Caspar Brekenfeld

NIHSS Score and Arteriographic Findings in Acute Ischemic Stroke

Background and Purpose— To test the hypothesis that the National Institutes of Health Stroke Scale (NIHSS) score is associated with the findings of arteriography performed within the first hours after ischemic stroke. Methods— We analyzed NIHSS scores on hospital admission and clinical and arteriographic findings of 226 consecutive patients (94 women, 132 men; mean age 62±12 years) who underwent arteriography within 6 hours of symptom onset in carotid stroke and within 12 hours in vertebrobasilar stroke. Results— From stroke onset to hospital admission, 155±97 minutes elapsed, and from stroke onset to arteriography 245±100 minutes elapsed. Median NIHSS was 14 (range 3 to 38), and scores differed depending on the arteriographic findings (P<0.001). NIHSS scores in basilar, internal carotid, and middle cerebral artery M1 and M2 segment occlusions (central occlusions) were higher than in more peripherally located, nonvisible, or absent occlusions. Patients with NIHSS scores ≥10 had positive predictive values (PPVs) to show arterial occlusions in 97% of carotid and 96% of vertebrobasilar strokes. With an NIHSS score of ≥12, PPV to find a central occlusion was 91%. In a multivariate analysis, NIHSS subitems such as “level of consciousness questions,” “gaze,” “motor leg,” and “neglect” were predictors of central occlusions. Conclusions— There is a significant association of NIHSS scores and the presence and location of a vessel occlusion. With an NIHSS score ≥10, a vessel occlusion will likely be seen on arteriography, and with a score ≥12, its location will probably be central.

Stent Placement in Acute Cerebral Artery Occlusion Use of a Self-Expandable Intracranial Stent for Acute Stroke Treatment

Background and Purpose— Stent placement has been applied in small case series as a rescue therapy in combination with different thrombolytic agents, percutaneous balloon angioplasty (PTA), and mechanical thromboembolectomy (MT) in acute stroke treatment. These studies report a considerable mortality and a high rate of intracranial hemorrhages when balloon-mounted stents were used. This study was performed to evaluate feasibility, efficacy, and safety of intracranial artery recanalization for acute ischemic stroke using a self-expandable stent. Methods— All patients treated with an intracranial stent for acute cerebral artery occlusion were included. Treatment comprised intraarterial thrombolysis, thromboaspiration, MT, PTA, and stent placement. Recanalization result was assessed by follow-up angiography immediately after stent placement. Complications related to the procedure and outcome at 3 months were assessed. Results— Twelve patients (median NIHSS 14, mean age 63 years) were treated with intracranial stents for acute ischemic stroke. Occlusions were located in the posterior vertebrobasilar circulation (n=6) and in the anterior circulation (n=6). Stent placement was feasible in all procedures and resulted in partial or complete recanalization (TIMI 2/3) in 92%. No vessel perforations, subarachnoid, or symptomatic intracerebral hemorrhages occurred. One dissection was found after thromboaspiration and PTA. Three patients (25%) had a good outcome (mRS 0 to 2), 3 (25%) a moderate outcome (mRS 3), and 6 (50%) a poor outcome (mRS 4 to 6). Mortality was 33.3%. Conclusions— Intracranial placement of a self-expandable stent for acute ischemic stroke is feasible and seems to be safe to achieve sufficient recanalization.

