Showing papers on "Middle cerebral artery published in 2008"
TL;DR: The involvement of miRNA regulation in brain pathogenesis associated with MCAo is reported for the first time and evidence that some of the miRNAs that are highly expressed in the ischemic brain can be detected in blood samples is provided.
Abstract: Background and Purpose— Several hundred small RNAs called microRNAs (miRNAs) have been identified and characterized from various organisms, including humans. In humans, some of these miRNAs have been found to regulate (patho)physiologic conditions such as tumor progression/regression, cholesterol and glucose homeostasis, etc. In this report, we present data on the miRNAs expressed under ischemic conditions in both the brain and blood of rats subjected to middle cerebral artery occlusion (MCAo). Methods— Sprague-Dawley rats subjected to MCAo were reperfused for either 24 or 48 hours, and both blood and brain samples were harvested. miRNA expression profiling and oligonucleotide microarray were carried out, and the data were validated by quantitative real-time polymerase chain reaction and correlated with published data on protein and gene expression in MCAo rats. Results— We report here for the first time the involvement of miRNA regulation in brain pathogenesis associated with MCAo. Comparison with the co...
522 citations
TL;DR: Pregnancy-induced hypertension, a family history of seizures, emergency cesarean section, and the need for resuscitation were more common among case subjects than control subjects and patterns of injury associated with symptomatic neonatal hypoglycemia were more varied than described previously.
Abstract: BACKGROUND. Symptomatic neonatal hypoglycemia may be associated with later neurodevelopmental impairment. Brain injury patterns identified on early MRI scans and their relationships to the nature of the hypoglycemic insult and neurodevelopmental outcomes are poorly defined. METHODS. We studied 35 term infants with early brain MRI scans after symptomatic neonatal hypoglycemia (median glucose level: 1 mmol/L) without evidence of hypoxic-ischemic encephalopathy. Perinatal data were compared with equivalent data from 229 term, neurologically normal infants (control subjects), to identify risk factors for hypoglycemia. Neurodevelopmental outcomes were assessed at a minimum of 18 months. RESULTS. White matter abnormalities occurred in 94% of infants with hypoglycemia, being severe in 43%, with a predominantly posterior pattern in 29% of cases. Cortical abnormalities occurred in 51% of infants; 30% had white matter hemorrhage, 40% basal ganglia/thalamic lesions, and 11% an abnormal posterior limb of the internal capsule. Three infants had middle cerebral artery territory infarctions. Twenty-three infants (65%) demonstrated impairments at 18 months, which were related to the severity of white matter injury and involvement of the posterior limb of the internal capsule. Fourteen infants demonstrated growth restriction, 1 had macrosomia, and 2 had mothers with diabetes mellitus. Pregnancy-induced hypertension, a family history of seizures, emergency cesarean section, and the need for resuscitation were more common among case subjects than control subjects. CONCLUSIONS. Patterns of injury associated with symptomatic neonatal hypoglycemia were more varied than described previously. White matter injury was not confined to the posterior regions; hemorrhage, middle cerebral artery infarction, and basal ganglia/thalamic abnormalities were seen, and cortical involvement was common. Early MRI findings were more instructive than the severity or duration of hypoglycemia for predicting neurodevelopmental outcomes.
429 citations
TL;DR: Findings indicate that Postcond inhibits focal cerebral I/R injury in the rat middle cerebral artery occlusion model, and this neuroprotective effect is likely achieved by antiapoptotic mechanisms.
Abstract: Background and Purpose— Ischemic postconditioning (Postcond) is defined as a series of intermittent interruptions of blood flow in the early phase of reperfusion that mechanically alters the hydrodynamics of reperfusion. A recent study showed that Postcond reduced infarct size in cerebral ischemia/reperfusion (I/R) injury. However, little is known about the mechanisms of Postcond in cerebral I/R injury. In the present study, we investigated the effects of Postcond in focal cerebral I/R injury in the rat middle cerebral artery occlusion model. Methods— Adult male Sprague-Dawley rats were treated with Postcond after 60 minutes of occlusion (beginning of reperfusion). Neurologic scores and infarct volumes were assessed at 24 and 72 hours. Oxidative stress was evaluated by malondialdehyde assay, and apoptosis-related molecules were studied by Western blotting. Results— Postcond treatment upregulated Bcl-2 and heat-shock protein 70 expression and downregulated cytochrome c release to the cytosol, Bax transloca...
235 citations
TL;DR: To assess the neurodevelopmental outcome at 2 years of age of children who had been small‐for‐gestational‐age (SGA) term babies with cerebral blood flow redistribution, a cerebrospinal fluid replacement study was conducted.
