Stenosis Of Major Cerebral Arteries Research Articles

The Utility of Arterial Transit Time Measurement for Evaluating the Hemodynamic Perfusion State of Patients with Chronic Cerebrovascular Stenosis or Occlusive Disease: Correlative Study between MR Imaging and 15O-labeled H2O Positron Emission Tomography.

To verify whether arterial transit time (ATT) mapping can correct arterial spin labeling-cerebral blood flow (ASL-CBF) values and to verify whether ATT is a parameter that correlates with positron emission tomography (PET)-oxygen extraction fraction (OEF) and PET-mean transit time (MTT). Eleven patients with unilateral major cerebral artery stenosis or occlusion underwent MRI and PET in the chronic or asymptomatic phase. ASL-MRI acquisitions were conducted with each of two post-label delay (PLD) settings (0.7s and 2.0s) using a pseudo-continuous ASL pulse sequence and 3D-spin echo spiral readout with vascular crusher gradient. ATT maps were obtained using a low-resolution pre-scan approach with five PLD settings. Using the ASL perfusion images and ATT mapping, ATT-corrected ASL-CBF images were obtained. Four kinds of ASL-CBF methods (PLD 0.7s with or without ATT correction and PLD 2.0s with or without ATT correction) were compared to PET-CBF, using vascular territory ROIs. ATT and OEF were compared for all ROIs, unaffected side ROIs, and affected side ROIs, respectively. ATT and MTT were compared by the ratio of the affected side to the unaffected side. Transit time-based ROIs were used for the comparison with ATT. Comparing ASL-CBF and PET-CBF, the correlation was higher with ATT correction than without correction, and for a PLD of 2.0s compared with 0.7s. The best correlation was for PLD of 2.0s with ATT correction (R2 = 0.547). ROIs on the affected side showed a low but significant correlation between ATT and PET-OEF (R2 = 0.141). There was a low correlation between the ATT ratio and the MTT ratio (R2 = 0.133). Low-resolution ATT correction may increase the accuracy of ASL-CBF measurements in patients with unilateral major cerebral artery stenosis or occlusion. In addition, ATT itself might have a potential role in detecting compromised hemodynamic state.

Desmoteplase After Ischemic Stroke in Patients With Occlusion or High-Grade Stenosis in Major Cerebral Arteries.

The beneficial effects of intravenous thrombolysis in ischemic stroke, reperfusion and improved outcome, have been directly correlated to time from onset to treatment. Recanalization of occluded intracranial arteries by tissue-type plasminogen activator (alteplase) has been shown to be effective only for the first few hours after symptom onset. Measured by transcranial Doppler monitoring, the effect of alteplase decreases over time, and treatment delay beyond 4.5 hours predicts lack of recanalization, especially in distal occlusions.1 Will the more fibrin-specific and longer acting fibrinolytics correct this problem in patients admitted beyond the accepted thrombolysis time window of ≤3 to 4.5 hours? A recent report by Albers et al2 provided the outcomes of patients treated with intravenous desmoteplase to reverse occlusion or high-grade stenosis of major cerebral arteries (Desmoteplase in Acute Ischemic Stroke [DIAS]-3 trial) but failed to give support to this idea. This first prospective, randomized, controlled phase 3 trial was designed to detect a possible benefit of a single intravenous bolus of 90 µg/kg of desmoteplase given 3 to 9 hours after onset in patients with confirmed major artery occlusion without substantial ischemic damage.2 Desmoteplase failed to improve functional outcomes at 90 days. It did not increase the rates of symptomatic brain hemorrhage, symptomatic brain edema, and death. On the other hand, significant (nominal P 7 hours after onset of stroke symptoms after a prespecified ordinal analysis.2 In view of a superb safety profile, it should be noted that a previous DIAS-2 trial had tested also a higher dose, 125 µg/kg, in the same time window and observed elevated mortality, albeit predominantly unrelated to the study …

Abstract 163: Carotid Stenosis and Stroke Recurrence in Minor Stroke Patients With Atrial Fibrillation

Background & Purpose: Both atrial fibrillation (AF) and carotid stenosis (CS) can be associated with acute stroke recurrence and consequent bad outcome even in minor stroke. We investigated stroke recurrence and outcome in Japanese minor stroke patients with AF and/or CS. Subjects & Methods: Among the consecutive 6246 stroke patients who were admitted to the 7 stroke centers within 7 days after the onset, 634 patients with acute ischemic stroke with AF, the initial NIH stroke scale score of 7 or less, and prior modified Rankin scale (mRS) of 0 or 1 were included in the present study. We observed an acute stroke recurrence during 3 weeks. Results: Acute stroke recurrence was observed in 27 (4.3%) patients. Major cerebral artery stenosis of 50% or more in diameter was observed in 159 (25.1%) patients, and among them 43 (6.8%) had carotid stenosis. Any major artery stenosis was more frequent in patients with than without stroke recurrence (55.6% vs 23.7%, p=0.0002). Carotid stenosis was more frequent in patients with than without stroke recurrence (25.9% vs 5.9%, p<0.0001). The initial NIHSS score was not different between patients with and without an acute stroke recurrence. Dyslipidemia, diabetes mellitus, and history of brain hemorrhage were more frequent, and HDL cholesterol and estimated GFR values were lower, and HbA1c, fasting glucose, BUN, and D-dimer values were higher, intima-media thickness 0f the common carotid artery was thicker in patients with than without an acute stroke recurrence. On the multivariate analysis, carotid stenosis (OR 4.93, 95%CI 1.60~15.2) and D-dimer value (OR 1.13, 95%CI 1.00~1.28) had a positive association with an acute stroke recurrence. Among 43 patients with both AF and CS, 7 had an acute stroke recurrence. With regard to the acute antithrombotic treatment, 5 patients were treated with only anticoagulant agents and other 2 patients were treated with both anticoagulant and antiplatelet agents. Conclusions: Carotid stenosis was a significant predictor for an acute stroke recurrence in patients with atrial fibrillation. Optimal antithrombotic treatment in the acute phase in stroke patients with both AF and CS should be investigated.

