Studying the imaging features and infarction mechanism of vertebrobasilar dolichoectasia with high-resolution magnetic resonance imaging.

The mechanisms underlying ischemic infarction in patients with vertebrobasilar dolichoectasia (VBD) remain unclear. In this study, we retrospectively analyzed the imaging characteristics of high-resolution magnetic resonance imaging (HR-MRI) in patients with VBD to explore the possible mechanisms of ischemic stroke (IS) in patients with VBD. Patients with VBD were recruited from the HR-MRI database between July 2017 and June 2021. HR-MRI was used to evaluate the diameter, bifurcation height, laterality, arterial dissection, and atherosclerotic plaques of the basilar artery (BA). Transcranial Doppler was used to measure the vertebrobasilar mean velocity (Vm), peak systolic velocity (Vs), end-diastolic velocity (Vd), and pulsatile index. Twenty-six patients with VBD were enrolled, of which 15 had IS and 11 did not. The incidence of classical vascular risk factors, including age, sex, hypertension, diabetes, and hypercholesterolemia, did not differ significantly between the two groups. The BA diameters of the stroke group were significantly higher than that of the nonstroke group (6.57 ± 1.00 mm vs. 5.06 ± 0.50 mm, p = 0.000). The height of the BA bifurcation in the stroke and nonstroke groups was statistically significant (p = 0.002). Compared with the nonstroke group, the Vm, Vs, and Vd of the BA in the stroke group were lower, but the difference was not significant. In the 16 patients with atherosclerotic stenosis, 30 atherosclerotic plaques were found in the BA, 18 (60%) in the greater curvature, and 12 (40%) in the lesser curvature. In addition, one artery dissection (on the lesser curvature) and two dissecting aneurysms (on the greater curvature) were found in the BA of three patients, respectively. The BA diameter and bifurcation height are factors related to IS in patients with VBD. The mechanism of stroke in patients with VBD may involve abnormal hemodynamics, artery dissection, and atherosclerosis. HR-MRI is a useful method for evaluating the risk and underlying mechanism of stroke in patients with VBD.

Reduction-Responsive Nucleic Acid Delivery Systems To Prevent In-Stent Restenosis in Rabbits.

Cardiovascular and cerebrovascular ischemic diseases seriously affect human health. Endovascular stent placement is an effective treatment but always leads to in-stent restenosis (ISR). Gene-eluting stent, which combines gene therapy with stent implantation, is a potential method to prevent ISR. In this study, an efficient gene-eluting stent was designed on the basis of one new nucleic acid delivery system to decrease the possibility of ISR. The reduction-responsive branched nucleic acid vector (SKP) with low cytotoxicity was first synthesized via ring-opening reaction. The impressive in vitro transfection performances of SKP were proved using luciferase reporter, enhanced green fluorescent protein plasmid, and vascular endothelial growth factor plasmid (pVEGF). Subsequently, SKP/pVEGF complexes were coated on the surfaces of pretreated clinical stents to construct gene-eluting stents (S-SKP/pVEGF). Antirestenosis performance of S-SKP/pVEGF was evaluated via implanting stents into rabbit aortas. S-SKP/pVEGF could lead to the localized upregulation of VEGF proteins, improve the progress of re-endothelialization, and inhibit the development of ISR in vivo. Such efficient pVEGF-eluting stent with responsive nucleic acid delivery systems is very promising to prevent in-stent restenosis of cerebrovascular diseases.

Clinical Manifestations and Mechanisms of Autoimmune Disease-Related Multiple Cerebral Infarcts.

