Objective
To analyze why numerous acute stroke treatments were successful in the laboratory but failed in large clinical trials.
Methods
We searched all phase 3 trials of medical treatments for acute ...ischemic stroke and corresponding early clinical and experimental studies. We compared the overall efficacy and assessed the impact of publication bias and study design on the efficacy. Furthermore, we estimated power and true report probability of experimental studies.
Results
We identified 50 phase 3 trials with 46,008 subjects, 75 early clinical trials with 12,391 subjects, and 209 experimental studies with >7,141 subjects. Three (6%) phase 3, 24 (32%) early clinical, and 143 (69.08%) experimental studies were positive. The mean treatment effect was 0.76 (95% confidence interval CI = 0.70–0.83) in experimental studies, 0.87 (95% CI = 0.71–1.06) in early clinical trials, and 1.00 (95% CI = 0.95–1.06) in phase 3 trials. Funnel plot asymmetry and trim‐and‐fill revealed a clear publication bias in experimental studies and early clinical trials. Study design and adherence to quality criteria had a considerable impact on estimated effect sizes. The mean power of experimental studies was 17%. Assuming a bias of 30% and pre‐study odds of 0.5 to 0.7, this leads to a true report probability of <50%.
Interpretation
Pivotal study design differences between experimental studies and clinical trials, including different primary end points and time to treatment, publication bias, neglected quality criteria and low power, contribute to the stepwise efficacy decline of stroke treatments from experimental studies to phase 3 clinical trials. Even under conservative estimates, less than half of published positive experimental stroke studies are truly positive. ANN NEUROL 2020;87:40–51
Objective
The purpose of this study was to characterize patients with ischemic stroke due to bacterial meningitis.
Methods
In a single‐center retrospective study, we analyzed 102 patients with ...bacterial meningitis of which 19 had an ischemic stroke. Clinical characteristics, cerebrospinal fluid (CSF) analyses, and spatiotemporal distribution of infarcts were assessed. In addition, we searched PubMed from database inception to August 2021 for observational studies on ischemic stroke in patients with bacterial meningitis, and performed a meta‐analysis to investigate the frequency and timing of stroke as well as its effect on mortality.
Results
In our cohort, 15 (78.9%) patients with stroke had an modified Rankin scale (mRS) ≥ 3 at discharge compared to 33 (39.8%) in patients without stroke (p < 0.01). Of 1,692 patients with bacterial meningitis from 15 cohort studies included in our meta‐analysis, cerebral infarcts were found in 332 (16%, 95% confidence interval CI = 0.13–0.20) patients. The occurrence of stroke was strongly associated with a higher mortality (odds ratio OR = 2.38, 95% CI = 1.70–3.34, p < 0.0001). There was no association of any specific causative pathogen with the occurrence of stroke. Infarcts were mainly distributed in territories of arteries located in the vicinity to the infection focus and peaked at 3 to –7 days and at 2 weeks after onset of meningitis. In patients with ischemic stroke, vasculopathy was found in 63.2% and additional intracerebral hemorrhage in 15.8%.
Interpretation
This study found that ischemic stroke due to bacterial meningitis is caused by cerebral vasculopathy located in the vicinity of the infection focus, and that the time course of infarctions might enable a therapeutic intervention. ANN NEUROL 2023;93:1094–1105
Objective
The objective of this study was to characterize patients with extracranial giant cell arteritis with intracranial involvement.
Methods
In a multicenter retrospective study, we included 31 ...patients with systemic giant cell arteritis (GCA) with intracranial involvement. Clinical characteristics, pattern of arterial involvement, and cytokine profiles were assessed. Patients with GCA without intracranial involvement (n = 17), and with intracranial atherosclerosis (n = 25) served as controls.
