Cathepsin K Knockout Exacerbates Haemorrhagic Transformation Induced by Recombinant Tissue Plasminogen Activator After Focal Cerebral Ischaemia in Mice.

Severe haemorrhagic transformation (HT), a common complication of recombinant tissue plasminogen activator (rtPA) treatment, predicts poor clinical outcomes in acute ischaemic stroke. The search for agents to mitigate this effect includes investigating biomolecules involved in neovascularization. This study examines the role of Cathepsin K (Ctsk) in rtPA-induced HT after focal cerebral ischaemia in mice. After knockout of Ctsk, the gene encoding Ctsk, the outcomes of Ctsk+/+ and Ctsk-/- mice were compared 24 h after rtPA-treated cerebral ischaemia with respect to HT severity, neurological deficits, brain oedema, infarct volume, number of apoptotic neurons and activated microglia/macrophage, blood-brain barrier integrity, vascular endothelial growth factor (VEGF) expression and Akt-mTOR pathway activation. We observed that haemoglobin levels, brain oedema and infarct volume were significantly greater and resulted in more severe neurological deficits in Ctsk-/- than in Ctsk+/+ mice. Consistent with our hypothesis, the number of NeuN-positive neurons was lower and the number of TUNEL-positive apoptotic neurons and activated microglia/macrophage was higher in Ctsk-/- than in Ctsk+/+ mice. Ctsk knockout mice exhibited more severe blood-brain barrier (BBB) disruption, with microvascular endothelial cells exhibiting greater VEGF expression and lower ratios of phospo-Akt/Akt and phospo-mTOR/mTOR than in Ctsk+/+ mice. This study is the first to provide molecular insights into Ctsk-regulated HT after cerebral ischaemia, suggesting that Ctsk deficiency may disrupt the BBB via Akt/mTOR/VEGF signalling, resulting in neurological deficits and neuron apoptosis. Ctsk administration has the potential as a novel modality for improving the safety of rtPA treatment following stroke.

Previous chronic symptomatic and asymptomatic cerebral hemorrhage in patients with acute ischemic stroke.

PURPOSE: Identifying previous chronic cerebral hemorrhage (PCH), especially asymptomatic cases in patients with ischemic stroke, is essential for proper antithrombotic management. The study aimed to further clarify the prevalence of PCH and the associated factors in patients with acute ischemic stroke using multi-modal neuroimaging including susceptibility-weighted MR imaging (SWI). METHODS: This was a retrospective cross-sectional study of 382 patients with acute ischemic stroke. All patients underwent 3.0-T MRI for cranial SWI, 1.5-T or 3.0-T conventional cranial MRI, and cranial CT. Patients found with PCH were matched 1:4 with patients without PCH. Clinical manifestation, computed tomography, conventional cranial MRI, and cranial SWI were used to determine PCH. Clinical and neuroimaging findings between the patients with symptomatic vs. asymptomatic PCH were compared. RESULTS: Thirty-six patients (36/382, 9.4%) were determined to have had a PCH. Of these 36 patients, 17 (17/36, 47.2%, or 17/382, 4.5%) had asymptomatic PCH. Multivariable analysis showed that serum total cholesterol (OR = 0.510, 95%CI 0.312-0.832, P = 0.007), cerebral microbleeds (OR = 6.251, 95%CI 2.220-17.601, P = 0.001), and antithrombotic drugs history (OR = 3.213, 95%CI 1.018-10.145, P = 0.047) were independently associated with PCH. Asymptomatic PCH had similar clinical and neuroimaging characteristics with symptomatic PCH. CONCLUSION: PCH is not uncommon in acute ischemic stroke patients. Total serum cholesterol, cerebral microbleeds on SWI, and history of antithrombotic drugs were independently associated with PCH in patients with acute ischemic stroke. Asymptomatic PCH, which is easier to be missed and has similar characteristics with symptomatic PCH, should draw much attention.

Structural changes of cerebellum and brainstem in migraine without aura.