It is important to investigate the clinical characteristics and identify the stroke mechanisms of patients with autoimmune disease-related stroke, which are necessary for early etiology diagnosis, accurate treatment and preventive strategies. In this article we retrospectively studied eight cases of acute ischemic stroke associated with autoimmune diseases, and without competing conventional stroke etiologies. The characteristics of stroke (clinical and radiological features), the laboratory tests especially serum D-dimer levels (as a marker of hypercoagulable state), and embolic signals on transcranial Doppler were evaluated for all eight patients. High-resolution magnetic resonance imaging (HRMRI), which can help to evaluate vasculitis was performed in four patients. The possible underlying mechanisms of these cases were discussed based on these manifestations. As a result, autoimmune diseases in our study included systemic lupus erythematosus (n=5), mixed connective tissue disease (n=1), central nervous system vasculitis (n=1), and Takayasu arteritis (n=1). All eight patients presented with acute infarction lesions in ≥2 vascular territories. Most patients presented with numerous small and medium infarction lesions located in the cortical and subcortical areas. Multiple stroke mechanisms were involved in these cases, including hypercoagulability (n=4), cardiac embolism (n=1) and vasculitis (n=3). Embolic signals could be detected on transcranial Doppler in all three stroke mechanisms. In conclusion, our study revealed the characteristics of autoimmune disease-related stroke. For patients with multiple acute cerebral infarcts within non-single arterial territories, autoimmune disease is an important etiology not to be neglected. Multiple stroke mechanisms were involved in these cases.

High resolution magnetic resonance imaging in pathogenesis diagnosis of single lenticulostriate infarction with nonstenotic middle cerebral artery, a retrospective study.

BACKGROUND: It is usually difficult to identify stroke pathogenesis for single lenticulostriate infarction with nonstenotic middle cerebral artery (MCA). Our aim is to differentiate the two pathogeneses, non-branch atheromatous small vessel disease and branch atheromatous disease (BAD) by high-resolution magnetic resonance imaging (HR-MRI). METHODS: Thirty-two single lenticulostriate infarction patients with nonstenotic MCA admitted to the China-Japan Friendship Hospital from December 2014 to August 2017 were enrolled for retrospective analysis. National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), atherosclerotic risk factors, imaging features, and the characteristic of MCA vessel wall in HR-MRI were evaluated. RESULTS: MCA plaques were detected in 15(46.9%) patients which implied BAD and 8 of 15 (53.3%) patients had plaques location in upper dorsal side of the vessel wall. Patients with HR-MRI identified plaques had a significantly larger infarction lesion length (1.95 ± 0.86 cm versus 1.38 ± 0.55 cm; P = 0.031) and larger lesion volume (2.95 ± 3.94 cm3 versus 0.90 ± 0.94 cm3; P = 0.027) than patients without plaques. Patients with HR-MRI identified plaques had a significant higher percentage of proximal lesions than patients without plaques (P = 0.055). However, according to the location of MCA plaques, there were no significant differences in terms of imaging features, NIHSS and mRS. CONCLUSION: We demonstrated high frequency of MCA atheromatous plaques visualized in single lenticulostriate infarction patients with nonstenotic MCA by using HR-MRI. Patients with HR-MRI identified plaque presented larger infarction lesions and more proximal lesions than patients without plaque, which were consistent with imaging features of BAD. HR-MRI is an important and effective tool for identifying stroke etiology in patients with nonstenotic MCA.

Plasma Exchange for Neuromyelitis Optica Spectrum Disorders in Chinese Patients and Factors Predictive of Short-term Outcome.

PURPOSE: The purposes of this article were to evaluate the short-term outcome of plasma exchange (PLEX) for neuromyelitis optica spectrum disorders (NMOSDs) in Chinese patients and to identify the factors predictive of a favorable response to therapy. METHODS: We retrospectively analyzed data from 29 Chinese patients with NMOSD. All patients received 2 to 7 sessions of PLEX every other day. Expanded Disability Status Scale (EDSS) scores were estimated at baseline, at relapse, and before and at follow-up after PLEX. Patients were assigned to 1 of 2 groups according to treatment responses of marked to moderate improvement and mild to no improvement. FINDINGS: Twenty-four of 29 patients (82.8%) showed functional improvement at 1 month after PLEX, 9 of whom experienced moderate to marked improvement. Early PLEX initiation and a lower baseline EDSS score were independent prognostic factors (both, P < 0.05). In addition, relapse symptoms of nonoptic neuritis and acute transverse myelitis plus circumventricular organs, seronegativity for aquaporin-4 antibodies, shorter initial therapy-PLEX interval, and no prior optic neuritis attacks were predictive factors significantly associated with a favorable response to treatment (all, P < 0.05). The delay time pre-PLEX was inversely correlated with reduction in EDSS score. The percentage reductions in EDSS score in groups receiving PLEX on days ≤15 and days 16 to 30 were significantly greater than those in the groups treated on days 31 to 60 and days 61 to 90 (all, P < 0.05). Most PLEX sessions were generally well tolerated. IMPLICATIONS: PLEX is an effective therapy for NMOSD in the Chinese population, and early PLEX initiation was associated with a favorable response. We recommend an optimum PLEX time of 30 days from the time of disease onset. Further long-term prospective, multicenter studies that include a larger sample of patients with NMOSD treated with PLEX are necessary.