Results
Erythrocyte sedimentation rate (ESR) was elevated in 18 patients (69.2%) with and in 16 patients (100%) without intracranial involvement (p = 0.02). Headache was complained by 15 patients (50.0%) with and 13 patients (76.5%) without intracranial involvement (p = 0.03). Posterior circulation arteries were affected in 26 patients (83.9%), anterior circulation arteries in 17 patients (54.8%), and both territories in 12 patients (38.7%). Patients with GCA had vertebral artery stenosis proximal and, in contrast, patients with atherosclerosis distal to the origin of posterior inferior cerebellar artery (PICA). Among patients with GCA with intracranial involvement, 11 patients (37.9%) had a rapid progressive disease course characterized by short‐term recurrent ischemic events. The median modified Rankin Scale (mRS) at follow‐up in these patients was 4 (interquartile range IQR = 2.0–6.0) and 4 patients (36.4%) died. Vessel wall expression of IL‐6 and IL‐17 was significantly increased in patients with rapid progressive course.
Interpretation
Typical characteristics of GCA, headache, and an elevated ESR, are frequently absent in patients with intracranial involvement. However, differentiation of intracranial GCA from atherosclerosis can be facilitated by the typical pattern of vertebral artery stenosis. About one‐third of patients with intracranial GCA had a rapid progressive course with poor outcome. IL‐17 and IL‐6 may represent potential future treatment targets. ANN NEUROL 2021;90:118–129
Abstract Demyelination of corticospinal tract neurons contributes to long‐term disability after cortical stroke. Nonetheless, poststroke myelin loss has not been addressed as a therapeutic target, so ...far. We hypothesized that an antibody‐mediated inhibition of the Nogo receptor‐interacting protein (LINGO‐1, leucine‐rich repeat and immunoglobulin domain‐containing Nogo receptor‐interacting protein) may counteract myelin loss, enhance remyelination and axonal growth, and thus promote functional recovery following stroke. To verify this hypothesis, mice were subjected to photothrombotic stroke and received either an antibody against LINGO‐1 ( n = 19) or a control treatment ( n = 18). Behavioral tests were performed to assess the effects of anti‐LINGO‐1 treatment on the functional recovery. Seven weeks after stroke, immunohistochemical analyses were performed to analyze the effect of anti‐LINGO‐1 treatment on myelination and axonal loss of corticospinal tract neurons, proliferation of oligodendrocytes and neurogenesis. Anti‐LINGO‐1 treatment resulted in significantly improved functional recovery ( p < 0.0001, repeated measures analysis of variance), and increased neurogenesis in the hippocampus and subventricular zone of the ipsilateral hemisphere ( p = 0.0094 and p = 0.032, t ‐test). Notably, we observed a significant increase in myelin ( p = 0.0295, t ‐test), platelet‐derived growth factor receptor α‐positive oligodendrocyte precursor cells ( p = 0.0356, t ‐test) and myelinating adenomatous polyposis coli‐positive cells within the ipsilateral internal capsule of anti‐LINGO‐1‐treated mice ( p = 0.0021, t ‐test). In conclusion, we identified anti‐LINGO‐1 as the first neuroregenerative treatment that counteracts poststroke demyelination of corticospinal tract neurons, presumably by increased proliferation of myelin precursor cells, and thereby improves functional recovery. Most importantly, our study presents myelin loss as a novel therapeutic target following stroke.
Aims
To distinguish between the genuine cellular impact of the ischemic cascade by leukocytes and unspecific effects of edema and humoral components, two knock‐in mouse lines were utilized. Mouse ...lines Y731F and Y685F possess point mutations in VE‐cadherin, which lead to a selective inhibition of transendothelial leukocyte migration or impaired vascular permeability.
Methods
Ischemic stroke was induced by a model of middle cerebral artery occlusion. Analysis contained structural outcomes (infarct volume and extent of brain edema), functional outcomes (survival analysis, rotarod test, and neuroscore), and the extent and spatial distribution of leukocyte migration (heatmaps and fluorescence‐activated cell sorting (FACS) analysis).
