Transcranial Color-coded Sonography Research Articles

Diagnostic feasibility of middle cerebral artery stenosis or occlusion evaluated by TCCS and CEUS: Repeatability, reproducibility, and diagnostic agreement with DSA

AimThis study aimed to evaluate the feasibility of transcranial color-coded sonography (TCCS) and contrast-enhanced ultrasound (CEUS) in assessing middle cerebral artery (MCA) stem stenosis or occlusion compared to digital subtraction angiography (DSA). MethodsA total of 48 cases including 96 MCAs suspected stem stenosis or obstruction in the MCA were assessed by TCCS, CE-TCCS, and DSA. The diameters of the most severe stenosis (Ds), proximal normal artery (Dn), and diameter stenosis rate of MCA were measured using both the color doppler flow imaging (CDFI) modality of TCCS or CEUS and the CEUS imaging modality. The intraclass correlation coefficients (ICCs) and 95 % confidence intervals (CI) were evaluated, and a weighted Kappa value was used to evaluate the intra-observer agreement, inter-observer agreement, agreement between CDFI modality and DSA stenosis or occlusion, and agreement between CEUS imaging modality and DSA stenosis or occlusion. ResultsThe ICC results indicated excellent repeatability and reproducibility (all ICCs > 0.75; weighted Kappa values >0.81). Compared with DSA, the weighted Kappa values and 95 % CIs of stenosis (the first measurement was taken by two observers) of CDFI modality and CEUS imaging modality were 0.175 (0.041, 0.308) and 0.779 (0.570, 0.988) for observers A and 0.181 (0.046, 0.316) and 0.779 (0.570, 0.988) for observers B respectively. ConclusionThis study indicates that inter- and intra-observer agreements were good for the direct method of measuring percentages of MCA stenosis by TCCS and CEUS. CEUS imaging modality is a new and reliable imaging modality approach to evaluate the MCAs stenosis and occlusion.

Assessment of Collateral Pathways in Carotid Occlusion: Investigating the Clinical Significance of Ultrasound and TCCS

Background: Carotid occlusion is a severe condition closely associated with ischemic stroke. The prompt identification of patients presenting with extracranial carotid artery occlusion and the evaluation of collateral circulation compensation in these individuals bear significant clinical importance for subsequent patient management. Ultrasound offers significant advantages in the diagnosis of extracranial carotid artery stenosis and occlusion, while Transcranial Color-Coded Sonography (TCCS) is increasingly pivotal in assessing intracranial artery stenosis and determining blood flow direction. The objective of our study was to assess the concordance between ultrasound combined with TCCS and digital subtraction angiography (DSA) in evaluating extracranial carotid occlusion and intracranial collateral circulation.
 Methods: Patients with severe stenosis in the extracranial carotid artery were recruited for our study. All patients suspected of having occlusion in the extracranial carotid arteries underwent ultrasound, transcranial color-coded sonography (TCCS), and digital subtraction angiography (DSA). Sensitivity, specificity, positive predictive value, negative predictive value, overall accuracy, and kappa value were employed to assess the effectiveness and consistency of ultrasound and TCCS compared to DSA.
 Results: Ultrasound demonstrated a sensitivity of 85.4%, specificity of 100%, positive predictive value of 100%, negative predictive value of 90.4%, and overall accuracy of 93.9% in the diagnosis of extracranial artery occlusion. The kappa value was calculated as 0.87 (P＜0.001), indicating substantial agreement between ultrasound and DSA measurements for consistency assessment. Transcranial color-coded sonography (TCCS) exhibited a sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of 97.6%, 100%, 100%, 66.7%, and 97.7% respectively in evaluating collateral circulation in patients with carotid artery occlusion. The kappa value was 0.79 (P＜0.001) in assessing the collateral circulation in patients with occluded carotid arteries.
 Conclusions: Ultrasound proved to be a valuable tool for evaluating patients with occluded carotid arteries, while TCCS emerged as a reliable approach for assessing collateral pathways in individuals with extracranial carotid artery occlusion.