Abstract: Objective
To assess the neurodevelopmental outcome at 2 years of age of children who had been small-for-gestational-age (SGA) term babies with cerebral blood flow redistribution.
Methods
Perinatal outcome was assessed in a cohort of 97 term singleton appropriate-for-gestational-age and 125 term singleton SGA fetuses with normal umbilical artery Doppler, stratified according to the presence of cerebral blood flow redistribution. Neurodevelopmental outcome was assessed prospectively at 2 years of age by means of the 24-month Age & Stage Questionnaire (ASQ).
Results
Of the 125 SGA fetuses, 25 had redistribution of the cerebral blood flow, and 100 did not. There were no significant differences in perinatal outcome between these two SGA groups. At 2 years of age, children who had been SGA fetuses with middle cerebral artery (MCA) pulsatility index (PI) < 5th centile had a higher incidence of suboptimal neurodevelopmental outcome compared with those with normal MCA-PI (52% vs. 31%; P = 0.049) and a lower mean centile in communication (53.1 vs. 67.4; P = 0.006) and problem-solving (39.7 vs. 47.4; P = 0.04) areas.
Conclusion
SGA fetuses with cerebral blood flow redistribution have a higher risk of subtle neurodevelopmental deficits at 2 years of age. This challenges the concept that fetal cerebral redistribution is an entirely protective mechanism and suggests MCA-PI as a risk stratifying factor for adverse neurodevelopmental outcome. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
229 citations
TL;DR: The role of adiponectin in the development of acute cerebral injury was explored in this paper, where the authors showed that adenovirus-mediated supplementation significantly reduced cerebral infarct size in WT and APN-deficient mice.
Abstract: Background— Adiponectin is a fat-derived plasma protein that has beneficial actions on cardiovascular disorders. A low level of plasma adiponectin is associated with increased mortality after ischemic stroke; however, the causal role of adiponectin in ischemic stroke is unknown. Methods and Results— To explore the role of adiponectin in the development of acute cerebral injury, we subjected adiponectin-deficient (APN-KO) and wild-type (WT) mice to 1 hour of middle cerebral artery occlusion followed by 23 hours of reperfusion. APN-KO mice exhibited enlarged brain infarction and increased neurological deficits after ischemia-reperfusion compared with WT mice. Conversely, adenovirus-mediated supplementation of adiponectin significantly reduced cerebral infarct size in WT and APN-KO mice. APN-KO mice showed decreased cerebral blood flow during ischemia by laser speckle flowmetry methods. Adiponectin colocalized within the cerebral vascular endothelium under transient ischemic conditions by immunohistochemical...
206 citations
TL;DR: In this small group of patients, cerebral perfusion assessed with transcranial Doppler and near-infrared spectroscopy did not differ between patients with and without sepsis-associated delirium, however, the state of autoregulation differed between the two groups.
Abstract: The pathophysiology of sepsis-associated delirium is not completely understood and the data on cerebral perfusion in sepsis are conflicting. We tested the hypothesis that cerebral perfusion and selected serum markers of inflammation and delirium differ in septic patients with and without sepsis-associated delirium. We investigated 23 adult patients with sepsis, severe sepsis, or septic shock with an extracranial focus of infection and no history of intracranial pathology. Patients were investigated after stabilisation within 48 hours after admission to the intensive care unit. Sepsis-associated delirium was diagnosed using the confusion assessment method for the intensive care unit. Mean arterial pressure (MAP), blood flow velocity (FV) in the middle cerebral artery using transcranial Doppler, and cerebral tissue oxygenation using near-infrared spectroscopy were monitored for 1 hour. An index of cerebrovascular autoregulation was calculated from MAP and FV data. C-reactive protein (CRP), interleukin-6 (IL-6), S-100β, and cortisol were measured during each data acquisition. Data from 16 patients, of whom 12 had sepsis-associated delirium, were analysed. There were no significant correlations or associations between MAP, cerebral blood FV, or tissue oxygenation and sepsis-associated delirium. However, we found a significant association between sepsis-associated delirium and disturbed autoregulation (P = 0.015). IL-6 did not differ between patients with and without sepsis-associated delirium, but we found a significant association between elevated CRP (P = 0.008), S-100β (P = 0.029), and cortisol (P = 0.011) and sepsis-associated delirium. Elevated CRP was significantly correlated with disturbed autoregulation (Spearman rho = 0.62, P = 0.010). In this small group of patients, cerebral perfusion assessed with transcranial Doppler and near-infrared spectroscopy did not differ between patients with and without sepsis-associated delirium. However, the state of autoregulation differed between the two groups. This may be due to inflammation impeding cerebrovascular endothelial function. Further investigations defining the role of S-100β and cortisol in the diagnosis of sepsis-associated delirium are warranted. ClinicalTrials.gov NCT00410111.
