Association of neonatal inflammatory markers and perinatal stroke subtypes.

OBJECTIVE: To examine the relationship between neonatal inflammatory cytokines and perinatal stroke using a systems biology approach analyzing serum and blood-spot cytokines from 47 patients. METHODS: This was a population-based, controlled cohort study with prospective and retrospective case ascertainment. Participants were recruited through the Alberta Perinatal Stroke Project. Stroke was classified as neonatal arterial ischemic stroke (NAIS), arterial presumed perinatal ischemic stroke (APPIS), or periventricular venous infarction (PVI). Biosamples were stored blood spots (retrospective) and acute serum (prospective). Controls had comparable gestational and maternal ages. Sixty-five cytokines were measured (Luminex). Hierarchical clustering analysis was performed to create heat maps. The Fisher linear discriminant analysis was used to create projection models to determine discriminatory boundaries between stroke types and controls. RESULTS: A total of 197 participants were analyzed (27 with NAIS, 8 with APPIS, 12 with PVI, 150 controls). Cytokines were quantifiable with quality control measures satisfied (standards testing, decay analysis). Linear discriminant analysis had high accuracy in using cytokine profiles to separate groups. Profiles in participants with PVI and controls were similar. NAIS separation was accurate (sensitivity 77%, specificity 97%). APPIS mapping was also distinguishable from NAIS (sensitivity 86%, specificity 99%). Classification tree analysis generated similar diagnostic accuracy. CONCLUSIONS: Unique inflammatory biomarker signatures are associated with specific perinatal stroke diseases. Findings support an acquired pathophysiology and suggest the possibility that at-risk pregnancies might be identified to develop prevention strategies. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that differences in acute neonatal serum cytokine profiles can discriminate between patients with specific perinatal stroke diseases and controls.

Intracranial Artery Injury in HIV-negative Tuberculous Meningitis : A High-Resolution Vessel Wall Imaging Study.

PURPOSE: The features of intracranial arterial injury in tuberculous meningitis (TBM) are of important diagnostic and prognostic value. The study aimed to elucidate the high-resolution vessel wall imaging (HR-VWI) manifestations of intracranial arterial insults in TBM. METHODS: The clinical data, routine cranial magnetic resonance imaging, magnetic resonance angiography (MRA) and HR-VWI before and after contrast enhancement of intracranial arteries in clinically diagnosed TBM patients were retrospectively analyzed. RESULTS: In this study 27 TBM patients were included. Abnormalities in the intracranial arteries were detected in all patients using HR-VWI. Typical vessel insults included nodular or granular lesions, related thickness and prominent enhancement in the wall, and lumen narrowing or occlusion. The most frequently involved arteries were the C4 segment of the internal carotid artery and the P1 segment of the posterior cerebral artery. The lesions were consistent with disease stage and disease duration and correlated with infarction. CONCLUSION: The use of HR-VWI revealed that cerebral artery involvement in patients with TBM is much more common and extensive than in previous radiological reports. The use of HR-VWI improves recognition of arterial pathologies and has diagnostic value in patients with TBM.

Absence of Collaterals is Associated with Larger Infarct Volume and Worse Outcome in Patients with Large Vessel Occlusion and Mild Symptoms.

