24-hour National Institutes Of Health Stroke Scale Research Articles

Validation of the transcranial Doppler rescue criteria for mechanical thrombectomy.

Transcranial Doppler (TCD) identifies acute stroke patients with arterial occlusion where treatment may not effectively open the blocked vessel. This study aimed to examine the clinical utility and prognostic value of TCD flow findings in patients enrolled in a multicenter prospective study (CLOTBUST-PRO). Patients enrolled with intracranial occlusion on computed tomography angiography (CTA) who underwent urgent TCD evaluation before intravenous thrombolysis was included in this analysis. TCD findings were assessed using the mean flow velocity (MFV) ratio, comparing the reciprocal ratios of the middle cerebral artery (MCA) depths bilaterally (affected MCA-to-contralateral MCA MFV [aMCA/cMCA MFV ratio]). A total of 222 patients with intracranial occlusion on CTA were included in the study (mean age: 64±14years, 62% men). Eighty-eight patients had M1 MCA occlusions; baseline mean National Institutes of Health Stroke Scale (NIHSS) score was 16, and a 24-hour mean NIHSS score was 10 points. An aMCA/cMCA MFV ratio of <.6 had a sensitivity of 99%, specificity of 16%, positive predictive value (PV) of 60%, and negative PV of 94% for identifying large vessel occlusion (LVO) including M1 MCA, terminal internal carotid artery, or tandem ICA/MCA. Thrombolysis in Brain Ischemia scale, with (grade ≥1) compared to without flow (grade 0), showed a sensitivity of 17.1%, specificity of 86.9%, positive PV of 62%, and negative PV of 46% for identifying LVO. TCD is a valuable modality for evaluating arterial circulation in acute ischemic stroke patients, demonstrating significant potential as a screening tool for intravenous/intra-arterial lysis protocols.

Predicting Functional Outcome Using 24-Hour Post-Treatment Characteristics: Application of Machine Learning Algorithms in the STRATIS Registry.

ML models, adaptive boost, random forest (RF), classification and regression trees (CART), C5.0 decision tree (C5.0), support vector machine (SVM), least absolute shrinkage and selection operator (LASSO), and logistic regression (LR), and traditional LR models were used to predict 90-day functional outcome (modified Rankin Scale score 0-2). Twenty-four-hour National Institutes of Health Stroke Scale (NIHSS) was examined as a continuous or dichotomous variable in all models. Model accuracy was assessed using the area under characteristic curve (AUC). The 24-hour NIHSS score was a top-predictor of functional outcome in all models. ML models using the continuous 24-hour NIHSS scored showed moderate-to-good predictive performance (range mean AUC: 0.76-0.92); however, RF (AUC: 0.92 ± 0.028) outperformed all ML models, except LASSO (AUC: 0.89 ± 0.023, p= 0.0958). Importantly, RF demonstrated a significantly higher predictive value than LR (AUC: 0.87 ± 0.031, p= 0.048) and traditional LR (AUC: 85 ± 0.06, p= 0.035) when using the 24-hour continuous NIHSS score. Predictive accuracy was similar between the 24-hour NIHSS score dichotomous and continuous ML models. In this substudy, we found similar predictive accuracy for functional outcome when using the 24-hour NIHSS score as a continuous or dichotomous variable in ML models. ML models had moderate-to-good predictive accuracy, with RF outperforming LR models. External validation of these ML models is warranted. ANN NEUROL 2023;93:40-49.

ASPECTS as a clinical outcome marker for MCA infarction treated with thrombolytic therapy: Non-contrast CT versus CTA source images