196 citations
TL;DR: Postsynaptic density-95 inhibitors administrated 3 hours after stroke onset reduced infarct volumes and improved long-term neurobehavioral functions in a wide therapeutic window, raising the possibility that they may have future clinical usefulness.
Abstract: Background and Purpose— Postsynaptic density-95 inhibitors reduce ischemic brain damage without inhibiting excitatory neurotransmission, circumventing the negative consequences of glutamatergic inhibition. However, their efficacy in permanent ischemia and in providing permanent neuroprotection and neurobehavioral improvement in a practical therapeutic window is unproven. These were tested here under conditions that included fever, which is a common occurrence in clinical stroke. Methods— Six studies were performed in unfasted Sprague-Dawley rats. Two involved permanent pial vessel occlusion in male and female rats. Two involved permanent middle cerebral artery occlusion, which induced severe hyperthermia, and 2 involved transient middle cerebral artery occlusion. Animals were treated with a single intravenous injection of postsynaptic density-95 inhibitors (Tat-NR2B9c[SDV] or Tat-NR2B9c[TDV]) 1 hour or 3 hours after stroke. Infarct volumes and neurobehavior were assessed in a blinded manner at 24 hours (p...
190 citations
TL;DR: Reversible cerebral vasoconstriction syndromes (RCVS) are characterized by thunderclap headaches and reversible cerebral vasconstrictions.
Abstract: Objective
Reversible cerebral vasoconstriction syndromes (RCVS) are characterized by thunderclap headaches and reversible cerebral vasoconstrictions. No systematic studies on cerebral hemodynamics have been published.
Methods
Patients with RCVS were consecutively recruited. Sequential transcranial color-coded sonography studies were performed on the middle cerebral artery (MCA) for 3 months. Mean flow velocities (VMCA) and Lindegaard Index (LI) were recorded and compared with those of controls.
Results
Thirty-two patients (all female; average age, 49.7 ± 6.8 years) were enrolled. Four developed of reversible posterior leukoencephalopathy syndrome, and two of them, ischemic strokes. One hundred and twenty-six sonography studies were performed on 57 eligible MCAs. The mean maximum VMCA (109.5 ± 30.8cm/sec) and LI (2.2 ± 0.7) of RCVS patients exceeded those of controls (VMCA: 66.3 ± 9.5cm/sec, p < 0.001; LI: 1.4 ± 0.3, p < 0.001). The VMCA and LI levels were still at their plateau at the mean time (day 22 after headache onset) of headache resolution. Fifteen (46.9%) patients had VMCA exceeding 120cm/sec, and 5 (16%) had LI exceeding 3. Patients fulfilling the criteria of subarachnoid hemorrhage mild vasospasm (n = 4; 13%), that is, both VMCA greater than 120cm/sec and LI greater than 3, had a greater risk of posterior leukoencephalopathy (75 vs 4%; p = 0.003) and ischemic strokes (50 vs 0%; p = 0.01) than those without.
Interpretation
Patients with RCVS experienced prolonged vasoconstriction, making the risk for posterior leukoencephalopathy and ischemic strokes outlast headache resolution. Patients fulfilling mild vasospasm criteria for subarachnoid hemorrhage carry a high risk. Ann Neurol 2008
177 citations
TL;DR: It is suggested that during recovery from acute hypotension, decreases in cerebral vascular conductance index were mediated by increases in arterial blood pressure and sympathetically mediated cerebral vasoconstriction.
Abstract: Background and Purpose— The effect of antihypertensive drugs on autonomic neural control of the cerebral circulation remains unclear. This study was designed to compare middle cerebral artery mean blood velocity responses to acute hypotension with and without α1-adrenoreceptor blockade (Prazosin) in young, healthy humans. Methods— Acute hypotension was induced nonpharmacologically in 6 healthy subjects (mean±SE; 28±2 years) by releasing bilateral thigh cuffs after 9 minutes of suprasystolic resting ischemia before and after an oral dose of Prazosin (1 mg/20 kg body weight). Results— Prazosin had no effect on thigh cuff release-induced reductions in mean arterial pressure and middle cerebral artery mean blood velocity. However, Prazosin attenuated the amount of peripheral vasoconstriction through the arterial baroreflex as evidenced by a slower return of mean arterial pressure to baseline (P=0.03). Immediately after cuff release, cerebral vascular conductance index increased through cerebral autoregulation...
174 citations
TL;DR: A promising role is suggested for regular cocoa flavanol’s consumption in the treatment of cerebrovascular ischemic syndromes, including dementias and stroke, as measured by transcranial Doppler ultrasound.