BACKGROUND: Mechanical thrombectomy is the standard of care for patients with large vessel occlusion (LVO) presenting with severe symptoms; however, little is known about the best treatment for patients with LVO and mild symptoms. The absence of good collaterals has been associated with a worse outcome in patients with LVO. In this study, we aim to assess the use of collateral score to identify patients with LVO and mild symptoms that might benefit from mechanical thrombectomy (MT). METHODS: A retrospective review of prospectively collected data on patients presenting with mild ischemic stroke (National Institute of Health Stroke Scale [NIHSS] <6) and anterior circulation LVO between September 2015 and July 2017 was performed. Collected data included baseline demographics, NIHSS on admission, Alberta Stroke Program Early CT Score (ASPECTS), location of occlusion, collateral score using Tan scoring system, final infarct volume, and 90-day modified Rankin Scale (mRS). Patients who underwent MT were excluded from this analysis. Two multivariable models were used to assess outcomes. A gamma distributed generalized linear regression model with a log link was used to examine the impact on final infarct volume. To predict the odds of a positive 90-day outcome we estimated a logistic regression. RESULTS: Forty-one patients were identified. Mean age was 67.7-years with 56.1% males. Median NIHSS on admission was 3. The most common vessels involved were the middle cerebral artery (26), internal carotid artery (14), and anterior cerebral artery (1). Twelve patients received intravenous alteplase. Median ASPECTS score was 9, median collateral score was 2.3. Median infarct volume was 10.7 mL. A good functional outcome (mRS 0-2) at 90 days was achieved in 86.4% of patients. There was a negative relationship between collateral score and final infarct volume (-.3134, P = .046). Multivariable regression results showed that with a one-point increase in NIHSS on admission there was a 25% increase in final infarct volume. Higher infarct volume was associated with lower odds of achieving good functional outcome (mRS 0-2) (odds ratio .96, P = .049 [95% confidence interval .918-.999). CONCLUSIONS: Most patients with anterior circulation LVO and low NIHSS achieve good long-term functional outcome, however, approximately 15% had significant disability. The absence of collaterals correlates with a larger final infarct volume and a worse long-term functional outcome. Collateral score might be a useful tool in identifying patients with LVO and low NIHSS who might benefit from MT.

Vascular Cognitive Disorder.

The term vascular cognitive disorder (VCD) refers to a heterogeneous group of disorders in which the primary feature is cognitive impairment attributable to cerebrovascular disease (CVD). This includes not only vascular dementia (VaD) but also cognitive impairment of insufficient severity to meet diagnostic criteria for dementia. VCD is recognized as the second most common cause of dementia after Alzheimer's disease (AD), but prevalence rates vary widely according to the diagnostic criteria employed. There have been recent attempts to standardize diagnostic criteria. VCD incorporates a range of neuropathological mechanisms including poststroke impairment, small and large vessel disease, and cases of mixed-pathology, with CVD interacting with AD and other neuropathologies. Recent neuroimaging data have improved our understanding of the etiology of VCD. Symptomatic treatments for VaD have modest benefit and there is increased focus on the primary and secondary preventative benefits of vascular risk factor control.

Speech and Language Impairments After Childhood Arterial Ischemic Stroke: Does Hemisphere Matter?

BACKGROUND: The association between left hemisphere stroke and acute speech and language impairment is well documented in adults. However, little is known about this association in childhood arterial ischemic stroke. Here we examined potential predictors of acute speech (dysarthria and apraxia) and language impairments after childhood arterial ischemic stroke, including site of lesion. METHODS: Children with radiologically confirmed acute arterial ischemic stroke, admitted to a tertiary pediatric hospital from 2004 to 2012, were identified from an institutional registry. We examined the prevalence of dysarthria, apraxia, and language impairment within two weeks of the stroke. Associations with age at stroke event, lesion side (left, right, or bilateral), and arterial territory affected (anterior, posterior, or both) were assessed using logistic regression. RESULTS: Sixty-two children with mean age eight years (range three to 17 years) were identified. Strokes were located in the left (32%), right (44%), or both hemispheres (24%). Dysarthria (74%) and language impairment (50%) were frequent. Verbal dyspraxia was less common (11%). There was little evidence that variables of interest, including site of lesion, were significantly associated with increased odds of dysarthria or language impairment (all P > 0.49). CONCLUSIONS: Regardless of age, children are at high risk of communication disorders after stroke. Unlike adults, left hemisphere stroke was not associated with either speech or language impairment in our cohort, suggesting there may be bihemispheric contribution to language function. Future studies are needed to examine whether the predictors examined here determine long-term outcomes.

Actionable vascular and other incidental findings on CTA in patients undergoing acute stroke intervention.

