JAK2 V617F Mutation and Large Cerebral Artery Disease in Patients with Myeloproliferative Neoplasms.

AIM: The aim of the present study was to clarify the association between the Janus kinase 2 (JAK2) V617F mutation and large cerebral artery disease (LCAD) in patients with myeloproliferative neoplasms (MPNs). METHODS: We retrospectively analysed patients diagnosed with MPNs between June 1992 and June 2022 who underwent brain magnetic resonance imaging. LCAD was defined as extracranial or intracranial large artery stenosis (≥ 50%) or occlusion on magnetic resonance angiography. RESULTS: A total of 86 patients (47 males; median age, 69 years old) were enrolled in this study. JAK2 V617F mutation was detected in 63 (73.3%) patients and LCAD in 35 (40.7%) patients. Univariate analysis showed that history of ischaemic stroke (LCAD, 62.9% vs. non-LCAD, 11.8%; P＜0.001), JAK2 V617F mutation (91.4% vs. 60.8%, P=0.002), and age ≥ 60 years (85.7% vs. 60.8%, P=0.016) were significantly associated with LCAD. Multiple logistic regression analysis showed that, in addition to ischaemic stroke, age ≥ 60 years and diabetes mellitus, JAK2 V617F mutation (odds ratio 29.2, 95% confidence interval 1.2-709.8, P=0.038) was independently associated with LCAD. LCAD was frequently observed in the intracranial carotid (14/35, 40.0%) and middle cerebral (13/35, 37.1%) arteries. CONCLUSIONS: This study revealed a significant association between the JAK2 V617F mutation and LCAD in patients with MPNs. This suggests that the JAK2 V617F mutation may promote cerebrovascular atherosclerosis and could be very important in determining therapeutic strategies for patients with not only JAK2 V617F-mutated MPNs but also LCAD-related stroke.

Short-term or long-term outcomes for stroke patients with cancer according to biological markers.

BACKGROUND: Although hypercoagulability using D-dimer levels may be a useful marker for predicting outcomes in ischemic stroke patients with cancer, other biological markers for predicting outcomes are unclear. We aimed to investigate the associations between several biological markers and short-term or long-term outcomes among ischemic stroke patients with cancer. METHODS: Consecutive acute ischemic stroke patients with cancer (n = 309) were registered. Biological markers such as hemoglobin, albumin, C-reactive protein and D-dimer levels were assessed. Stroke outcomes, namely, a 3-month modified Rankin Scale score indicating poor functional outcome (mRS score of 3-6) and 1-year survival, were assessed. RESULTS: Of the 277 patients who could be assessed for 3 months outcome, 131 patients (47.3%) had a poor outcome at 3 months. Multivariable analysis revealed that increased D-dimer levels and decreased albumin levels were independently associated with poor stroke outcomes (adjusted odds ratio [aOR]: 1.04, 95% confidence interval [CI]: 1.00-1.08, and aOR: 0.50, 95% CI: 0.31-0.80, respectively). Of 309 patients, 70 patients (22.7%) died during the follow-up period (median, 241 days). Multivariate Cox proportional hazard analyses showed that high D-dimer levels and hypoalbuminemia were independently associated with mortality (adjusted hazard ratio [aHR]: 2.65, 95% CI: 1.37-5.12, and aHR: 2.29, 95% CI: 1.21-4.49, respectively). The effect of each biological marker on mortality was notably observed among patients with active cancer but not among those with nonactive cancer. CONCLUSION: Low albumin levels were independently associated with short- and long-term outcomes, as were D-dimer levels, in acute ischemic stroke patients with cancer.

Clinical characteristics and tumor markers in ischemic stroke patients with active cancer.

