Early recurrent ischemic stroke in stroke patients undergoing intravenous thrombolysis

BACKGROUND: We assessed the incidence of early recurrent ischemic stroke in stroke patients treated with intravenous tissue-type plasminogen activator (tPA) and the temporal pattern of its occurrence compared with symptomatic intracranial hemorrhage (ICH). METHODS AND RESULTS: Prospectively collected, population-based data for 341 consecutive acute stroke patients (62% men; mean age, 66 years) treated with tPA according to the National Institute of Neurological Disorders and Stroke study protocol at 8 medical centers in Switzerland (3 academic and 5 community) between January 2001 and November 2004 were retrospectively analyzed. The primary outcome measure was neurological deterioration > or = 4 points on the National Institutes of Health Stroke Scale occurring within 24 hours of tPA treatment and caused either by recurrent ischemic stroke (defined as the occurrence of new neurological symptoms suggesting involvement of initially unaffected vascular territories and evidence of corresponding ischemic lesions on cranial computed tomography scans, in the absence of ICH) or by ICH. Early recurrent ischemic stroke was diagnosed in 2 patients (0.59%; 95% confidence interval, 0.07% to 2.10%) and symptomatic ICH in 15 patients (4.40%; 95% confidence interval, 2.48% to 7.15%). Both recurrent ischemic strokes occurred during thrombolysis, whereas symptomatic ICHs occurred 2 to 22 hours after termination of tPA infusion. CONCLUSIONS: Recurrent ischemic stroke is a rare cause of early neurological deterioration in acute stroke patients undergoing intravenous thrombolysis, with a different temporal pattern compared with that of symptomatic ICH.

Effects of somatosensory stimulation on use-dependent plasticity in chronic stroke

BACKGROUND AND PURPOSE: There is a need to develop strategies to enhance the beneficial effects of motor training, including use-dependent plasticity (UDP), in neurorehabilitation. Peripheral nerve stimulation (PNS) modulates motor cortical excitability in healthy humans and could influence training effects in stroke patients. METHODS: We compared the ability of PNS applied to the (1) arm, (2) leg, and (3) idle time to influence training effects in the paretic hand in 7 chronic stroke patients. The end point measure was the magnitude of UDP. RESULTS: UDP was more prominent with arm stimulation (increased by 22.8%) than with idle time (by 2.9%) or leg stimulation (by 6.4%). CONCLUSIONS: PNS applied to the paretic limb paired with motor training enhances training effects on cortical plasticity in stroke patients.

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 /=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.

Frequent atrial premature beats predict paroxysmal atrial fibrillation in stroke patients: an opportunity for a new diagnostic strategy

BACKGROUND AND PURPOSE: For patients having suffered ischemic stroke, the current diagnostic strategies often fail to detect atrial fibrillation as a potential cause of embolic events. The aim of the study was to identify paroxysmal atrial fibrillation in stroke patients. We hypothesized that patients with frequent atrial premature beats (APBs) recorded in 24-hour ECG will show more often atrial fibrillation when followed by repeated long-term ECG recordings than patients without or infrequent APBs. METHODS: 127 patients with acute ischemic stroke and without known AF were enrolled in a prospective study to detect paroxysmal AF. Patients were stratified according to the number of APBs recorded in a 24-hour ECG (> or =70 APBs versus <70 APBs). Subsequently, they all underwent serial 7-day event-recorder monitoring at 0, 3, and 6 months. RESULTS: Serial extended ECG monitoring identified AF in 26% of patients with frequent APBs but only in 6.5% when APBs were infrequent (P=0.0021). A multivariate analysis showed that the presence of frequent APBs in the initial 24-hour ECG was the only independent predictor of paroxysmal AF during follow-up (odds ratio 6.6, 95% confidence intervals 1.6 to 28.2, P=0.01). CONCLUSIONS: In patients with acute ischemic stroke, frequent APBs (> or = 70/24 hours) are a marker for individuals who are at greater risk to develop or have paroxysmal AF. For such patients, we propose a diagnostic workup with repeated prolonged ECG monitoring to diagnose paroxysmal AF.