Results
Inhibition of transendothelial leukocyte migration as in Y731F mice leads to smaller infarct volumes (52.33 ± 4719 vs. 70.43 ± 6483 mm3, p = .0252) and improved motor skills (rotarod test: 85.52 ± 13.24 s vs. 43.06 ± 15.32 s, p = .0285). An impaired vascular permeability as in Y685F mice showed no effect on structural or functional outcomes. Both VE‐cadherin mutations did not influence the total immune cell count or spatial distribution in ischemic brain parenchyma.
Conclusion
Selective inhibition of transendothelial leukocyte migration by VE‐cadherin mutation after ischemic stroke in a mouse model leads to smaller infarct volumes and improved motor skills.
Inhibition of leukocyte migration after ischemic stroke by VE‐cadherin mutation in a mouse model leads to reduced infarct volumes and improved motor skills. VE‐cadherin mutation Y731F is associated with a selective inhibition of transendothelial leukocyte migration. In a mouse model of ischemic stroke, it led to smaller infarct volumes and improved motor skills. VE‐cadherin mutation Y685F had no effect on structural or functional outcomes on the same mouse model of ischemic stroke.
Inflammation triggers secondary brain damage after stroke. The meninges and other CNS border compartments serve as invasion sites for leukocyte influx into the brain thus promoting tissue damage ...after stroke. However, the post-ischemic immune response of border compartments compared to brain parenchyma remains poorly characterized. Here, we deeply characterize tissue-resident leukocytes in meninges and brain parenchyma and discover that leukocytes respond differently to stroke depending on their site of residence. We thereby discover a unique phenotype of myeloid cells exclusive to the brain after stroke. These stroke-associated myeloid cells partially resemble neurodegenerative disease-associated microglia. They are mainly of resident microglial origin, partially conserved in humans and exhibit a lipid-phagocytosing phenotype. Blocking markers specific for these cells partially ameliorates stroke outcome thus providing a potential therapeutic target. The injury-response of myeloid cells in the CNS is thus compartmentalized, adjusted to the type of injury and may represent a therapeutic target.
Sodium chloride promotes vascular fibrosis, arterial hypertension, pro-inflammatory immune cell polarization and endothelial dysfunction, all of which might influence outcomes following stroke. But ...despite enormous translational relevance, the functional importance of sodium chloride in the pathophysiology of acute ischemic stroke is still unclear. In the current study, we show that high-salt diet leads to significantly worse functional outcomes, increased infarct volumes, and a loss of astrocytes and cortical neurons in acute ischemic stroke. While analyzing the underlying pathologic processes, we identified the migrasome as a novel, sodium chloride-driven pathomechanism in acute ischemic stroke. The migrasome was previously described in vitro as a migrating organelle, which incorporates and dispatches cytosol of surrounding cells and plays a role in intercellular signaling, whereas a pathophysiological meaning has not been elaborated. We here confirm previously reported characteristics of the migrasome in vivo. Immunohistochemistry, electron microscopy and proteomic analyses further demonstrate that the migrasome incorporates and dispatches cytosol of surrounding neurons following stroke. The clinical relevance of these findings is emphasized by neuropathological examinations, which detected migrasome formation in infarcted brain parenchyma of human stroke patients. In summary, we demonstrate that high-salt diet aggravates stroke outcomes, and we characterize the migrasome as a novel mechanism in acute stroke pathophysiology.
Aims
Cardiomyopathy in Fabry disease (FD) is a major determinant of morbidity and mortality. This study investigates the effects of FD-specific treatment using enzyme replacement therapy (ERT) and ...chaperone therapy on left atrial (LA) function using two-dimensional speckle tracking echocardiography (2DSTE).
