Simvastatin and atorvastatin improve neurological outcome after experimental intracerebral hemorrhage.

BACKGROUND AND PURPOSE: This study investigates the effects of statin treatment on experimental intracerebral hemorrhage (ICH) using behavioral, histological, and MRI measures of recovery. METHODS: Primary ICH was induced in rats. Simvastatin (2 mg/kg), atorvastatin (2 mg/kg), or phosphate-buffered saline (n=6 per group) was given daily for 1 week. MRI studies were performed 2 to 3 days before ICH, and at 1 to 2 hours and 1, 2, 7, 14, and 28 days after ICH. The ICH evolution was assessed via hematoma volume measurements using susceptibility-weighted imaging (SWI) and tissue loss using T2 maps and hematoxylin and eosin (H&E) histology. Neurobehavioral tests were done before ICH and at various time points post-ICH. Additional histological measures were performed with doublecortin neuronal nuclei and bromodeoxyuridine stainings. RESULTS: Initial ICH volumes determined by SWI were similar across all groups. Simvastatin significantly reduced hematoma volume at 4 weeks (P=0.002 versus control with acute volumes as baseline), whereas that for atorvastatin was marginal (P=0.09). MRI estimates of tissue loss (% of contralateral hemisphere) for treated rats were significantly lower (P=0.0003 and 0.001, respectively) than for control at 4 weeks. Similar results were obtained for H&E histology (P=0.0003 and 0.02, respectively). Tissue loss estimates between MRI and histology were well correlated (R2=0.764, P<0.0001). Significant improvement in neurological function was seen 2 to 4 weeks post-ICH with increased neurogenesis observed. CONCLUSIONS: Simvastatin and atorvastatin significantly improved neurological recovery, decreased tissue loss, and increased neurogenesis when administered for 1 week after ICH.

Temporal MRI assessment of intracerebral hemorrhage in rats.

BACKGROUND AND PURPOSE: MRI was used to evaluate the effects of experimental intracerebral hemorrhage (ICH) on brain tissue injury and recovery. METHODS: Primary ICH was induced in rats (n=6) by direct infusion of autologous blood into the striatum. The evolution of ICH damage was assessed by MRI estimates of T(2) and T(1sat) relaxation times, cerebral blood flow, vascular permeability, and susceptibility-weighted imaging before surgery (baseline) and at 2 hours and 1, 7, and 14 days post-ICH. Behavioral testing was done before and at 1, 7, and 14 days post-ICH. Animals were euthanized for histology at 14 days. RESULTS: The MRI appearance of the hemorrhage and surrounding regions changed in a consistent manner over time. Two primary regions of interest were identified based on T(2) values. These included a core, corresponding to the bulk of the hemorrhage, and an adjacent rim; both varied with time. The core was associated with significantly lower cerebral blood flow values at all post-ICH time points, whereas cerebral blood flow varied in the rim. Increases in vascular permeability were noted at 1, 7, and 14 days. Changes in T(1sat) were similar to those of T(2). MRI and histological estimates of tissue loss were well correlated and showed approximately 9% hemispheric tissue loss. CONCLUSIONS: Although the cerebral blood flow changes observed with this ICH model may not exactly mimic the clinical situation, our results suggest that the evolution of ICH injury can be accurately characterized with MRI. These methods may be useful to evaluate therapeutic interventions after experimental ICH and eventually in humans.

Mannitol enhances delivery of marrow stromal cells to the brain after experimental intracerebral hemorrhage.

Previous studies show that intravascular injection of human bone marrow stromal cells (hBMSCs) significantly improves neurological functional recovery in a rat model of intracerebral hemorrhage (ICH). In the present study, we tested the hypothesis that mannitol improves the efficiency of intraarterial MSC delivery (i.e., fewer injected cells required for therapeutic efficacy) after ICH. There were four post-ICH groups (N=9): group 1, negative control with only intraarterial injection of 1 million human fibroblasts in phosphate-buffered saline (PBS); group 2, intravenous injection of mannitol alone in PBS (1.5 g/kg); group 3, intraarterial injection of 1 million hBMSCs alone in PBS; and group 4, intravenous injection of mannitol (1.5 g/kg) in PBS followed by intraarterial injection of 1 million hBMSCs in PBS. Group 4 exhibited significantly improved neurological functional outcome as assessed by neurological severity score (NSS) and corner test scores. Immunohistochemical staining of group 4 suggested increased synaptogenesis, proliferating immature neurons, and neuronal migration. The number of hBMSCs recruited to the injured region increased strikingly in group 4. Tissue loss was notably reduced in group 4. In summary, the beneficial effects of intraarterial infusion of MSCs are amplified with intravenous injection of mannitol. Preadministration of mannitol significantly increases the number of hBMSCs located in the ICH region, improves histochemical parameters of neural regeneration, and reduces the anatomical and pathological consequences of ICH.

