Jian-Ren Liu

Increased default mode network connectivity and increased regional homogeneity in migraineurs without aura

BackgroundThe precuneus/posterior cingulate cortex, which has been associated with pain sensitivity, plays a pivotal role in the default mode network. However, information regarding migraine-related alterations in resting-state brain functional connectivity in the default mode network and in local regional spontaneous neuronal activity is not adequate.MethodsThis study used functional magnetic resonance imaging to acquire resting-state scans in 22 migraineurs without aura and in 22 healthy matched controls. Independent component analysis, a data-driven method, was used to calculate the resting-state functional connectivity of the default mode network in the patient and healthy control groups. Regional homogeneity (ReHo) was used to analyse the local features of spontaneous resting-state brain activity in the migraineurs without aura.ResultsCompared with the healthy controls, migraineurs without aura showed increased functional connectivity in the left precuneus/posterior cingulate cortex within the default mode network and significant increase in ReHo values in the bilateral precuneus/posterior cingulate cortex, left pons and trigeminal nerve entry zone. In addition, functional connectivity was decreased between the areas with abnormal ReHo (using the peaks in the precuneus/posterior cingulate cortex) and other brain areas.ConclusionsThe abnormalities in the precuneus/posterior cingulate cortex suggest that migraineurs without aura may exhibit information transfer and multimodal integration dysfunction and that pain sensitivity and pian processing may also be affected.

Blood Pressure Reduction in the Acute Phase of an Ischemic Stroke Does Not Improve Short- or Long-Term Dependency or Mortality: A Meta-Analysis of Current Literature

Abstract The purpose of this study was to perform a meta-analysis of current literature to determine whether lowering blood pressure (BP) during the acute phase of an ischemic stroke improves short- and long-term outcomes. PubMed, Cochrane, and Embase were searched until September 5, 2014 using combinations of the search terms: blood pressure reduction, reduced blood pressure, lowering blood pressure, ischemic stroke, acute stroke, and intra-cerebral hemorrhage. Inclusion criteria were randomized controlled trial and patients with acute stroke (ischemic or hemorrhagic) treated with an antihypertensive agent or placebo. Outcome measures were change in systolic and diastolic BP (SBP, DBP) after treatment, and short- and long-term dependency and mortality rates. A total of 459 studies were identified, and ultimately 22 studies were included in the meta-analysis. The total number of participants in the treatment groups was 5672 (range, 6–2308), and in the control groups was 5416 (range, 6–2033). In most studies, more than 50% of the participants were males and the mean age was more than 60 years. The mean follow-up time ranged from 5 days to 12 months. As expected, treatment groups had a greater decrease in BP than control groups, and this effect was seen with different classes of antihypertensive drugs. Short-term and long-term dependency rates were similar between treatment and control groups (short-term dependency: pooled odds ratio [OR] = 1.041, 95% confidence interval [CI]: 0.936–1.159, P = 0.457; long-term dependency: pooled OR = 1.013, 95% CI: 0.915–1.120, P = 0.806). Short-term or long-term mortality was similar between the treatment and control groups (short-term mortality: pooled OR = 1.020, 95% CI: 0.749–1.388, P = .902; long-term mortality: pooled OR = 1.039, 95% CI: 0.883–1.222, P = 0.644). Antihypertensive agents effectively reduce BP during the acute phase of an ischemic stroke, but provide no benefit with respect to short- and long-term dependency and mortality.

Assessment of gray and white matter structural alterations in migraineurs without aura

BackgroundMigraine constitute a disorder characterized by recurrent headaches, and have a high prevalence, a high socio-economic burden and severe effects on quality of life. Our previous fMRI study demonstrated that some brain regions are functional alterations in migraineurs. As the function of the human brain is related to its structure, we further investigated white and gray matter structural alterations in migraineurs.MethodsIn current study, we used surface-based morphometry, voxel-based morphometry and diffusion tensor imaging analyses to detect structural alterations of the white matter and gray matter in 32 migraineurs without aura compared with 32 age- and gender-matched healthy controls.ResultsWe found that migraineurs without aura exhibited significantly increased gray matter volume in the bilateral cerebellar culmen, increased cortical thickness in the lateral occipital-temporal cortex, decreased cortical thickness in the right insula, increased gyrification index in left postcentral gyrus, superior parietal lobule and right lateral occipital cortex, and decreased gyrification index in the left rostral middle frontal gyrus compared with controls. No significant change in white matter microstructure was found in DTI analyses.ConclusionThe significantly altered gray matter brain regions were known to be associated with sensory discrimination of pain, multi-sensory integration and nociceptive information processing and were consistent with our previous fMRI study, and may be involved in the pathological mechanism of migraine without aura.