Methods and results
In this prospective observational single-center study, 20 FD patients 10 (50%) females treated with migalastat, 48 FD patients 24 (50%) females treated with ERT (agalsidase-alfa and agalsidase-beta), and 30 untreated FD patients (all females) as controls were analyzed. The mean follow-up time ranged from 26 to 81 months. 2DSTE was performed for left ventricle strain, right ventricle strain, and LA strain (LAS). FD-specific treated patients presented with increased left ventricular mass index (LVMi) and higher frequency of left ventricular hypertrophy at baseline, whereas untreated control patients showed normal baseline values. FD-specific treated (including migalastat and ERT) patients showed stabilization of LAS over time (
p
> 0.05). LVMi was also stable in treated FD patients during observation (
p
> 0.05).
Conclusion
In patients with FD, treated with either ERT or chaperone therapy, LAS values measured by echocardiographic speckle tracking were stable over time, pointing toward disease stabilization.
The "translational roadblock" between successful animal stroke studies and neutral clinical trials is usually attributed to conceptual weaknesses. However, we hypothesized that rodent studies cannot ...inform the human disease due to intrinsic pathophysiological differences between rodents and humans., i.e., differences in infarct evolution.
To verify our hypothesis, we employed a mixed study design and compared findings from meta-analyses of animal studies and a retrospective clinical cohort study. For animal data, we systematically searched pubmed to identify all rodent studies, in which stroke was induced by MCAO and at least two sequential MRI scans were performed for infarct volume assessment within the first two days. For clinical data, we included 107 consecutive stroke patients with large artery occlusion, who received MRI scans upon admission and one or two days later.
Our preclinical meta-analyses included 50 studies with 676 animals. Untreated animals had a median post-reperfusion infarct volume growth of 74%. Neuroprotective treatments reduced this infarct volume growth to 23%. A retrospective clinical cohort study showed that stroke patients had a median infarct volume growth of only 2% after successful recanalization. Stroke patients with unsuccessful recanalization, by contrast, experienced a meaningful median infarct growth of 148%.
Our study shows that rodents have a significant post-reperfusion infarct growth, and that this post-reperfusion infarct growth is the target of neuroprotective treatments. Stroke patients with successful recanalization do not have such infarct growth and thus have no target for neuroprotection.
Objective: In rare cases, Lyme neuroborreliosis (LNB) can induce cerebral vasculitis leading to severe stenosis of the cerebral vasculature and consecutive ischemia. Therapy is based on anti-biotic ...treatment of the tick-borne disease, whereas interventional therapeutic options have not been assessed yet. Material and Methods: We report on a patient with LNB and concomitant stenoses and progressive and fatal vasculitis of the cerebral vessels despite all therapeutic efforts by the departments of neurology and interventional neuroradiology. In this context, we also conducted a literature review on endovascular treatment of LNB-associated cerebral ischemia. Results: A 52-year-old female presented with transient neglect and psychomotor slowdown (initial NIHSS = 0). MRI and serology led to the diagnosis of basal meningitis due to LNB with vasculitis of cerebral arteries. Despite immediate treatment with antibiotics and steroids, neurologic deterioration (NIHSS 8) led to an emergency angiography on day 2 after admission. Hemodynamically relevant stenoses of the MCA were treated via spasmolysis and PTA, leading to almost complete neurological recovery. Despite intensified medical treatment, the vasculitis progressed and could only be transiently ameliorated via repetitive spasmolysis. On day 19, she again presented with significant neurologic deterioration (NIHSS 9), and PTA and stenting of the nearly occluded MCA were performed with a patent vessel, initially without hemorrhagic complications. Despite all therapeutic efforts and preserved stent perfusion, vasculitis worsened and the concurrent occurrence of subdural hemorrhage led to the death of the patient. Conclusion: Neuroradiological interventions, i.e., spasmolysis, PTA, and, if necessary, stenting, can and should be considered in cases of LNB-induced vasculitis and stroke that are refractory to best medical treatment alone. Key point: Neuroradiological interventions can be considered in patients with vascular complications of Lyme neuroborreliosis as an additional extension of the primary drug therapy.
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