Cancer-associated ischemic stroke (CAS) refers to a hypercoagulation disorder related to malignant tumors, especially adenocarcinoma. Carbohydrate antigen (CA) 125 is a mucinous serum marker that might reflect hypercoagulation status, but the association between CA 125 and CAS is unclear across various types of cancer. The aim of this study was to investigate the associations among tumor markers, coagulation markers, and clinical factors in acute ischemic stroke (AIS) patients with active cancer. Consecutive AIS patients with active cancer (a diagnosis or ongoing active therapy for cancer within 6 months) were prospectively enrolled at four hospitals. D-dimer, C-reactive protein (CRP), carcinoembryonic antigen (CEA), CA19-9, and CA 125 levels were measured. Of 120 AIS patients with active cancer, 47 were diagnosed with CAS. CA 125 had the strongest correlations with D-dimer and CRP (ρ = 0.543, p < 0.001 and ρ = 0.452, p < 0.001, respectively). The areas under the receiver-operating characteristic curves for the diagnosis of CAS were 0.812 (95% CI 0.718-0.878) for CA 125, 0.714 (95% CI 0.602-0.801) for CEA, and 0.663 (95% CI 0.552-0.759) for CA 19-9. Multivariable analysis revealed that CA 125 levels in the highest quartile (OR 2.91, 95% CI 1.68-5.53), multiple lesions in multiple vascular territories observed on diffusion-weighted imaging, the absence of dyslipidemia, and the absence of atrial fibrillation were independently associated with CAS. Increased CA 125 levels, which indicate hypercoagulability, were useful for diagnosing CAS in AIS patients with active cancer.

Increased plasma plasmin-α2-plasmin inhibitor complex levels correlate with postoperative rebleeding after endoscopic surgery for spontaneous intracerebral hemorrhage.

BACKGROUND: Postoperative rebleeding (PR) is one of the most severe complications of endoscopic surgery, often performed to remove spontaneous intracerebral hemorrhage (sICH). However, the risk factors for PR remain unclear. OBJECTIVE: This study retrospectively investigated whether increased preoperative plasma plasmin-α2-plasmin inhibitor complex (PIC) levels, indicating activation of fibrinolysis, are associated with PR. METHODS: A total of 101 patients underwent endoscopic surgery to evacuate sICH at our institution from January 2010 to June 2019, and 79 patients who underwent examinations of plasma PIC levels at admission with available radiographical data were included. Correlations between PR and increased plasma PIC levels were retrospectively evaluated. RESULTS: PR occurred in eight patients (10.1%), and high PIC levels (≥ 4 or 6 µg/ml) were significantly associated with PR. The sensitivities employing high PIC levels of ≥ 4 µg/ml and ≥ 6 µg/ml were both 0.63, and the specificities using the same PIC levels were 0.86 and 0.92, respectively. Multivariable analyses showed that high plasma PIC levels of ≥ 4 µg/ml (odds ratio (OR), 12.77; 95% confidence interval (CI), 1.65-98.77; p = 0.02) or ≥ 6 µg/ml (OR, 18.33; 95% CI, 2.32-144.82; p = 0.006) were independent predictors of PR. CONCLUSIONS: This study found that increased plasma PIC levels were associated with PR following the endoscopic evacuation of sICHs, indicating that increased plasma PIC levels could be potentially used to predict PR. Further studies are needed to establish new surgical strategies and adjuvant treatments to improve surgical outcomes in patients with sICH prone to PR.

Does Noncontrast Computed Tomography Scan Predict Rebleeding After Endoscopic Surgery for Spontaneous Intracerebral Hemorrhage?

BACKGROUND: The relationship between noncontrast computed tomography (CT) markers, which predict the expansion of spontaneous intracerebral hemorrhage (sICH) under conservative treatment, and postoperative rebleeding (PR) after treatment by directly removing the sICH is unknown. This study investigated the relationship between noncontrast CT markers and PR in patients with sICH treated by endoscopic surgery. METHODS: The study population included 92 patients with available data who underwent endoscopic surgery for sICH at our institution from January 2010 to September 2018. The correlations between PR and preoperative noncontrast CT markers, including the blend sign, hypodensities, black hole sign, heterogeneous density, and island signs, were retrospectively evaluated. RESULTS: In 5 of the 18 patients (27.8%) with the blend sign, PR developed, whereas only 5 of 74 patients (6.8%) without the blend sign developed PR. In the univariate regression analyses, manifestation of hydrocephalus (odds ratio [OR], 8.75; 95% confidence interval [CI], 2.15-35.68; P = 0.002), presence of the blend sign (OR, 5.31; 95% CI, 1.34-20.97; P = 0.02), and insertion of external ventricular drainage (OR, 13.88; 95% CI, 3.22-59.77; P < 0.001) were significant risk factors. The other radiographic markers were not associated with PR. In a multivariate analysis, the presence of the blend sign (OR, 22.07; 95% CI, 2.18-223.60; P = 0.009) was the only independent predictor of PR. CONCLUSIONS: The blend sign is likely to be a strong predictor for PR in patients who undergo endoscopic surgery for sICH. To improve the prognosis of patients with sICH, further studies are needed to establish new treatment strategies and surgical procedures.