Usefulness of Stent Implantation for Treatment of Intracranial Atherosclerotic Stenoses

PurposeWe evaluated the usefulness of intracranial stent implantation for treating patients with atherosclerotic stenosis and with recurrent, ischemic, neurological symptoms despite having undergone medical therapy.Materials and MethodsBetween March 2004 and April 2010, we attempted intracranial, stent-assisted angioplasty in 77 patients with 85 lesions (anterior circulation 73 cases, posterior circulation 12 cases) and who had ischemic neurological symptoms with more than 50% major cerebral artery stenosis. We analyzed the results regarding the technical success rate, complication rate, and restenosis rate during the mean 29.4 month follow-up period.ResultsIntracranial stent implantation was successfully performed in 74 cases (87.1%). In nine cases among the 11, failed cases, stent implantation failure was due to the tortuosity of the target vessel. One patient experienced middle cerebral artery rupture during the procedure, and we embolized the vessel using a microcoil. Five patients developed cerebral infarction in three weeks after the procedure, three of whom improved using conservative management, although the other, two patients expired. The mean number of residual stenoses decreased from 72.3% to 14.7%. Three patients demonstrated significant in-stent restenosis, i.e. more than 50%, during the follow-up period.ConclusionAs stent-assisted angioplasty in intracranial, atherosclerotic stenosis is effective and relatively safe, it can be considered as an alternative treatment for patients with recurrent, ischemic, neurologic symptoms despite having undergone medical therapy.

Laterality of the command center in relation to handedness and simple reaction time: a clinical perspective

To the extent that handedness has been a faithful guide to clinicians as to laterality of motor control in their patients (at least among the right-handers), the recent contrary pronouncement by [Gonzalez and colleagues (2006)][1] in the Journal invites comments. For more than a century, clinical

Significance of white matter high intensity lesions as a predictor of stroke from arteriolosclerosis

Objectives: To determine whether the extent of white matter high intensity lesions (WML) on magnetic resonance imaging (MRI) is an independent predictor of risk for stroke from arteriolosclerosis, and whether...

Abnormalities of the central nervous system in very young children with sickle cell anemia

To determine whether abnormalities of the CNS are present in very young children with sickle cell anemia. Thirty-nine children with hemoglobin SS between the ages of 7 and 48 months were examined with magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). No child had a history of clinical stroke, although 3 had a history of seizures (2 neonatal). Twenty-one patients underwent developmental testing with the Bayley or McCarthy Scales. The overall prevalence of CNS abnormalities in asymptomatic children was 4 of 36 (11%, confidence interval 3, 26%). One patient had a silent infarct observed on MRI and a stenotic lesion on MRA; 3 other patients had stenotic lesions on MRA. The 3 patients who had a history of seizures all had lesions consistent with infarcts on MRI. Of the asymptomatic patients who had psychometric testing, 1 of 18 was developmentally delayed. One of 3 with a history of seizures had mild developmental delay. Very young children with sickle cell anemia (and no history of clinical stroke) have infarction in the brain and/or stenosis of major cerebral arteries, similar to those reported in older children. These findings indicate a need for larger studies to define the incidence of CNS lesions in this age group and to determine the need for early therapeutic intervention to prevent CNS sequelae of sickle cell disease.

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We report excellent initial results of stenting for stenosis of major cerebral arteries experienced between April 1997 and June 1998. Patients ranged in age from 61 to 78 year old (mean 65 year old). The location of the lesion included cervical carotid artery: 10, orifice of vertebral artery: 3, subclavian artery: 3. All lesion were high grade more than 60%. Ten were symptomatic (TIA 5, minor stroke 1, VBI 2. others 2), and six were asymptomatic. Stents utilized were Palmaz stents, the balloon expandable type originally developed for peripheral arteries. Stents were placed at the lesion after predilatation in some patients and primarily in other patients. Almost complete dilatation was obtained in every patient without any permanent adverse event. Bradycardia and mild hypotension due to vaso-vagal reflex was observed in two patients with carotid stenosis until next day after treatment. TIA was experienced in two patients with carotid stenosis. No further ischemic events were observed during the short-term follow-up period. Usefulness of stenting for major cerebral artery stenosis was indicated by our initial results. Stenting will play an important role in the treatment of cerebrovascular disease in the near future, though the development of better stents for the cerebral arteries and long-term follow-up are mandatory.