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Biomedical subjects

W Hacke

Publications and source records attributed to W Hacke.

At least 37 records · Page 2Linked to original sources
PubMed2002

The Carotid Surgery for Ischemic Stroke trial: a prospective observational study on carotid endarterectomy in the early period after ischemic stroke.

OBJECTIVE: The purpose of this study was to examine the safety of carotid endarterectomy (CEA) within 6 weeks after a nondisabling carotid-related ischemic stroke. Endpoints were the perioperative stroke or mortality rate and the incidence rate of cerebral bleedings. METHODS: This prospective observational multicenter trial was performed in community and university centers. One hundred sixty-four hospitalized patients with nondisabling carotid-related ischemic stroke were included. The patients were identified clinically with the modified Rankin scale (initial neurologic deficit grade >/= 2, n = 160). Four patients with evidence of ischemic territorial infarction on cerebral computed tomographic (CT) scan but no persisting functional deficit were also included. CEA was performed within 6 weeks after stroke. Neurologic examinations were performed initially, before surgery, 3 days after surgery, and 6 weeks after CEA. Worsening of more than 1 grade on the Rankin scale was considered as a new stroke or stroke extension. Unenhanced CT scans of the brain were performed before and after surgery. CT scans were evaluated blind to clinical patient data. Statistical analysis included univariate and multivariate analysis. RESULTS: The combined stroke or mortality rate within 30 days after CEA was 6.7%. Ten patients had a new ipsilateral stroke or stroke extension, and one patient died after surgery of a myocardial infarction. One patient (0.6%) had parenchymatous cerebral bleeding, and in 10 patients, hemorrhagic transformation within the preexisting ischemic infarction was detected but no infarct extension was observed. In the multivariate analysis, American Society of Anesthesiology (ASA) grades III and IV and decreasing age were significant predictors for an increased perioperative risk. Patients with a higher risk profile (ASA classification grades III and IV) had a high perioperative risk when CEA was performed within the first 3 weeks (14.6% versus 4.8% beyond 3 weeks). Patients without severe concomitant diseases (ASA grades I/II) had a low perioperative risk of 3.4% if CEA was performed within the first 3 weeks. CONCLUSION: Early CEA within 6 weeks after a carotid-related ischemic stroke can be performed with a perioperative stroke or mortality rate comparable with the results reported in the European Carotid Surgery Trial and the North American Symptomatic Carotid Endarterectomy Trial. The risk of parenchymatous bleeding is low. ASA grades III and IV and decreasing age were predictive of an increased perioperative risk, especially if CEA was performed within the first 3 weeks. Patients at low risk can undergo operation safely within the first 3 weeks. Individual patient selection in an interdisciplinary approach between neurologists, anesthesiologists, and vascular surgeons remains mandatory in these patients.

Aged↗
PubMed2002

Thrombolytic therapy within 3 to 6 hours after onset of ischemic stroke: useful or harmful?

BACKGROUND: The use of recombinant tissue plasminogen activator (rtPA) within 3 hours after onset of an ischemic stroke is an established therapy. Because the use of intravenous rtPA beyond a time window of 3 hours after stroke onset is still a matter of debate, we sought to review the evidence for the use of thrombolytic therapy in a time window up to 6 hours after onset of symptoms of ischemic stroke. SUMMARY OF REVIEW: The meta-analyses of the major trials (National Institute of Neurological Disorders and Stroke rtPA Stroke Study, European Cooperative Acute Stroke Study [ECASS] I, ECASS II) showed a benefit of thrombolytic therapy with intravenous rtPA even within 6 hours after onset of symptoms of ischemic stroke. The rate of intracerebral hemorrhage was slightly increased in the 6-hour time window compared with the 3-hour time window (odds ratio, 3.23 versus 2.68), but this was without statistical significance because of wide confidence intervals. A positive effect of 37% relative odds reduction with the use of a dichotomization of < or =2 versus > or =3 on the modified Rankin Scale remains for rtPA treatment within 6 hours. However, the Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) Study, in which a 3- to 5-hour time window was used, failed to show a benefit of rtPA. Still, when the results of ATLANTIS are included into meta-analyses such as the Cochrane Library, the positive effect of rtPA treatment in the 6-hour time window remains, with a "number needed to treat" value of 11. Treating patients only within a 3- to 6-hour time window would lead to a number needed to treat value of 25. CONCLUSIONS: Consequently, from our point of view it appears unjustified to limit thrombolytic therapy to 3 hours. Because of lack of approvals for 3 to 6 hours, thrombolytic therapy within this time window should be done only as part of an institutional protocol after extensive information is obtained from the patient and the patient's relatives. Better methods for patient selection are required; in particular, newer MRI techniques, such as diffusion- and perfusion-weighted imaging, can play a key role. The aim is to qualify and individualize the time window according to the findings in each patient's imaging results rather than to use a strictly time-defined therapeutic window.