Exploratory Investigation of Intestinal Function and Bacterial Translocation After Focal Cerebral Ischemia in the Mouse.

Background and Purpose: The gut communicates with the brain bidirectionally via neural, humoral and immune pathways. All these pathways are affected by acute brain lesions, such as stroke. Brain-gut communication may therefore impact on the overall outcome after CNS-injury. Until now, contradictory reports on intestinal function and translocation of gut bacteria after experimental stroke have been published. Accordingly, we aimed to specifically investigate the effects of transient focal cerebral ischemia on intestinal permeability, gut associated lymphoid tissue and bacterial translocation in an exploratory study using a well-characterized murine stroke model. Methods: After 60 min of middle cerebral artery occlusion (MCAO) we assessed intestinal morphology (time points after surgery day 0, 3, 5, 14, 21) and tight junction protein expression (occludin and claudin-1 at day 1 and 3) in 12-week-old male C57Bl/6J mice. Lactulose/mannitol/sucralose test was performed to assess intestinal permeability 24-72 h after surgery. To investigate the influence of cerebral ischemia on the local immune system of the gut, main immune cell populations in Peyer's patches (PP) were quantified by flow cytometry. Finally, we evaluated bacterial translocation to extraintestinal organs 24 and 72 h after MCAO by microbiological culture and fluorescence in situ hybridization targeting bacterial 16S rRNA. Results: Transient MCAO decreased claudin-1 expression in the ileum but not in the colon. Intestinal morphology (assessed by light microscopy) and permeability did not change measurably after MCAO. After MCAO, animals had significantly fewer B cells in PP compared to naïve mice. Conclusions: In a murine model of stroke, which leads to large brain infarctions in the middle cerebral artery territory, we did not find evidence for overt alterations neither in gut morphology, barrier proteins and permeability nor presence of intestinal bacterial translocation.

Recurrent Stroke Due to Metastatic Pulmonary Tumor Emboli as an Important Clinical Entity.

We present an autopsy case of repetitive stroke due to tumor emboli, indistinguishable from thromboembolism with a hypercoagulable state in its clinical course. A 72-year-old man diagnosed with stage IVA oropharyngeal squamous cell carcinoma received chemoradiotherapy. Follow-up imaging revealed mediastinal lymph nodes and pulmonary metastasis. One year later, the patient experienced right arm weakness, and brain magnetic resonance imaging showed acute ischemic lesions in multiple vascular territories. He was diagnosed with paradoxical cerebral embolism due to cancer-associated venous thrombosis and treated with rivaroxaban. However, newly developed cerebral infarcts were confirmed 1 month later. Then, rivaroxaban treatment was switched to subcutaneous unfractionated heparin injection. He was admitted again for stroke recurrence and died of respiratory failure 8 days after admission. Autopsy demonstrated pulmonary metastasis invading the veins and tumor emboli in the culprit cerebral arteries. D-dimer was kept constant at a slightly higher level, ranging from 1 to 3 µg/mL during the course of recurrence. We should consider tumor embolism in the differential diagnosis of recurrent stroke along with pulmonary tumor and resistance to heparin preparations with unchanged D-dimer levels.

Diagnostic Utility of Contrast-enhanced 3D T1-weighted Imaging in Acute Cerebral Infarction Associated with Graves Disease.