Dural arteriovenous fistula disguised as cerebral venous sinus thrombosis.

Dural arteriovenous fistulas (DAVFs) are direct communications between the intracranial arterial and venous systems without an intervening nidus. Clinicians sometimes fail to give a correct diagnosis of DAVF. Given the similarity of their clinical and magnetic resonance imaging (MRI) manifestations, diagnostic confusion may arise between DAVF and cerebral venous sinus thrombosis (CVST) (Simon et al., 2009). The clinical management of DAVFs differs from that of CVST (Ma et al., 2015; Yang et al., 2015). Anticoagulation therapy is restricted in some cases of DAVFs, especially when they are associated with retrograde venous flow, due to the increased risk of hemorrhage. Here we present a case of a DAVF patient who had been initially misdiagnosed as CVST. We summarize the reasons for misdiagnosis and give some recommendations to address this problem.

Curcumin Attenuates Beta-Amyloid-Induced Neuroinflammation via Activation of Peroxisome Proliferator-Activated Receptor-Gamma Function in a Rat Model of Alzheimer's Disease.

Neuroinflammation is known to have a pivotal role in the pathogenesis of Alzheimer's disease (AD), and curcumin has been reported to have therapeutical effects on AD because of its anti-inflammatory effects. Curcumin is not only a potent PPARγ agonist, but also has neuroprotective effects on cerebral ischemic injury. However, whether PPARγ activated by curcumin is responsible for the anti-neuroinflammation and neuroprotection on AD remains unclear, and needs to be further investigated. Here, using both APP/PS1 transgenic mice and beta-amyloid-induced neuroinflammation in mixed neuronal/glial cultures, we showed that curcumin significantly alleviated spatial memory deficits in APP/PS1 mice and promoted cholinergic neuronal function in vivo and in vitro. Curcumin also reduced the activation of microglia and astrocytes, as well as cytokine production and inhibited nuclear factor kappa B (NF-κB) signaling pathway, suggesting the beneficial effects of curcumin on AD are attributable to the suppression of neuroinflammation. Attenuation of these beneficial effects occurred when co-administrated with PPARγ antagonist GW9662 or silence of PPARγ gene expression, indicating that PPARγ might be involved in anti-inflammatory effects. Circular dichroism and co-immunoprecipitation analysis showed that curcumin directly bound to PPARγ and increased the transcriptional activity and protein levels of PPARγ. Taking together, these data suggested that PPARγ might be a potential target of curcumin, acting to alleviate neuroinflammation and improve neuronal function in AD.

[Clinical analysis of carotid angioplasty stenting for high-grade extracranial carotid artery stenosis combined with severe tortuosity].