Brain Ischemia↗
PubMed2002

CT and diffusion-weighted MR imaging in randomized order: diffusion-weighted imaging results in higher accuracy and lower interrater variability in the diagnosis of hyperacute ischemic stroke.

BACKGROUND AND PURPOSE: Diffusion-weighted MRI (DWI) has become a commonly used imaging modality in stroke centers. The value of this method as a routine procedure is still being discussed. In previous studies, CT was always performed before DWI. Therefore, infarct progression could be a reason for the better result in DWI. METHODS: All hyperacute (<6 hours) stroke patients admitted to our emergency department with a National Institutes of Health Stroke Scale (NIHSS) score >3 were prospectively randomized for the order in which CT and MRI were performed. Five stroke experts and 4 residents blinded to clinical data judged stroke signs and lesion size on the images. To determine the interrater variability, we calculated kappa values for both rating groups. RESULTS: A total of 50 patients with ischemic stroke and 4 patients with transient symptoms of acute stroke (median NIHSS score, 11; range, 3 to 27) were analyzed. Of the 50 patients, 55% were examined with DWI first. The mean delay from symptom onset until CT was 180 minutes; that from symptom onset until DWI was 189 minutes. The mean delay between DWI and CT was 30 minutes. The sensitivity of infarct detection by the experts was significantly better when based on DWI (CT/DWI, 61/91%). Accuracy was 91% when based on DWI (CT, 61%). Interrater variability of lesion detection was also significantly better for DWI (CT/DWI, kappa=0.51/0.84). The assessment of lesion extent was less homogeneous on CT (CT/DWI, kappa=0.38/0.62). The differences between the 2 modalities were stronger in the residents' ratings (CT/DWI: sensitivity, 46/81%; kappa=0.38/0.76). CONCLUSIONS: CT and DWI performed with the same delay after onset of ischemic stroke resulted in significant differences in diagnostic accuracy. DWI gives good interrater homogeneity and has a substantially better sensitivity and accuracy than CT even if the raters have limited experience.

Acute Disease↗
PubMed2002

Effect of intravenous thrombolysis on MRI parameters and functional outcome in acute stroke <6 hours.

BACKGROUND AND PURPOSE: The goals of this study were to examine MRI baseline characteristics of patients with acute ischemic stroke (AIS) and to study the influence of intravenous tissue plasminogen activator (tPA) on MR parameters and functional outcome using a multicenter approach. METHODS: In this open-label, nonrandomized study of AIS patients with suspected anterior circulation stroke, subjects received a multiparametric stroke MRI protocol (diffusion- and perfusion-weighted imaging and MR angiography) within 6 hours after symptom onset and on follow-up. Patients were treated either with tPA (thrombolysis group) or conservatively (no thrombolysis group). Functional outcome was assessed on day 90 (modified Rankin Score; mRS). RESULTS: We enrolled 139 AIS patients (no thrombolysis group, n=63; thrombolysis group, n=76). Patients treated with tPA were more severely affected (National Institutes of Health Stroke Scale score, 10 versus 13; P=0.002). Recanalization rates were higher in the thrombolysis group (Thrombolysis in Myocardial Infarction criteria 1 through 3 on day 1; 66.2% versus 32.7%; P<0.001). Proximal vessel occlusions resulted in larger infarct volumes and worse outcome (P=0.02). Thrombolysis was associated with a better outcome regardless of the time point of tPA treatment (< or =3 hours or 3 to 6 hours) (univariate analysis: mRS < or =2, P=0.017; mRS < or =1, P=0.023). Age (P=0.003), thrombolytic therapy at 0 to 6 hours (P=0.01), recanalization (P=0.016), lesion volume on day 7 (P=0.001), and initial National Institutes of Health Stroke Scale score (P=0.001) affected functional outcome (mRS on day 90) positively (multivariate analysis). The time point of tPA therapy affected the recanalization rate (P=0.024) but not final infarct volume. CONCLUSIONS: In this pilot study, tPA therapy had a beneficial effect on vessel recanalization and functional outcome. Multiparametric MRI delineates tissue at risk of infarction in AIS patients, which may be helpful for the selection of patients for tPA therapy. tPA therapy appeared safe and effective beyond a 3-hour time window. This study delivers the rationale for a randomized, MR-based tPA trial.