Outcome of Stroke With Mild or Rapidly Improving Symptoms

Background and Purpose— Acute ischemic stroke with mild or rapidly improving symptoms is expected to result in good functional outcome, whether treated or not. Therefore, thrombolysis with its potential risks does not seem to be justified in such patients. However, recent studies indicate that the outcome is not invariably benign. Methods— We analyzed clinical and radiological data of patients with stroke who presented within 6 hours of stroke onset and did not receive thrombolysis because of mild or rapidly improving symptoms. Univariate and logistic regression analyses were performed to define predictors of clinical outcome. Results— One hundred sixty-two consecutive patients (110 men and 52 women) aged 63±13 years were included. The median National Institutes of Health Stroke Scale score on admission was 2 (range, 1 to 14). All patients presented within 6 hours of symptom onset. After 3 months, modified Rankin Scale score was ≤1 in 122 patients (75%), indicating a favorable outcome. Thirty-eight patients (23.5%) had an unfavorable outcome (modified Rankin Scale 2 to 5) and 2 patients (1.3%) had died. Baseline National Institutes of Health Stroke Scale score ≥10 points increased the odds of unfavorable outcome or death 16.9-fold (95% CI: 1.8 to 159.5; P<0.013), and proximal vessel occlusion increased the odds 7.13-fold (95% CI: 1.1 to 45.5; P<0.038). Conclusions— Seventy-five percent of patients with mild or rapidly improving symptoms will have a favorable outcome after 3 months. Therefore, a decision against thrombolysis seems to be justified in the majority of patients. However, selected patients, especially those with proximal vessel occlusions and baseline National Institutes of Health Stroke Scale scores ≥10 points, might derive a benefit from thrombolysis.

Intra-arterial thrombolysis in 24 consecutive patients with internal carotid artery T occlusions

Objectives: To determine the safety, efficacy, and predictors of favourable outcome of intra-arterial thrombolysis in acute stroke attributable to internal carotid “T”occlusion Methods: The authors analysed 24 consecutive patients with T occlusions of the internal carotid artery treated by local intra-arterial thrombolysis using urokinase. Results: The median baseline National Institutes of Health Stroke Scale was 19. The average time from symptom onset to treatment was 237 minutes. Four patients (16.6%) had a favourable (modified Rankin Scale score (mRS⩽2)) and 10 patients (41.7%) a poor outcome (mRS 3 or 4) after three months. Ten patients (41.7%) died. One symptomatic intracerebral haemorrhage (4.2%) occurred. Partial recanalisation of the intracranial internal carotid artery was achieved in 15 (63%), of the middle cerebral artery in four (17%), and of the anterior cerebral artery in eight patients (33%). Complete recanalisation never occurred. Sufficient leptomeningeal collaterals as seen on arteriography (p=0.02) and age <60 years (p=0.012) were the only predictors of favourable clinical outcome. Conclusions: Acute stroke attributable to carotid T occlusion remains a condition with a generally poor prognosis even when intra-arterial thrombolysis is performed. Favourable outcome was seen only in patients with sufficient leptomeningeal collaterals.

What Is a Minor Stroke

Background and Purpose— The term “minor stroke” is often used; however a consensus definition is lacking. We explored the relationship of 6 “minor stroke” definitions and outcome and tested their validity in subgroups of patients. Methods— A total of 760 consecutive patients with acute ischemic strokes were classified according to the following definitions: A, score ≤1 on every National Institutes of Health Stroke Scale (NIHSS) item and normal consciousness; B, lacunar-like syndrome; C, motor deficits with or without sensory deficits; D, NIHSS ≤9 excluding those with aphasia, neglect, or decreased consciousness; E, NIHSS ≤9; and F, NIHSS ≤3. Short-term outcome was considered favorable when patients were discharged home, and favorable medium-term outcome was defined as a modified Rankin Scale score of ≤2 at 3 months. The following subgroup analyses were performed by definition: sex, age, anterior versus posterior and right versus left hemispheric stroke, and early (0 to 6 hours) versus late admission (6 to 24 hours) to the hospital. Results— Short-term and medium-term outcomes were most favorable in patients with definition A (74% and 90%, respectively) and F (71% and 90%, respectively). Patients with definition C and anterior circulation strokes were more likely to be discharged home than patients with posterior circulation strokes (P=0.021). The medium-term outcome of older patients with definition E was less favorable compared with the outcome of younger ones (P=0.001), whereas patients with definition A, D, and F did not show different outcomes in any subgroup. Conclusions— Patients fulfilling definition A and F had best short-term and medium-term outcomes. They would be best suited to the definition of “minor stroke.”