Management of arteriovenous malformations in the elderly: a single-center case series and analysis of outcomes.

OBJECT Treatment of brain arteriovenous malformations (bAVMs) in the elderly remains a challenge for cerebrovascular surgeons. In this study the authors reviewed the patient characteristics, treatments, angiographic results, and clinical outcomes in 28 patients over 65 years of age who were treated at Henry Ford Hospital between 1990 and 2014. METHODS The bAVM database at the authors' institution was queried for records of elderly patients with bAVMs, and data regarding patient demographics, presenting symptoms, bAVM angioarchitecture, treatment modalities, angiographic results, clinical outcomes, and treatment complications were tabulated and analyzed. RESULTS There were 9 male (32%) and 19 female (68%) patients, with an average age ( ± SD) of 73.0 ± 6.95 years. The most common symptoms on presentation were hemorrhage (36%) and headaches (18%). The bAVMs were equally distributed between the supra- and infratentorial compartments. The most common Spetzler-Martin grade was II, observed in 57% of the patients. Eleven patients (39.3%) underwent resection, 4 patients (14.3%) received standalone radiation therapy, and 13 patients (46%) did not receive treatment or were managed expectantly. Four patients (14.3%) were lost to follow-up. Complete bAVM obliteration was achieved in 87% of the treated patients. None of the patients who received any form of treatment died; the overall mortality rate was 3.6%. CONCLUSIONS Surgical management of bAVMs in the elderly can result in complete obliteration and acceptable clinical outcomes.

Acute Statin Treatment Improves Recovery after Experimental Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: We have previously demonstrated that 2-week treatment of experimental intracerebral hemorrhage (ICH) with a daily dose of 2 mg/kg statin starting 24 hours post-injury exerts a neuroprotective effect. The present study extends our previous investigation and tests the effect of acute high-dose (within 24 hours) statin therapy on experimental ICH. MATERIAL AND METHODS: Fifty-six male Wistar rats were subjected to ICH by stereotactic injection of 100 µl of autologous blood into the striatum. Rats were divided randomly into seven groups: saline control group (n = 8); 10, 20 and 40 mg/kg simvastatin-treated groups (n = 8); and 10, 20 and 40 mg/kg atorvastatin-treated groups (n = 8). Simvastatin or atorvastatin were administered orally at 3 and 24 hours after ICH. Neurological functional outcome was evaluated using behavioral tests (mNSS and corner turn test) at multiple time points after ICH. Animals were sacrificed at 28 days after treatment, and histological studies were completed. RESULTS: Acute treatment with simvastatin or atorvastatin at doses of 10 and 20 mg/kg, but not at 40 mg/kg, significantly enhanced recovery of neurological function starting from 2 weeks post-ICH and persisting for up to 4 weeks post ICH. In addition, at doses of 10 mg/kg and 20 mg/kg, histological evaluations revealed that simvastatin or atorvastatin reduced tissue loss, increased cell proliferation in the subventricular zone and enhanced vascular density and synaptogenesis in the hematoma boundary zone when compared to saline-treated rats. CONCLUSIONS: Treatment with simvastatin or atorvastatin at doses of 10 and 20 mg/kg significantly improves neurological recovery after administration during the first 24 hours after ICH. Decreased tissue loss, increased cell proliferation and vascularity likely contribute to improved functional recovery in rats treated with statins after ICH.

Statins Protect the Blood Brain Barrier Acutely after Experimental Intracerebral Hemorrhage.

OBJECTIVES: The goal of this study was to measure the impact of simvastatin and atorvastatin treatment on blood brain barrier (BBB) integrity after experimental intracerebral hemorrhage (ICH). METHODS: Primary ICH was induced in 27 male Wistar rats by stereotactic injection of 100 µL of autologous blood into the striatum. Rats were divided into three groups (n= 9/group): 1) oral treatment (2 mg/kg) of atorvastatin, 2) oral treatment (2 mg/kg) simvastatin, or 3) phosphate buffered saline daily starting 24-hours post-ICH and continuing daily for the next 3 days. On the fourth day, the animals underwent magnetic resonance imaging (MRI) for measurements of T1sat (a marker for BBB integrity), T2 (edema), and cerebral blood flow (CBF). After MRI, the animals were sacrificed and immunohistology or Western blotting was performed. RESULTS: MRI data for animals receiving simvastatin treatment showed significantly reduced BBB dysfunction and improved CBF in the ICH rim compared to controls (P<0.05) 4 days after ICH. Simvastatin also significantly reduced edema (T2) in the rim at 4 days after ICH (P<0.05). Both statin-treated groups demonstrated increased occludin and endothelial barrier antigen levels within the vessel walls, indicating better preservation of BBB function (P<0.05) and increased number of blood vessels (P<0.05). CONCLUSIONS: Simvastatin treatment administered acutely after ICH protects BBB integrity as measured by MRI and correlative immunohistochemistry. There was also evidence of improved CBF and reduced edema by MRI. Conversely, atorvastatin showed a non-significant trend by MRI measurement.