Transcranial Color-Coded Sonography With Angle Correction As a Screening Tool for Raised Intracranial Pressure.

Transcranial Doppler (TCD) has been evaluated as a noninvasive intracranial pressure (ICP) assessment tool. Correction for insonation angle, a potential source of error, with transcranial color-coded sonography (TCCS) has not previously been reported while evaluating ICP with TCD. Our objective was to study the accuracy of TCCS for detection of ICP elevation, with and without the use of angle correction. Prospective study of diagnostic accuracy. Academic neurocritical care unit. Consecutive adults with invasive ICP monitors. Ultrasound assessment with TCCS. End-diastolic velocity (EDV), time-averaged peak velocity (TAPV), and pulsatility index (PI) were measured in the bilateral middle cerebral arteries with and without angle correction. Concomitant mean arterial pressure (MAP) and ICP were recorded. Estimated cerebral perfusion pressure (CPP) was calculated as estimated CPP (CPPe) = MAP × (EDV/TAPV) + 14, and estimated ICP (ICPe) = MAP-CPPe. Sixty patients were enrolled and 55 underwent TCCS. Receiver operating characteristic curve analysis of ICPe for detection of invasive ICP greater than 22 mm Hg revealed area under the curve (AUC) 0.51 (0.37-0.64) without angle correction and 0.73 (0.58-0.84) with angle correction. The optimal threshold without angle correction was ICPe greater than 18 mm Hg with sensitivity 71% (29-96%) and specificity 28% (16-43%). With angle correction, the optimal threshold was ICPe greater than 21 mm Hg with sensitivity 100% (54-100%) and specificity 30% (17-46%). The AUC for PI was 0.61 (0.47-0.74) without angle correction and 0.70 (0.55-0.92) with angle correction. Angle correction improved the accuracy of TCCS for detection of elevated ICP. Sensitivity was high, as appropriate for a screening tool, but specificity remained low.

Early haemodynamic predictors of poor functional outcomes in patients with acute ischaemic stroke receiving endovascular therapy: a single-centre retrospective study in China.

Changes in cerebral haemodynamics following endovascular therapy (EVT) for large-vessel occlusion stroke may affect the outcomes of patients with acute ischaemic stroke (AIS); however, evidence supporting this belief is limited. This study aims to identify the early haemodynamic predictors of poor outcomes in patients with AIS caused by anterior circulation large-artery occlusion after undergoing EVT and to evaluate the usefulness of these indicators in predicting functional outcomes at 90 days. This retrospective study was conducted at a single academic hospital, using prospectively collected data. We enrolled adult patients with acute anterior circulation stroke who underwent EVT. Transcranial colour-coded sonography (TCCS) examinations of the recanalised and contralateral middle cerebral artery (MCA) were performed within 12 h after undergoing EVT. Haemodynamic indicators were analysed to determine their association with poor functional outcomes (modified Rankin Scale: 3-6) 90 days after stroke. Receiver operating characteristic (ROC) curves were used to evaluate the usefulness of haemodynamic indicators in predicting functional outcomes. In total, 108 patients (median age: 66 years; 69.4% males) were enrolled in this study. Complete recanalization was achieved in 93 patients (86.1%); however, 60 patients (55.6%) had a poor 90-day outcome. The peak systolic velocity (PSV) ratio, adjusted PSV ratio, mean flow velocity (MFV) ratio, and adjusted MFV ratio of the MCA were significantly higher in patients with poor prognosis than in patients with good prognosis (p<0.02). A multivariate logistic regression analysis showed that higher PSV ratio, adjusted PSV ratio, MFV ratio, and adjusted MFV ratio were independently associated with a poor 90-day outcomes (adjusted odds ratio: 1.11-1.48 for every 0.1 increase; p<0.03). Furthermore, adding the adjusted MFV ratio significantly improved the prediction ability of the basic model for the 90-day poor functional outcome using the ROC analysis, the areas under ROC curves increased from 0.75 to 0.85 (p=0.013). Early TCCS examination may help in predicting poor functional outcomes at 90 days in patients with AIS who underwent EVT. Moreover, combining novel TCCS indicators (adjusted MFV ratio) with conventional parameters improved the prediction ability of the base model.