Providing a fast and accurate diagnosis of acute large-vessel occlusion on computed tomography angiograms (CTAs) is essential for timely intervention and good stroke outcomes. However, the detection and appropriate management of incidental findings are also important parts of any clinical radiology practice and can greatly affect patient care. The intricate anatomy covered by CTAs of the head and neck coupled with the time pressures of acute stroke diagnosis creates an environment in which unrelated, important findings can potentially be missed. The purpose of our study was to document clinically actionable incidental findings on CTA in 225 patients undergoing acute stroke intervention. After institutional review board approval, a retrospective six-year review of CTAs of the head and neck in patients undergoing acute stroke intervention was performed for actionable incidental vascular and nonvascular findings. A total of 225 patients undergoing acute stroke intervention with documented intracranial large-vessel occlusion on CTAs were consecutively enrolled in the study. Incidental vascular findings were identified in 17 of 225 patients (7.5%, 95% confidence interval 5% to 12%). Previously unreported aneurysms ranging from 2 mm to 10 mm in size represented 18 of 19 vascular findings in these patients. Incidental nonvascular findings were identified in 32 patients (14%, 95% confidence interval 5% to 12%). These included malpositioned support lines and tubes; pneumothorax; interstitial lung disease; newly diagnosed metastatic disease; nasopharyngeal, parotid, and pituitary masses; and cervical spine compression fractures. CTAs of the head and neck in patients undergoing acute stroke intervention contain a relatively high frequency of vascular and nonvascular incidental findings requiring further follow-up, and therefore should be evaluated carefully and systematically.

Specific Factors to Predict Large-Vessel Occlusion in Acute Stroke Patients.

BACKGROUND: The effectiveness of thrombectomy for acute ischemic stroke has been established, and earlier treatment produces better outcomes. If possible to identify large-vessel occlusion (LVO) at the prehospital phase, eligible patients can be shipped directly to a hospital that can perform thrombectomy. The purpose of this study was to determine factors that are specific to LVO and can be known before hospital arrival. METHODS: The subjects were stroke patients during the period between July 2014 and June 2016, who had a National Institutes of Health Stroke Scale (NIHSS) score of 8 or higher and came to our hospital within 6 hours of onset. These patients were divided into an LVO group and a non-LVO group, and background factors, mode of onset, individual NIHSS item scores, and blood pressure at the time of the visit were retrospectively investigated. The selected factors were compared with LVO prediction scales reported in the past. RESULTS: There were 196 stroke patients who had NIHSS scores of 8 or higher and arrived at the hospital within 6 hours. Of these 196 patients, 56 had LVO. This LVO group included a significantly higher number of patients with the 2 items of atrial fibrillation (odds ratio [OR], 11.5: 95% confidence interval [CI], 4.04-32.9; P < .0001) and systolic blood pressure of 170 mm Hg or lower (OR, 2.99: 95% CI, 1.33-6.71, P = .008). These 2 items predicted LVO equally to existing LVO prediction scales. CONCLUSIONS: The 2 items of atrial fibrillation and systolic blood pressure of 170 mm Hg or lower were significantly correlated with LVO.

The Utility of Collaterals as a Biomarker in Pediatric Unilateral Intracranial Arteriopathy.

BACKGROUND: Intracranial arteriopathies are frequent causes of pediatric stroke and important risk factors for stroke recurrence. Without tissue diagnosis, vascular imaging is relied upon to identify the underlying etiology and prognosis. We hypothesized that children with unilateral intracranial arteriopathy with lenticulostriate collaterals would demonstrate distinct vascular outcomes compared with children without collaterals. METHODS: We retrospectively identified children with unilateral intracranial arteriopathy from two institutions. Two blinded raters from each institution reviewed magnetic resonance or digital subtraction angiography at baseline and ≥12 months. Patients were grouped according to presence or absence of lenticulostriate collaterals. Clinical features and vascular imaging outcomes were compared using univariate analysis and multivariate logistic regression. RESULTS: Forty-four children were included: 22 males, median age 8.2 years (range two to 16.9 years), and further stratified into the collateral group (n = 20) and non-collateral group (n = 24), with median follow-up of 25.5 months and 23 months, respectively. Both groups demonstrated similar rates of progression on vascular imaging at ≥12 months, 50% in the collateral group versus 37.5% in the non-collateral group (P > 0.05). The collateral group was associated with asymptomatic clinical presentation, normal brain MRI, border zone infarcts, and either vascular stabilization or new contralateral disease. The non-collateral group demonstrated either vascular improvement or discordant progression (combination of improved and progressive lesions). Using a multivariate model, collaterals continued to be an independent predictor of vascular outcome. CONCLUSIONS: This study suggests that lenticulostriate collaterals in children with unilateral intracranial arteriopathy may serve as a useful neuroimaging biomarker that helps to stratify patients with distinct clinical features and patterns of vascular evolution.