BACKGROUND: Increasing evidence has suggested that the cerebellum is associated with pain and migraine. In addition, the descending pain system of the brainstem is the major site of trigeminal pain processing and modulation and has been discussed as a main player in the pathophysiology of migraine. Cerebellar and brainstem structural changes associated with migraineurs remain to be further investigated. METHODS: Voxel-based morphometry (VBM) (50 controls, 50 migraineurs without aura (MWoAs)) and diffusion tensor imaging (DTI) (46 controls, 46 MWoAs) were used to assess cerebellum and brainstem anatomical alterations associated with MWoAs. We utilized a spatially unbiased infratentorial template toolbox (SUIT) to perform cerebellum and brainstem optimized VBM and DTI analysis. We extracted the average diffusion values from a probabilistic cerebellar white matter atlas to investigate whether MWoAs exhibited microstructure alterations in the cerebellar peduncle tracts. RESULTS: MWoAs showed decreased fractional anisotropy (FA) in the vermis VI extending to the bilateral lobules V and VI of the cerebellum. We also found higher axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) in the right inferior cerebellum peduncle tract in MWoAs. MWoAs exhibited both reduced gray matter volume and increased AD, MD and RD in the spinal trigeminal nucleus (SpV). CONCLUSION: MWoAs exhibited microstructural changes in the cerebellum and the local brainstem. These structural differences might contribute to dysfunction of the transmission and modulation of noxious information, trigeminal nociception, and conduction and integration of multimodal information in MWoAs. These findings further suggest involvement of the cerebellum and the brainstem in the pathology of migraine without aura.

Relationship between intracranial internal carotid artery calcification and enlarged cerebral perivascular space.

PURPOSE: The association between intracranial internal carotid artery (IICA) calcification and lacunes, white matter hyperintensity (WMH), and cerebral microbleeds (CMBs) has been well researched. However, enlarged cerebral perivascular space (PVS) has not yet been reported to correlate with intracranial internal carotid artery calcification. Therefore, the primary aim of this study was to investigate the relationship between IICA calcification and enlarged PVS. METHODS: A total of 189 patients with ischemic stroke in the middle cerebral artery territory who presented within 7 days of ictus from 2012 to 2015 were enrolled respectively. All patients were required to have undergone head computed tomography, magnetic resonance imaging, susceptibility-weighted magnetic resonance imaging, magnetic resonance angiography, or computed tomography angiography. Clinical characteristics were recorded. IICA calcification and enlarged PVS were semi-quantitatively evaluated, and the presence of lacunes, WMH, and CMBs was recorded. RESULTS: Of the 189 patients, 63.5% were male. Mean age of the patients was 68.6 ± 12.2 years. There were 104 patients with IICA calcification. Age, diabetes mellitus, lacunes, and white matter hyperintensity were significantly associated with IICA calcification (P < 0.05). Multivariate logistic regression analysis showed that age, diabetes mellitus, and lacunes were independent predictors of IICA calcification (P < 0.05). A lower risk of IICA calcification was found in patients with a higher enlarged PVS score (P = 0.004). CONCLUSION: Higher enlarged PVS scores were associated with a lesser degree of IICA calcification. There appears to be a relationship between reduced risk of IICA calcification and enlarged PVS.

DNA Methylation Analysis Identifies Differentially Methylated Sites Associated with Early-Onset Intracranial Atherosclerotic Stenosis.

AIM: Studies have suggested that genetic and environmental factors do not account for all risks and mechanisms of intracranial atherosclerotic stenosis (ICAS). DNA methylation may play a role in the progression of ICAS. METHODS: DNA methylation profiles of peripheral blood leucocytes from 7 patients with early-onset ICAS and 7 perfectly matched controls were interrogated for the first time using the Illumina Infinium Human MethylationEPIC BeadChip. Afterward, functional analysis for differentially methylated genes was conducted. In addition, pyrosequencing verification was performed in an independent cohort comprising 21 patients with early-onset ICAS and 21 age- and gender-matched controls. RESULTS: A total of 318 cytosine-phosphate-guanine sites were found to be differentially methylated based on the established standards. Functional analysis annotated differentially methylated sites to atherosclerosis-related processes and pathways, such as the negative regulation of hydrolase activity (GO 0051346), type II diabetes mellitus (KEGG hsa04930), and the insulin signaling pathway (KEGG hsa04910). In addition, a differentially methylated site was also validated, cg22443212 in gene Rnf213, which showed significant hypermethylation in patients with early-onset ICAS compared with controls 59.56% (49.77%, 88.55%) vs. 44.65% (25.07%, 53.21%), respectively; P=0.010). Receiver operating characteristic curve analysis showed that the area under the curve value of cg22443212 was 0.744 (95% confidence interval, 0.586-0.866; P=0.002). CONCLUSIONS: We revealed that altered DNA methylation may play a role in the occurrence and development of ICAS. These results provided new epigenetic insights into ICAS.