Predictive role of CHADS2 and CHA2DS2-VASc scores on stroke and thromboembolism in patients without atrial fibrillation: a meta-analysis

Abstract Objective: CHA2DS2-VASc is the extension of the CHADS2 score developed by Birmingham 2009. This risk stratification schema is often used in clinical setting when considering additional risk factors for developing stroke in AF patients. However, its role in the non-AF population is unknown. This study was designed to evaluate the accuracy of the CHADS2 and the CHA2DS2-VASc scoring systems. Methods: Studies designed for CHADS2 and CHA2DS2-VASc score in stratifying the risks for stroke development in non-AF patients were included. Results: Among the 114 studies identified, six trials were chosen finally and included for meta-analysis. The pooled diagnostic odds ratio (DOR) for CHADS2 and CHA2DS2-VASc was 2.86 (95% CI =1.83–4.28) and 2.80 (95% CI =1.83–4.28), respectively. CHA2DS2-VASc score was of better sensitivity than CHADS2 score (0.920 vs. 0.768). However, both scores were showed to have inherent heterogeneity and poor specificity. Conclusions: Though having good diagnostic accuracy, the clinical application of the CHADS2 and CHA2DS2-VASc scores in predicting risk of stroke development in non-AF patients still needs further validation. Key message The overall diagnostic accuracy of CHADS2 and CHA2DS2-VASc in stroke-risk stratification was good in patients with non-atrial fibrillation.

Acid‐sensing Ion Channels Activation and Hypoxia Upregulate Homer1a Expression

Recent studies have indicated that dynamic alterations in the structure of postsynaptic density (PSD) are involved in the pathogenesis of many central nervous system disorders, including ischemic stroke. Homer is the newly identified scaffolding protein located at PSD and regulates synaptic function. Homer1a, an immediate early gene, has been shown to be induced by several stimulations, such as glutamate, brain‐derived neurotrophic factor, and trauma. However, whether acidosis mediated by acid‐sensing ion channels (ASICs) and hypoxia during cerebral ischemia can change Homer1a expression remains to be determined.

Visual cortex and cerebellum hyperactivation during negative emotion picture stimuli in migraine patients

Migraines are a common and undertreated disease and often have psychiatric comorbidities; however, the abnormal mechanism of emotional processing in migraine patients has not been well clarified. This study sought to investigate the different brain functional activation to neutral, positive and negative emotional stimuli between migraine and healthy subjects. Twenty-six adults with migraines and 26 healthy adults, group-matched for sex and age, participated in this experiment. Although there were no significant differences between two groups during the viewing of positive affective pictures vs. neutral affective pictures, there were different activation patterns during the viewing of negative to neutral affective pictures in the two groups; the control group showed both increased and decreased activation patterns, while the migraine subjects showed only increased activation. Negative affective pictures elicited stronger activation than neutral affective pictures in migraineurs, which included the bilateral cerebellum anterior lobe/culmen, the bilateral lingual gyri, the bilateral precuneus and the left cuneus. Our data indicated that migraine patients were hypersensitive to negative stimuli, which might provide clues to aid in the understanding of the pathophysiology and psychiatric comorbidities of migraines.

The sensorimotor network dysfunction in migraineurs without aura: a resting-state fMRI study

Migraine is a common recurrent neurological disorder combining nausea, vomiting, and hypersensitivities to visual, auditory, olfactory and somatosensory stimuli. However, the dysfunction of the sensorimotor network in migraineurs has not been well clarified. In the present study, we evaluated the dysfunction of the sensorimotor network in 30 migraineurs without aura and in 31 controls by combining regional homogeneity (ReHo), amplitudes of low-frequency fluctuation (ALFF) and degree centrality (DC) analysis methods based on resting-state fMRI. A seed-based functional connectivity (FC) analysis was used to investigate whether the dysfunctional areas within the sensorimotor network exhibited abnormal FC with other brain areas. Compared to the controls, the migraineurs without aura exhibited significantly smaller ReHo, ALFF and DC values in the primary somatosensory cortex (S1) and right premotor cortex (PMC). The migraineurs showed weaker FC between the S1 and brain areas within the pain intensity and spatial discrimination pathways and trigemino-thalamo-cortical nociceptive pathway. We proposed that the dysfunction of the S1 and PMC and the decreased FC between the S1 and brain areas in migraineurs without aura may disrupt the discrimination of sensory features of pain and affect nociception pathways, and would be involved in the dysfunctional mechanism in migraine.