Acute Disease↗
PubMed2001

Effect and feasibility of controlled rewarming after moderate hypothermia in stroke patients with malignant infarction of the middle cerebral artery.

BACKGROUND AND PURPOSE: Moderate hypothermia has been found to reduce intracranial pressure (ICP) significantly in patients who have severe middle cerebral artery infarction. However, during passive rewarming, ICP continuously rises and some patients suffer transtentorial herniation. METHODS: We investigated the question of whether slower rewarming leads to slower increase in ICP and slower decrease in cerebral perfusion pressure (CPP). Furthermore, we studied feasibility of slow, controlled rewarming. ICP, CPP, and core body temperature were monitored continuously. Achievement of rewarming protocol was assessed by hit rate of temperature target intervals. Side effects of hypothermia were assessed. RESULTS: Rates of change of both ICP and CPP were correlated significantly with increase in temperature (ICP r=0.62, P=0.002; CPP r=-0.50, P=0.017). In feasibility analysis of 13 controlled rewarmed patients, hit rate of temperature target intervals was 63% (median; range 48% to 81%); hit rate within the target interval or below was 79% (median; range 62% to 94%). CONCLUSIONS: Slow, controlled rewarming is feasible and may be used for ICP and CPP control after moderate hypothermia for space-occupying infarction.

Body Temperature↗
PubMed2001

Masking of vertebral artery dissection by severe trauma to the cervical spine.

STUDY DESIGN: A prospective case study was performed. OBJECTIVES: To illustrate the association of cervical trauma with vertebral artery dissection, and to propose a diagnostic and therapeutic algorithm for suspected traumatic vertebral artery dissection. SUMMARY OF BACKGROUND DATA: Vertebral artery dissection is a recognized but underdiagnosed complication of trauma to the cervical spine. Symptoms of spinal cord injury, however, may obscure those of vertebral artery dissection, presumably causing gross underdiagnosis of this complication. METHODS: All patients with vertebral artery dissection admitted to the authors' facility between 1992 and 1997 were screened for cervical trauma. RESULTS: This article presents four patients with severe trauma to the cervical spine, defined as luxation, subluxation, or fracture, in whom symptoms of vertebral artery dissection developed after a delay ranging from several hours to weeks. The traumatic vertebral artery dissection typically was located at the site of vertebral injury or cranial to it. One patient with fracture of the odontoid process survived symptom free without ischemic brain infarctions. Another patient survived with traumatic quadriplegia in addition to large cerebellar and posterior cerebral artery infarctions. Two patients died as a result of fulminant vertebrobasilar infarctions, both with only moderate impairment from the primary spinal cord injury. CONCLUSIONS: Early signs of vertebral artery dissection include head and neck pain, often localized to the site of intimal disruption, which may be disguised by the signs of the spinal injury. Early Doppler ultrasound and duplex sonography as a noninvasive screening method should be performed for patients with severe trauma to the cervical spine. In cases of vertebral artery dissection, immediate anticoagulation should be initiated. Traumatologists should be aware of this complication in evaluating patients with severe trauma of the cervical spine, and also for a variety of forensic reasons.

Adult↗
PubMed2001

Superiority of clopidogrel versus aspirin in patients with prior cardiac surgery.

BACKGROUND: After coronary artery bypass surgery, patients have a high cumulative rate of graft closure and recurrent ischemic events. We sought to determine whether antiplatelet therapy with clopidogrel would be more effective than aspirin, the accepted standard, in these patients. METHODS AND RESULTS: The event rates for all-cause mortality, vascular death, myocardial infarction, stroke, and rehospitalization were determined for the 1480 patients with a history of cardiac surgery randomized to either clopidogrel or aspirin in a trial of 19 185 patients. The event rate per year of vascular death, myocardial infarction, stroke, or rehospitalization was 22.3% in the 705 patients randomized to aspirin and 15.9% in the 775 patients randomized to clopidogrel (P:=0.001). A risk reduction was also seen in each of the individual end points examined, including a 42.8% relative risk reduction in vascular death in patients on clopidogrel versus aspirin (P:=0.030). In a multivariate model incorporating baseline clinical characteristics, clopidogrel therapy was independently associated with a decrease in vascular death, myocardial infarction, stroke, or rehospitalization in patients with a history of cardiac surgery, with a 31.2% relative risk reduction (95% CI, 15.8 to 43.8; P:=0.0003). Although clopidogrel therapy was efficacious in the entire Clopidogrel Versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) population, multivariate analysis demonstrated that patients with previous cardiac surgery derived particular benefit (P:=0.015). CONCLUSION: Compared with aspirin, clopidogrel therapy results in a striking reduction in the elevated risk for recurrent ischemic events seen in patients with a history of prior cardiac surgery, along with a decreased risk of bleeding.

