Regional leptomeningeal score on CT angiography predicts clinical and imaging outcomes in patients with acute anterior circulation occlusions.
01 Oct 2011-American Journal of Neuroradiology (American Society of Neuroradiology)-Vol. 32, Iss: 9, pp 1640-1645
TL;DR: The regional leptomeningeal score is a strong imaging parameter on CT angiography for predicting clinical outcomes in patients with acute ischemic strokes and can therefore be used for imaging based patient selection.
Abstract: BACKGROUND AND PURPOSE: The regional leptomeningeal score is a strong and reliable imaging predictor of good clinical outcomes in acute anterior circulation ischemic strokes and can therefore be used for imaging based patient selection. Efforts to determine biological determinants of collateral status are needed if techniques to alter collateral behavior and extend time windows are to succeed. MATERIALS AND METHODS: This was a retrospective Institutional Review Board–approved study of patients with acute ischemic stroke and M1 middle cerebral artery+/− intracranial internal carotid artery occlusion at our center from 2003 to 2009. The rLMC score is based on scoring pial and lenticulostriate arteries (0, no; 1, less; 2, equal or more prominent compared with matching region in opposite hemisphere) in 6 ASPECTS regions (M1–6) plus anterior cerebral artery region and basal ganglia. Pial arteries in the Sylvian sulcus are scored 0, 2, or 4. Good clinical outcome was defined as mRS ≤2 at 90 days. RESULTS: The analysis included 138 patients: 37.6% had a good (17–20), 40.5% a medium (11–16), and 21.7% a poor (0–10) rLMC score. Interrater reliability was high, with an intraclass correlation coefficient of 0.87 (95% CI, 0.77%–0.95%). On univariate analysis, no single vascular risk factor was associated with the presence of poor rLMCs (P ≥ .20 for all comparisons). In multivariable analysis, the rLMC score (good versus poor: OR, 16.7; 95% CI, 2.9%–97.4%; medium versus poor: OR, 9.2, 95% CI, 1.7%–50.6%), age ( CONCLUSIONS: The rLMC score is a strong imaging parameter on CT angiography for predicting clinical outcomes in patients with acute ischemic strokes.
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TL;DR: Multiphase CT angiography is a reliable tool for imaging selection in patients with acute ischemic stroke and its interrater reliability and ability to help determine clinical outcome are demonstrated.
Abstract: We describe multiphase CT angiography, an imaging tool for clinical decision making in patients with acute ischemic stroke; in the current study, we demonstrate its reliability and ability to help predict clinical outcome.
514 citations
TL;DR: Novel treatment paradigms can be envisioned combining neuroprotection with IA device treatment to potentially increase the number of patients who can be treated despite long transport times and to ameliorate the consequences of reperfusion injury.
Abstract: The treatment of acute ischemic stroke has undergone dramatic changes recently subsequent to the demonstrated efficacy of intra-arterial (IA) device-based therapy in multiple trials. The selection of patients for both intravenous and IA therapy is based on timely imaging with either computed tomography or magnetic resonance imaging, and if IA therapy is considered noninvasive, angiography with one of these modalities is necessary to document a large-vessel occlusion amenable for intervention. More advanced computed tomography and magnetic resonance imaging studies are available that can be used to identify a small ischemic core and ischemic penumbra, and this information will contribute increasingly in treatment decisions as the therapeutic time window is lengthened. Intravenous thrombolysis with tissue-type plasminogen activator remains the mainstay of acute stroke therapy within the initial 4.5 hours after stroke onset, despite the lack of Food and Drug Administration approval in the 3- to 4.5-hour time window. In patients with proximal, large-vessel occlusions, IA device-based treatment should be initiated in patients with small/moderate-sized ischemic cores who can be treated within 6 hours of stroke onset. The organization and implementation of regional stroke care systems will be needed to treat as many eligible patients as expeditiously as possible. Novel treatment paradigms can be envisioned combining neuroprotection with IA device treatment to potentially increase the number of patients who can be treated despite long transport times and to ameliorate the consequences of reperfusion injury. Acute stroke treatment has entered a golden age, and many additional advances can be anticipated.
235 citations
Cites background from "Regional leptomeningeal score on CT..."
...Both the regional leptomeningeal collateral and collateral score have been shown to independently predict poor outcome (mRS score >2), infarct volume, and propensity for hemorrhagic transformation in the setting of an acute occlusion.(39,42) The aforementioned evaluations of collateral status use a single conventional CTA maximal intensity projection image (single phase)....