Altered Cerebral Vasoreactivity on Transcranial Color-Coded Sonography Related to Akinetic-Rigid Phenotype of Parkinson's Disease: Interim Analysis of a Cross-Sectional Study.

A correlation between worse functional outcomes in Parkinson's disease (PD) patients with cerebrovascular disease (CVD) or the Akinetic-rigid phenotype has been argued in recent studies. We aimed to evaluate the association of cerebral hemodynamics impairments, assessed by Transcranial Color-coded Doppler sonography (TCCS), on PD patients with different phenotypes of the disease and with risk factors for CVD. Idiopathic PD patients (n = 51) were divided into motor subtypes: Akinetic-rigid (AR) (n = 27) and Tremor-dominant (TD) (n = 24) and into two groups regarding vascular risk factors: when ≥2 were present (PDvasc) (n = 18) and <2 (PDnvasc) (n = 33). In a parallel analysis, the Fazekas scale on brain magnetic resonance imaging (MRI) was applied to a sample to assess the degree of leukoaraiosis. TCCS examinations were prospectively performed obtaining middle cerebral artery Mean Flow Velocities (Vm), Resistance Index (RI), and Pulsatility Index (PI). The Breath-Holding Index (BHI) was calculated to assess cerebrovascular reactivity (cVR). Standardized functional scales were administered (UPDRS III and Hoehn&Yahr). The phenotype groups were similar in age, disease duration and demographic parameters, but there were significantly higher H&Y scores than TD group. cVR was impaired in 66.7% of AR vs. 37.5% of TD. AR group exhibited lower BHI (0.53 ± 0.31 vs. 0.91 ± 0.62; p = 0.000), lower Vm after apnea (44.3 ± 9.0 cm/s vs. 53.4 ± 11.4 cm/s; p = 0.003), higher PI (0.91 ± 0.26 vs. 0.76 ± 0.12; p = 0.000) and RI (0.58 ± 0.11 vs. 0.52 ± 0.06; p = 0.021). PDvasc group showed higher PI (0.98 vs. 0.76; p = 0.001) and higher frequency of altered cVR (72.2% vs. 42.2%; p = 0.004). There was a significant predominance of higher values on Fazekas scale in the PDvasc group. We found no difference between the Fazekas scale when comparing motor subtypes groups but there was a trend toward higher scores in the AR phenotype. TCCS, a cost-effective method, displayed impaired cVR in Parkinsonian patients with risk factors for CVD with higher degree of MRI leukoaraiosis. PD patients with the AR disease phenotype also presented impaired cVR on TCCS and greater functional impairment, although with just a trend to higher scores on MRI Fazekas.

Application of the Intracranial Arterial Pulsatility Index for Determination of Prognosis after Lacunar Infarct.

We aimed to investigate the usefulness of intracranial arterial pulsatility index to assess the prognosis of lacunar infarcts. Forty-nine patients with confirmed acute lacunar infarct were enrolled in the study. A transcranial color-coded sonography was performed to assess the pulsatility index of bilateral middle cerebral, posterior cerebral, vertebral, and proximal internal carotid arteries. Patients' clinical status was assessed using a modified Rankin scale. Spearman correlation was used for reporting the relation between quantitative data. Statistical significance was defined as a two-tail p-value of less than 0.05. The mean age ± standard deviation was 64.1 ± 9.07 years old, and 57.1% of the patients were male. Upon discharge, only 8.2% of the patients were ranked as 0 on the modified Rankin scale; however, after a 6-month follow-up period, this number increased to 49%. There were no significant differences between the left and right pulsatility index measurements in any of the assessed arteries. Patients with vertebral artery pulsatility indexes >1 on their primary assessment had significantly worse outcomes during the first, third, and sixth months follow-up (all r > 0.3, p-values < 0.01). Pulsatility indexes from other arteries did not predict the prognosis. Sonography-assisted assessment of the vertebral artery blood flow during the early stage of lacunar infarct provides a reliable reference for prognosis estimation.