OBJECTIVE: To observe the feasibility and safety of carotid angioplasty stenting (CAS) for high-grade extracranial carotid artery stenosis combined with severe tortuosity. METHODS: Twenty patients diagnosed with high-grade extracranial carotid artery stenosis combined with severe tortuosity by cerebral angiography, who were in hospital in neurology department of China-Janpan friendship from June 2011 to June 2014. Twelve of these patients were symptomatic. All cases weren't suit for or disagreed with carotid endarterectomy (CEA) to accept CAS. We retrospectively discussed the rates of technical success, the perioperative complications and clinical improvement. During the follow-up for 4 to 40 months we observed the events of cured carotid artery territory stroke and death, and record the plaque hyperplasia in stent, in-stent restenosis, stent deformation or fracture by color doppler ultrasonography or craniocervical CT angiography. RESULTS: (1) The results of operation: the rate of technical success was 19/20 and the rate of the distal protection device placement was 18/20. One stent and 2 distal protection device were difficult to pass the tortuous access vessels. The kinking was the most common in circuity classification of internal carotid artery. The stenosis was significantly improved after stenting, and the mean degree of stenosis was reduced from (82% ± 9%) before stenting to (7% ± 6%) after stenting. Although 5 patients were with perioperative complications, all symptoms disappeared within 1 weeks, and there was no stent related death and disability. There were 4 cases with vascular spasm, one of them was combined with carotid sinus reaction, and anther with transient ischemic attack (TIA) during operation. There was one with ipsilateral carotid territory minor stroke. (2) The results of prognosis and follow up: The clinical symptoms from 12 symptomatic patients were improved significantly on discharge, and the average NIHSS scores on admission were reduced from (4 ± 4) to (2 ± 2) on discharge. One patient experienced ipsilateral carotid territory minor stroke and another patient experienced ipsilateral carotid territory TIA during the follow-up for an average of 19 months, and there were 5 cases with mild plaque hyperplasia in stent and no in-stent restenosis, stent deformation or fracture. CONCLUSION: The severe tortuosity of extracranial carotid artery may affect the using of intervention materials and increase the complexity of CAS, but for the patients who disagree with CEA or were with the contraindications to CEA, CAS may be still a relatively safe, effective and alternative treatment.

[Association between basilar artery hypoplasia and posterior circulation infarction].

OBJECTIVE: To explore the relationship between basal artery hypoplasia (BAH) and posterior circulation ischemic stroke and its clinical characteristics to improve the understanding of BAH. METHODS: A total of 328 hospitalized patients from April 2012 to April 2014 were enrolled retrospectively. With normal course and regular shape of basilar artery on brain magnetic resonance angiography (MRA), other causes of posterior circulation ischemic stroke were excluded. They were divided into BAH (n = 48) and non-BAH (n = 280) groups according to the morphology and diameter of basilar artery on head MRA. We compared the general information and intracranial vascular variations between two groups, especially the incidence rate of posterior circulation infarction and mean blood flow velocity (Vm) of basal artery by analyzing clinical information and MRI findings. Meantime, their clinical outcomes were observed through follow-ups. And detailed clinical features were discussed for the patients with posterior circulation infarction in the BAH group. RESULTS: (1) The concurrent lesions included vertebral artery intracranial segment hypoplasia (n = 24, VAH), fetal type posterior artery (n = 18, FTPA), persistent trigeminal artery (n = 1) and giant fenestration variation on vertebral artery (n = 1) in the BAH group. In comparison, it was more liable to cranial vascular variations in the BAH group (P < 0.05). (2) The incidence rates of posterior circulation infarction for two groups were 35.4% (17/48) and 8.6% (24/280) respectively. In comparison, these cases in the BAH group were more likely to suffer from posterior circulation ischemic stroke (P < 0.05) and the Vm of basal artery in the BAH group was obviously lower than that in the non-BAH group (P < 0.05). (3) these cases with stroke in two groups had no mortality during a follow-up period of 4-28 months. There were 3 cases with recurrent posterior circulation stroke in the non-BAH group. The number of cases with mRS scoring 2 points or less in the BAH group was more than that in the non-BAH group at discharge, 30 or 90 days after discharge (P < 0.05). (4) these cases with posterior circulation stroke in the BAH group often presented as lacunar syndrome (9/17), paramedian infarction in pons (9/17) and bilateral VAH plus unilateral FTPA (8/17). CONCLUSION: As a relatively rare disease, BAH often has other intracranial vascular variants. Posterior circulation stroke occurs due to reduced blood supply of vertebrobasilar system, especially pons infarction. Though with relatively good clinical outcomes, we still need to make an early diagnosis and strengthen stroke prevention.