Abstract: BACKGROUND AND PURPOSE Cerebral ischemia is a common, morbid condition accompanied by cognitive decline. Recent reports on the vascular health benefits of flavanol-containing foods signify a promising approach to the treatment of cerebral ischemia. Our study was designed to investigate the effects of flavanol-rich cocoa (FRC) consumption on cerebral blood flow in older healthy volunteers. METHODS We used transcranial Doppler (TCD) ultrasound to measure mean blood flow velocity (MFV) in the middle cerebral artery (MCA) in thirty-four healthy elderly volunteers (72 +/- 6 years) in response to the regular intake of FRC or flavanol-poor cocoa (FPC). RESULTS In response to two weeks of FRC intake, MFV increased by 8% +/- 4% at one week (p = 0.01) and 10% +/- 4% (p = 0.04) at two weeks. In response to one week of cocoa, significantly more subjects in the FRC as compared with the FPC group had an increase in their MFV (p < 0.05). CONCLUSIONS In summary, we show that dietary intake of FRC is associated with a significant increase in cerebral blood flow velocity in the MCA as measured by TCD. Our data suggest a promising role for regular cocoa flavanol's consumption in the treatment of cerebrovascular ischemic syndromes, including dementias and stroke.
159 citations
TL;DR: This small randomized study indicates a beneficial impact of transcranial ultrasound on recanalization and short-term outcome in subjects with middle cerebral artery main stem occlusion and recombinant tissue-type plasminogen activator treatment.
Abstract: Background and Purpose— Sonothrombolysis is a new treatment approach in acute ischemic stroke. The results of a monocenter, randomized clinical study are presented. Methods— Subjects with acute middle cerebral artery main stem occlusion were randomized into a target group receiving 1-hour transcranial continuous insonation using a 1.8-MHz Doppler ultrasound (US) probe or a control group. All underwent standard thrombolysis with intravenous recombinant tissue-type plasminogen activator. Results— Thirty-seven subjects were included; 19 subjects were treated in the target (US) group and 18 in the control (no-US) group, all with no residual flow in the middle cerebral artery main stem occlusion (Thrombolysis in Brain Ischemia recanalization grade 0). Compared with the no-US group, the US group showed greater improvement in National Institutes of Health Stroke Scale values at days 1 and 4 and a higher median Thrombolysis in Brain Ischemia grade 1 hour after recombinant tissue-type plasminogen activator initiat...
TL;DR: Luminal stenosis caused by atherosclerotic plaque, percentage of lipid area and presence of intraplaque neovasculature may play a key role in leading to ischemic stroke.
Abstract: Background: Atherosclerotic stenosis of large intracranial arteries, especially the middle cerebral artery (MCA), is a common cause of stroke in Chinese patients. We aimed to descri
TL;DR: The data suggest that mild induced hypertension increases collateral cerebral blood flow and oxygenation and improves cerebral metabolic rate of oxygen in the core and penumbra, supporting its use as bridging therapy in acute ischemic stroke until arterial recanalization is achieved.
Abstract: Background and Purpose— In focal ischemic cortex, cerebral blood flow autoregulation is impaired, and perfusion passively follows blood pressure variations. Although it is generally agreed that profound hypotension is harmful in acute stroke, the hemodynamic and metabolic impact of increased blood pressure on the ischemic core and penumbra are less well understood. We, therefore, tested whether pharmacologically induced hypertension improves cerebral blood flow and metabolism and tissue outcome in acute stroke using optical imaging with high spatiotemporal resolution. Methods— Cerebral blood flow, oxyhemoglobin, and cerebral metabolic rate of oxygen were measured noninvasively using simultaneous multispectral reflectance imaging and laser speckle flowmetry during distal middle cerebral artery occlusion in mice. Hypertension was induced by phenylephrine infusion starting 10 or 60 minutes after ischemia to raise blood pressure by 30% for the duration of ischemia; control groups received saline infusion. Res...
TL;DR: It is found that recovery of dendritic structure can occur after reperfusion after even 60 min of ischemia, but is likely restricted to a relatively small penumbra region with partial blood flow or oxygenation.