Background &amp; Objective: Computed tomography angiography (CTA) in acute stroke has been widely used to demonstrate arterial occlusion. Alberta Stroke Program Early CT Score (ASPECTS) is used to detect early ischemic signs in non-contrast computed tomography (NCCT) in the middle cerebral artery region. We hypothesized that computed tomography angiography source image (CTA-SI) is superior to NCCT in predicting final infarct volume, 24 hour National Institutes of Health Stroke Scale (NIHSS) score and 90-day clinical outcome. Methods: Patients who had an acute ischemic stroke due to middle cerebral artery (MCA) occlusion and treated with tissue plasminogen activator (tPA) were retrospectively evaluated. ASPECTS was evaluated by two experienced stroke neurologists in acute NCCT, CTA-SI, and follow up imaging. The final ASPECTS was compared with the mean baseline ASPECTS of NCCT and CTA-SI. The relation of both scores with 24-hour NIHSS and clinical outcome was compared. The Modified Rankin Scale (mRS) was utilized to evaluate the 90-day outcomes. mRS score of 0-2 was considered a “good outcome”. Results: Fifty-three patients were evaluated. We observed a significant relation among CTA-SI ASPECTS and after treatment 24hr ASPECTS (y= -3.9 + 1.4 x; 95% CI, -7.6 to -0.2) (y= -26.04 + 3.5 x; CI, -41 to -10). The median baseline 24-hr NHISS was 6 (0 - 22). We found a better correlation between CTA-SI ASPECTS and 24-hr NHISS (y= 363.06 + -37.03 x; CI, -148 to 864) than between NCCT ASPECTS and 24h NHISS (y=529.80 + -62.55 x; CI, 180 - 829). Median 90 days mRS score was 2 (0 - 6). According to Deming regression analysis, the CTA-SI ASPECTS (y= 76.10 + -7.69 x; 95% CI, -36 to 188) was more consistent with the 90 day mRS compared to NCCT ASPECTS (y=149.86 + -17.67 x; 95% CI, 23 - 267) CTA-SI was superior in predicting 24hr NIHSS and day 90 mRS compared to NCCT ASPECTS. Conclusion: Prediction of CTA-SI ASPECTs is better than NCCT ASPECTs at 24hr NIHSS, 3-month mRS and final infarct size in acute ischemic stroke patients treated with tPA.

Accurate Prediction of Persistent Upper Extremity Impairment in Patients With Ischemic Stroke

ObjectiveTo develop a simple and effective risk score for predicting which stroke patients will have persistent impairment of upper extremity motor function at 90 days. DesignPost hoc analysis of clinical trial patients hospitalized with acute ischemic stroke who were followed for 90 days to determine functional outcome. SettingPatient were hospitalized at facilities across the United States. ParticipantsWe created a harmonized cohort of individual patients (N=1653) from the NINDS tPA, ALIAS part 2, IMS-III, DEFUSE 3, and FAST-MAG trials. We split the cohort into balanced derivation and validation samples. InterventionsNot applicable. Main Outcome MeasuresThe primary outcome was persistent arm impairment, defined as a National Institutes of Health Stroke Scale (NIHSS) arm domain score of 2 to 4 at 90 days in patients who had a 24-hour NIHSS arm score of 1 or more. We used least absolute shrinkage and selection operator regression to determine the elements of the persistent upper extremity impairment (PUPPI) index, which we validated as a predictive tool. ResultsWe included 1653 patients (827 derivation, 826 validation), of whom 803 (48.6%) had persistent arm impairment. The PUPPI index gives 1 point each for age 55 years or older and NIHSS values of worse arm (4), worse leg (>2), facial palsy (3), and total NIHSS (≥10). The optimal cutpoint for the PUPPI index was 3 or greater, at which the area under the curve was greater than 0.75 for the derivation and validation cohorts and when using NIHSS values from either 24 hours or in a subacute or discharge time window. Results were similar across different levels of stroke severity. ConclusionThe PUPPI index uses readily available information to accurately predict persistent upper extremity motor impairment at 90 days poststroke. The PUPPI index can be administered in minutes and could be used as inclusion criterion in recovery-related clinical trials or, with additional development, as a prognostic tool for patients, caregivers, and clinicians.

