Xenon-enhanced CT assessment of cerebral blood flow in stroke-in-progress patients with unilateral internal carotid artery or middle cerebral artery stenosis.
Ontology highlight
ABSTRACT:
SUBMITTER: Guo ZN
PROVIDER: S-EPMC5562546 | biostudies-other | 2013 Dec
REPOSITORIES: biostudies-other
Similar Datasets
Project description:BackgroundAcute tandem cervical dissecting internal carotid artery (ICA) occlusion and intracranial embolic middle cerebral artery (MCA) occlusion can be devastating, and the optimal treatment strategy for this condition has not been established yet.Case descriptionA 45-year-old male presented with aphasia and right hemiparesis preceded by neck pain. Computed tomography showed a high-density signal along the left MCA, suggesting extensive emboli. Magnetic resonance angiography demonstrated tandem occlusion of the left cervical ICA and intracranial MCA with minimal diffusion-weighted imaging lesion. Emergent surgical embolectomy was performed, and long intracranial MCA emboli were retrieved with collateral cross-flow restoration. The cervical ICA was exposed, and dissection was confirmed. The cervical ICA was ligated, and superficial temporal artery (STA)-MCA anastomosis was added. Postoperatively, the patient demonstrated recovery from right hemiparesis and aphasia. At the 6(th) postoperative month, follow-up studies demonstrated a robustly patent STA-MCA bypass and no additional ischemic lesion on T2-weighted imaging.ConclusionsSurgical embolectomy in conjunction with ligation of the cervical ICA followed by STA-MCA bypass might be a safe alternative method to endovascular recanalization, when the cervical dissection is extensive and when huge secondary emboli are present along the MCA.
| S-EPMC4697205 | biostudies-literature
Project description:PURPOSE:Cerebral blood flow (CBF) and glucose metabolism are important and significant factors in ischaemic cerebrovascular disease. The objective of this study was to use quantitative hybrid PET/MR to evaluate the effects of surgery treatment on the symptomatic unilateral internal carotid artery/middle cerebral artery steno-occlusive disease. METHODS:Fifteen patients diagnosed with ischaemic cerebrovascular disease were evaluated using a hybrid TOF PET/MR system (Signa, GE Healthcare). The CBF value measured by arterial spin labelling (ASL) and the standardized uptake value ratio (SUVR) measured by 18F-FDG PET were obtained, except for the infarct area and its contralateral side, before and after bypass surgery. The asymmetry index (AI) was calculated from the CBF and SUVR of the ipsilateral and contralateral cerebral hemispheres, respectively. The ?CBF and ?SUVR were calculated as the percent changes of CBF and SUVR between before and after surgery, and paired t tests were used to determine whether a significant change occurred. Spearman's rank correlation was also used to compare CBF with glucose metabolism in the same region. RESULTS:The analysis primarily revealed that after bypass surgery, a statistically significant increase occurred in the CBF on the affected side (P < 0.01). The postprocedural SUVR was not significantly higher than the preprocedural SUVR (P > 0.05). However, the postprocedural AI values for CBF and SUVR were significantly lower after surgery than before surgery (P < 0.01). A significant correlation was found between the AI values for preoperative CBF and SUVR on the ipsilateral hemisphere (P < 0.01). CONCLUSIONS:The present study demonstrates that a combination of ASL and 18F-FDG PET could be used to simultaneously analyse changes in patients' cerebral haemodynamic patterns and metabolism between before and after superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery. This therefore represents an essential tool for the evaluation of critical haemodynamic and metabolic status in patients with symptomatic unilateral ischaemic cerebrovascular disease.
| S-EPMC7248051 | biostudies-literature
Project description:BackgroundFew studies have focused on cerebral hemodynamics in the early stage following carotid artery stenting (CAS). This retrospective cohort study aimed to investigate cerebral hemodynamic changes within 6 hours of unilateral CAS in patients with different degrees of carotid stenosis.MethodsA total of 104 patients who underwent CAS accompanied by transcranial color-code Doppler or transcranial Doppler were enrolled in the study. The participants were divided into the following 3 groups based on the degree of carotid stenosis: severe stenosis group, extreme stenosis group, and near occlusion group. Bilateral middle cerebral artery (MCA) peak systolic velocity (PSV) and pulsatility index (PI) were measured using transcranial color-code Doppler before and 1 and 3 hours following CAS. Blood pressure, MCA-PSV, and PI were compared among the 3 groups.ResultsAt 1 hour following CAS, ipsilateral MCA-PSV increased compared to the baseline in the severe stenosis group [84±21 vs. 93±27 cm/s; 8.1%; interquartile range (IQR), 1.4-20.1%; P<0.001]. A similar hemodynamic change, but of a larger magnitude, was observed in the extreme stenosis group (83±24 vs. 100±29 cm/s; 20.8%; IQR, 5.3-33.1%; P<0.001) and near occlusion group (73±24 vs. 109±29 cm/s, 45.8%; IQR, 24.3-73.1%; P<0.001). At 3 hours after CAS, the hemodynamic changes were the same as those at 1 hour. PI increased in all 3 groups following CAS. A subgroup analysis was performed according to symptoms, sex, smoking status, history of hypertension, and presence of hyperlipidemia or diabetes, and the increase in ipsilateral MCA-PSV was not significant. In terms of adverse events, only 4 patients in the near occlusion group experienced transient post-CAS hyperperfusion.ConclusionsThe ipsilateral MCA-PSV and PI in patients following unilateral CAS increased significantly in the initial hours. The increase in ipsilateral MCA-PSV was considerably higher in patients with a severe degree of stenosis. Near occlusion of the carotid artery was an independent risk factor for hyperperfusion after unilateral CAS.