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...The regional leptomeningeal collateral score assesses the presence and quality of collateral vessels in the 6 MCA cortical ASPECTS locations (M1–M6), parasagittal anterior cerebral artery territory, and the basal ganglia compared with the contralateral side with a maximum score of 20.(42) Another example, the collateral score, grades collaterals as either absent (=0), present in <50% of the downstream territory (=1), >50% (=2), or in 100% of the territory (=3)....
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TL;DR: Collateral flow is dynamic and failure is associated with infarct growth, and changes in collateral quality and Tmax hypoperfusion severity were assessed between baseline and days 3 to 5 perfusion-diffusion MRI.
Abstract: Changes in collateral blood flow, which sustains brain viability distal to arterial occlusion, may impact infarct evolution but have not previously been demonstrated in humans. We correlated leptomeningeal collateral flow, assessed using novel perfusion magnetic resonance imaging (MRI) processing at baseline and 3 to 5 days, with simultaneous assessment of perfusion parameters. Perfusion raw data were averaged across three consecutive slices to increase leptomeningeal collateral vessel continuity after subtraction of baseline signal analogous to digital subtraction angiography. Changes in collateral quality, Tmax hypoperfusion severity, and infarct growth were assessed between baseline and days 3 to 5 perfusion-diffusion MRI. Acute MRI was analysed for 88 patients imaged 3 to 6 hours after ischemic stroke onset. Better collateral flow at baseline was associated with larger perfusion-diffusion mismatch (Spearman's Rho 0.51, P<0.001) and smaller baseline diffusion lesion volume (Rho -0.70, P<0.001). In 30 patients without reperfusion at day 3 to 5, deterioration in collateral quality between baseline and subacute imaging was strongly associated with absolute (P=0.02) and relative (P<0.001) infarct growth. The deterioration in collateral grade correlated with increased mean Tmax hypoperfusion severity (Rho -0.68, P<0.001). Deterioration in Tmax hypoperfusion severity was also significantly associated with absolute (P=0.003) and relative (P=0.002) infarct growth. Collateral flow is dynamic and failure is associated with infarct growth.
230 citations
TL;DR: The benefit of IAT was greatest in patients with good collaterals on baseline computed tomographic angiography in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN).
Abstract: Background and Purpose— Recent randomized trials have proven the benefit of intra-arterial treatment (IAT) with retrievable stents in acute ischemic stroke. Patients with poor or absent collaterals (preexistent anastomoses to maintain blood flow in case of a primary vessel occlusion) may gain less clinical benefit from IAT. In this post hoc analysis, we aimed to assess whether the effect of IAT was modified by collateral status on baseline computed tomographic angiography in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN).
Methods— MR CLEAN was a multicenter, randomized trial of IAT versus no IAT. Primary outcome was the modified Rankin Scale at 90 days. The primary effect parameter was the adjusted common odds ratio for a shift in direction of a better outcome on the modified Rankin Scale. Collaterals were graded from 0 (absent) to 3 (good). We used multivariable ordinal logistic regression analysis with interaction terms to estimate treatment effect modification by collateral status.
Results— We found a significant modification of treatment effect by collaterals ( P =0.038). The strongest benefit (adjusted common odds ratio 3.2 [95% confidence intervals 1.7–6.2]) was found in patients with good collaterals (grade 3). The adjusted common odds ratio was 1.6 [95% confidence intervals 1.0–2.7] for moderate collaterals (grade 2), 1.2 [95% confidence intervals 0.7–2.3] for poor collaterals (grade 1), and 1.0 [95% confidence intervals 0.1–8.7] for patients with absent collaterals (grade 0).
Conclusions— In MR CLEAN, baseline computed tomographic angiography collateral status modified the treatment effect. The benefit of IAT was greatest in patients with good collaterals on baseline computed tomographic angiography. Treatment benefit appeared less and may be absent in patients with absent or poor collaterals.
Clinical Trial Registration— URL: and . Unique identifier: (NTR)1804 and [ISRCTN10888758][1], respectively.
[1]: /external-ref?link_type=ISRCTN&access_num=ISRCTN10888758
218 citations
TL;DR: This work sought to identify potentially modifiable determinants associated with variability in leptomeningeal collateral status in patients with acute ischemic stroke.