Challenges of Estimating Accurate Prevalence of Arm Weakness Early After Stroke

Background. Recent studies have reported lower statistics of upper limb (UL) weakness (48-57%) compared to widely cited values collected over 2 decades ago (70-80%). Objective. To explore potential factors contributing to the accuracy of prevalence values of UL weakness using a case study from a single regional centre. Methods. All patients admitted to the acute stroke unit with suspected diagnosis of stroke were screened from February 2016 to August 2017. Upper limb weakness was captured (a) prospectively using the Shoulder Abduction and Finger Extension (SAFE) score performed by unit physical therapists within 7 days post-stroke and (b) retrospectively via chart review using the National Institutes of Health Stroke Scale (NIHSS) arm score at admission and 24 hours post-admission. Results. A total of 656 patients were admitted with a first-ever stroke, and 621 (95%) individuals were administered the SAFE score. A total of 40% of individuals had UL weakness using the SAFE score (SAFE ≤8) at a mean time of 1.9 (SD 1.5) days post-stroke. In the same sample, 57% and 49% had UL weakness using the admission and 24-hour post-admission NIHSS arm score, respectively. Conclusions. The accuracy of population-level UL weakness prevalence values can be affected by weakness measure and score cut-off, time post-stroke weakness is captured, sample characteristics and use of single or multiple sites. Researchers using prevalence values for clinical trial planning should consider these attributes when using prevalence data for estimating recruitment rates and resource needs.

Redefined Measure of Early Neurological Improvement Shows Treatment Benefit of Alteplase Over Placebo.

Background and Purpose- The first of the 2 NINDS (National Institute of Neurological Disorders and Stroke) Study trials did not show a significant increase in early neurological improvement, defined as National Institutes of Health Stroke Scale (NIHSS) improvement by ≥4, with alteplase treatment. We hypothesized that early neurological improvement defined as a percentage change in NIHSS (percent change NIHSS) at 24 hours is superior to other definitions in predicting 3-month functional outcomes and using this definition there would be treatment benefit of alteplase over placebo at 24 hours. Methods- We analyzed the NINDS rt-PA Stroke Study (Parts 1 and 2) trial data. Percent change NIHSS was defined as ([admission NIHSS score-24-hour NIHSS score]×100/admission NIHSS score] and delta NIHSS as (admission NIHSS score-24-hour NIHSS score). We compared early neurological improvement using these definitions between alteplase versus placebo patients. We also used receiver operating characteristic curve to determine the predictive association of early neurological improvement with excellent 3-month functional outcomes (Barthel Index score of 95-100 and modified Rankin Scale score of 0-1), good 3-month functional outcome (modified Rankin Scale score of 0-2), and 3-month infarct volume. Results- There was a significantly greater improvement in the 24-hour median percent change NIHSS among patients treated with alteplase compared with the placebo group (28% versus 15%; P=0.045) but not median delta NIHSS (3 versus 2; P=0.471). Receiver operating characteristic curve comparison showed that percent change NIHSS (ROCpercent) was better than delta NIHSS (ROCdelta) and admission NIHSS (ROCadmission) with regards to excellent 3-month Barthel Index (ROCpercent, 0.83; ROCdelta, 0.76; ROCadmission, 0.75), excellent 3-month modified Rankin Scale (ROCpercent, 0.83; ROCdelta, 0.74; ROCadmission, 0.78), and good 3-month modified Rankin Scale (ROCpercent, 0.83; ROCdelta, 0.76; ROCadmission, 0.78). Conclusions- In the NINDS rt-PA trial, alteplase was associated with a significant percent change improvement in NIHSS at 24 hours. Percent change in NIHSS may be a better surrogate marker of thrombolytic activity and 3-month outcomes.

Predictor of 90-day functional outcome after mechanical thrombectomy for large vessel occlusion stroke: NIHSS score of 10 or less at 24 hours.

