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Background and Purpose-Studies suggest statins ameliorate aneurysmal subarachnoid hemorrhage (SAH)-induced cerebral vasospasm and ischemic complications. We tested safety and feasibility of simvastatin 80 mg/d for vasospasm prevention in SAH patients. Methods-Thirty-nine statin-naïve Fisher grade 3 SAH subjects were double-blind randomized to receive simvastatin 80 mg/d (nϭ19) or placebo (nϭ20), stratified by Hunt and Hess grade. Primary end points were death and drug morbidity. Results-Mortality was 3/20 in the placebo and 0/19 in the simvastatin group. Study drug was withdrawn in 1 subject in each treatment group for reversible liver enzyme or creatine phosphokinase elevation. MethodsThirty-nine adults (age Ͼ18) with Fisher grade 3 SAH were included. Subjects were eligible if their ruptured aneurysm(s) were secured and if study drug can be started within 96 hours of aneurysm rupture. Patients at high risk for early mortality (Hunt and Hess grade V, or intracranial pressure Ͼ30 cm H 2 O for Ͼ30 minutes) were excluded. Other exclusion criteria were abnormal baseline serum creatine phosphokinase (CPK), alanine aminotransferase (ALT), or aspartate aminotransferase (AST), prior statin use, and contraindication for statin use. The institutional review board approved this study (ClinicalTrials.gov Identifier: NCT00235963).After informed consent from patient or health-care proxy, subjects were double-blind randomized to receive placebo or simvastatin 80 mg/d (until discharge from neurointensive care unit, or a maximum of 21 days), stratified by Hunt and Hess scores (I-II versus III-IV) to ensure an even distribution of this important outcome predictor. Plasma CPK, ALT and AST were monitored every 7 days. Study drug was stopped on unexplained 3-fold elevation of CPK or ALT/AST on 2 consecutive measurements 24 hours apart.Primary end points of this study were death and incidence of drug morbidity defined as CK/AST/ALT elevation. Secondary outcomes included incidence of transcranial Doppler (TCD), angiographic or clinical vasospasm, vasospasm-related infarcts, clinical outcomes at discharge, and cardiac and infectious morbidities.Angiographic vasospasm was defined as focal or generalized reduction of cerebral arterial caliber on conventional cerebral angiogram confirmed by a neuroradiologist and a neurocritical care physician. TCD vasospasm was defined as any peak systolic middle cerebral artery velocity (PSV MCA ) Ͼ200 cm/s and a Lindegaard ratio of Ͼ3. Clinically, delayed ischemic neurological deficit (DIND) was defined as any 2 or more point fall in modified Glasgow Coma Scale or unaccountable new focal neurological deficit lasting Ն2 hours. Vasospasm-related ischemic infarct was defined as the development of a new lesion consistent with infarction on CT or MRI in the vascular territory of angiographic or TCD vasospasm.All patients received nimodipine and an anticonvulsant, were kept euthermic, euvolemic, and euglycemic, and had daily TCD monitoring per standardized protocols. Patients with abnormal TCD velocities or...

Growing evidences suggest that stroke is a systemic disease affecting many organ systems beyond the brain. Stroke-related systemic inflammatory response and immune dysregulations may play an important role in brain injury, recovery, and stroke outcome. The two main phenomena in stroke-related peripheral immune dysregulations are systemic inflammation and post-stroke immunosuppression. There is emerging evidence suggesting that the spleen contracts following ischemic stroke, activates peripheral immune response and this may further potentiate brain injury. Whether similar brain–immune crosstalk occurs in hemorrhagic strokes such as intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) is not established. In this review, we systematically examined animal and human evidence to date on peripheral immune responses associated with hemorrhagic strokes. Specifically, we reviewed the impact of clinical systemic inflammatory response syndrome (SIRS), inflammation- and immune-associated biomarkers, the brain–spleen interaction, and cellular mediators of peripheral immune responses to ICH and SAH including regulatory T cells (Tregs). While there is growing data suggesting that peripheral immune dysregulation following hemorrhagic strokes may be important in brain injury pathogenesis and outcome, details of this brain-immune system cross-talk remain insufficiently understood. This is an important unmet scientific need that may lead to novel therapeutic strategies in this highly morbid condition.