Abstract: Objective: We sought to identify potentially modifiable determinants associated with variability in leptomeningeal collateral status in patients with acute ischemic stroke. Methods: Data are from the Keimyung Stroke Registry. Consecutive patients with M1 segment middle cerebral artery 6intracranial internal carotid artery occlusions on baseline computed tomographic angiography (CTA) from May 2004 to July 2009 were included. Baseline and follow-up imaging was analyzed blinded to all clinical information. Two raters assessed leptomeningeal collaterals on baseline CTA by consensus, using a previously validated regional leptomeningeal score (rLMC). Results: Baseline characteristics (N 5 206) were: mean age 5 66.9 6 11.6 years, median baseline National Institutes of Health Stroke Scale 5 14 (interquartile range [IQR] 5 11–20), and median time from stroke symptom onset to CTA 5 166 minutes (IQR 5 96–262). Poor collateral status at baseline (rLMC score 5 0–10) was seen in 73 of 206 patients (35.4%). On univariate analyses, patients with poor collateral status at baseline were older; were hypertensive; had higher white blood cell count, blood glucose, D-dimer, and serum uric acid levels; and were more likely to have metabolic syndrome. Multivariate modeling identified metabolic syndrome (odds ratio [OR] 5 3.22, 95% confidence interval [CI] 5 1.69–6.15, p <0.001), hyperuricemia (per 1mg/dl serum uric acid; OR 5 1.35, 95% CI 5 1.12– 1.62, p <0.01), and older age (per 10 years; OR 5 1.34, 95% CI 5 1.02–1.77, p 5 0.03) as independent predictors of poor leptomeningeal collateral status at baseline. Interpretation: Metabolic syndrome, hyperuricemia, and age are associated with poor leptomeningeal collateral status in patients with acute ischemic stroke. ANN NEUROL 2013;74:241–248
154 citations
Cites background or methods from "Regional leptomeningeal score on CT..."
...The score has demonstrated good inter-rater reliability.(3) Both readers were blinded to all clinical information and follow-up data at the time of reading the scans....
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...Age, ischemic preconditioning, and presence of cardiovascular risk factors are all hypothesized as determinants of native collateral status.(3,10,11) We sought to examine potential determinants of native leptomeningeal collaterals in a large cohort of well-studied acute ischemic stroke patients....
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...This ordinal 20-point score assesses pial arterial enhancement within the total vascular territory supplied by the occluded arterial segment when compared to similar maximal enhancement on the opposite unaffected hemisphere using an ASPECTS-based template.(3,15) The score has demonstrated good inter-rater reliability....
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...The primary outcome was the rLMC score, dichotomized as 0 to 10 (poor) versus 11 to 20 (good).(3) Sensitivity anal-...
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...) using the regional leptomeningeal score (rLMC).(3) This ordinal 20-point score assesses pial arterial enhancement within the total vascular territory supplied by the occluded arterial segment when compared to similar maximal enhancement on the opposite unaffected hemisphere using an ASPECTS-based template....
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References
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TL;DR: This CT score is simple and reliable and identifies stroke patients unlikely to make an independent recovery despite thrombolytic treatment as well as primary outcomes, including symptomatic intracerebral haemorrhage and 3-month functional outcome.
2,044 citations
"Regional leptomeningeal score on CT..." refers methods in this paper
...The rLMC score is a semiquantitative system of scoring based on the major anatomic regions of the anterior circulation and is comparable to the ASPECTS method of scoring head CTs.(11) We have demonstrated a strong correlation between the rLMC score at baseline and both radiologic and clinical outcomes....
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...for early ischemic changes and reduced contrast opacification, respectively, by using the ASPECTS system.(11) Clot burden score was calculated on the CTA....
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...The rLMC score is a semiquantitative system of scoring based on the major anatomic regions of the anterior circulation and is comparable to the ASPECTS method of scoring head CTs.11 We have demonstrated a strong correlation between the rLMC score at baseline and both radiologic and clinical outcomes....
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TL;DR: Problems in distinguishing between arteries and veins, the geometric disposition of cortical vessels, different types of anastomoses and particular vascular features whose significance remains unclear, are discussed.
745 citations
"Regional leptomeningeal score on CT..." refers background in this paper
...They provide a vascular network with the potential to maintain cerebral blood flow at levels that prolong or indefinitely sustain brain tissue viability beyond an occlusion.(14) Good flow through collateral pathways is associated with a larger penumbra and smaller infarct core at baseline(15,16) and by extending the survival time of penumbra, can extend the time window for viable reperfusion....
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TL;DR: In patients with proximal vessel occlusion, perfusion computed tomography mismatch is a prerequisite for a favourable clinical response, but good collateral status appears a critical determinant of ultimate outcome, particularly if major reperfusion occurs.