Low awareness of transient ischemic attacks and risk factors of stroke in a Swiss urban community

BACKGROUND AND PURPOSE: Time delays from stroke onset to arrival at the hospital are the main obstacles for widespread use of thrombolysis. In order to decrease the delays, educational campaigns try to inform the general public how to act optimally in case of stroke. To determine the content of such a campaign, we assessed the stroke knowledge in our population. METHODS: The stroke knowledge was studied by means of a closed-ended questionnaire. 422 randomly chosen inhabitants of Bern, Switzerland, were interviewed. RESULTS: The knowledge of stroke warning signs (WS) was classified as good in 64.7%. A good knowledge of stroke risk factors (RF) was noted in 6.4%. 4.2% knew both the WS and the RF of stroke indicating a very good global knowledge of stroke. Only 8.3% recognized TIA as symptoms of stroke resolving within 24 hours, and only 2.8% identified TIA as a disease requiring immediate medical help. In multivariate analysis being a woman, advancing age, and having an afflicted relative were associated with a good knowledge of WS (p = 0.048, p < 0.001 and p = 0.043). Good knowledge of RF was related to university education (p < 0.001). The good knowledge of TIA did not depend on age, sex, level of education or having an afflicted relative. CONCLUSIONS: The study brings to light relevant deficits of stroke knowledge in our population. A small number of participants could recognize TIA as stroke related symptoms resolving completely within 24 hours. Only a third of the surveyed persons would seek immediate medical help in case of TIA. The information obtained will be used in the development of future educational campaigns.

Comparison of intraarterial and intravenous thrombolysis for ischemic stroke with hyperdense middle cerebral artery sign

BACKGROUND AND PURPOSE: It is unclear whether intraarterial (IAT) or intravenous (IVT) thrombolysis is more effective for ischemic stroke with hyperdense middle cerebral artery sign (HMCAS) on computed tomography (CT). The aim of this study was to compare IAT and IVT in stroke patients with HMCAS. METHODS: Comparison of data from 2 stroke units with similar management of stroke associated with HMCAS, except that 1 unit performed IAT with urokinase and the other IVT with plasminogen activator. Time to treatment was up to 6 hours for IAT and up to 3 hours for IVT. Outcome was measured by mortality and the modified Rankin Scale (mRS), dichotomized at 3 months into favorable (mRS 0 to 2) and unfavorable (mRS 3 to 6). RESULTS: One hundred twelve patients exhibited a HMCAS, 55 of 268 patients treated with IAT and 57 of 249 patients who underwent IVT. Stroke severity at baseline and patient age were similar in both groups. Mean time to treatment was longer in the IAT group (244+/-63 minutes) than in the IVT group (156+/-21 minutes; P=0.0001). However, favorable outcome was more frequent after IAT (n=29, 53%) than after IVT (n=13, 23%; P=0.001), and mortality was lower after IAT (n=4, 7%) than after IVT (n=13, 23%; P=0.022). After multiple regression analysis IAT was associated with a more favorable outcome than IVT (P=0.003) but similar mortality (P=0.192). CONCLUSIONS: In this observational study intraarterial thrombolysis was more beneficial than IVT in the specific group of stroke patients presenting with HMCAS on CT, even though IAT was started later. Our results indicate that a randomized trial comparing both thrombolytic treatments in patients with middle cerebral artery occlusion is warranted.

Neuro-imaging of cerebral ischemic stroke

Major progress has recently been made in the neuro-imaging of stroke as a result of improvements in imaging hardware and software. Imaging may be based on either magnetic resonance imaging (MRI) or computed tomography (CT) techniques. Imaging should provide information on the entire vascular cervical and intracranial network, from the aortic arch to the circle of Willis. Equally, it should also give information on the viability of brain tissue and brain hemodynamics. CT has the advantage in the detection of acute hemorrhage whereas MRI offers more accurate pathophysiological information in the follow-up of patients.