Mechanical thrombectomy is the established treatment for acute ischemic stroke due to large vessel occlusion (LVO). The authors sought to identify early predictors of a favorable outcome in stroke patients treated with mechanical thrombectomy. Consecutive patients with ischemic stroke due to LVO who underwent mechanical thrombectomy at a Comprehensive Stroke Center in the US between 2016 and 2018 were retrospectively reviewed. Demographics, stroke and treatment characteristics, as well as functional outcome at 90 days were collected. Clinical predictors of 90-day functional outcome were assessed and compared to existing indices for prompt neurological improvement. Analyses of area under the receiver operating characteristic curve were performed to estimate the optimal thresholds for absolute 24-hour and delta (change in) National Institutes of Health Stroke Scale (NIHSS) scores for functional outcome prediction. A total of 156 patients (median age 71.5 years) underwent 159 mechanical thrombectomies. The M1 segment of the middle cerebral artery was the most frequent site of occlusion (57.2%). The median NIHSS score before thrombectomy was 18 (IQR 14-24). A postthrombectomy Thrombolysis in Cerebral Infarction score of 2B or 3 was achieved in 147 procedures (92.4%). The median NIHSS score 24 hours after thrombectomy was 14 (IQR 6-22). Good functional outcome at 90 days (modified Rankin Scale score 0-2) was achieved in 37 thrombectomies (23.9%). An absolute 24-hour NIHSS score ≤ 10 (OR 25.929, 95% CI 8.448-79.582, p < 0.001) and a delta NIHSS score ≥ 8 between baseline and 24 hours (OR 4.929, 95% CI 2.245-10.818, p < 0.001) were associated with good functional outcome at 90 days. The 24-hour NIHSS score cutoff of 10 outperformed existing indices for prompt neurological improvement in the ability to predict 90-day functional outcome. An NIHSS score ≤ 10 at 24 hours after mechanical thrombectomy was independently associated with good functional outcome at 90 days.

Qualitative Posttreatment Diffusion-Weighted Imaging as a Predictor of 90-day Outcome in Stroke Intervention.

The aim was to assess the ability of post-treatment diffusion-weighted imaging (DWI) to predict 90-day functional outcome in patients with endovascular therapy (EVT) for large vessel occlusion in acute ischemic stroke (AIS). We examined a retrospective cohort from March 2016 to January 2018, of consecutive patients with AIS who received EVT. Planimetric DWI was obtained and infarct volume calculated. Four blinded readers were asked to predict modified Rankin Score (mRS) at 90 days post-thrombectomy. Fifty-one patients received endovascular treatment (mean age 65.1 years, median National Institutes of Health Stroke Scale (NIHSS) 18). Mean infarct volume was 43.7 mL. The baseline NIHSS, 24-hour NIHSS, and the DWI volume were lower for the mRS 0-2 group. Also, the thrombolysis in cerebral infarction (TICI) 2b/3 rate was higher in the mRS 0-2 group. No differences were found in terms of the occlusion level, reperfusion technique, or recombinant tissue plasminogen activator use. There was a significant association noted between average infarct volume and mRS at 90 days. On multivariable analysis, higher infarct volume was significantly associated with 90-day mRS 3-5 when adjusted to TICI scores and occlusion location (OR 1.01; CI 95% 1.001-1.03; p = 0.008). Area under curve analysis showed poor performance of DWI volume reader ability to qualitatively predict 90-day mRS. The subjective impression of DWI as a predictor of clinical outcome is poorly correlated when controlling for premorbid status and other confounders. Qualitative DWI by experienced readers both overestimated the severity of stroke for patients who achieved good recovery and underestimated the mRS for poor outcome patients. Infarct core quantitation was reliable.

Abstract TP165: Association of Admission versus 24-Hour NIHSS Score With Early Ambulation After Stroke

Introduction: Predicting who will be ambulatory within the first several days after stroke may help support resource allocation, and discharge and rehabilitation planning. The National Institutes of Health Stroke Scale (NIHSS) is commonly used to rate stroke severity. Due to medical intervention or stroke progression, the NIHSS score at admission versus 24 hours can be drastically different. We explored whether presence of leg weakness at admission or 24 hours was most predictive of early ambulation, and other NIHSS score components associated with early ambulation. Methods: A consecutive sample of patients admitted to a stroke unit at a comprehensive stroke center was included in this retrospective study. Initial and 24-hour NIHSS scores were examined in conjunction with various demographic and stroke details. Multivariable logistic regression models identified predictors of ambulation within the first week of admission. Results: Of 513 stroke patients, 273 (53%) were able to walk with or without assistance within the first 3-5 days post-stroke. The multivariable model utilizing the 24-hour NIHSS combined right and left lower extremity weakness scores had greater predictive value (area under the curve [AUC] = 0.85; 95% confidence interval [CI] 0.81 - 0.88) than the initial score (AUC = 0.74; 95% CI 0.69 - 0.78). In the multivariable analysis, 24-hour combined leg weakness (odds ratio [OR] 0.29; 95% CI 0.22 - 0.39), ataxia (OR 0.63; 95% CI 0.43 - 0.91), and sensation (OR 0.58; 95% CI 0.37 - 0.91) scores were all associated with early ambulation capacity. Conclusions: The prediction of early ambulation is more accurate after 24 hours post-stroke. Leg weakness, ataxia, and sensory loss at 24 hours are all negatively associated with ability to ambulate after stroke.