Abstract: Filament occlusion of the middle cerebral artery (MCA) is a well accepted animal model of focal ischemia. Advantages of the model are relatively long occlusion times and a large penumbra region that simulates aspects of human stroke. Here, we use two-photon and confocal microscopy in combination with regional measurement of blood flow using laser speckle to assess the spatial relationship between the borders of the MCA ischemic territory and loss of dendrite structure, as well as the effect of reperfusion on dendritic damage in adult YFP (yellow fluorescent protein) and GFP (green fluorescent protein) C57BL/6 transgenic mice with fluorescent (predominantly layer 5) neurons. By examining the spatial extent of dendritic damage, we determined that 60 min of MCA occlusion produced a core with severe structural damage that did not recover after reperfusion (begins approximately 3.8 mm lateral to midline), a reversibly damaged area up to 0.6 mm medial to the core that recovered after reperfusion (penumbra), and a relatively structurally intact area ( approximately 1 mm wide; medial penumbra) with hypoperfusion. Loss of structure was preceded by a single ischemic depolarization 122.1 +/- 10.2 s after occlusion onset. Reperfusion of animals after 60 min of ischemia was not associated with exacerbation of damage (reperfusion injury) and resulted in a significant restoration of blebbed dendritic structure, but only within approximately 0.6 mm lateral of the dendritic damage structural border. In summary, we find that recovery of dendritic structure can occur after reperfusion after even 60 min of ischemia, but is likely restricted to a relatively small penumbra region with partial blood flow or oxygenation.
TL;DR: A reconstrainable stent was used to provide a temporary endovascular bypass to achieve MCA recanalization without permanent stent implantation and yielded immediate and durable revascularization of an acutely occluded middle cerebral artery.
Abstract: Background and Purpose— Although self-expanding intracranial microstents have been used to treat acute middle cerebral artery (MCA) stroke, there are disadvantages associated with placing a permanent endovascular implant We describe a technique in which a reconstrainable stent was used to provide a temporary endovascular bypass to achieve MCA recanalization without permanent stent implantation Methods— A 55-year-old male presented with acute onset left hemiplegia (National Institutes of Health Stroke Score (NIHSS) of 20 Angiography showed an occluded right cervical internal carotid artery (ICA), a patent anterior communicating artery (ACOMM), and embolic occlusion of the right middle cerebral artery (MCA), M1 segment Results— Working through a 6F guide-catheter positioned in the left cervical ICA, an SL-10 microcatheter, and 0014-inch Synchro-2 microwire were manipulated across the anterior communicating artery and into the right M1 segment occlusion 5 mg of abciximab and 3 mg tPA were infused direc
TL;DR: Long-term follow-up appeared to indicate a reduction in further ischemic events in surviving patients compared with the natural history, and Cerebral perfusion dynamics improved postoperatively in all 36 surviving patients.
Abstract: Object The authors report the long-term results of a series of direct superficial temporal artery–middle cerebral artery (STA–MCA) bypass procedures in patients with moyamoya disease from the western US. Methods All patients with moyamoya disease treated at the University of Washington from 1990 through 2004 (39 patients) were included in this study. Patients underwent pre- and postoperative evaluation of cerebral perfusion dynamics. Surgical revascularization procedures were performed in all patients with impaired cerebral blood flow (CBF) findings. Results The mean age of patients at diagnosis was 34 years (range 10–55 years). All 39 patients had impaired CBF and/or vasomotor reserve and underwent revascularization procedures: 26 patients underwent bilateral operations, 13 unilateral (65 total procedures). An STA–MCA bypass was technically possible in 56 procedures (86.2%); saphenous vein interposition grafts were required in 3 procedures (4.6%); encephaloduroarteriosynangiosis was performed in 6 proced...
TL;DR: The data indicate that the outcome of neonatal stroke may not be as positive as previously reported, as four of the patients had developed epilepsy and had become obviously hemiplegic as gross motor development proceeded.
Abstract: Six children with neonatal cerebral infarction of the middle cerebral artery are reported. Seizures or respiratory distress were the initial symptoms. In some cases abnormal findings appeared earlier on EEG than on ultrasound. The EEG changes were concordant with the localization of the lesion. Ultrasound examinations revealed an echodense structure within the vascular territory, after a phase of appearing to be normal, highly suggestive of cerebral infarction. The diagnosis was confirmed by CT scan. Findings on EEG, cranial ultrasound and CT suggested that the stroke represented a late intra-uterine event. At long-term follow-up, six children had failed to develop normally for age and had become obviously hemiplegic as gross motor development proceeded. Four of the patients had developed epilepsy. These data indicate that the outcome of neonatal stroke may not be as positive as previously reported.
TL;DR: Investigation of the relationship between transient neurological deterioration and changes in cerebral perfusion after superficial temporal artery/middle cerebral artery (STA-MCA) bypass found postoperative transient relative hyperperfusion is a common phenomenon and may be one of the causes of postoperative temporary neurological deterioration after STA- MCA bypass surgery for ischemic cerebral diseases.
Abstract: Background: This study was designed to investigate the relationship between transient neurological deterioration and changes in cerebral perfusion after superficial temporal artery/
TL;DR: Angiographic balloon test occlusion with transcranial Doppler monitoring can be performed ultra-swiftly at a risk equal to conventional neuroangiography and with correct prediction of the hemodynamic outcome of arterial sacrifice.
