health Stroke Scale score >0 (RR 3.23 1.72-6.06). All the assessed computed tomography parameters (acute stroke on noncontrast computed tomography and intracranial or extracranial stenosis or occlusion) were individually predictive of functional impairment. A composite computed tomography imaging 'at risk' metric, defined by acute stroke on noncontrast computed tomography, Circle of Willis intracranial vessel occlusion or >or=50% stenosis, extracranial occlusion or >or=50% stenosis, was associated with poorer outcome (RR 2.92 CI(95) 1.81-4.71).

CONCLUSIONS

The presence of an acute stroke on noncontrast computed tomography or an intracranial or extracranial occlusion or stenosis was associated with an increased risk of functional impairment. Multi-modal computed tomography could be used to identify high-risk transient ischaemic attack or minor stroke patients.

Ultrasound Assisted Thrombolysis in Acute Ischaemic Stroke: Preliminary Experience in Singapore

Background and Aim: Intravenously-administered tissue plasminogen activator (IV-TPA) induces thrombolysis and remains the only FDA-approved therapy for acute ischaemic stroke. IV-TPA thrombolysis has been approved recently in Singapore for acute stroke. Continuous exposure of clot to 2-MHz pulsed-wave transcranial Doppler (TCD) ultrasound during IV-TPA infusion is known to augment thrombolysis. We aimed to determine the feasibility, safety and efficacy of ultrasound-assisted thrombolysis in acute ischaemic stroke in Singapore. Subjects and Methods: Consecutive patients with acute ischaemic stroke due to intracranial arterial-occlusions were treated with standard IV-tPA and continuously monitored with 2-MHz TCD according to the CLOTBUST-trial protocol. Arterial recanalisation was determined with Thrombolysis in Brain Ischemia (TIBI) flow-grading system. Safety and efficacy of ultrasoundassisted thrombolysis were assessed by rates of symptomatic intracranial haemorrhage (sICH) and functional recovery at 1 month, respectively. Results: Five consecutive patients (mean age 58 years, 3 men and 3 of Chinese ethnicity) were included. Mean time elapsed between symptom onset and presentation to emergency room was 98 minutes (range, 50 to 135 minutes) while the mean time interval between symptom onset to IV-TPA bolus was 144 minutes (range, 125 to 180 minutes). Partial or complete recanalisation with reduction in the stroke severity was noted in 4 out of the 5 patients during IV-TPA infusion (mean change in NIHSS = 4 points; range 2 to 8 points). None of our patients developed sICH while 4 patients demonstrated good functional outcome at 1 month. Conclusions: Our preliminary study demonstrates the feasibility, safety and efficacy of ultrasound-assisted thrombolysis in acute ischaemic stroke in Singapore. Continuous TCD-monitoring during IV-TPA infusion provides real-time information, enhances thrombolysis and improves functional outcomes in acute ischaemic stroke. Key words: Acute ischaemic stroke, Thrombolysis, Transcranial Doppler

Intracranial stenting of severe symptomatic intracranial stenosis: results of 100 consecutive patients

BACKGROUND AND PURPOSE

There are a few reports regarding the outcome evaluation of balloon-expandable intracranial stent placement (BEICS). The purpose of our study was to evaluate the outcome and factors related to the adverse events (AEs) of BEICS.

MATERIALS AND METHODS

We evaluated 100 consecutive patients who underwent BEICS. We assessed the procedural success (residual stenosis < 50%), AEs (minor strokes, major strokes, and death), clinical outcome, and restenosis (> 50%) at 6 months. We also analyzed 18 factors including symptom patterns related to AE rate. Symptom patterns revealed 1) stable patients (n = 73) with improving, stationary, or resolved symptoms; and 2) unstable patients (n = 27) with gradual worsening or fluctuating symptoms (National Institutes of Health Stroke Scale [NIHSS] > or = 4) within 2 days before stent placement.

RESULTS

The procedural success rate was 99%. Overall, there were 10 (10%) AEs within the 6 months: 4 (4%) minor strokes, 3 (3%) major strokes, and 3 (3%) deaths including a death from myocardial infarction. AE rate was 4.1% in stable and 25.9% in unstable patients. Restenosis at 6 months revealed 0% (0/59). Good outcome (modified Rankin Scale < or = 2) at 6 months was 97% (71/73) in stable and 67% (18/27) in unstable patients. Stepwise logistic regression model revealed that symptom pattern (unstable versus stable) was the only significant risk factor (OR, 8.167; 95% CI, 1.933-34.500; P = .004).

CONCLUSION

BEICS revealed a low AE and good outcome rate at 6 months, especially in the stable patients. Midterm outcome was also favorable in the unstable patient group.

Prognostic value of transcranial sonography in acute stroke patients

Accurate assessment of stroke is critical for patient prognosis and selection of appropriate treatment regimens in order to optimize patient outcomes. Advanced neurosonologic techniques are straightforward, portable, and cost-effective, representing significant advantages over other noninvasive imaging modalities for monitoring of the hemodynamic status of acute ischemic stroke. Ultrasound findings acquired both early (<3 h from onset of stroke) and later (6-24 h after stroke) have demonstrated feasibility and validity for the detection of stenosis/occlusion of key intracranial structures, such as the middle cerebral artery, and for immediate and unambiguous indication of flow velocities, particularly when contrast enhancement is used. In addition, the target of thrombolysis can be identified and localized, and the success of therapy monitored, by transcranial ultrasound. Finally, transcranial ultrasound can be used to gauge the appropriateness of more complex and costly imaging studies, thereby optimizing utilization of health care resources.

Role of transcranial Doppler ultrasonography in evaluation of patients with cerebrovascular disease

Transcranial Doppler ultrasonography (TCD) is the only noninvasive examination method that enables the reliable evaluation of blood flow from the basal intracerebral vessels, adding physiologic information to the anatomic images. TCD is relatively inexpensive, can be performed at bedside, and allows monitoring in acute emergency settings and for prolonged periods with a high temporal resolution, making it ideal for studying dynamic cerebrovascular responses. In acute stroke, TCD is capable of providing rapid information about the hemodynamic status of the cerebral circulation and monitoring recanalization in real-time, with a potential for enhancing tissue plasminogen activator-induced thrombolysis. Extended applications such as emboli monitoring, right-to-left shunt detection, and vasomotor reactivity make TCD an important and valuable tool for evaluating stroke mechanisms, planning and monitoring treatment, and determining prognosis.

Reversible brain ischemia: lessons from transient ischemic attack

PURPOSE OF REVIEW

In recent years, there has been considerable scientific inquiry regarding transient ischemic attack. In an effort to synthesize at times conflicting data, this paper will review the recent evidence and provide a critical overview of reversible brain ischemia.

RECENT FINDINGS

Transient ischemic attack is now understood to indicate a higher risk of recurrence than completed ischemic stroke. Efforts to unravel the mechanisms of this instability following transient ischemic attack using imaging studies have led to new concepts and definitions, and sparked further debate. While imaging has increased diagnostic certainty, it has yet to provide reliable prognostic markers. The evidence suggests that risk of clinical recurrence is most closely linked to the degree to which the initial deficit reverses. From a tissue level, however, there are also data to support the notion of a 'stroke-prone state' following both transient ischemic attack and completed stroke, suggesting that mechanistically they may be less distinct than previously thought. Transient ischemic attack may simply highlight the dynamic nature of all acute ischemic cerebrovascular syndromes.

SUMMARY

Reversible brain ischemia is a harbinger for subsequent ischemic stroke. Although recent advances have focused on imaging markers, the most important predictor of risk following brain ischemia is degree of early clinical reversibility.