Altered Spontaneous Activity and Functional Connectivity in the Posterior Pons of Patients With Migraine Without Aura.

The brainstem has been discussed as the main player in the pathogenesis of migraine. Dysfunctional brainstem nuclei and their abnormal connections to other key brain centers may contribute to headache and other symptoms of migraine. In the present study, 32 patients with migraine without aura (MWoA) and 32 age- and sex-matched healthy controls (HCs) underwent resting-state fMRI scans. We used masked independent analysis (mICA) to investigate whether patients with MWoA exhibited abnormal brainstem nuclei-cortical functional connectivity (FC). The mICA can suppress adjacent physiological noise and prevent results from being driven by the much stronger signals of the surrounding structures. Regional homogeneity (ReHo) was used to investigate whether the brainstem regions with abnormal FC to other brain areas exhibited abnormal regional neuronal activity. Patients with MWoA showed significantly weaker FC between the posterior pons and the left superior parietal lobule, the left middle temporal gyrus, and the left middle frontal gyrus. Furthermore, patients with MWoA exhibited significantly decreased ReHo values in the posterior pons compared with HCs, and the posterior pons ReHo value was significantly negatively correlated with HIT-6 scores in the MWoA group. Patients with MWoA exhibited functional abnormalities in the posterior pons and weakened connections between the posterior pons and several key cortical brain areas involved in pain processing during the resting state. PERSPECTIVE: This study provided increased evidence that the pons is involved in the pathophysiological mechanism of migraine, and weakened connections suggest that the touch and pain sensation of migraine sufferers may not be properly relayed to cortical processing areas, which may be associated with the pathogenesis of MWoA.

Blood Pressure Variability during Angiography in Patients with Ischemic Stroke and Intracranial Artery Stenosis.

Our aim was to investigate factors predicting blood pressure (BP) variability during diagnostic cerebral angiography and associations between BP variability and clinical outcomes in patients with acute and subacute ischemic stroke and intracranial artery stenosis. 114 patients with ischemic stroke and intracranial artery stenosis (stenosis rate >50%) were recruited. Patients who underwent cerebral angiography within 3 days and 3-14 days of disease onset are referred to be Group A and Group S, respectively. BP variability in Group A was defined as the coefficient of variance (CV) of BP. Univariate and multivariate regression analyses were used to identify predictors of CV of BP and associations between CV of BP and clinical outcomes at discharge. In Group A patients, advanced age was associated with increased CV of SBP and diastolic blood pressure (DBP), and antihypertensive use was associated with lower CV of SBP. Male was associated with lower CV of DBP. In Group S, higher CV of SBP was associated with hypertension and antihypertensive use. Males had lower CV of SBP than females. The calcium channel blocker was associated with lower CV of DBP. Higher scores of the Stroke Scale at admission were significantly associated with poor clinical outcomes for both groups, while BP variability was not. Factors associated with BP variability are significantly different between stroke patients undergoing angiography within 3 days vs. 3-14 days after disease onset. BP variability is not significantly associated with clinical outcomes at discharge.

Higher Platelet-to-Lymphocyte Ratio Is Associated With Worse Outcomes After Intravenous Thrombolysis in Acute Ischaemic Stroke.