Abstract: Objective Treatment of certain cerebral aneurysms, caroticocavernous fistulae, and tumors of the neck or cranial base may involve therapeutic arterial sacrifice, which requires preoperative knowledge of the feasibility of permanent occlusion of the internal carotid artery (ICA) or vertebral artery or arteries. Methods Retrospective study of transcranial Doppler ultrasonography-monitored angiographic balloon test occlusion and therapeutic sacrifice of the ICA or vertebral artery. Results We performed transcranial Doppler-guided balloon test occlusion in 136 patients at a procedural risk equivalent to that of conventional neuroangiography, and with correct prediction of the hemodynamic result of therapeutic arterial sacrifice in all instances. Patients with an immediate drop in ipsilateral middle cerebral artery (MCA) velocity to 65% or more of baseline values upon ICA balloon occlusion tolerated ICA sacrifice well, whereas hemodynamic infarction is likely in those with a corresponding drop in MCA velocity to 54% or less. When ICA balloon occlusion caused a drop in MCA velocity to between 55 and 64% of baseline, the pulsatility of the MCA signal had to be analyzed. Patients who tolerated bilateral vertebral artery closure had reversal of flow and an increase in velocity in the P1 section of the posterior cerebral artery. In 212 patient-years of observation after therapeutic arterial sacrifice, no de novo aneurysms formed. Conclusion Angiographic balloon test occlusion with transcranial Doppler monitoring can be performed ultra-swiftly at a risk equal to conventional neuroangiography and with correct prediction of the hemodynamic outcome of arterial sacrifice. Elective therapeutic arterial occlusion is a safe and efficient treatment of large cerebral aneurysms and caroticocavernous fistulae.
TL;DR: In a retrospective cohort of MCA infarcts imaged <3 hours from stroke onset, ASPECTS was most accurately determined on CT perfusion CBV maps.
Abstract: BACKGROUND AND PURPOSE: The Alberta Stroke Program Early CT Score (ASPECTS) is a reliable method of delineating the extent of middle cerebral artery (MCA) stroke. Our aim was to retrospectively compare the accuracy of ASPECTS on noncontrast CT, CT angiography (CTA) source images, and CT perfusion maps of cerebral blood volume (CBV) during the first 3 hours of middle cerebral artery (MCA) stroke. MATERIALS AND METHODS: First-time patients with MCA stroke who presented RESULTS: Twenty-eight patients satisfied the criteria with DWI performed at a mean of 50.3 hours (range, 22–125 hours) post-CT imaging. Of 280 ASPECTS regions, 100 were infarcted on DWI. The accuracy of noncontrast CT, CTA source images, and CT perfusion CBV for detecting regional infarct was 80.0%, 84.3%, and 96.8%, respectively (P CONCLUSION: In a retrospective cohort of MCA infarcts imaged
TL;DR: The use of Doppler ultrasound evaluation to measure the peak systolic velocity of the fetal middle cerebral artery has been a major breakthrough in the noninvasive detection of fetal anemia and has also proved useful in the detection of other anemic states that include Kell alloimmunization.
TL;DR: The frequency of cerebral palsy, degree of disability, and predictors of disability were assessed in children in a perinatal arterial stroke database and risk factors were assessed at the univariate level and at the multivariate level using logistic regression analysis.
Abstract: The frequency of cerebral palsy, degree of disability, and predictors of disability were assessed in children in a perinatal arterial stroke database. Risk factors were assessed at the univariate level using the Pearson chi(2) and Fisher exact test and at the multivariate level using logistic regression analysis. Seventy-six of 111 children with perinatal stroke (68%) had cerebral palsy, most commonly hemiplegic (66/76; 87%). Multivariate analysis of the entire cohort showed both delayed presentation (OR,9.96; 95% CI, 3.10-32.02) and male sex (OR, 2.55; 95% CI, 1.03-6.32) were associated with cerebral palsy. In subgroup multivariate analyses: in children with neonatal presentation, bilateral infarcts were associated with triplegia or quadriplegia (OR, 5.33; 95% CI, 1.28-22.27); in children with unilateral middle cerebral artery infarcts, delayed presentation (OR, 10.60; 95% CI, 2.28-72.92) and large-branch infarction (OR, 8.78; 95% CI, 2.18-43.67) were associated with cerebral palsy. These data will aid physicians in planning long-term rehabilitative care for children with perinatal stroke.
TL;DR: A simple, but reliable stroke model using permanent middle cerebral artery occlusion in sheep is introduced that could be used as an alternative to existing large animal models, especially for longitudinal analyses of the safety and therapeutic impact of novel therapies in the field of translational stroke research.