Aspirin↗
PubMed2001

[Value of MRI in intracerebral and subarachnoid hemorrhage].

Intracranial hemorrhage (ICH) accounts for 15% of all strokes. In hyperacute emergency assessment, CT is the diagnostic standard for differentiating between hyperacute ICH and ischemic stroke. At this stage, MRI is considered to be of little value for the diagnosis of ICH or subarachnoidal hemorrhage (SAH). We review the current literature and characterize the role of MRI in the diagnosis of ICH and SAH as well as hyperacute stroke in general: While MRI is considered superior to CT in the diagnosis of subacute and chronic ICH/SAH, in hyperacute ICH this is still a matter of debate. MRI signal characteristics of ICH depend on hemoglobin degradation. Deoxyhemoglobin is the MRI substrate for demonstration of blood due to its paramagnetic properties causing signal loss on susceptibility weighted images (T2*-WI). Preliminary data, however, suggest that the sensitivity of modern stroke MRI protocols is sufficiently high for hyperacute ICH and SAH and may render additional information with regard to the etiology of ICH or SAH. Further interest is focused on perihemorrhagic pathophysiologic processes, which may help to improve therapeutic decision making in patients with ICH.

Cerebral Hemorrhage↗
PubMed2001

[Thrombolysis in cerebral ischemia. An overview].

Thrombolytic therapy for acute ischemic stroke within the 3-h time window has been approved. In the US, where FDA approval has existed for about 4 years, less than 2% of stroke patients presently receive thrombolytic therapy. This review illustrates all completed trials of intravenous and intra-arterial thrombolytic therapy for carotid artery and vertebrobasilar artery stroke and includes recommendations for therapy, diagnostic procedures and their effect on patient selection, meta-analyses, phase IV trials, and cost efficacy analyses.

Cerebral Infarction↗
PubMed2001

Comparison of CT with diffusion-weighted MRI in patients with hyperacute stroke.

Tissue changes in ischaemic stroke are detectable by diffusion-weighted MRI (DWI) within minutes of the onset of symptoms. However, in daily routine CT is still the preferred imaging modality for patients with acute stroke. Our purpose of this study was to determine how early and reliably ischaemic brain infarcts can be identified by CT and DWI. Three neuroradiologists, blinded to clinical signs but aware that they were dealing with stroke, analysed the CT and DWI of 31 patients with an acute ischaemic stroke. We calculated kappa-values to analyse inter-rater variability. The ratings were compared with follow-up studies showing the extent of the infarct. The combined assessment of all observers gave positive findings in 77.4% of all CT examinations, with kappa = 0.58. Areas of high signal were seen on all DWI studies by all observers (kappa = 1). Estimation of the extent of the infarct based on DWI yeilded kappa = 0.70 and that based on CT kappa = 0.39. DWI was much more reliable than CT in the detection of early ischaemic lesions and we believe that it should be used in acute ischaemic stroke before aggressive therapeutic intervention.

Aged↗
PubMed2001

Thrombolytic therapy for ischemic stroke--a review. Part I--Intravenous thrombolysis.