Improving the Evaluation of Collateral Circulation by Multiphase Computed Tomography Angiography in Acute Stroke Patients Treated with Endovascular Reperfusion Therapies

Good collateral circulation (CC) is associated with favorable outcomes in acute stroke, but the best technique to evaluate collaterals is controversial. Single-phase computed tomography angiography (sCTA) is widely used but lacks temporal resolution. We aim to compare CC evaluation by sCTA and multiphase CTA (mCTA) as predictors of outcome in endovascular treated patients. Methods: Consecutive endovascular treated patients with M1 middle cerebral artery (MCA) or terminal intracranial carotid artery (TICA) occlusion confirmed by sCTA were included. Two more CTA acquisitions with 8- and 16-second delays were performed for mCTA. Endovascular thrombectomy was performed independently of the CC status according to a local protocol [Alberta Stroke Program Early CT score (ASPECTS) >6, modified Rankin scale (mRS) score <3]. CC on sCTA and mCTA were compared. Results: 108 patients were included. Their mean age was 69.6 ± 13 years and their median National Institutes of Health Stroke Scale (NIHSS) score was 17 (interquartile range 8). 79 (73.1%) had M1 MCA and 29 (26.9%) TICA occlusions. The mean time from symptom onset to CTA was 146.8 ± 96.5 min. On sCTA, 50.9% patients presented good CC vs. 57.5% on mCTA. Good CC status in both sCTA and mCTA had a lower 24-hour infarct volume (27.4 vs. 74.8 cm³ on sCTA, p = 0.04; 17.2 vs. 97.8 cm³ on mCTA, p < 0.01). However, only good CC on mCTA was associated with lower 24-hour (5 vs. 8.5, p = 0.04) and median discharge NIHSS (2 vs. 4.5, p = 0.04) scores and functional independency (mRS score <3) at 3 months (76.9 vs. 23.1%, p < 0.01). In a logistic regression model including age, NIHSS, ASPECTS and recanalization, only age (OR 0.96, 95% CI 0.93-0.99, p = 0.02) and good CC on mCTA (OR 5, 95% CI 1.99-12.6, p < 0.01) were independent predictors of functional outcome at 3 months. Conclusion: CC evaluation by mCTA is a better prognostic marker than CC evaluation by sCTA for clinical and functional endpoints in acute stroke patients treated with endovascular thrombectomy.

Stroke Severity and Comorbidity Index for Prediction of Mortality after Ischemic Stroke from the Virtual International Stroke Trials Archive–Acute Collaboration

There is increasing interest in the use of administrative data (incorporating comorbidity index) and stroke severity score to predict ischemic stroke mortality. The aim of this study was to determine the optimal timing for the collection of stroke severity data and the minimum clinical dataset to be included in models of stroke mortality. To address these issues, we chose the Virtual International Stroke Trials Archive (VISTA), which contains National Institutes of Health Stroke Scale (NIHSS) on admission and at 24 hours, as well as outcome at 90 days. VISTA was searched for patients who had baseline and 24-hour NIHSS. Improvement in regression models was performed by the net reclassification improvement (NRI) method. The clinical data among 5206 patients were mean age, 69 ± 13; comorbidity index, 3.3 ± .9; median NIHSS at baseline, 12 (interquartile range [IQR] 8-17); NIHSS at 24 hours, 9 (IQR 8-15); and death at 90 days in 15%. The baseline model consists of age, gender, and comorbidity index. Adding the baseline NIHSS to model 1 improved the NRI by 0.671 (95% confidence interval [CI] 0.595-0.747) [or 67.1% correct reclassification between model 1 and model 2]. Adding the 24 hour NIHSS term to model 1 (model 3) improved the NRI by 0.929 (95% CI 0.857-1.000) for model 3 versus model 1. Adding the variable thrombolysis to model 3 (model 4) improve NRI by 0.1 (95% CI 0.023-0.178) [model 4 versus model 3]. The optimal model for the prediction of mortality was achieved by adding the 24-hour NIHSS and thrombolysis to the baseline model.

