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Background: Radiation treatment for diseases of the brain can result in hemorrhagic adverse radiation effects. The underlying pathologic substrate of brain bleeding after irradiation has not been elucidated, nor potential associations with induced somatic mutations., Methods: We retrospectively reviewed our department's pathology database over 5 years and identified 5 biopsy specimens (4 patients) for hemorrhagic lesions after brain irradiation. Tissues with active malignancy were excluded. Samples were characterized using H&E, Perl's Prussian Blue, and Masson's Trichrome; immunostaining for B-cells (anti-CD20), T-cells (anti-CD3), endothelium (anti-CD31), macrophages (anti-CD163), α-smooth muscle actin, and TUNEL. DNA analysis was done by two panels of next-generation sequencing for somatic mutations associated with known cerebrovascular anomalies., Results: One lesion involved hemorrhagic expansion among multifocal microbleeds that had developed after craniospinal irradiation for distant medulloblastoma treatment. Three bleeds arose in the bed of focally irradiated arteriovenous malformations (AVM) after confirmed obliteration. A fifth specimen involved the radiation field distinct from an irradiated AVM bed. From these, 2 patterns of hemorrhagic vascular pathology were identified: encapsulated hematomas and cavernous-like malformations. All lesions included telangiectasias with dysmorphic endothelium, consistent with primordial cavernous malformations with an associated inflammatory response. DNA analysis demonstrated genetic variants in PIK3CA and/or PTEN genes but excluded mutations in CCM genes., Conclusions: Despite pathologic heterogeneity, brain bleeding after irradiation is uniformly associated with primordial cavernous-like telangiectasias and disruption of genes implicated in dysangiogenesis but not genes implicated as causative of cerebral cavernous malformations. This may implicate a novel signaling axis as an area for future study., Competing Interests: Declaration of competing interest Drs. Awad and Marchuk receive grant funding from the U.S. National Institutes of Health and the Department of Defense. Dr. Awad is a consultant to Neurelis, Inc. The other authors report no conflicts, (Copyright © 2024. Published by Elsevier Inc.)

Objectives: To study the molecular mechanisms of miR-18a aggravating intracranial hemorrhage (ICH) by increasing the blood-brain barrier (BBB) permeability., Methods: Brain microvascular endothelial cells (BMVECs) and astrocytes were isolated, identified, and co-cultured to establish in vitro BBB model. BMVECs co-cultured with astrocytes were stimulated with or without thrombase and then transfected with miR-18a mimic and/or si-RUNX1. The trans-endothelial electric resistance (TEER) and FlNa flux were measured, respectively. The potential interaction between RUNX1 and miR-18a was also detected. Additionally, SD rats were injected with fresh autologous non-anticoagulant blood into the brain basal ganglia to establish ICH model. After administration with miR-18a, sh-miR-18a, miR-18a+RUNX1, sh-miR-18a+sh-RUNX1, respectively, BBB permeability was assessed., Results: After overexpressing miR-18a, the expression levels of RUNX1, Occludin and ZO-1 were decreased, but the Evan's blue contents and brain water contents were significantly increased in ICH rats. Additionally, rat neurological function was impaired, accompanying with an increase of TEER and fluorescein sodium flux. MiR-18a was a direct target of RUNX1 and it could bind to the promoters of RUNX1 to inhibit the expression of Occuldin and ZO-1. Consistently, these phenomena could also be observed in the corresponding cell model. Conversely, miR-18a knockdown or RUNX1 overexpression just presented an improvement effect on ICH., Conclusions: MiR-18a plays a critical role during ICH because it targets to RUNX1 to inhibit the expression of tight junction proteins (Occludin and ZO-1) and then disrupt BBB permeability. MiR-18a might be a probable therapeutic target for ICH diseases., Competing Interests: Declaration of Competing Interest The authors report no conflicts of interest., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Mutations in type four collagens, specifically COL4A1 and COL4A2, have been associated with cerebral small vessel disease (SVD), defined as lacunar infarcts, deep intracerebral hemorrhages (ICH), and leukoaraiosis. We present a case of a man with recurrent cerebral infarcts, related to a novel COL4A2 mutation, the p.A1534S variant. Magnetic resonance imaging demonstrated multiple lacunar infarcts, numerous deep and lobar microhemorrhages and advanced leukoaraiosis. Evaluation for COL4A2 mutations should be considered when suspecting a genetic cerebral small vessel disease., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Our objective is to reported a Chinese CARASIL patient caused by novel compound heterozygous mutations in HTRA1. Detailed clinical and neuroimaging examination were conducted in proband and her available family members. Sanger sequencing of NOTCH3 and HTRA1 was used to investigate causative mutations. The patient was born in an outbred family. She experienced recurrent transient ischemic attacks, hair loss, and low back pain. Brain magnetic resonance imaging showed multiple lacunar infarctions, diffuse leukoencephalopathy, and multiple microbleeds of white matter. A compound heterozygous mutation, c.958G > A (p.D320N) and c.1021G > A (p.G341J), were identified in the proband. This report highlights that screening of HTRA1 should be considered in young SVD patient despite from outbred families., (Copyright © 2018. Published by Elsevier Inc.)