Abstract: As effective stroke treatment by thrombolysis is bound to a narrow time window excluding most patients, numerous experimental treatment strategies have been developed to gain new options for stroke treatment. However, all approaches using neuroprotective agents that have been successfully evaluated in rodents have subsequently failed in clinical trials. Existing large animal models are of significant scientific value, but sometimes limited by ethical drawbacks and mostly do not allow for long-term observation. In this study, we are introducing a simple, but reliable stroke model using permanent middle cerebral artery occlusion in sheep. This model allows for control of ischemic lesion size and subsequent neurofunctional impact, and it is monitored by behavioral phenotyping, magnetic resonance imaging, and positron emission tomography. Neuropathologic and (immuno)-histologic investigations showed typical ischemic lesion patterns whereas commercially available antibodies against vascular, neuronal, astrogli...
TL;DR: Dysfunction of dynamic cerebral autoregulation in subjects with Type 2 diabetes appears to be an early manifestation of microvascular disease prior to the clinical expression of diabetic nephropathy, retinopathy or cardiovascular autonomic neuropathy.
Abstract: Type 2 diabetes is associated with an increased risk of endothelial dysfunction and microvascular complications with impaired autoregulation of tissue perfusion. Both microvascular disease and cardiovascular autonomic neuropathy may affect cerebral autoregulation. In the present study, we tested the hypothesis that, in the absence of cardiovascular autonomic neuropathy, cerebral autoregulation is impaired in subjects with DM+ (Type 2 diabetes with microvascular complications) but intact in subjects with DM- (Type 2 diabetes without microvascular complications). Dynamic cerebral autoregulation and the steady-state cerebrovascular response to postural change were studied in subjects with DM+ and DM-, in the absence of cardiovascular autonomic neuropathy, and in CTRL (healthy control) subjects. The relationship between spontaneous changes in MCA V(mean) (middle cerebral artery mean blood velocity) and MAP (mean arterial pressure) was evaluated using frequency domain analysis. In the low-frequency region (0.07-0.15 Hz), the phase lead of the MAP-to-MCA V(mean) transfer function was 52+/-10 degrees in CTRL subjects, reduced in subjects with DM- (40+/-6 degrees ; P<0.01 compared with CTRL subjects) and impaired in subjects with DM+ (30+/-5 degrees ; P<0.01 compared with subjects with DM-), indicating less dampening of blood pressure oscillations by affected dynamic cerebral autoregulation. The steady-state response of MCA V(mean) to postural change was comparable for all groups (-12+/-6% in CTRL subjects, -15+/-6% in subjects with DM- and -15+/-7% in subjects with DM+). HbA(1c) (glycated haemoglobin) and the duration of diabetes, but not blood pressure, were determinants of transfer function phase. In conclusion, dysfunction of dynamic cerebral autoregulation in subjects with Type 2 diabetes appears to be an early manifestation of microvascular disease prior to the clinical expression of diabetic nephropathy, retinopathy or cardiovascular autonomic neuropathy.
TL;DR: Early angiographic diagnosis with immediate endovascular treatment provided an effective approach for TICA detection and management and offers a valuable alternative to surgery, allowing early aneurysm exclusion with excellent results.
Abstract: OBJECTIVE: To present results of early angiographic diagnosis and endovascular treatment of traumatic intracranial aneurysms (TICA). METHODS: From June 2002 to December 2006, diagnostic angiography was performed on patients with moderate to severe traumatic brain injury that involved a cranial base fracture or a penetrating brain injury with a tract from the penetrating agent that entered at the pterional area, went through the middle cerebral artery candelabra, and crossed the midline. TICAs were treated by various endovascular techniques during the same angiographic procedure. RESULTS: Thirty-four patients with traumatic brain injury underwent angiography (25 penetrating brain injuries, nine blunt injuries); 13 TICAs were diagnosed (10 penetrating brain injuries, three blunt injuries). The Glasgow Coma Scale score at diagnosis ranged from 5 to 15. Angiography was performed for screening in eight patients and for clinical indications in five patients; 11 TICAs were diagnosed before rupture. Seven aneurysms were located on branches of the middle cerebral artery, two on pericallosal branches of the anterior cerebral artery, and four on the internal carotid artery. No recanalization was detected in 12 patients. One patient treated with a bare stent and coiling had a growing intracavernous pseudoaneurysm; therefore, internal carotid artery occlusion with extracranial-intracranial microvascular bypass was performed. Six patients refused angiographic follow-up, but computed tomographic angiography has failed to show recanalization. No patient presented with delayed bleeding (mean follow-up, 2.6 yr). There were no procedure-related complications or mortality. CONCLUSION: Early angiographic diagnosis with immediate endovascular treatment provided an effective approach for TICA detection and management. Endovascular therapy is versatile and offers a valuable alternative to surgery, allowing early aneurysm exclusion with excellent results.