Characteristics and Outcome of Ischemic Stroke Patients Who Are Free of Symptoms at 24 Hours following Thrombolysis

Background: A part of ischemic stroke patients score 0 on the National Institutes of Health Stroke Scale (NIHSS) within 24 h following thrombolysis. Their clinical characteristics and long-term outcome are poorly studied. We report a single-center assessment of such patients. Methods: The cohort comprises 874 consecutive patients from the Helsinki Stroke Thrombolysis Registry, out of whom 113 scored 0 on 24-hour NIHSS. We analyzed their baseline demographic, clinical and radiological characteristics and 3-month outcome (modified Rankin Scale, mRS). Associations between the study parameters were tested by multivariate analysis. Results: Patients with a 24-hour NIHSS score = 0 (n = 113) were younger than the rest of the population (n = 761; median: 65.6 vs. 71.5 years; p < 0.001), their NIHSS score on admission was lower (median: 5 vs. 10; p < 0.001), as was their glucose level (median: 6.2 vs. 6.7 mmol/l; p = 0.02). The onset-to-treatment time was similar in both groups (median: 120 vs. 115 min; p = 0.89). Patients with a 24-hour NIHSS score = 0 more often achieved an excellent outcome (mRS scores: 0–1; 81 vs. 31%; p < 0.001) and had lower mortality (1.8 vs. 11.8%; p < 0.01). One third of these patients had a brain infarction visible on 24-hour imaging. Lower baseline NIHSS score and younger age were independently associated with 24-hour NIHSS score = 0, which, in turn, was independently associated with excellent 3-month outcome. Conclusions: Patients with an NIHSS score = 0 at 24 h following thrombolysis are younger, have milder symptoms and have a lower glucose level on admission. They achieve more often excellent outcome and lower mortality. Still, 8% of them required help in daily activities or were dead at 3 months (mRS scores: 3–6).

J-Shaped Association Between Serum Glucose and Functional Outcome in Acute Ischemic Stroke

Hyperglycemia after stroke is associated with larger infarct volume and poorer functional outcome. In an animal stroke model, the association between serum glucose and infarct volume is described by a U-shaped curve with a nadir ≈7 mmol/L. However, a similar curve in human studies was never reported. The objective of the present study is to investigate the association between serum glucose levels and functional outcome in patients with acute ischemic stroke. We analyzed 1446 consecutive patients with acute ischemic stroke. Serum glucose was measured on admission at the emergency department together with multiple other metabolic, clinical, and radiological parameters. National Institutes of Health Stroke Scale (NIHSS) score was recorded at 24 hours, and Rankin score was recorded at 3 and 12 months. The association between serum glucose and favorable outcome (Rankin score ≤2) was explored in univariate and multivariate analysis. The model was further analyzed in a robust regression model based on fractional polynomial (-2-2) functions. Serum glucose is independently correlated with functional outcome at 12 months (OR, 1.15; P=0.01). Other predictors of outcome include admission NIHSS score (OR, 1.18; P<0001), age (OR, 1.06; P<0.001), prestroke Rankin score (OR, 20.8; P=0.004), and leukoaraiosis (OR, 2.21; P=0.016). Using these factors in multiple logistic regression analysis, the area under the receiver-operator characteristic curve is 0.869. The association between serum glucose and Rankin score at 12 months is described by a J-shaped curve with a nadir of 5 mmol/L. Glucose values between 3.7 and 7.3 mmol/L are associated with favorable outcome. A similar curve was generated for the association of glucose and 24-hour NIHSS score, for which glucose values between 4.0 and 7.2 mmol/L are associated with a NIHSS score <7. Discussion-Both hypoglycemia and hyperglycemia are dangerous in acute ischemic stroke as shown by a J-shaped association between serum glucose and 24-hour and 12-month outcome. Initial serum glucose values between 3.7 and 7.3 mmol/L are associated with favorable outcome.