| S-EPMC10006111 | biostudies-literature
Project description:BACKGROUND:Only a very few studies had compared the differences in topographic patterns of cerebral infarcts between middle cerebral artery (MCA) and internal carotid artery (ICA) disease. Besides, the comparison of clinical features and outcomes between MCA and ICA disease had rarely been reported. OBJECTIVES:To compare the clinical, imaging features and outcome of MCA versus ICA disease. METHODS:We prospectively enrolled 1172 patients with noncardiogenic ischemic stroke in ipsilateral ICA or MCA territory. Clinical, neuroradiologic and outcome of the two groups were compared in this observational cohort study. RESULTS:The ICA group more frequently presented with decreased alertness, gaze palsy, aphasia, and neglect than the MCA group at admission, and more often had higher National Institute of Health stroke scale score at admission and discharge. Meanwhile, the ICA group more frequently had multiple acute infarcts, watershed infarcts, territorial infarct, small cortical infarct, and responsible artery stenosis ≥70%. Whereas penetrating artery infarct and parent artery occluding penetrating artery was more often associated with MCA disease. The ICA group more frequently had inhospital complications of pneumonia and deep vein thrombosis, more often had disability at discharge, and had more recurrent ischemic stroke or transient ischemic attack in 1 Year. Multivariable logistic regression identified male (OR, 1.99; 95% CI, 1.30 to 3.05; P = 0.002), history of coronary heart disease (OR, 1.85; 95% CI, 1.03 to 3.32; P = 0.041), multiple acute infarcts (OR, 4.18; 95% CI, 2.07 to 8.45; P<0.0001), and territorial infarct (OR, 2.23; 95% CI, 1.52 to 3.27; P<0.0001) was more often associated with ICA territory disease. CONCLUSIONS:The clinical, radiologic characteristics and outcome are distinctively different between ICA and MCA disease. Compared to MCA disease, ICA disease has more serious clinical and radiologic manifestation, and poorer outcome.
| S-EPMC6894760 | biostudies-literature
Project description:Transcranial Doppler (TCD) is frequently used to evaluate peripheral cerebral resistance and cerebral blood flow (CBF) in the middle cerebral artery prior to and during carotid endarterectomy (CEA). Patients with symptomatic carotid artery stenosis may have reduced peripheral cerebral resistance to compensate for inadequate CBF. The authors aim to determine whether symptomatic patients with reduced peripheral cerebral resistance prior to CEA demonstrate increased CBF and cognitive improvement as early as 1 day after CEA.Fifty-three patients with symptomatic CEA were included in this observational study. All patients underwent neuropsychometric evaluation 24 hours or less preoperatively and 1 day postoperatively. The MCA was evaluated using TCD for CBF mean velocity (MV) and pulsatility index (PI). Pulsatility index ? 0.80 was used as a cutoff for reduced peripheral cerebral resistance.Significantly more patients with baseline PI ? 0.80 exhibited cognitive improvement 1 day after CEA than those with PI > 0.80 (35.0% vs 6.1%, p = 0.007). Patients with cognitive improvement had a significantly greater increase in CBF MV than patients without cognitive improvement (13.4 ± 17.1 cm/sec vs 4.3 ± 9.9 cm/sec, p = 0.03). In multivariate regression model, a baseline PI ? 0.80 was significantly associated with increased odds of cognitive improvement (OR 7.32 [1.40-59.49], p = 0.02).Symptomatic CEA patients with reduced peripheral cerebral resistance, measured as PI ? 0.80, are likely to have increased CBF and improved cognitive performance as early as 1 day after CEA for symptomatic carotid artery stenosis. Revascularization in this cohort may afford benefits beyond prevention of future stroke. Clinical trial registration no: NCT00597883 ( ClinicalTrials.gov ).