Therapeutic effect of human umbilical tissue-derived cell treatment in rats with experimental intracerebral hemorrhage.

BACKGROUND AND PURPOSE: The present study examines whether human umbilical tissue-derived cells (hUTC) have a neuro-restorative effect and improve functional recovery after intracerebral hemorrhage (ICH) in rats. METHODS: Primary ICH was induced in male Wistar rats by stereotactic injection of 100µL of autologous blood into the striatal region adjacent to the subventricular zone. Briefly, the rats were randomly divided into six groups, each group was intravenously injected either with 2mL phosphate-buffered saline (PBS) or 3million hUTC in PBS at 1, 3 or 7days after ICH (n=8/group). To evaluate neurological functional outcome, each animal was subjected to the modified neurological severity score (mNSS) and corner turn tests at different time points after ICH. At four weeks post treatment, each group was anesthetized intraperitoneally, sacrificed, and brain tissues were processed histologically. Immunohistochemistry was employed to measure vascularity (vWF), neurogenesis (BrdU TUJ1, DCX and NeuN), synaptogenesis (synaptophysin) and apoptosis (TUNEL). RESULTS: The hUTC-treated animals showed significantly improved neurological functional outcomes as assessed by mNSS and corner turn tests at 14, 21 and 28days post-injection in each treatment group (P<0.05) as compared to the PBS controls. Animals treated with hUTC were seen to have significantly increased cell proliferation, vascularity and synaptogenesis, as well as reduced apoptosis in the hematoma rim compared to the corresponding control group (P<0.05). CONCLUSIONS: Intravenously infused hUTC have a beneficial effect after experimental ICH by functional and histochemical measurements of neural cell proliferation and synaptogenesis in the ICH border zone. This brain region also shows correlative evidence of neuronal recovery with increased vascularity.

Statins Enhance Expression of Growth Factors and Activate the PI3K/Akt-mediated Signaling Pathway after Experimental Intracerebral Hemorrhage.

Previous studies have demonstrates that statins improve neurological outcome and promote neurovascular recovery after ICH. This study is designed to examine whether simvastatin and atorvastatin affect levels of growth factors and activate the Akt signaling pathway during the recovery phase after intracerebral hemorrhage (ICH) in rats. Sixty (60) male Wistar rats were subjected to ICH by stereotactic injection of 100 µL of autologous blood into the striatum and were treated with or without simvastatin or atorvastatin. Neurological functional outcome was evaluated by behavioral tests (mNSS and corner turn test) at different time points after ICH. Brain extracts were utilized for Enzyme-linked immunosorbent assay (ELISA) analyses to measure vascular endothelial growth factor (VEGF); brain-derived neurotrophin factor (BDNF) expression, and nerve growth factor (NGF). Western blot was used to measure the changes in the Akt-mediated signaling pathway. Both the simvastatin- and atorvastatin-treated animals had significant neurological improvement at 2 weeks post-ICH. Simvastatin and atorvastatin treatment increased the expression of BDNF, VEGF and NGF in both low- and high-dose groups at 7 days after ICH (p < 0.05). Phosphorylation of Akt, glycogen synthase kinase-3ß (GSK-3ß), and cAMP response element-binding proteins (CREB) were also increased at 7 days after statin treatment. These results suggest that the therapeutic effects of statins after experimental ICH may be mediated by the transient induction of BDNF, VEGF and NGF expression and the activation of the Akt-mediated signaling pathway.

Improvement in recovery after experimental intracerebral hemorrhage using a selective cathepsin B and L inhibitor.