Application value of transcranial contrast-enhanced ultrasonography in evaluating middle cerebral artery stenosis.

To detect the display rate and flow velocity of intracranial circle of Willis (anterior, middle, and posterior cerebral arteries) with transcranial contrast-enhanced transcranial color-coded sonography (CE-TCCS), using digital subtraction angiography (DSA) as the golden diagnostic standard. We collected data from 104 patients with suspected stroke treated in our hospital between December 2019 and October 2021. The detection rate of the intracranial circle of Willis, anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) were analyzed based on routine TCCS and CE-TCCS data. Based on digital subtraction angiography (DSA) data, the degree of MCA stenosis was divided into mild stenosis (<50%), moderate stenosis (50-69%), severe stenosis (70-99%), and bilateral middle cerebral artery CE-TCCS examinations were performed. We evaluated MCA color blood flow on CE-TCCS, and recorded the peak systolic velocity (PSV), end-diastolic velocity (EDV), and mean flow velocity (MFV). The display rates of ACA, MCA, and PCA were significantly improved on the CE-TCCS, and the PSV, EDV and MFV of the MCA stenosis group were higher than those of the normal group. The flow velocity of each stenosis subgroup was increased compared to the normal group. The optimal cutoff values of normal and stenosis under the receiver operating characteristic (ROC) curve were PSV = 168.5 cm/s, EDV = 61.5 cm/s, and MFV = 110.5 cm/s. The optimal cutoff values for mild and moderate stenosis and for moderate and severe stenosis were PSV = 201.5 cm/s and 249.5 m/s, EDV = 95.2 cm/s and 141.5 cm/s, and MFV = 137.6 cm/s and 160.5 cm/s, respectively. PSV and MFV had the most significant sensitivity, specificity, and accuracy. Transcranial contrast-enhanced ultrasonography can improve the display rate of intracranial blood vessels and can accurately diagnose MCA stenosis.

Ultrasound fusion imaging system in neurology practice.

The ultrasound fusion imaging (UFI) system is a new promising imaging modality that combines live ultrasound investigations with preregistered CT, MRI, or PET images. In this study, we want to present our initial experience with the new method that combines the transcranial color-coded sonography (TCCS) in different insonation planes and the 3T-weighted MRI cerebral images. The study validates the diagnostic capabilities of the system to detect different normal cerebral structures in healthy volunteers. In the present paper, we also discuss the advantages of US fusion imaging technology and its clinical applications in Neurology.

Associations Between Cerebral Vasoreactivity and Cognitive Function in the Middle-Aged Non-Demented Population.

Increasing evidence shows early vascular dysregulation in the pathophysiology of Alzheimer's disease (AD) in elderly population. We wondered about the relationship between vascular health and cognitive performance in middle-aged adults. The present study aims to evaluate whether and which brain vascular hemodynamic parameters are associated with cognitive functions in a middle-aged, non-demented population. We recruited 490 middle-aged community-based participants (30-60 years). Transcranial color-coded sonography was used to measure cerebral vascular hemodynamics, including mean flow velocity, pulsatility index, and breath-holding index (BHI) in the middle cerebral arteries (MCAs). Cognitive functions were assessed using the Montreal Cognitive Assessment (MoCA). A multivariate linear regression model was used to determine the association between the MoCA scores and each intracranial hemodynamic parameter. In 369 participants (median age 52 years [IQR 47-56], 48.8% men) with robust acoustic windows, the factors related to poorer MoCA scores were older age, less education extent, and the habitats of cigarette smoking or alcohol consumption. Multivariate analyses did not show a significant association between any intracranial hemodynamic parameters in both MCAs and MoCA scores in the total study population. Left MCA BHI was found to be significantly and independently correlated with the MoCA scores only in people aged 55-60 years (n = 111, B = 0.70, 95% confidence interval, 0.13-1.26, p = 0.017), however, not in people younger than 55 years. Our results emphasize the role of neurovascular abnormalities in the early pathophysiology of cognitive impairment and suggest cerebral vasoreactivity as the earliest detectable cognition-associated hemodynamic parameter.