| S-EPMC4040216 | biostudies-literature
Project description:Background and purposeIntracranial atherosclerosis is a common cause of ischemic stroke. Intracranial stenosis is most commonly quantified by the Warfarin-Aspirin Symptomatic Intracranial Disease method, which involves calculating a ratio of luminal diameter measurements on conventional angiography. Our purpose was to determine whether a single linear measurement of the narrowest caliber of the intracranial ICA on MRA can accurately predict Warfarin-Aspirin Symptomatic Intracranial Disease stenosis measurements.Materials and methodsWe identified patients from a prospective stroke registry who had undergone head MRAs to quantitatively evaluate the degree of Warfarin-Aspirin Symptomatic Intracranial Disease-derived stenosis in each intracranial ICA. We also made a single linear millimeter measurement at the site of maximal narrowing of the ICA. We calculated a correlation coefficient between the lumen diameter in millimeters and percentage Warfarin-Aspirin Symptomatic Intracranial Disease stenosis. We performed receiver operating characteristic analysis to determine optimal luminal diameter cutoff values.ResultsIn 386 unique intracranial ICAs, we found a strong linear relationship between single lumen measurements and Warfarin-Aspirin Symptomatic Intracranial Disease-style stenosis measurements (R = -0.84, P < .0001). We found that ICA lumen diameters of ≤2.1 and ≤1.3 mm were optimal cutoffs for identifying patients with ≥50% stenosis and ≥70% stenosis, respectively (area under the curve = 0.96 and 0.99, respectively).ConclusionsThere is a strong linear relationship between the narrowest lumen diameter of the intracranial ICA and percentage stenosis. Our results suggest that a single lumen diameter measurement on MRA allows accurate estimation of Warfarin-Aspirin Symptomatic Intracranial Disease stenosis, which may affect risk stratification and treatment decisions.
| S-EPMC5433892 | biostudies-literature
Project description:BackgroundWe investigated changes of cortical thickness and its association with cognitive performance in patients with high-grade carotid artery stenosis without ischemic brain lesions.MethodsWe studied 25 patients with unilateral carotid artery stenosis ≥50% and 25 age-matched controls. All subjects underwent T1-weighted MRI, and cortical thickness was measured in 33 regions of interest in each hemisphere, as well as in brain regions belonging to the vascular territory of the middle cerebral artery (MCA). General linear mixed models were fitted to the dependent variable cortical thickness. Cognitive assessment comprised the Stroop Test and Trail Making Test B.ResultsIn the linear mixed model, presence of carotid stenosis had no effect on cortical thickness. There was a significant interaction of stenosis and region with a trend towards lower cortical thickness in the MCA region on the side of carotid stenosis. Patients with carotid stenosis performed significantly worse on the Stroop test than controls, but there was no correlation with cortical thickness.ConclusionIn patients with carotid stenosis without ischemic brain lesions, neither a clear pattern of reduced cortical thickness nor an association of cortical thickness with cognitive function was observed. Our data do not support the hypothesized association of cortical thinning and cognitive impairment in carotid stenosis.
| S-EPMC6593546 | biostudies-literature
Project description:ObjectiveWe have shown that almost 50% of patients with asymptomatic carotid stenosis (ACS) will demonstrate cognitive impairment. Recent evidence has suggested that cerebral hypoperfusion is an important cause of cognitive impairment. Carotid stenosis can restrict blood flow to the brain, with consequent cerebral hypoperfusion. In contrast, cross-hemispheric collateral compensation through the Circle of Willis, and cerebrovascular vasodilation can also mitigate the effects of flow restriction. It is, therefore, critical to develop a clinically relevant measure of net brain perfusion in patients with ACS that could help in risk stratification and in determining the appropriate treatment. To determine whether ACS results in cerebral hypoperfusion, we developed a novel approach to quantify interhemispheric cerebral perfusion differences, measured as the time to peak (TTP) and mean transit time (MTT) delays using perfusion-weighted magnetic resonance imaging (PWI) of the whole brain. To evaluate the utility of using clinical duplex ultrasonography (DUS) to infer brain perfusion, we also assessed the relationship between the PWI findings and ultrasound-based peak systolic velocity (PSV).MethodsStructural and PWI of the brain and magnetic resonance angiography of the carotid arteries were performed in 20 patients with ≥70% ACS. DUS provided the PSV, and magnetic resonance angiography provided plaque geometric measures at the stenosis. Volumetric perfusion maps of the entire brain from PWI were analyzed to obtain the mean interhemispheric differences for the TTP and MTT delays. In addition, the proportion of brain volume that demonstrated a delay in TTP and MTT was also measured. These proportions were measured for increasing severity of perfusion delays (0.5, 1.0, and 2.0 seconds). Finally, perfusion asymmetries on PWI were correlated with the PSV and stenosis features on DUS using Pearson's correlation coefficients.ResultsOf the 20 patients, 18 had unilateral stenosis (8 right and 10 left) and 2 had bilateral stenoses. The interhemispheric (left-right) TTP delays measured for the whole brain volume identified impaired perfusion in the hemisphere ipsilateral to the stenosis in 16 of the 18 patients. More than 45% of the patients had had ischemia in at least one half of their brain volume, with a TTP delay >0.5 second. The TTP and MTT delays showed strong correlations with PSV. In contrast, the correlations with the percentage of stenosis were weaker. The correlations for the PSV were strongest with the perfusion deficits (TTP and MTT delays) measured for the whole brain using our proposed algorithm (r = 0.80 and r = 0.74, respectively) rather than when measured on a single magnetic resonance angiography slice as performed in current clinical protocols (r = 0.31 and r = 0.58, respectively).ConclusionsInterhemispheric TTP and MTT delay measured for the whole brain using PWI has provided a new tool for assessing cerebral perfusion deficits in patients with ACS. Carotid stenosis was associated with a detectable reduction in ipsilateral brain perfusion compared with the opposite hemisphere in >80% of patients. The PSV measured at the carotid stenosis using ultrasonography correlated with TTP and MTT delays and might serve as a clinically useful surrogate to brain hypoperfusion in these patients.