Endovascular Therapy of 623 Patients With Anterior Circulation Stroke

Background and Purpose— Endovascular therapy of acute ischemic stroke has been shown to be beneficial for selected patients. The purpose of this study is to determine predictors of outcome in a large cohort of patients treated with intra-arterial thrombolysis, mechanical revascularization techniques, or both. Methods— We prospectively acquired data for 623 patients with acute cerebral infarcts in the carotid artery territory who received endovascular treatment at a single center. Logistic regression analysis was performed to determine predictors of outcome. Results— Median National Institutes of Health Stroke Scale (NIHSS) at admission was 15. Partial or complete recanalization was achieved in 70.3% of patients; it was independently associated with hypercholesterolemia (P=0.02), absence of coronary artery disease (P=0.023), and more proximal occlusion site (P<0.0001). After 3 months, 80.5% of patients had survived, and 48.9% of patients reached favorable outcome (modified Rankin scale score 0–2). Good collaterals (P<0.0001), recanalization (P=0.023), hypercholesterolemia (P=0.03), lower NIHSS at admission (P=0.001), and younger age (P<0.0001) were independent predictors for survival. More peripheral occlusion site (P<0.0001), recanalization (P<0.0001), hypercholesterolemia (P=0.002), good collaterals (P=0.002), lower NIHSS (P<0.0001), younger age (P<0.0001), absence of diabetes (P=0.002), and no previous antithrombotic therapy (P=0.036) predicted favorable outcome. Time to treatment was only a predictor of outcome, when collaterals were excluded from the model. Symptomatic intracerebral hemorrhage occurred in 5.5% and was independently predicted by poor collaterals (P=0.004). Conclusions— Several independent predictors for outcome and complications were identified. Unlike in intravenous thrombolysis trials, time to treatment was a predictor of outcome only when collaterals were excluded from the model, indicating the important role of collaterals for the time window.

Pre- and in-hospital delays from stroke onset to intra-arterial thrombolysis.

Background and Purpose— Thrombolysis for treatment of acute ischemic stroke should be administered as fast as possible after symptom onset. The aim of this study was to examine, in our tertiary care center, the time intervals preceding intra-arterial thrombolysis in order to accelerate and optimize the management of acute strokes. Methods— Between January 1, 2000, and April 30, 2002, 597 patients with acute stroke were admitted to our stroke center. One hundred forty-eight patients underwent diagnostic arteriography, and 100 (16.8%) received intra-arterial thrombolysis. For all patients, we prospectively recorded and analyzed the time of symptom onset, admission, CT and/or MRI scan, diagnostic arteriography, and, if performed, intra-arterial thrombolysis. Results— The mean time to arrival in the emergency department was 99 minutes for patients who were admitted directly (Bern patients), 127 minutes for those who were referred from community hospitals without a CT scanner (non-Bern/−CT patients), and 210 minutes for patients from hospitals with imaging facilities (non-Bern/+CT patients). The mean delay from symptom onset to treatment was 234 minutes for Bern patients, 269 minutes for non-Bern/−CT patients, and 302 minutes for non-Bern/+CT patients. The patients from the last group needed longer to receive intra-arterial thrombolysis than did patients who were admitted directly (P =0.002) or who were transferred from a hospital without a CT scanner (P =0.03). Conclusions— This prospective study indicates that direct referral without prior imaging at community hospitals shortens the time until intra-arterial thrombolysis. In addition, our in-hospital delay preceding intra-arterial thrombolysis is longer than the delays reported for intravenous thrombolysis and indicates potential for improvement.

The Benefits of Intravenous Thrombolysis Relate to the Site of Baseline Arterial Occlusion in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET)

Background and Purpose— In ischemic stroke, the site of arterial obstruction has been shown to influence recanalization and clinical outcomes. However, this has not been studied in randomized controlled trials, nor has the impact of arterial obstruction site on reperfusion and infarct growth been assessed. We studied the influence of site and degree of arterial obstruction patients enrolled in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). Methods— EPITHET was a prospective, randomized, placebo-controlled trial of intravenous tissue plasminogen activator (tPA) in the 3- to 6-hour time window. Arterial obstruction site and degree were rated on magnetic resonance angiography blinded to treatment allocation and outcomes. Results— In 101 EPITHET patients, 87 had adequate quality magnetic resonance angiography, of whom 54 had baseline arterial obstruction. Infarct growth attenuation was greater in those with tPA treatment compared to placebo among patients with middle cerebral artery (MCA) obstruction (P=0.037). The treatment benefit of tPA over placebo in attenuating infarct growth was greater for MCA than internal carotid artery (ICA) obstruction (P=0.060). With tPA treatment, good clinical outcome was more likely with MCA than with ICA obstruction (P=0.005). Most patients with ICA obstruction did not achieve good clinical outcome, whether treated with tPA (100%) or placebo (77%). The study was underpowered to prove any treatment benefit of tPA among patients with any or severe degree of arterial obstruction. Conclusions— Arterial obstruction site strongly predicts outcomes. ICA obstruction carries a uniformly poor prognosis, whereas good outcomes with MCA obstruction are associated with tPA therapy.