Impact of Side Branches on the Computation of Fractional Flow in Intracranial Arterial Stenosis Using the Computational Fluid Dynamics Method.

BACKGROUND: Computational fluid dynamics (CFD) allows noninvasive fractional flow (FF) computation in intracranial arterial stenosis. Removal of small artery branches is necessary in CFD simulation. The consequent effects on FF value needs to be judged. METHODS: An idealized vascular model was built with 70% focal luminal stenosis. A branch with one third or one half of the radius of the parent vessel was added at a distance of 5, 10, 15 and 20 mm to the lesion. With pressure and flow rate applied as inlet and outlet boundary conditions, CFD simulations were performed. Flow distribution at bifurcations followed Murray's law. By including or removing side branches, five patient-specific intracranial artery models were simulated. Transient simulation was performed on a patient-specific model, with a larger branch for validation. Branching effect was considered trivial if the FF difference between paired models (branches included or removed) was within 5%. RESULTS: Compared with the control model without a branch, in all idealized models the relative differences of FF was within 2%. In five pairs of cerebral arteries (branches included/removed), FFs were 0.876 and 0.877, 0.853 and 0.858, 0.874 and 0.869, 0.865 and 0.858, 0.952 and 0.948. The relative difference in each pair was less than 1%. In transient model, the relative difference of FF was 3.5%. CONCLUSION: The impact of removing side branches with radius less than 50% of the parent vessel on FF measurement accuracy is negligible in static CFD simulations, and minor in transient CFD simulation.

Measurement Conditions of End-Diastolic Ratio of Common Carotid Arteries Alter Diagnostic Ability for Large Artery Intracranial Occlusive Disease.

BACKGROUND: End-diastolic ratio, calculated by the side-to-side ratio of end-diastolic flow velocities of the common carotid arteries, is an indicator for large artery intracranial occlusive disease. However, the diagnostic ability of end-diastolic ratios derived from different measurement conditions is unclear. METHODS: End-diastolic ratios were measured twice by single carotid duplex ultrasonography. End-diastolic ratio1st was calculated from separate end-diastolic flow velocities measured during routine assessment. End-diastolic ratio2nd was calculated almost simultaneously without head rotation. For each end-diastolic ratio, the measurement conditions and prediction ability for occlusions of the internal carotid artery or proximal portion of the middle cerebral artery using an established cutoff of 1.4 or greater were compared. RESULTS: Two hundred thirty-three patients (147 men, median 67 years) were registered, with available intracranial artery information in 158 patients (67.8%) and occlusions detected in 7 patients (4.4%). End-diastolic ratio1st was significantly higher than end-diastolic ratio2nd (median 1.21 versus 1.08, P < .001). Compared with end-diastolic ratio1st, end-diastolic ratio2nd had a significantly shorter time interval (median 709 versus 28 seconds, P < .001) and smaller pulse rate difference (1.54 ± 5.10 versus .25 ± 4.63 beats per minute, P = .004). To predict occlusions, the sensitivity, specificity, and overall accuracy for end-diastolic ratio1st of 1.4 or greater were 85.7%, 70.9%, and 71.5%, respectively, and for end-diastolic ratio2nd of 1.4 or greater were 85.7%, 98.0%, and 97.5%, respectively. End-diastolic ratio2nd had better specificity and overall accuracy than end-diastolic ratio1st (P < .001). CONCLUSIONS: End-diastolic ratio varies with measurement conditions. Combined end-diastolic flow velocities measurement may improve diagnostic ability for large artery intracranial occlusive disease.

Local blood pressure associates with the degree of luminal stenosis in patients with atherosclerotic disease in the middle cerebral artery.