Objective: The platelet-to-lymphocyte ratio (PLR) is a new marker of atherosclerotic inflammation and has been identified as a predictive factor in cardiovascular diseases, but its significance in patients with acute ischaemic stroke (AIS) who have undergone intravenous thrombolysis (IVT) is still unknown. Methods: Consecutive patients who were treated with IVT using recombinant tissue plasminogen activator (rtPA) for AIS were included from May 2012 to August 2018. The PLR was calculated according to platelet and lymphocyte counts within 24 h after thrombolysis therapy. Functional outcomes were assessed by the modified Rankin Scale (mRS) at 3 months after thrombolysis. Stroke severity was assessed by National Institutes of Health Stroke Scale (NIHSS) scores. The primary endpoint was an unfavorable outcome (mRS > 2), and the secondary endpoint was death at 3 months. Results: A total of 286 patients were included in the study. The median age was 69.5 (59.0-80.0) years, and 59.1% of patients were men. A total of 120 (42.0%) patients had an unfavorable outcome, and 38 (13.2%) died. Patients with an unfavorable outcome had significantly higher PLR values compared with those with a favorable outcome [172.5 (105.3-239.0) vs. 139 (97.0-194.5), P = 0.008], and the PLR values of the patients who died at 3 months were higher than those of the surviving patients [189.5 (127.5-289.0) vs. 142.0 (98.0-215.5), P = 0.006]. After adjustment for other variables, the PLR was independently associated with the two endpoints: unfavorable outcome (OR 2.220, 95% CI 1.245-3.957, P = 0.007) and death (OR 2.825, 95% CI 1.050-7.601, P = 0.040) at 3 months after thrombolysis. In addition, PLR was correlated with the NIHSS score (R = 0.230, P < 0.001). Conclusions: Higher PLR levels were independently associated with an unfavorable outcome and death at 3 months in AIS patients treated with IVT.

Increased plasma levels of miR-124-3p, miR-125b-5p and miR-192-5p are associated with outcomes in acute ischaemic stroke patients receiving thrombolysis.

BACKGROUND AND AIMS: Circulating microRNAs (miRNAs) have recently emerged as promising biomarkers for acute ischaemic stroke (AIS). However, the expression profiles of miRNAs in AIS patients receiving intravenous thrombolysis, and their associations with outcome have not been investigated. METHODS: In a prospective cohort study, a total of 84 AIS patients, who received intravenous thrombolysis (21.4% received combined reperfusion therapy) and completed 3 month follow-up visits, were included. Favourable and unfavourable outcomes were defined as modified Rankin Scale (mRS) scores of 0-1 and 2-6, respectively. Plasma samples were collected at 24 h after thrombolysis. We used RNA sequencing to study miRNA profiles in 5 patients with unfavourable outcomes and 5 matched patients with favourable outcomes. Differentially expressed miRNAs were further validated in all cohorts using quantitative real-time polymerase chain reaction assays. RESULTS: After identification and validation, we found that miR-124-3p, miR-125b-5p and miR-192-5p levels were higher in patients with unfavourable outcomes than in patients with favourable outcomes. Logistic regressions and receiver-operating characteristic curve analyses demonstrated that these altered miRNAs may function as predictive biomarkers for outcome in AIS patients receiving thrombolysis, whether combined with endovascular thrombectomy or not. In addition, miR-124-3p and miR-125b-5p were closely associated with stroke severity. CONCLUSIONS: A set of circulating microRNAs (miR-124-3p, miR-125b-5p and miR-192-5p) are associated with unfavourable 3 month outcomes and might have clinical utility in AIS patients receiving thrombolysis.

Lack of Correlation Between Intracranial Carotid Artery Modified Woodcock Calcification Score and Prognosis of Patients With Acute Ischemic Stroke After Intravenous Thrombolysis.

There have been few studies about the association between intracranial carotid artery calcification (ICAC) and acute ischemic stroke (AIS) prognosis after intravenous thrombolysis (IVT). We aimed to analyze the association between ICAC and prognosis (including symptomatic intracranial hemorrhage (sICH), functional outcome and death) of AIS patients treated with IVT. In this retrospective study, we consecutively included 232 AIS patients treated with IVT between April 2012 and December 2018. ICAC was evaluated using the modified Woodcock calcification visual score on non-enhanced cranial computed tomography scans. Poor functional outcome was defined as a modified Rankin Scale score > 2 at 3 months. We found that the modified Woodcock calcification score was associated with ICH, poor outcome, and death in univariable analyses on the symptomatic side and/or bilaterally. However, after adjustment for other different covariates, the results showed no significant difference. We documented that the presence and severity of ICAC did not significantly modify the beneficial effects of rtPA treatment in AIS.

Cerebellar functional abnormalities in early stage drug-naïve and medicated Parkinson's disease.