| S-EPMC8209736 | biostudies-literature
Project description:BackgroundVertebral artery (VA) to middle cerebral artery (MCA) bypass is a rarely selected technique because a complex expanded dissection is required, and often, a better donor artery than VA exists. A good indication for VA-MCA bypass is the treatment of head-and-neck malignancies with the sacrifice of the internal carotid artery (ICA) or for carotid artery rupture.MethodsA 23-year-old man with epipharyngeal carcinoma, treated by ligating the carotid artery with a VAMCA bypass before chemoradiotherapy, was reported. Radiographic findings showed that the bone of the carotid canal was dissolved, and the right ICA was engulfed by the tumor. As epipharyngeal carcinoma is hypersensitive to radiation, in cases where the tumor rapidly disappears, ICA may dangle in the pharynx and rupture may occur. In addition, to irradiate sufficiently, the ICA may become an obstacle. Hence, we decided to perform carotid ligation with a VA-MCA bypass before radiation and chemotherapy for the primary lesion. We selected the V3 portion of the VA as the donor on the ipsilateral side, as it can supply high-flow cerebral blood flow, which is not influenced by carcinoma and less influenced by irradiation for the epipharynx.ResultsThe VA-MCA bypass was completed without complications followed by endovascular occlusion of the ICA. Induction chemotherapy was initiated for the patient 2 weeks after surgery. The patient achieved a complete response following chemoradiotherapy.ConclusionICA ligation with VA-MCA high-flow bypass earlier than chemoradiotherapy is useful for epipharyngeal carcinoma as it prevents carotid artery rupture and allows radical intervention.
| S-EPMC8088539 | biostudies-literature
Project description:Three-dimensional pseudocontinuous arterial spin labeling with multiple postlabeling delays has been used to assess cerebral blood flow (CBF). We used this modality to estimate antegrade and collateral flow in patients with unilateral middle cerebral artery stenosis.Consecutive patients with unilateral middle cerebral artery 50% to 99% stenosis at 2 centers underwent pseudocontinuous arterial spin labeling with a postlabeling delays of 1.5 and 2.5 s. Mean CBF of bilateral middle cerebral artery territory at the postlabeling delays 1.5 and 2.5 s was measured. Early-arriving flow proportion was defined as (CBF 1.5 s at lesion side/CBF 2.5 s at normal side)×100%. Late-arriving retrograde flow proportion was defined as ([CBF 2.5 s-CBF 1.5 s] at lesion side-[CBF 2.5 s-CBF 1.5 s] at normal side)/CBF 2.5 s at normal side×100%. Antegrade and collateral scales were evaluated in patients with conventional angiography. Spearman correlation coefficients were calculated between early-arriving flow and late-arriving retrograde flow proportions on arterial spin labeling and antegrade and collateral scales on conventional angiography, respectively.Forty-one patients (46.0±12.0 years) were enrolled. The mean early-arriving flow proportion was 78.3±14.9%. The mean late-arriving retrograde flow proportion was 16.1±10.2%. In 21 patients with conventional angiography, Spearman correlation coefficient was 0.53 (95% confidence interval, 0.11-0.79) between antegrade grade and early-arriving flow proportion (P=0.01) and 0.81 (95% confidence interval, 0.56-0.92) between collateral grade and late-arriving retrograde flow proportion (P<0.0001).Three-dimensional pseudocontinuous arterial spin labeling with 2 postlabeling delays may provide an empirical approach for estimating antegrade and collateral flow in patients with unilateral middle cerebral artery stenosis.URL: http://www.clinicaltrials.gov. Unique identifier: NCT02479243.
| S-EPMC4729602 | biostudies-literature