The mechanism underlying atherosclerotic ischemic events within the middle cerebral artery (MCA) is unclear. High structural stress induced by blood pressure might be a potential aetiology as plaque rupture occurs when such mechanical loading exceeds its material strength. To perform reliable analyses quantifying the mechanical loading within a plaque, the local blood pressure is needed. However, data on MCA blood pressure is currently lacking. In this study, the arterial pressure proximal to the stenotic site in the MCA was measured in 15 patients scheduled for intervention. The relationships between these local measurements and pre-intervention and intra-intervention non-invasive arm measurements were assessed. The impact of luminal stenosis on the local blood pressure was quantified. Compared with the pre-intervention arm measurement, the intra-intervention arm pressure decreased significantly by 23.9 ± 11.8 and 9.3 ± 14.7 % at diastole and systole, respectively. The pressure proximal to the stenosis was much lower than the pre-intervention arm measurement (diastole: 65.3 ± 15.7 vs 82.0 ± 9.7, p < 0.01; systole: 81.1 ± 15.9 vs 133.9 ± 18.7, p < 0.01; unit: mmHg). The systolic pressure in the MCA in patients with stenosis <70 % (n = 6) was significantly higher than the value in patients with stenosis ≥70 % (n = 9) (92.0 ± 7.3 vs 73.9 ± 16.1, p = 0.02; unit: mmHg), as was pulse pressure (22.8 ± 6.4 vs 11.1 ± 8.3, p = 0.01; unit: mmHg). However, diastolic pressure remained unaffected (69.2 ± 9.3 vs 62.8 ± 19.0, p = 0.58; unit: mmHg). In conclusion, the obtained results are helpful in understanding the local hemodynamic environment modulated by the presence of atherosclerosis. The local pressure measurements can be used for computational analysis to quantify the critical mechanical condition within an MCA lesion.

Severity assessment of intracranial large artery stenosis by pressure gradient measurements: A feasibility study.

BACKGROUND: Fractional flow reserve (FFR)-guided revascularization strategy is popular in coronary intervention. However, the feasibility of assessing stenotic severity in intracranial large arteries using pressure gradient measurements still remains unclear. METHODS: Between March 2013 and May 2014, 12 consecutive patients with intracranial large artery stenosis (including intracranial internal carotid artery, middle cerebral M1 segment, intracranial vertebral artery, and basilar artery) were enrolled in this study. The trans-stenotic pressure gradient was measured before and/or after percutaneous transluminal angioplasty and stenting (PTAS), and was then compared with percent diameter stenosis. A Pd /Pa cut-off of ≤0.70 was used to guide stenting of hemodynamically significant stenoses. The device-related and procedure-related serious adverse events and recurrent cerebral ischemic events were recorded. RESULTS: The target vessel could be reached in all cases. No technical complications occurred due to the specific study protocol. Excellent pressure signals were obtained in all patients. For seven patients who performed PTAS, the mean pre-procedural pressure gradient decreased from 59.0 ± 17.2 to 13.3 ± 13.6 mm Hg after the procedure (P < 0.01). Only one patient who refused stenting experienced a TIA event in the ipsilateral MCA territory. No recurrent ischemic event was observed in other patients. CONCLUSION: Mean trans-stenotic pressure gradients can be safely and easily measured with a 0.014-inch fluid-filled guide wire in intracranial large arteries. © 2016 Wiley Periodicals, Inc.

Detection of Cerebral Vasculopathy by Transcranial Doppler in Children With Neurofibromatosis Type 1.

Neurofibromatosis type 1 is characterized by nerve sheath neurofibromas associated with a number of additional clinical features, including cerebrovascular disease. The aim of this study was to use transcranial Doppler as a screening method for identifying cerebral vasculopathy in children with neurofibromatosis type 1. Forty children with neurofibromatosis type 1, aged 5 to 18 years old, were examined by transcranial Doppler. Patients presenting with hemodynamic features of arterial stenosis/occlusion on transcranial Doppler underwent magnetic resonance angiography to confirm the findings. Magnetic resonance angiography was performed on 4 children who exhibited a transcranial Doppler hemodynamic pattern indicative of cerebral vasculopathy. Among these cases, 2 presented internal carotid artery stenosis/occlusion, 1 had bilateral middle cerebral artery stenosis, and 1 presented a normal magnetic resonance angiography result. Transcranial Doppler can be used routinely in the investigation of cerebrovascular disease in neurofibromatosis type 1 patients, where magnetic resonance angiography can be subsequently applied to confirm the diagnosis, further contributing to the prevention of cerebrovascular events.

Pathophysiology, presentation, prognosis, and management of intracranial arterial dolichoectasia.