Prediction of long-term outcome by percent improvement after the first day of thrombolytic treatment in stroke patients

Background We investigated a method for assessing early improvement and predictive factors of early and late outcomes in patients receiving thrombolytic therapy. Methods A total of 160 consecutive patients who received thrombolytic therapy were included in the study. Using National Institutes of Health Stroke Scale (NIHSS) scores, percent improvement [(baseline NIHSS score − 24-hour NIHSS score) / baseline NIHSS score × 100] was calculated and compared with delta (baseline NIHSS score − 24-hour NIHSS score) and with major neurological improvement (MNI, NIHSS score of 0–1 or ≥ 8 point improvement at 24 h) by receiver operating characteristic (ROC) curve analysis. Finally, we investigated the independent predictors of improvement at 24 h after the thrombolytic therapy and of favorable 3-month outcome (modified Rankin scale score 0–2). Results By pairwise comparison of ROC curves, percent improvement was stronger than delta ( p = 0.004) and MNI ( p < 0.001) in predicting long-term outcome. First day improvement (FDI), defined as greater than 20% improvement, was a strong predictor of favorable 3-month outcome (OR 12.55, 95% CI 5.41–29.10). Recanalization (OR 3.30, 95% CI 1.28–8.45), absence of carotid T occlusion (OR 0.09, 95% CI 0.02–0.42) and hemorrhagic transformation (OR 0.25, 95% CI 0.09–0.73) were independent predictors of FDI. Independent predictors of favorable 3-month outcome were FDI, current smoking, absence of carotid T occlusion and hemorrhagic transformation. Conclusions Percent improvement at 24 h after thrombolytic therapy is a useful surrogate marker for predicting the long-term outcome. Our findings highlight the importance of early stroke management.

Late Endovascular Revascularization in Acute Ischemic Stroke Based on Clinical-Diffusion Mismatch

A clinical-diffusion mismatch (CDM) among stroke patients presenting within 12-24 hours has been correlated with neurologic deterioration and infarct expansion. We sought to study the feasibility and safety of reperfusion therapy in a series of 11 consecutive patients fulfilling this criterion. Patients presenting with large vessel syndromes were considered for revascularization therapy. Of these patients, we identified those presenting beyond 8 hours who scored > or =8 on the National Institutes of Health Stroke Scale (NIHSS) and had limited abnormalities on diffusion-weighted MR imaging. One- and 7-day NIHSS scores were obtained. Rates of early neurologic deterioration (END, increase in NIHSS score by > or =4 points) and early neurologic improvement (ENI, decrease in NIHSS score by > or =4 points) at 1 week were determined. Follow-up imaging was obtained to evaluate intracranial hemorrhage (ICH). Eleven patients were identified, 8 of whom were successfully revascularized. The mean age of all patients was 55 years with mean initial, 24-hour, and 1-week NIHSS scores of 14 +/- 4, 11 +/- 7, and 6 +/- 5, respectively, with lower scores at 24 hours and 1 week (8 +/- 5 and 4 +/- 3, respectively) among patients successfully revascularized. Eight of the treated patients (72% of the total, 100% of those successfully revascularized) experienced ENI. No patient had END or ICH. Endovascular treatment for acute ischemic stroke beyond 8 hours is feasible and may prevent END and promote ENI in patients fulfilling the criteria of a CDM. A prospective study is planned.

Predictors of Early Arterial Reocclusion After Tissue Plasminogen Activator-Induced Recanalization in Acute Ischemic Stroke