OBJECTIVE: Thrombolytic therapy for acute ischemic stroke was implemented into clinical routine 4 yrs ago. Unfortunately, at present <2% of eligible patients receive thrombolytic therapy. We present an overview of all hitherto completed trials of intravenous thrombolytic therapy for carotid artery stroke including recommendations for therapy and diagnostic procedures and their impact on patient selection and meta-analyses. DATA SOURCES: We performed an extensive literature search not only to identify the larger and well-known randomized trials but also to identify smaller pilot studies and case series. Trials included in this review, among others, are the National Institute of Neurologic Disorders and Stroke (NINDS) study, European Cooperative Acute Stroke Study I and II, and Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) A and B and two large meta-analyses, including the Cochrane Library report. CONCLUSION: Intravenous thrombolytic therapy with recombinant tissue plasminogen activator has demonstrated a significant benefit and has proven to be safe for patients who can be treated within 3-6 hrs after symptom onset. This benefit is at the cost of an increased rate of symptomatic intracranial hemorrhage without a significant effect on overall mortality. In general, the benefit of thrombolysis decreases and the risks increase with progressing time after symptom onset. Presently, thrombolytic therapy is still underutilized because of problems with clinical and time criteria, and lack of public and professional education to regard stroke as a treatable emergency. If applied more widely, thrombolytic therapy may result in profound cost savings in health care and reduction of long-term disability of stroke patients.

Fibrinolytic Agents↗
PubMed2001

Thrombolytic therapy for ischemic stroke--a review. Part II--Intra-arterial thrombolysis, vertebrobasilar stroke, phase IV trials, and stroke imaging.

OBJECTIVE: Intra-arterial thrombolytic therapy for carotid and vertebrobasilar stroke may result in a more rapid clot lysis and higher recanalization rates than can be achieved with intravenous thrombolysis and thus may warrant the more invasive and time-consuming therapeutic approach. We present an overview of all hitherto completed trials of intra-arterial thrombolytic therapy for carotid and vertebrobasilar artery stroke including recommendations for therapy and a meta-analysis. Furthermore, new imaging techniques such as diffusion- and perfusion-weighted magnetic resonance imaging and their impact on patient selection are discussed. Finally, phase IV trials of thrombolysis in general and cost efficacy analyses are presented. DATA SOURCES: We performed an extensive literature search not only to identify the larger and well-known randomized trials but also to identify smaller pilot studies and case series. Trials included in this review, among others, are the PROACT I and PROACT II studies and the Cochrane Library report. CONCLUSION: Intra-arterial thrombolytic therapy of acute M1 and M2 occlusions with 9 mg/2 hrs pro-urokinase significantly improves outcome if administered within 6 hrs after stroke onset. Seven patients need to be treated to prevent one patient from death or dependence. Vertebrobasilar occlusion has a grim prognosis and intra-arterial thrombolytic therapy to date is the only life-saving therapy that has demonstrated benefit with regard to mortality and outcome, albeit not in a randomized trial. New magnetic resonance imaging techniques may facilitate and improve the selection of patients for thrombolytic therapy. Presently, thrombolytic therapy is still underutilized because of problems with clinical and time criteria, and lack of public and professional education to regard stroke as a treatable emergency. If applied more widely, thrombolytic therapy may result in profound cost savings in health care and reduction of long-term disability of stroke patients.

Fibrinolytic Agents↗
PubMed2001

Deep brain stimulation for the treatment of Parkinson's disease: subthalamic nucleus versus globus pallidus internus.

OBJECTIVES: Deep brain stimulation of the basal ganglia has become a promising treatment option for patients with Parkinson's disease who have side effects from drugs. Which is the best target-globus pallidus internus (GPi) or subthalamic nucleus (STN)-is still a matter of discussion. The aim of this prospective study is to compare the long term effects of GPi and STN stimulation in patients with severe Parkinson's disease. PATIENTS AND METHODS: Bilateral deep brain stimulators were implanted in the GPi in six patients and in the STN in 12 patients with severe Parkinson's disease. Presurgery and 3, 6, and 12 months postsurgery patients were scored according to the CAPIT protocol. RESULTS: Stimulation of the STN increased best Schwab and England scale score significantly from 62 before surgery to 81 at 12 months after surgery; GPi stimulation did not have an effect on the Schwab and England scale. Stimulation of the GPi reduced dyskinesias directly whereas STN stimulation seemed to reduce dyskinesias by a reduction of medication. Whereas STN stimulation increased the unified Parkinson's disease rating scale (UPDRS) motor score, GPi stimulation did not have a significant effect. Fluctuations were reduced only by STN stimulation and STN stimulation suppressed tremor very effectively. CONCLUSION: Stimulation of the GPi reduces medication side effects, which leads to a better drug tolerance. There was no direct improvement of bradykinesia or tremor by GPi stimulation. Stimulation of the STN ameliorated all parkinsonian symptoms. Daily drug intake was reduced by STN stimulation. The STN is the target of choice for treating patients with severe Parkinson's disease who have side effects from drugs.

Aged↗