Up to 12% of patients with stroke have intracranial arterial dolichoectasia (IADE) and the basilar artery is affected in 80% of these cases. Diagnostic criteria and prognosis studies of IADE are based on basilar artery diameter, which is a good quantitative marker for the severity of the disease. The pathophysiology is largely unknown, but IADE can be viewed as a common final pathway of arterial wall response or damage in the tunica media due to various mechanisms, such as matrix metalloproteinase dysfunction or muscle cell or elastic fibre injury. No randomised controlled trials have been undertaken in IADE and thus little high-level evidence is available on which to base treatment guidelines. IADE management depends on clinical presentation and disease severity, and includes blood pressure control, antithrombotic treatments, endovascular procedures, and surgery. Further studies are needed to better define IADE in the general population, to establish its prevalence and pathophysiology, to identify subgroups at risk of life-threatening complications, and to offer effective treatment options.

Improvement in cerebral hemodynamic parameters and outcomes after superficial temporal artery-middle cerebral artery bypass in patients with severe stenoocclusive disease of the intracranial internal carotid or middle cerebral arteries.

OBJECT: Both the older and the recent extracranial-intracranial (EC-IC) bypass trials for symptomatic carotid occlusion failed to demonstrate a reduction in stroke recurrence. However, the role of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with symptomatic intracranial stenoocclusive disease has been rarely evaluated. The authors evaluated serial changes in various cerebral hemodynamic parameters in patients with severe stenoocclusive disease of the intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated by STA-MCA bypass surgery or medical treatment. METHODS: Patients with severe stenoocclusive disease of the intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using the breath-holding index (BHI). Patients with impaired BHI (< 0.69) were further evaluated with acetazolamide-challenge technitium-99m hexamethylpropyleneamine oxime ((99m)Tc HMPAO) SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4 ± 1 months and were followed up for cerebral ischemic events. RESULTS: A total of 112 patients were included. This total included 73 men, and the mean age of the entire study population was 56 years (range 23-78 years). (99m)Tc HMPAO SPECT demonstrated impaired CVR in 77 patients (69%). Of these 77 patients, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenge (99m)Tc HMPAO SPECT repeated at 4 ± 1 months showed significant improvement in the STA-MCA bypass group. During a mean follow-up of 34 months (range 18-39 months), only 6 (13%) of 46 patients in the bypass group developed cerebral ischemic events, as compared with 14 (45%) of 31 patients receiving medical therapy (absolute risk reduction 32%, p = 0.008). CONCLUSIONS: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial stenoocclusive disease of the intracranial ICA or MCA results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection.

Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.

Different blood pressure indexes on intracranial arterial stenosis in Asymptomatic Polyvascular Abnormalities in Community study in China.

BACKGROUND: The association between hypertension and cerebrovascular events is shown in some large-scale studies, but it remains unclear which blood pressure index is the most sensitive risk factor for cerebrovascular stenosis. METHODS: We investigated the potential associations between different blood pressure indexes and intracranial arterial stenosis (ICAS) in the study. The population-based Asymptomatic Polyvascular Abnormalities in Community study examined asymptomatic intracranial arterial abnormalities in a Chinese population and included participants aged more than 40 years without a history of stroke, transient ischemic attack, and coronary heart disease. ICAS was diagnosed by transcranial Doppler sonography. Blood pressure was measured with a mercury manometer three times; an average result of SBP and DBP was used, and mean arterial pressure (MAP) and pulse pressure (PP) were calculated for the statistical analysis. RESULTS: Out of the 4422 study participants, 711 (16.1%) showed an asymptomatic ICAS. After adjusting for age, waist circumference, drinking, diabetes, dyslipidemia, and blood concentration of uric acid, C-reactive protein, and homocysteine, ICAS was significantly associated with a higher SBP [from decile 6, odds ratio (OR) 3.093; 95% confidence interval (CI) 1.909, 5.012; P < 0.01), a higher MAP (from decile 7, OR 2.889; 95% CI 1.853, 4.504; P < 0.01), and a higher PP (from decile 5, OR 2.295;95% CI 1.463, 3.601; P < 0.01). Using a receiver-operating characteristic curve to estimate the predictive value of different blood pressure indexes for ICAS, SBP, MAP, and PP, were predictive indexes for ICAS and PP showed the largest predictive value (area under the curve = 0.737). CONCLUSIONS: The current study results suggest that SBP, MAP, and PP are all associated with asymptomatic ICAS. PP may be the most sensitive index to predict ICAS.