We aimed to determine clinical and hemodynamic predictors of early reocclusion (RO) in stroke patients treated with intravenous tissue plasminogen activator (tPA). We studied 142 consecutive stroke patients with a documented middle cerebral artery (MCA) occlusion treated with intravenous tPA. All patients underwent carotid ultrasound and transcranial Doppler (TCD) examination before tPA bolus. National Institutes of Health Stroke Scale (NIHSS) scores were performed at baseline and serially for <24 hours. TCD monitoring of MCA recanalization (RE) and RO was performed during the first 2 hours after tPA bolus and repeated when clinical deterioration occurred <24 hours after documented RE in absence of intracranial hemorrhage. After 1 hour of tPA administration, RE occurred in 84 (61%) patients (53 partial, 31 complete). Of these, 21 (25%) patients worsened after an initial improvement and 17 (12%) of them showed RO on TCD. RO was identified at a mean time of 65+/-55 minutes after documented RE. RO was associated (P=0.034) with a lower degree of 24-hour NIHSS score improvement than sustained RE, and a higher modified Rankin scale score at 3 months (P=0.002). Age older than 75 years (P=0.012), previous antiplatelet treatment (P=0.048), baseline NIHSS score >16 points (P=0.009), higher leukocytes count (P=0.042), beginning of RE <60 minutes after tPA bolus (P=0.039), and ipsilateral severe carotid stenosis/occlusion (P=0.001) were significantly associated with RO. In a logistic regression model, NIHSS score >16 at baseline (odds ratio [OR], 7.1; 95% CI, 1.3 to 32) and severe ipsilateral carotid disease (OR, 13.3; 95% CI, 3.2 to 54) remained as independent predictors of RO. Stroke severity and ipsilateral severe carotid artery disease independently predict RO after tPA-induced MCA RE.

Are patients with acutely recovered cerebral ischemia more unstable?

Recent studies suggest that the short-term risk of stroke may be greater after transient ischemic attack (TIA) than after stroke. We compared risks of neurological deterioration in those with and without TIA in the National Institute of Neurological Disorders and Stroke (NINDS) tissue plasminogen activator (tPA) trial, a randomized trial of intravenous tPA given within 3 hours of onset of cerebral ischemia, after excluding those with cerebral hemorrhage and those dying before 90 days of causes other than new ischemic stroke. TIA was defined as a National Institutes of Health Stroke Scale (NIHSS) score of zero at 24 hours. We chose subsequent deterioration as our outcome, defined as a worsening on the NIHSS at 90 days compared with 24 hours, so that episodes of new ischemia that may have been attributed to other causes would be included. Of 498 subjects meeting entry criteria, 40 (8%) had TIA. Subsequent deterioration occurred in 30% of those with TIA and 10% of others (P=0.001, Fisher exact test). In multivariable models with adjustment for age, sex, ethnicity, 24-hour NIHSS score, tPA administration, presumed stroke subtype, and baseline systolic blood pressure, temperature, and glucose, TIA was an independent predictor of subsequent deterioration (odds ratio, 5.0; 95% CI, 2.0 to 12.5; P=0.001). Subsequent deterioration was not associated with tPA treatment, and there was no interaction between tPA administration, TIA, and subsequent deterioration. Lesser degrees of substantial acute recovery were also associated with greater risk of subsequent deterioration. Patients with TIA may be a greater risk of subsequent neurological deterioration from causes other than hemorrhage. Substantial acute recovery may be an indicator of greater instability more broadly.

Correlation of perfusion- and diffusion-weighted MRI with NIHSS score in acute (&lt;6.5 hour) ischemic stroke

Diffusion-weighted (DWI) and perfusion-weighted (PWI) MRI are powerful new techniques for the assessment of acute cerebral ischemia. However, quantitative data comparing the severity of clinical neurologic deficit with the results of DWI or PWI in the earliest phases of stroke are scarce. Such information is vital if MRI is potentially to be used as an objective adjunctive measure of stroke severity and outcome. The authors compared initial DWI and PWI lesion volumes with subsequent 24-hour neurologic deficit as determined by National Institutes of Health Stroke Scale (NIHSS) score in acute stroke patients. Initial DWI and PWI volumes were also compared with T2W MRI lesion volume at 1 week to assess the accuracy of these MRI techniques for the detection of acute cerebral ischemia. Patients with stroke underwent MRI scanning within 6.5 hours of symptom onset. Lesion volumes on DWI and PWI were measured and compared with 24-hour NIHSS score. Initial DWI and PWI volumes were also compared with T2W lesion size at 1 week. There was a high correlation between 24-hour NIHSS score and lesion volume as determined by PWI (r = 0.96, p < 0.001) or DWI (r = 0.67, p = 0.03). A similar high correlation was seen between T2W stroke size at 7 days and initial DWI and PWI lesion size (r = 0.99, p < 0.00001). Both DWI and PWI are highly correlated with severity of neurologic deficit by 24-hour NIHSS score. These findings may have substantial implications for the use of MRI scanning in the assessment and management of acute stroke patients.