OBJECT: This study investigates a potential novel application of a selective cathepsin B and L inhibitor in experimental intracerebral hemorrhage (ICH) in rats. METHODS: Forty adult male Wistar rats received an ICH by stereotactic injection of 100 µl of autologous blood or sham via needle insertion into the right striatum. The rats were treated with a selective cathepsin B and L inhibitor (CP-1) or 1% dimethyl sulfoxide sterile saline intravenously at 2 and 4 hours after injury. Modified neurological severity scores were obtained and corner turn tests were performed at 1, 4, 7, and 14 days after ICH. The rats were sacrificed at 3 and 14 days after ICH for immunohistological analysis of tissue loss, neurogenesis, angiogenesis, and apoptosis. RESULTS: The animals treated with CP-1 demonstrated significantly reduced apoptosis as well as tissue loss compared with controls (p < 0.05 for each). Neurological function as assessed by modified neurological severity score and corner turn tests showed improvement after CP-1 treatment at 7 and 14 days (p < 0.05). Angiogenesis and neurogenesis parameters demonstrated improvement after CP-1 treatment compared with controls (p < 0.05) at 14 days. CONCLUSIONS: This study is the first report of treatment of ICH with a selective cathepsin B and L inhibitor. Cathepsin B and L inhibition has been shown to be beneficial after cerebral ischemia, likely because of its upstream regulation of the other prominent cysteine proteases, calpains, and caspases. While ICH may not induce a major component of ischemia, the cellular stress in the border zone may activate these proteolytic pathways. The observation that cathepsin B and L blockade is efficacious in this model is provocative for further investigation.

Vascular recovery promoted by atorvastatin and simvastatin after experimental intracerebral hemorrhage: magnetic resonance imaging and histological study.

OBJECT: Longitudinal multiparametric MR imaging and histological studies were performed on simvastatin- or atorvastatin-treated rats to evaluate vascular repair mechanisms after experimental intracerebral hemorrhage (ICH). METHODS: Primary ICH was induced in adult Wistar rats by direct infusion of 100 µl of autologous blood into the striatal region adjacent to the subventricular zone. Atorvastatin (2 mg/kg), simvastatin (2 mg/kg), or phosphate-buffered saline was given orally at 24 hours post-ICH and continued daily for 7 days. The temporal evolution of ICH in each group was assessed by MR imaging measurements of T2, T1(sat), and cerebral blood flow in brain areas corresponding to the bulk of the hemorrhage (core) and edematous border (rim). Rats were killed after the final MR imaging examination at 28 days, and histological studies were performed. A small group of sham-operated animals was also studied. Neurobehavioral testing was performed in all animals. Analysis of variance methods were used to compare results from the treatment and control groups, with significance inferred at p ≤ 0.05. RESULTS: Using histological indices, animals treated with simvastatin and atorvastatin had significantly increased angiogenesis and synaptogenesis in the hematoma rim compared with the control group (p ≤ 0.05). The statin-treated animals exhibited significantly increased cerebral blood flow in the hematoma rim at 4 weeks, while blood-brain barrier permeability (T1(sat)) and edema (T2) in the corresponding regions were reduced. Both statin-treated groups showed significant neurological improvement from 2 weeks post-ICH onward. CONCLUSIONS: The results of the present study demonstrate that simvastatin and atorvastatin significantly improve the recovery of rats from ICH, possibly via angiogenesis and synaptic plasticity. In addition, in vivo multiparametric MR imaging measurements over time can be effectively applied to the experimental ICH model for longitudinal assessment of the therapeutic intervention.

Localization of bone marrow stromal cells to the injury site after intracerebral hemorrhage in rats.

OBJECT: Previous studies demonstrated that intravascular injection of bone marrow stromal cells (BMSCs) significantly improved neurological functional recovery in a rat model of intracerebral hemorrhage (ICH). To further investigate the fate of transplanted cells, we examined the effect of male rat BMSCs administered to female rats after ICH. METHODS: Twenty-seven female Wistar rats were subjected to ICH surgery. At 24 hours after ICH, these rats were randomly divided into 3 groups and injected intravenously with 1 ml phosphate-buffered saline or 0.5 million or 1 million male rat BMSCs in phosphate-buffered saline. To evaluate the neurological functional outcome, each rat was subjected to a series of behavioral tests (modified neurological severity score and corner turn test) at 1, 7, and 14 days after ICH. The rats were anesthetized intraperitoneally and killed, and the brain tissues were processed at Day 14 after ICH. Immunohistochemistry and in situ hybridization were used to identify cell-specific markers. RESULTS: The male rat BMSCs significantly improved the neurological functional outcome and also significantly diminished tissue loss when intravenously transplanted into the rats after ICH. Immunoassay for bromodeoxyuridine (BrdU) and neuronal markers demonstrated a significant increase in the number of BrdU-positive cells, which indicated endogenous neurogenesis, and a significant increase in the number of cells positive for immature neuronal markers. In situ hybridization showed that more BMSCs resided around the hematoma of the rats treated with the 1-million-cell dose compared with the 0.5-million-cell-dose group. In addition, a subfraction of Y chromosome-positive cells were co-immunostained with the neuronal marker microtubule-associated protein-2 or the astrocytic marker glial fibrillary acidic protein. CONCLUSIONS: Male rat BMSCs improve neurological outcome and increase histochemical parameters of neurogenesis when administered to female rats after ICH. This study has shown that the intravenously administered male rat BMSCs enter the brain, migrate to the perihematomal area, and express parenchymal markers.