EPITHET: Positive result after reanalysis using baseline diffusion-weighted imaging/perfusion-weighted imaging co-registration

Background and Purpose— The Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) was a prospective, randomized, double-blinded, placebo-controlled, phase II trial of alteplase between 3 and 6 hours after stroke onset. The primary outcome of infarct growth attenuation on MRI with alteplase in mismatch patients was negative when mismatch volumes were assessed volumetrically, without coregistration, which underestimates mismatch volumes. We hypothesized that assessing the extent of mismatch by coregistration of perfusion and diffusion MRI maps may more accurately allow the effects of alteplase vs placebo to be evaluated. Methods— Patients were classified as having mismatch if perfusion-weighted imaging divided by coregistered diffusion-weighted imaging volume ratio was >1.2 and total coregistered mismatch volume was ≥10 mL. The primary outcome was a comparison of infarct growth in alteplase vs placebo patients with coregistered mismatch. Results— Of 99 patients with baseline diffusion-weighted imaging and perfusion-weighted imaging, coregistration of both images was possible in 95 patients. Coregistered mismatch was present in 93% (88/95) compared to 85% (81/95) with standard volumetric mismatch. In the coregistered mismatch patients, of whom 45 received alteplase and 43 received placebo, the primary outcome measure of geometric mean infarct growth was significantly attenuated by a ratio of 0.58 with alteplase compared to placebo (1.02 vs 1.77; 95% CI, 0.33–0.99; P=0.0459). Conclusions— When using coregistration techniques to determine the presence of mismatch at study entry, alteplase significantly attenuated infarct growth. This highlights the necessity for a randomized, placebo-controlled, phase III clinical trial of alteplase using penumbral selection beyond 3 hours.

Mechanical Thrombectomy for Acute Ischemic Stroke Thrombus–Device Interaction, Efficiency, and Complications In Vivo

Background and Purpose— Mechanical thrombectomy is a promising new modality of interventional stroke treatment. The various devices differ with regard to where they apply force on the thrombus, taking a proximal approach such as aspiration devices or a distal approach such as basket-like devices. The study compares the in vivo effectiveness and thrombus–device interaction of these 2 approaches. Methods— Angiography and embolization with a radioopaque whole blood thrombus was performed in 10 swine. Mechanical thrombectomy was performed in 20 cranial vessels using a proximal aspiration device (Vasco35) and a distal basket-like device (Catch) with and without proximal balloon occlusion. Fifty-six retrieval attempts were made. Results— The proximal device allowed fast repeated application with a low risk of thromboembolic events (3%) and vasospasm, but it had a significantly lower success rate (39.4%) in retrieving thrombotic material than the distal device (DD) (82.6%; odds ratio, 7.3; 95% CI, 2.0 to 26.4). The compaction of the thrombus during retrieval with DD increased the risk of vessel wall irritation significantly (P<0.01) and complicated retrieval into the guiding catheter. The number of embolic events was significantly higher with DD (26%; odds ratio, 11.3; 95% CI, 1.35 to 101.6) unless proximal balloon occlusion was used. Conclusions— The proximal and the distal approaches to mechanical thrombectomy proved to be effective at achieving recanalization of cranial vessels. The proximal device is faster in application and allowed repeated attempts with a low complication rate. The DD is more successful at removing thrombotic material, but its method of application and attendant thrombus compaction increase the risk of thromboembolic events and vasospasms.