Symptomatic intracranial haemorrhage after intra-arterial thrombolysis in acute ischaemic stroke: assessment of 294 patients treated with urokinase

BACKGROUND: The PROACT II trial showed that intra-arterial thrombolysis (IAT) is effective for treatment of acute ischaemic stroke attributable to M1 and M2 segment occlusions. Incidence of symptomatic intracranial haemorrhage (sICH) was 10%. OBJECTIVE: To evaluate the risk and predictors of sICH after IAT by using urokinase in a large number of patients presenting with the whole spectrum of cerebral vessel occlusions. METHODS: 294 patients with stroke treated with intra-arterial urokinase were retrospectively analysed. The risk of sICH as well as bleeding characteristics were assessed. Demographic and radiological data, time to treatment, urokinase dose, recanalisation rates, stroke aetiology and severity were analysed for predictors. RESULTS: sICH occurred in 14 of 294 (4.8%) patients. The median National Institute of Health Stroke Scale score of all patients was 15. All but one sICH were located in the infarcted brain tissue, and no sICH occurred in patients with peripheral vessel occlusions (M3 or M4 segments of the middle cerebral artery). Poor collaterals (p = 0.001), early signs of ischaemia on computed tomography (p = 0.003), higher urokinase dose (p = 0.019), lower recanalisation rate (p = 0.02) and higher diastolic blood pressure on admission (p = 0.04) were found to be correlated with sICH on univariate analysis. On multivariate analysis, poor collaterals (p = 0.004), urokinase dose (p = 0.021) and early signs on computed tomography (p = 0.026) remained predictors of sICH. CONCLUSIONS: With regard to the whole spectrum of cerebral vessel occlusions, an incidence of <5% sICH after IAT is distinctly low. This result underlines the important role of IAT in the treatment of acute stroke.

"Death may come on like a stroke of lightening ..." : Phenomenological and morphological aspects of fatalities caused by manure gas

Due to the decomposition of biological material, hydrogen sulphide (H(2)S) is produced. In low concentrations, the well-known smell of "rotten eggs" is associated with H(2)S. In higher concentrations, H(2)S is an odourless and colourless gas that may cause rapid loss of consciousness, neurological and respiratory depression and imminent death-"... like a stroke of lightening". Hydrogen sulphide poisoning is an un-common incident that is often associated with colleague fatalities. In this study, 4 fatal accidents with 10 deceased victims are reported and the morphological and phenomenological aspects are presented. In these cases, the morphological findings, namely, discolouration of the livores, pulmonary pathologies and sub-mucosal or sub-serosal congestion bleeding were found in nearly all cases. Also the impending threat for colleagues, first aid helpers and professional rescue teams is demonstrated. The suspicion of a fatal H(2)S intoxication should be based on a precise scene analysis with respect to the possibility of life-threatening H(2)S intoxication for the helpers, the typical scent of rotten eggs, which may be noted on the corpses and the abovementioned morphological findings. The diagnosis should be confirmed by a qualitative and, if possible, quantitative analysis of H(2)S.

Mechanical thromboembolectomy for acute ischemic stroke: comparison of the catch thrombectomy device and the Merci Retriever in vivo

BACKGROUND AND PURPOSE: The purpose of the study was to compare efficacy and potential complications of 2 commercially available devices for mechanical thromboembolectomy. METHODS: Devices were tested in an established animal model allowing the use of routine angiography catheters and thrombectomy devices. Radio-opaque thrombi were used for visualization of thrombus-device interaction during angiography. The Merci Retrieval System and the Catch Thromboembolectomy System were assessed each in 10 vessel occlusions. For every occluded vessel up to 5 retrieval attempts were performed. RESULTS: Sufficient recanalization was achieved with the Merci Retriever in 90% of occlusions, and with the Catch device recanalization was achieved in 70% of occlusions. Recanalization at the first attempt occurred significantly more often with the Merci Retriever compared to the Catch device (OR, 21; 95% CI, 1.78-248.11). Consequently, significantly more attempts (P=0.02) had to be performed with the Catch device; therefore, time to recanalization was longer. Thrombus fragmentations during retrieval were caused more often by the Catch device compared to the Merci Retriever (OR, 15.6; 95% CI, 1.73-140.84), resulting in a higher distal embolization rate. During retrieval both devices lost thrombotic material at the tip of the guide catheter, which was then aspirated in most cases. CONCLUSIONS: Both distal devices are effective for thromboembolectomy. To avoid loss of thrombotic material and distal embolization, the use of large luminal balloon guide catheters and aspiration during retrieval seems to be mandatory. The design of the Merci Retriever appears to be more efficient during thrombus mobilization and retrieval with less fragmentation compared to the Catch Thromboembolectomy System.