Progressive Hemorrhagic Transformation Following Dual Antiplatelet Therapy

Dual antiplatelet therapy (DAT) is often used after endovascular interventional treatment to prevent the recurrence of a stroke. However, DAT may lead to cerebral hemorrhage. We describe two stroke patients with subacute progressive cerebral hemorrhagic transformation (HT) following DAT with aspirin and Plavix. One patient experienced HT 3 weeks after carotid artery stenting that was performed 3 days after an acute stroke; the other patient developed progressive HT within 4 weeks following emergent thrombectomy for acute occlusion of the inferior M2 branch of the right middle cerebral artery (MCA). The first patient was a 54-year-old male with a history of hypertension and smoking. He was admitted for acute cerebral infarction in the left temporoparietal lobe and received intravenous thrombolysis (Figure 1A). He was found to have significant stenosis in the proximal portion of the left internal carotid artery (ICA) (Figure 1B). Three days after the stroke, the patient underwent successful angioplasty (4 9 20 mm Sterling Monorail balloon, Boston Scientific, Natick, MA) and stenting (7 9 30 mm Wallstent, Boston Scientific, Natick, MA) of the stenotic left carotid artery (Figure 1C). One week after the procedure, the patient was discharged with partial motor aphasia, right facial palsy, and right limb hemiplegia (upper, grade 0/5; lower, grade 4/5). Aspirin (100 mg qd), Plavix (75 mg qd), and atorvastatin (20 mg qn) were used for secondary prevention. Three weeks after the procedure, the patient complained of dizziness, headache, nausea, and vomit(A) (B) (C)

A small deletion in SERPINC1 causes type I antithrombin deficiency by promoting endoplasmic reticulum stress

Antithrombin (AT) deficiency is an autosomal dominant disorder, and identification of mutation AT variants would improve our understanding of the anticoagulant function of this serine protease inhibitor (SERPIN) and the molecular pathways underlying this disorder. In the present study, we performed whole-exome sequencing of a Chinese family with deep vein thrombosis, and identified a new small deletion that eliminates four amino acids (INEL) from exon 4 of SERPINC1 gene. This causes type I AT deficiency by enhancing the intracellular retention of this protein. AT retention leads to endoplasmic reticulum (ER) stress, which further inhibits AT release. In addition, ER stress activates ER-associated degradation, which promotes AT degradation. Suppression of ER stress enhanced the secretion of AT, while inhibition of ER-associated degradation suppressed AT release. Thus, our study identified a new mutation (INEL deletion) causing type I AT deficiency, and uncovered a novel mechanism for AT retention through enhanced ER stress, which may provide an innovative approach for treating AT deficiency.

Rivaroxaban does not influence hemorrhagic transformation in a diabetes ischemic stroke and endovascular thrombectomy model

Managing endovascular thrombectomy (ET) in diabetic ischemic stroke (IS) with novel anticoagulants is challenging due to putative risk of intracerebral hemorrhage. The study evaluates increased hemorrhagic transformation (HT) risk in Rivaroxaban-treated diabetic rats post ET. Diabetes was induced in male Sprague-Dawley rats by intraperitoneal injection of 60 mg/kg streptozotocin. After 4-weeks, rats were pretreated orally with 30 mg/kg Rivaroxaban/saline; prothrombin time was monitored. IS and ET was induced after 1 h, by thread-induced transient middle cerebral artery occlusion (tMCAO) that mimicked mechanical ET for proximal MCA occlusion at 60 min. After 24 h reperfusion, infarct volumes, HT, blood-brain barrier (BBB) permeability, tight junction at peri-ischemic lesion and matrix metalloproteinase-9 (MMP-9) activity was measured. Diabetic rats seemed to exhibit increased infarct volume and HT at 24 h after ET than normal rats. Infarct volumes and functional outcomes did not differ between Rivaroxaban and diabetic control groups. A significant increase in HT volumes and BBB permeability under Rivaroxaban treatment was not detected. Compared to diabetic control group, neither the occludin expression was remarkably lower in the Rivaroxaban group nor the MMP-9 activity was higher. Together, Rivaroxaban does not increase HT after ET in diabetic rats with proximal MCA occlusion, since Rivaroxaban has fewer effects on post-ischemic BBB permeability.