Abstract: It is unknown whether collateral vessel status, as seen on computed tomography angiography, can predict the fate of penumbral tissue identified on perfusion computed tomography and thereby influence clinical outcome. We tested this hypothesis in consecutive patients who underwent perfusion computed tomography/computed tomography angiography within 6 h of anterior circulation stroke, who also had repeat perfusion/infarct volume imaging at 24 h, and modified Rankin Scale at 3 months. Collateral status was graded as good or reduced depending on the extent of contrast visualized distal to the occlusion on computed tomography angiography. 'Perfusion computed tomography mismatch' ratio was calculated from the ratio of the mean transit time lesion/cerebral blood volume lesion. Of 92 patients with proximal intracranial vessel occlusion, good collateral status (51/92) was significantly associated with reduced infarct expansion and more favourable functional outcomes (modified Rankin Scale 0-2). Significant univariate predictors of favourable outcome were good collateral status, major reperfusion at 24 h, presence of perfusion computed tomography mismatch (for a range of ratios: > or = 1.2, > or = 2, > or = 3, > or = 3.5) and baseline National Institutes of Health Stroke Scale score. Notably, none of the 37 patients with a perfusion computed tomography mismatch ratio < 3.0 had a favourable outcome. In patients with perfusion computed tomography mismatch, significant independent predictors of favourable outcome were good collateral status, major reperfusion and baseline National Institutes of Health Stroke Scale score. There was also a strong interaction between major reperfusion and good collateral status in the regression models. In patients with proximal vessel occlusion, perfusion computed tomography mismatch is a prerequisite for a favourable clinical response, but good collateral status appears a critical determinant of ultimate outcome, particularly if major reperfusion occurs.
411 citations
"Regional leptomeningeal score on CT..." refers result in this paper
...Our findings are consistent with other studies showing that time to imaging correlates poorly with collateral status.(7,16) As in other studies, we substituted the time the patient was last seen normal when the exact onset time was unknown....
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TL;DR: The data suggest that angiographic collateral grade and penumbral volume interactively shape tissue fate in patients undergoing endovascular recanalisation therapy, and provide complementary information about residual blood flow that may help guide treatment decision making in acute cerebral ischaemia.
Abstract: Background: Collaterals may sustain penumbra prior to recanalisation yet the influence of baseline collateral flow on infarct growth following endovascular therapy remains unknown. Methods: Consecutive patients underwent serial diffusion and perfusion MRI before and after endovascular therapy for acute cerebral ischaemia. We assessed the relationship between MRI diffusion and perfusion lesion indices, angiographic collateral grade and infarct growth. Tmax perfusion lesion maps were generated and diffusion–perfusion mismatch regions were divided into Tmax ⩾4 s (severe delay) and Tmax ⩾2 but Results: Among 44 patients, collateral grade was poor in 7 (15.9%), intermediate in 20 (45.5%) and good in 17 (38.6%) patients. Although diffusion–perfusion mismatch volume was not different depending on the collateral grade, patients with good collaterals had larger areas of milder perfusion delay than those with poor collaterals (p = 0.005). Among 32 patients who underwent day 3–5 post-treatment MRIs, the degree of pretreatment collateral circulation (r = −0.476, p = 0.006) and volume of diffusion–perfusion mismatch (r = 0.371, p = 0.037) were correlated with infarct growth. Greatest infarct growth occurred in patients with both non-recanalisation and poor collaterals. Multiple regression analysis revealed that pretreatment collateral grade was independently associated with infarct growth. Conclusion: Our data suggest that angiographic collateral grade and penumbral volume interactively shape tissue fate in patients undergoing endovascular recanalisation therapy. These angiographic and MRI parameters provide complementary information about residual blood flow that may help guide treatment decision making in acute cerebral ischaemia.
341 citations
TL;DR: Most patients with proximal middle cerebral artery occlusion rapidly recruit sufficient collaterals and follow a clinical course similar to patients with no occlusions, but a subset with diminished collateral is at high risk for worsening.
Abstract: Background and Purpose— Despite the abundance of emerging multimodal imaging techniques in the field of stroke, there is a paucity of data demonstrating a strong correlation between imaging findings and clinical outcome. This study explored how proximal arterial occlusions alter flow in collateral vessels and whether occlusion or extent of collaterals correlates with prehospital symptoms of fluctuation and worsening since onset or predict in-hospital worsening. Methods— Among 741 patients enrolled in a prospective cohort study involving CT angiographic imaging in acute stroke, 134 cases with proximal middle cerebral artery occlusion and 235 control subjects with no occlusions were identified. CT angiography was used to identify occlusions and grade the extent of collateral vessels in the sylvian fissure and leptomeningeal convexity. History of symptom fluctuation or progressive worsening was obtained on admission. Results— Prehospital symptoms were unrelated to occlusion or collateral status. In cases, 37...
330 citations