Consequence Of Intracerebral Hemorrhage Research Articles

Intracerebral Hemorrhage: Blood Components and Neurotoxicity.

Intracerebral hemorrhage (ICH) is a subtype of stroke which is associated with the highest mortality and morbidity rates of all strokes. Although it is a major public health problem, there is no effective treatment for ICH. As a consequence of ICH, various blood components accumulate in the brain parenchyma and are responsible for much of the secondary brain damage and ICH-induced neurological deficits. Therefore, the strategies that could attenuate the blood component-induced neurotoxicity and improve hematoma resolution are highly needed. The present article provides an overview of blood-induced brain injury after ICH and emphasizes the need to conduct further studies elucidating the mechanisms of hematoma resolution after ICH.

Brain Injury Biomarker Behavior in Spontaneous Intracerebral Hemorrhage

S100B and neuron-specific enolase (NSE) have been widely studied in diverse neurocritical pathologies, being recognized as the most promising biomarkers for brain injury assessment. However, their role in intracerebral hemorrhage (ICH) has not been widely analyzed. This was an observational prospective cohort study of patients with ICH admitted to a neurocritical care unit. Blood samples were collected on admission and at 24 hours, 48 hours, and 72 hours. Patient outcomes were assessed at 6 months after the event. Thirty-six patients with ICH were included in the study. The mortality rate was 36%. Nonsurvivors had higher S100B values than survivors at admission, 24 hours, and 48 hours (P < 0.05). Likewise, S100B levels were higher in patients with poor outcomes (modified Rankin Scale [mRS] score >4) compared with those with good outcome (mRS score ≤3) in the 24-hour, 48-hour, and 72-hour samples. Receiver operating characteristic (ROC) curve analysis showed that S100B at admission, 24 hours, and 48 hours can discriminate between patients who survive and those who die as a consequence of ICH. The 48-hour sample (area under the ROC curve, 0.817; P= 0.003) reached the best values for sensitivity (75%) and specificity (80%); cutoff, 0.250 μg/L. For 6-month functional outcome, S100B protein could differentiate between groups at 24, 48, and 72 hours. The S100B 24-hour sample had the best values for sensitivity (82.6%) and specificity (72.7%), with a cutoff of 0.202 μg/L. We found no clear relationship between NSE values and clinical characteristics. S100B protein acts as early predictor of mortality and functional outcome in patients with ICH. This biomarker measurement can provide additional information beyond clinical and radiologic findings to guide physicians in the management of these patients.

Emerging Risk Factors for Stroke: What Have We Learned From Mendelian Randomization Studies?

Establishing new approaches for the prevention and treatment of stroke relies on identifying modifiable risk factors that contribute to the development of this complex disease. Mendelian randomization (MR) studies, analogous to naturally occurring randomized trials, can assess causality of potentially modifiable biomarkers and offer new insights into biological pathways. Stroke is the second leading cause of death worldwide and the chief determinant of long-term disability. Stroke is a heterogeneous disease arising from several distinct underlying pathologies and is typically classified as ischemic or hemorrhagic, and further subclassified using imaging data. Ischemic stroke (IS), including its 3 main subtypes: small vessel disease, large vessel disease, and cardioembolic stroke, accounts for ≈80% of stroke and is the result of an interrupted blood supply, leading to localized areas of ischemia in the brain. Small vessel disease may be a consequence of nonatherosclerotic, as well as atherosclerotic, mechanisms that result in an occlusion of the small perforating arteries, whereas large vessel disease results from occlusions or emboli from plaque rupture in larger vessels, such as a carotid artery. Cardioembolic stroke arises typically from emboli from the heart. By contrast, hemorrhagic stroke is a consequence of intracerebral hemorrhage (bleeding into the brain) or subarachnoid hemorrhage (bleeding into the subarachnoid space). These diverse stroke subtypes have distinct underlying pathologies reflecting different risk factor distributions. MR studies, using genetic variants as instrumental variables, afford a powerful approach to assessing causality of risk factors and avoid biases inherent in observational studies, including confounding and reverse causation. This review considers the contribution of MR studies to stroke epidemiology and their relevance to understanding risk factors and new therapeutic targets for stroke. Meta-analyses of large prospective studies have enhanced our knowledge of classical and emerging risk factors for stroke.1–4 Classical risk factors for stroke include nonmodifiable characteristics, …

Cleaning up after ICH: the role of Nrf2 in modulating microglia function and hematoma clearance.

As a consequence of intracerebral hemorrhage (ICH), blood components enter brain parenchyma causing progressive damage to the surrounding brain. Unless hematoma is cleared, the reservoirs of blood continue to inflict injury to neurovascular structures and blunt the brain repair processes. Microglia/macrophages (MMΦ) represent the primary phagocytic system that mediates the cleanup of hematoma. Thus, the efficacy of phagocytic function by MMΦ is an essential step in limiting ICH-mediated damage. Using primary microglia to model red blood cell (main component of hematoma) clearance, we studied the role of transcription factor nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), a master-regulator of antioxidative defense, in the hematoma clearance process. We showed that in cultured microglia, activators of Nrf2 (i) induce antioxidative defense components, (ii) reduce peroxide formation, (iii) up-regulate phagocytosis-mediating scavenger receptor CD36, and (iv) enhance red blood cells (RBC) phagocytosis. Through inhibiting Nrf2 or CD36 in microglia, by DNA decoy or neutralizing antibody, we documented the important role of Nrf2 and CD36 in RBC phagocytosis. Using autologous blood injection ICH model to measure hematoma resolution, we showed that Nrf2 activator, sulforaphane, injected to animals after the onset of ICH, induced CD36 expression in ICH-affected brain and improved hematoma clearance in rats and wild-type mice, but expectedly not in Nrf2 knockout (KO) mice. Normal hematoma clearance was impaired in Nrf2-KO mice. Our experiments suggest that Nrf2 in microglia play an important role in augmenting the antioxidative capacity, phagocytosis, and hematoma clearance after ICH.

Allogeneic bone marrow stromal cell transplantation after cerebral hemorrhage achieves cell transdifferentiation and modulates endogenous neurogenesis

When a severe neurologic lesion occurs as a consequence of intracerebral hemorrhage (ICH), there is no effective treatment available for improving the outcome. However, cell therapy has opened new perspectives on reducing neurologic sequels subsequent to this disease. In this study, ICH was induced by stereotactic injection of 0.5 U collagenase type IV in the striatum of adult Wistar rats, and 2 h later a group of animals (n = 48) was subjected to intracerebral injection of 2 × 10(6) allogeneic bone marrow stromal cells (BMSC), while a control group (n = 48) received saline only. Eight animals from each group were killed at 48 h, 72 h, 7 days, 14 days, 21 days and 28 days. At these time-points, endogenous neurogenesis and survival of transplanted BMSC were studied. Our findings show that after allogeneic BMSC transplantation, donor cells can survive in the brain tissue expressing neuronal and astroglial markers. Furthermore, BMSC transplantation enhances endogenous neurogenesis and inhibits apoptosis of newborn neural cells. Although these results should be extrapolated to human disease with caution, it is obvious that cell therapy using allogeneic BMSC transplantation offers great promise for developing novel and efficacious strategies in patients suffering ICH.