Graves disease is rarely complicated with cerebrovascular steno-occlusive diseases. Previous studies have suggested several hypotheses for this occurrence, including excess thyroid hormone, which stimulates the sympathetic nervous system, which in turn causes an abnormal hemodynamic response with consequent atherosclerotic changes, and antithyroid antibodies cause local vascular inflammation in patients with Graves disease. However, radiological findings of vasculitis in patients with Graves disease and cerebral infarction remain less known. We report the case of a 30-year-old Japanese woman with acute cerebral infarction due to vasculitis associated with Graves disease. She was admitted to our hospital with a 4-day history of intermittent transient dysarthria and limb shaking of the left leg when standing. Three weeks before admission, she went to a local hospital because of general malaise and was diagnosed with Graves disease. Neurological examination revealed paralytic dysarthria, left central facial nerve palsy, and left hemiparesis (manual muscle testing, 4 of 5). Blood examinations showed hyperthyroidism (thyroid-stimulating hormone ≤.010 µU/mL; free T3 ≥25.0 pg/mL; free T4 ≥8.0 ng/dL) and elevation of antithyroid antibody levels (thyroid peroxidase antibody, 87 IU/mL). The vessel wall of the right internal carotid artery was markedly enhanced on contrast-enhanced three-dimensional T1-weighted magnetic resonance imaging, suggesting vasculitis. Magnetic resonance angiography revealed right internal carotid artery occlusion after the branching ophthalmic artery. Arterial stenosis due to vasculitis was considered the cause of hemodynamic ischemic stroke. Vessel wall imaging such as high-resolution contrast-enhanced T1-weighted imaging seems useful for assessing the underlying mechanism of stroke in patients with Graves disease.

Depletion of Cultivatable Gut Microbiota by Broad-Spectrum Antibiotic Pretreatment Worsens Outcome After Murine Stroke.

BACKGROUND AND PURPOSE: Antibiotics disturbing microbiota are often used in treatment of poststroke infections. A bidirectional brain-gut microbiota axis was recently suggested as a modulator of nervous system diseases. We hypothesized that gut microbiota may be an important player in the course of stroke. METHODS: We investigated the outcome of focal cerebral ischemia in C57BL/6J mice after an 8-week decontamination with quintuple broad-spectrum antibiotic cocktail. These microbiota-depleted animals were subjected to 60 minutes middle cerebral artery occlusion or sham operation. Infarct volume was measured using magnetic resonance imaging, and mice were monitored clinically throughout the whole experiment. At the end point, tissues were preserved for further analysis, comprising histology and immunologic investigations using flow cytometry. RESULTS: We found significantly decreased survival in the middle cerebral artery occlusion microbiota-depleted mice when the antibiotic cocktail was stopped 3 days before surgery (compared with middle cerebral artery occlusion specific pathogen-free and sham-operated microbiota-depleted mice). Moreover, all microbiota-depleted animals in which antibiotic treatment was terminated developed severe acute colitis. This phenotype was rescued by continuous antibiotic treatment or colonization with specific pathogen-free microbiota before surgery. Further, infarct volumes on day one did not differ between any of the experimental groups. CONCLUSIONS: Conventional microbiota ensures intestinal protection in the mouse model of experimental stroke and prevents development of acute and severe colitis in microbiota-depleted mice not given antibiotic protection after cerebral ischemia. Our experiments raise the clinically important question as to whether microbial colonization or specific microbiota are crucial for stroke outcome.

Chronic Elevation of Tumor Necrosis Factor-α Mediates the Impairment of Leptomeningeal Arteriogenesis in db/db Mice.

BACKGROUND AND PURPOSE: Leptomeningeal collateral growth is a key factor that defines the severity of ischemic stroke. Patients with stroke generally have vascular risk factors, such as diabetes mellitus; however, consensus is lacking on how diabetes mellitus affects leptomeningeal arteriogenesis. We investigate the influence of diabetes mellitus on the leptomeningeal arteriogenesis. METHODS: We measured the vessel diameter of the leptomeningeal anastomoses 14 days after the common carotid artery occlusion in db/db, db/+, and streptozotocin-induced hyperglycemic mice. In another set of these mice, we measured the infarct volume attributed to subsequent middle cerebral artery occlusion 14 days after the common carotid artery occlusion. Mac-2-positive cells on the dorsal brain surface and the mRNA expression of several macrophage-related factors in the cerebral cortex were examined. Finally, we tested whether the leptomeningeal arteriogenesis could be restored by pharmaceutical intervention in the db/db mice. RESULTS: Cerebral hypoperfusion led to significant ipsilateral leptomeningeal collateral growth in db/+ mice and streptozotocin-induced hyperglycemic mice. The collateral growth contributed to reduced infarct volume. In contrast, leptomeningeal arteriogenesis was impaired in the db/db mice. The number of Mac-2-positive cells was increased and tumor necrosis factor-α mRNA expression was induced after common carotid artery occlusion in the db/+ mice. However, these responses were not observed in the db/db mice. Administration of the tumor necrosis factor-α inhibitor etanercept before common carotid artery occlusion restored the hypoperfusion-induced leptomeningeal collateral growth in db/db mice. CONCLUSIONS: These results indicate that leptomeningeal arteriogenesis is impaired in db/db mice and that suppression of the tumor necrosis factor-α response to hypoperfusion is the major contributing factor.