TL;DR: Cerebral amyloid angiopathy (CAA) was associated with decreased vascular reactivity in response to visual stimulation, possibly reflecting the occipital predilection of the disease.
Abstract: Objective: Animal models of cerebral amyloid angiopathy (CAA) exhibit abnormal vascular reactivity. We determined whether vascular reactivity, measured by transcranial Doppler ultrasound (TCD), is reduced in humans with CAA. Methods: Cases were recruited from an established prospective study of CAA. Healthy controls were recruited from a study of normal aging. Evoked mean flow velocity increase in the posterior cerebral artery (PCA) was measured while subjects viewed a flashing alternating checkerboard stimulus. In a separate but partially overlapping cohort we measured the mean flow velocity increase in the middle cerebral artery (MCA) while subjects inhaled carbon dioxide. Results: The visual evoked mean flow velocity increase was 8.0 ± 6.1% in CAA (n = 11) compared to 17.4 ± 5.7% in controls (n = 9, p = 0.002). The PCA pulsatility index, a marker of distal vascular resistance, was higher in CAA (CAA 1.35 ± 0.35, control 1.04 ± 0.14, p = 0.03). Among CAA subjects, lower visual evoked mean flow velocity increase was associated with a higher number of hemorrhages seen on MRI (r = −0.87, p = 0.0005) and higher MRI white matter hyperintensity volume (r = −0.67, p = 0.02). The MCA response to carbon dioxide did not differ between CAA and control in 20 subjects (9 CAA, 11 control, p = 0.54). Conclusions: Cerebral amyloid angiopathy (CAA) was associated with decreased vascular reactivity in response to visual stimulation, possibly reflecting the occipital predilection of the disease. The association of posterior cerebral artery (PCA) evoked flow velocity response with elevated PCA pulsatility index and MRI markers of small vessel disease suggests that abnormal PCA evoked flow velocity in CAA is caused by pathology of the distal resistance vessels.
TL;DR: The effect of intravenous human alpha-C GRP (hαCGRP) on intracranial hemodynamics is investigated, finding that it dilates cerebral arteries, but the effect is so small that it is unlikely to be the only mechanism of CGRP-induced migraine.
Abstract: Calcitonin gene-related peptide (CGRP)-containing nerves are closely associated with cranial blood vessels. CGRP is the most potent vasodilator known in isolated cerebral blood vessels. CGRP can induce migraine attacks, and two selective CGRP receptor antagonists are effective in the treatment of migraine attacks. It is therefore important to investigate its mechanism of action in patients with migraine. We here investigate the effects of intravenous human alpha-CGRP (hαCGRP) on intracranial hemodynamics. In a double-blind, cross-over study, the effect of intravenous infusion of hαCGRP (2 μg/min) or placebo for 20 min was studied in 12 patients with migraine without aura outside attacks. Xenon-133 inhalation SPECT-determined regional cerebral blood flow (rCBF) and transcranial Doppler (TCD)-determined blood velocity (Vmean) in the middle cerebral artery (MCA), as well as the heart rate and blood pressure, were the outcome parameters. No change of rCBF was observed at the end of infusion [1.2% ± 1.7 with hαCGRP, vs. −1.6% ± 3.1 with placebo (mean ± SD)] (P = 0.43). Vmean in MCA decreased to 13.5% ± 3.6 with hαCGRP versus 0.6% ± 1.8 with placebo (P < 0.005). Since rCBF was unchanged, this indicates a dilation of the MCA. hαCGRP induced a decrease in MAP (12%) (P < 0.005) and an increase in heart rate (58%) (P < 0.0001). CGRP dilates cerebral arteries, but the effect is so small that it is unlikely to be the only mechanism of CGRP-induced migraine.
TL;DR: The results suggest that cannabidiol inhibits monocyte/macropharge expressing HMGB1 followed by preventing glial activation and neurological impairment induced by cerebral ischemia will open new therapeutic possibilities for post-ischemic injury viaHMGB1-inhibiting mechanism.
TL;DR: Findings indicate that obesity can adversely affect cerebral blood flow and resistance in the cerebrovascular bed, independent of diagnosis of type-2 diabetes, hypertension or stroke.
Abstract: Objective
Obesity is a risk factor for cerebrovascular disease. We aimed to determine the effects of high body mass index (BMI) on cerebral blood flow regulation in patients with type-2 diabetes mellitus, hypertension, and stroke.
TL;DR: It is indicated that medium and high-dose Ang-(1-7) stimulate NO release and upregulate eNOS expression in ischemic tissues following focal cerebral ischemia/reperfusion in rats.