Compensatory intracranial arterial dilatation in extracranial carotid atherosclerosis: the Northern Manhattan study.

BACKGROUND: There is a scarcity of data supporting the association between atherosclerosis and dolichoectasia in unbiased samples. AIMS: To test the hypothesis that the association between dolichoectasia and extracranial carotid atherosclerosis depends on the degree of collateral circulation. METHODS: The Northern Manhattan Study magnetic resonance imaging substudy consists of 1290 participants who remained stroke-free at the time of magnetic resonance imaging. Arterial diameters were collected in all participants with available magnetic resonance angiography. Dolichoectasia was defined as a head-size adjusted diameter >2 standard deviation for each artery. Carotid Doppler was used to evaluate for carotid atherosclerosis (carotid plaque, maximum plaque thickness and carotid intima media thickness). RESULTS: We included 994 participants with available Doppler and magnetic resonance angiography data (mean age 63 years, 60% female). Any dolichoectasia was reported in 16% of participants, 54% had at least one carotid plaque and the mean carotid intima media thickness was 0·92 ± 0·09 mm. After adjusting for demographic and clinical characteristics, there was no association between markers of carotid atherosclerosis and dolichoectasia. However, stratifying by collaterals, it was observed that dolichoectasia was more likely in the anterior and posterior circulations when collaterals were available among participants with carotid atherosclerosis. These associations were confirmed by noting an increment in arterial diameters in the corresponding arteries ipsilateral and contralateral to each carotid as well as in the posterior circulation. CONCLUSIONS: We did not find an association of extracranial carotid atherosclerosis with dolichoectasia. However, we found that dolichoectasia is more frequent when intracranial collaterals are available suggesting a compensatory process that needs further investigation.

Reduced CMRO2 and cerebrovascular reserve in patients with severe intracranial arterial stenosis: a combined multiparametric qBOLD oxygenation and BOLD fMRI study.

Multiparametric quantitative blood oxygenation level dependent (mqBOLD) magnetic resonance Imaging (MRI) approach allows mapping tissular oxygen saturation (StO2 ) and cerebral metabolic rate of oxygen (CMRO2 ). To identify hemodynamic alteration related to severe intracranial arterial stenosis (SIAS), functional MRI of cerebrovascular reserve (CVR BOLD fMRI) to hypercapnia has been proposed. Diffusion imaging suggests chronic low grade ischemia in patients with impaired CVR. The aim of the present study was to evaluate how oxygen parameters (StO2 and CMRO2 ), assessed with mqBOLD approach, correlate with CVR in patients (n = 12) with SIAS and without arterial occlusion. The perfusion (dynamic susceptibility contrast), oxygenation, and CVR were compared. The MRI protocol conducted at 3T lasted approximately 1 h. Regions of interest measures on maps were delineated on segmented gray matter (GM) of middle cerebral artery territories. We have shown that decreased CVR is spatially associated with decreased CMRO2 in GM of patients with SIAS. Further, the degree of ipsilateral CVR reduction was well-correlated with the amplitude of the CMRO2 deficit. The altered CMRO2 suggests the presence of a moderate ischemia explained by both a decrease in perfusion and in CVR. CVR and mqBOLD method may be helpful in the selection of patients with SIAS to advocate for medical therapy or percutaneous transluminal angioplasty-stenting.

Paediatric stroke: pressing issues and promising directions.

Stroke occurs across the lifespan with unique issues in the fetus, neonate, and child. The past decade has seen substantial advances in paediatric stroke research and clinical care, but many unanswered questions and controversies remain. The pathobiology of perinatal stroke needs to be better understood if prevention strategies are to be realised. Similarly, enhanced understanding of the mechanisms underlying childhood stroke, including cerebral arteriopathies, could inform the development of mechanism-specific treatments. Emerging clinical trials, including studies of neonatal sinovenous thrombosis and childhood arterial stroke, offer the hope of evidence-based treatment options in the near future. Early recognition of stroke in children is a key educational target for both the public and health-care professionals, and has translational potential to advance the application of neuroprotective, thrombolytic, and antithrombotic interventions and rehabilitation strategies to the earliest possible timepoints after stroke onset, improving outcomes and quality of life for affected children and their families.