Granulocyte colony-stimulating factor enhances arteriogenesis and ameliorates cerebral damage in a mouse model of ischemic stroke.

BACKGROUND AND PURPOSE: Enhancing collateral artery growth is a potent therapeutic approach to treat cardiovascular ischemic disease from occlusive artery. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has gained attention for its ability to promote arteriogenesis, ameliorating brain damage, by the mechanisms involving monocyte upregulation. However, the recent clinical study testing its efficacy in myocardial ischemia has raised the question about its safety. We tested alternative colony-stimulating factors for their effects on collateral artery growth and brain protection. METHODS: Brain hypoperfusion was produced by occluding the left common carotid artery in C57/BL6 mice. After the surgery, granulocyte colony-stimulating factor, macrophage colony-stimulating factor, or GM-CSF (100 µg/kg/day) was administered daily for 5 days. The angioarchitecture for leptomeningeal anastomoses and the circle of Willis were visualized after the colony-stimulating factor treatment. Circulating blood monocytes and Mac-2-positive cells in the dorsal surface of the brain were determined. A set of animals underwent subsequent ipsilateral middle cerebral artery occlusion and infarct volume was assessed. RESULTS: Granulocyte colony-stimulating factor as well as GM-CSF promoted leptomeningeal collateral growth after common carotid artery occlusion. Both granulocyte colony-stimulating factor and GM-CSF increased circulating blood monocytes and Mac-2-positive cells in the dorsal brain surface, suggesting the mechanisms coupled to monocyte upregulation might be shared. Infarct volume after middle cerebral artery occlusion was reduced by granulocyte colony-stimulating factor, similarly to GM-CSF. Macrophage colony-stimulating factor showed none of theses effects. CONCLUSIONS: Granulocyte colony-stimulating factor enhances collateral artery growth and reduces infarct volume in a mouse model of brain ischemia, similarly to GM-CSF.

Granulocyte-macrophage colony-stimulating factor enhances leptomeningeal collateral growth induced by common carotid artery occlusion.

BACKGROUND AND PURPOSE: Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been reported to accelerate collateral growth (arteriogenesis) at the circle of Willis in rat brain. However, the effect of GM-CSF on leptomeningeal collateral growth has not been established. We examined the effect of unilateral common carotid artery (CCA) occlusion and GM-CSF treatment on leptomeningeal collateral growth in mice. METHODS: Adult mice were subjected to unilateral CCA occlusion or sham surgery followed by an alternate-day regimen of GM-CSF (20 microg/kg) or saline injection. On day 7, latex perfusion was performed in 1 set of mice to visualize the leptomeningeal vessels, and the number of Mac-2(+) monocytes/macrophages on the dorsal surface of the brain was counted. In another set of mice, on day 7, permanent ipsilateral middle cerebral artery (MCA) occlusion was performed, and infarct volume was measured. RESULTS: Leptomeningeal collateral growth was observed after CCA occlusion, and that was enhanced by GM-CSF treatment. An increase in the number of Mac-2(+) cells on the surface of the brain occurred after CCA occlusion and was enhanced by GM-CSF treatment. Seven days after CCA occlusion, GM-CSF treatment decreased the infarct size attributable to subsequent MCA occlusion. CONCLUSIONS: After CCA occlusion, GM-CSF treatment enhanced leptomeningeal collateral growth and decreased the infarct size after MCA occlusion in mice.