Intracerebral hemorrhage (ICH) is a devastating form of stroke affecting millions of people worldwide. Parenchymal hematoma triggers a series of reactions leading to primary and secondary brain injuries and permanent neurological deficits. Microglia and macrophages carry out hematoma clearance, thereby facilitating functional recovery after ICH. Here, we elucidate a pivotal role for the interleukin (IL)-4)/signal transducer and activator of transcription 6 (STAT6) axis in promoting long-term recovery in both blood- and collagenase-injection mouse models of ICH, through modulation of microglia/macrophage functions. In both ICH models, STAT6 was activated in microglia/macrophages (i.e., enhanced expression of phospho-STAT6 in Iba1+cells). Intranasal delivery of IL-4 nanoparticles after ICH hastened STAT6 activation and facilitated hematoma resolution. IL-4 treatment improved long-term functional recovery in young and aged male and young female mice. In contrast, STAT6 knockout (KO) mice exhibited worse outcomes than WT mice in both ICH models and were less responsive to IL-4 treatment. The construction of bone marrow chimera mice demonstrated that STAT6 KO in either the CNS or periphery exacerbated ICH outcomes. STAT6 KO impaired the capacity of phagocytes to engulf red blood cells in the ICH brain and in primary cultures. Transcriptional analyses identified lower level of IL-1 receptor-like 1 (ST2) expression in microglia/macrophages of STAT6 KO mice after ICH. ST2 KO diminished the beneficial effects of IL-4 after ICH. Collectively, these data confirm the importance of IL-4/STAT6/ST2 signaling in hematoma resolution and functional recovery after ICH. Intranasal IL-4 treatment warrants further investigation as a clinically feasible therapy for ICH.

There is growing evidence supporting the role of inflammation in early brain injury and cerebral vasospasm following subarachnoid hemorrhage (SAH). Matrix metalloproteinases (MMPs) are released by inflammatory cells and can mediate early brain injury via disruption of the extracellular matrix and mediate vasospasm by cleaving endothelin-1 into vasoactive fragments. We hypothesize that inflammation marked by neutrophil elevation and MMP-9 release in human SAH is associated with vasospasm and with poor clinical outcome. We enrolled consecutive SAH subjects (N = 55), banked serial blood and cerebrospinal fluid (CSF) samples, and evaluated their 3-month modified Rankin scores (mRS). Vasospasm was defined as >50% vessel caliber reduction on angiography 6–8 days post-SAH. A poor outcome was defined as mRS > 2. We compared blood leukocyte and neutrophil counts during post-SAH days 0–14 with respect to vasospasm and 3-month outcome. In a subset of SAH subjects (N = 35), we compared blood and CSF MMP-9 by enzyme-linked immunosorbent assay (ELISA) on post-SAH days 0–1, 2–3, 4–5, 6–8, and 10–14 with respect to vasospasm and to 3-month outcome. Persistent elevation of blood leukocyte (p = 0.0003) and neutrophil (p = 0.0002) counts during post-SAH days 0–14 are independently associated with vasospasm after adjustment for major confounders. In the same time period, blood neutrophil count (post-SAH days 2–3, p = 0.018), blood MMP-9 (post-SAH days 4–5, p = 0.045), and CSF MMP-9 (post-SAH days 2–3, p = 0.05) are associated with poor 3-month SAH clinical outcome. Neutrophil count correlates with blood MMP-9 (post-SAH days 6–8, R = 0.39; p = 0.055; post-SAH days 10–14, R = 0.79; p < 0.0001), and blood MMP-9 correlates with CSF MMP-9 (post-SAH days 4–5, R = 0.72; p = 0.0002). Elevation of CSF MMP-9 during post-SAH days 0–14 is associated with poor 3-month outcome (p = 0.0078). Neither CSF nor blood MMP-9 correlates with vasospasm. Early rise in blood neutrophil count and blood and CSF MMP-9 are associated with poor 3-month SAH clinical outcome. In blood, neutrophil count correlates with MMP-9 levels, suggesting that neutrophils may be an important source of blood MMP-9 early in SAH. Similarly, CSF and blood MMP-9 correlate positively early in the course of SAH, suggesting that blood may be an important source of CSF MMP-9. Blood and CSF MMP-9 are associated with clinical outcome but not with vasospasm, suggesting that MMP-9 may mediate brain injury independent of vasospasm in SAH. Future in vitro studies are needed to investigate the role of MMP-9 in SAH-related brain injury. Larger clinical studies are needed to validate blood and CSF MMP-9 as potential biomarkers for SAH outcome.

Objective Subarachnoid hemorrhage (SAH) is associated with inflammation which may mediate poor outcome in SAH. We hypothesize that elevated serum tumor necrosis factor-alpha (TNFα) and interleukin-6 (IL-6) are associated with vasospasm and poor outcome in SAH. Methods In 52 consecutive SAH subjects, we compared TNFα and IL-6 levels on post-SAH days 0–1, 2–3, 4–5, 6–8, and 10–14 with respect to vasospasm and to poor outcome at 3- and 6-months. Vasospasm was defined as >50% reduction in vessel caliber on angiography. Poor outcome was defined as modified Rankin score >2. Results Elevated TNFα on post-SAH days 2–3 was associated with poor 3-month outcome (p=0.0004). Global elevation of TNFα over time (post-SAH days 0–14) was independently associated with poor 3-month outcome after adjusting for Hunt-and-Hess grade and age (p=0.02). Neither cross-sectional nor IL-6 levels over time were associated with outcome. Neither TNFα nor IL-6 levels were associated with vasospasm. Conclusions Elevation in serum TNFα on post-SAH days 2–3 and global elevation of TNFα over time are associated with poor outcome but not with angiographic vasospasm in this small cohort. Future studies are needed to define the role of TNFα in SAH-related brain injury and its potential as a SAH outcome biomarker.

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