Oculomeningovascular amyloidosis is a variant of transthyretin (TTR) amyloidotic polyneuropathy, which is associated with blindness and brain ischemia, microhemorrages, and siderosis due to prominent production of the abnormal TTR in the eye and in the choroid plexuses. Tafamidis is a TTR stabilizer that is orally administered and, by interfering with amyloid fibril formation and deposition, is capable of slowing progression of TTR polyneuropathy and of early-stage cardiomyopathy. However, the ocular manifestations of amyloid deposition progressed despite tafamidis therapy in Val30Met TTR amyloidosis, and the effects of tafamidis on meningovascular amyloidosis are unknown. We observed failure of tafamidis to halt progression of oculomeningovascular amyloid deposition in a patient with familial Ala36Pro TTR amyloidosis. She received molecular diagnosis at age 24 and presented at age 26 with paresthesias of the lower limbs and bowel dysfunction. Echography showed minimal amyloid opacities in the corpus vitreum. Treatment with tafamidis meglumine was started. Sixteen months later, she complained of severe headache followed by left hemiparesthesias and numbness lasting 20 minutes. Magnetic resonance imaging showed multiple focal and diffuse hemosiderin deposits compatible with microbleeds and early siderosis. Echography showed a marked increase of "vitreal opacities." Our observation confirms that tafamidis fails in halting increase of vitreal amyloid deposits and indicates that it is presumably ineffective in preventing clinical onset due to progression of meningovascular amyloidosis. These failures may be due to the incapability of tafamidis to cross the blood-retina and blood-brain barriers. Therapeutic options targeting oculomeningovascular TTR amyloidoses in humans are required., (Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Background: The number of deaths from hemorrhagic strokes is about twice as high than the number of deaths from ischemic strokes. Genetic risk assessment could play important roles in preventive and therapeutic strategies. The present study was aimed to evaluate whether the MTHFR gene polymorphisms could increase the risk of cerebral hemorrhage in Moroccan patients., Methods: A total of 113 patients with hemorrhagic stroke and 323 healthy controls were included in this case-control study. The C677T (rs1801133) and A1298C (rs1801131) MTHFR gene polymorphisms were genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method in all patients and controls. The genotype and allele frequencies were compared between groups using appropriate statistical analyses., Results: Both groups, patients and controls, were in accordance with the Hardy-Weinberg Equilibrium. For the C677T polymorphism, the frequencies of the CC, CT, and TT genotypes were 50.44% versus 46.13%, 39.82% versus 43.03, and 9.73% versus 10.84% in controls versus patients, respectively, whereas for the A1298C polymorphism, the frequencies of the AA, AC, and CC genotypes were 56.64% versus 57.59%, 40.71% versus 37.15, and 2.65% versus 5.26% in controls versus patients, respectively. No statistically significant difference has been proved between patients and controls frequencies (P >.05) for all additive, recessive, and dominant models. Additional analyses including genotypes combination, allelic frequencies, and hemorrhagic stroke patient subtypes did not show any statistically significant difference between controls and patients/subgroup patients., Conclusions: Our findings suggested no association between MTHFR gene polymorphisms and susceptibility to hemorrhagic strokes in Moroccan patients. Further investigations should be conducted to elucidate the roles of other gene variants in the pathogenesis of this condition., (Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Isolated cortical vein thrombosis (ICVT) accounts for less than 1% of strokes. We report a 47-year-old female patient who had a frontal hemorrhage with headache associated with contralateral hemiparesis and hemisensory deficit on presentation. This hemorrhagic stroke was localized in a nonarterial territory, and it was caused by ipsilateral and isolated thrombosis of the vein of Labbe found on catheter angiogram that demonstrated a filling defect of the vein of Labbe at its connection with the transverse sinus. There were no filling defects in the superficial middle cerebral veins. Our patient had a family history of cardiovascular disease, stroke, and factor V Leiden mutation and cigarette smoking as stroke risk factors. Complete prothrombotic state laboratory workup revealed a heterozygous prothrombin G20210 A gene mutation. The patient's hospital course was uneventful. Neurologic exam was normal at stroke clinic follow-up 6 weeks later. To our knowledge, this is the first report of an ICVT associated with prothrombin gene mutation., (Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.)