Parkinson's disease (PD) is a progressive neurological degenerative disorder characterized by impaired motor function and non-motor dysfunctions. While recent studies have highlighted the role of the cerebellum in PD, our understanding of its role in PD remains limited. In the present study, we used resting-state fMRI to evaluate dysfunctions within the cerebellum in PD patients treated with medication and drug-naïve PD patients. We applied amplitude of low-frequency fluctuation (ALFF) and degree centrality (DC) analysis methods. Thirty-one patients with early stage PD (22 drug-naïve and 9 medicated patients) and 31 gender- and age-matched healthy controls were recruited in this study. ALFFs increased in the left cerebellar areas (lobules VI/VIIb/CruI/CruII and the dentate gyrus) and right cerebellar areas (lobules VI/VIIb/VIIIa/CruI/CruII and the dentate gyrus) of all PD patients and in the left and right cerebellar areas (lobules VI/VIIb/CruI and the dentate gyrus) of drug-naive PD patients but were not significantly changed in medicated PD patients. DC increased in the right cerebellar areas of all PD patients and medicated PD patients. All PD patients and all drug-naive PD patients showed significantly weaker functional connectivity (FC) between the left cerebellum and the left medial frontal gyrus. However, FC was significantly stronger between the right cerebellum and the left precentral and right middle occipital gyri in the medicated PD patients than in controls. Furthermore, a correlation analyses revealed that ALFF z scores in the left cerebellum (lobule VI) and right cerebellum (lobule VI/CruI and dentate gyrus) were negatively correlated with Mini-Mental State Examination (MMSE) scores in all PD patients and drug-naive patients. These results indicate that the cerebellum plays an important role in PD, mainly by exerting a compensatory effect in early stage PD. Additionally, antiparkinsonian medication would modified PD-induced changes in local neural activity and FC in PD patients. The results of this study offer novel insights into the roles of the cerebellum in early stage drug-naïve PD.

Brain functional changes in patients with botulism after illegal cosmetic injections of botulinum toxin: A resting-state fMRI study.

BACKGROUND: Botulinum toxin type A (BoNT-A) is generally considered safe and is widely used to treat a variety of clinical conditions involving muscle hyperactivity and for cosmetic purposes. However, the effects of BoNT-A poisoning (botulism) on brain function are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Herein, we investigated brain functions in 9 patients who received illegal cosmetic injections of botulinum and 18 matched controls by combining the analysis methods of regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF) based on resting-state fMRI. Compared with the controls, the patients with botulism exhibited significantly reduced ReHo values in the left posterior lobe of the cerebellum extending to the right anterior lobe of the cerebellum, as well as in the right anterior lobe of the cerebellum extending to the parahippocampal gyrus and right posterior lobe of the cerebellum. The patients with botulism also showed weakened ALFF values in the right anterior lobe of the cerebellum extending to the left anterior lobe of the cerebellum and right posterior lobe of the cerebellum, as well as in the right anterior lobe of the cerebellum. CONCLUSIONS/SIGNIFICANCE: The results indicate that BoNT-A may modulate cerebral activation in specific areas, which may play roles in both the adverse effects of botulism and the mechanism underlying clinical treatment with BoNT-A.

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.

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.

The Posterior Insula Shows Disrupted Brain Functional Connectivity in Female Migraineurs Without Aura Based on Brainnetome Atlas.

Long-term headache attacks may cause human brain network reorganization in patients with migraine. In the current study, we calculated the topologic properties of functional networks based on the Brainnetome atlas using graph theory analysis in 29 female migraineurs without aura (MWoA) and in 29 female age-matched healthy controls. Compared with controls, female MWoA exhibited that the network properties altered, and the nodal centralities decreased/increased in some brain areas. In particular, the right posterior insula and the left medial superior occipital gyrus of patients exhibited significantly decreased nodal centrality compared with healthy controls. Furthermore, female MWoA exhibited a disrupted functional network, and notably, the two sub-regions of the right posterior insula exhibited decreased functional connectivity with many other brain regions. The topological metrics of functional networks in female MWoA included alterations in the nodal centrality of brain regions and disrupted connections between pair regions primarily involved in the discrimination of sensory features of pain, pain modulation or processing and sensory integration processing. In addition, the posterior insula decreased the nodal centrality, and exhibited disrupted connectivity with many other brain areas in female migraineurs, which suggests that the posterior insula plays an important role in female migraine pathology.