Low Vertebrobasilar Velocity Is Associated with a Higher Risk of Posterior Circulation Ischemic Lesions.

Background: Transcranial color-coded sonography (TCCS) is used as a real-time tool to evaluate patients suspected of having vertebrobasilar insufficiency (VBI). However, the sonographic criteria for VBI remain inconclusive. The purpose of this study was to analyze the velocity in the vertebrobasilar system, which links the risk for posterior circulation infarction (POCI) and total ischemic stroke (TIS) in patients with VBI. Methods: Patients’ data were retrospectively reviewed if they were suspected of having VBI within a 2-year period. Baseline characteristics, brain images, and a series of sonography data were recorded and analyzed. We compared vertebrobasilar (VB) velocities in different age groups and in patients with infarctions. Results: A total of 875 patients were enrolled, with 112 and 427 candidates in the POCI and TIS groups, respectively. The mean velocity (MV)s of BA and bilateral VAs were all negatively correlated with age (all p < 0.001). The adjusted odds ratio was 2.55 (1.58–4.13, p < 0.001) in POCI and 1.75 (1.15–2.67, p = 0.009) in TIS if the mean velocity of the VB arteries was below 15 cm/s. Conclusions: Low VB velocity detected in TCCS was more commonly associated with ageing-related changes and a higher risk of both POCI and TIS. Recognition and aggressive treatment for these patients are necessary.

Blood volume flow in the superficial temporal artery assessed by duplex sonography: predicting extracranial-intracranial bypass patency in moyamoya disease.

Superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery is an important therapy for symptomatic moyamoya disease. Its success depends on bypass function, which may be impaired by primary or secondary bypass insufficiency. Catheter angiography is the current gold standard to assess bypass function, whereas the diagnostic value of ultrasonography (US) has not been systematically analyzed so far. The authors analyzed 50 STA-MCA bypasses in 39 patients (age 45 ± 14 years [mean ± SD]; 26 female, 13 male). Bypass patency was evaluated by catheter angiography, which was performed within 24 hours after US. The collateral circulation through the bypass was classified into 4 types as follows: the bypass supplies more than two-thirds (type A); between one-third and two-thirds (type B); or less than one-third (type C) of the MCA territory; or there is bypass occlusion (type D). The authors assessed the mean blood flow velocity (BFV), the blood volume flow (BVF), and the pulsatility index (PI) in the external carotid artery and STA by duplex sonography. Additionally, they analyzed the flow direction of the MCA by transcranial color-coded sonography. US findings were compared between bypasses with higher (types A and B) and lower (types C and D) capacity. Catheter angiography revealed high STA-MCA bypass capacity in 35 cases (type A: n = 22, type B: n = 13), whereas low bypass capacity was noted in the remaining 15 cases (type C: n = 12, type D: n = 3). The BVF values in the STA were 60 ± 28 ml/min (range 4-121 ml/min) in the former and 12 ± 4 ml/min (range 6-18 ml/min) in the latter group (p < 0.0001). Corresponding values of mean BFV and PI were 57 ± 21 cm/sec (range 16-100 cm/sec) versus 22 ± 8 cm/sec (range 10-38 cm/sec) (p < 0.0001) and 0.8 ± 0.2 (range 0.4-1.3) versus 1.4 ± 0.5 (range 0.5-2.4) (p < 0.0001), respectively. Differences in the external carotid artery were less distinct: BVF 217 ± 71 ml/min (range 110-425 ml/min) versus 151 ± 41 ml/min (range 87-229 ml/min) (p = 0.001); mean BFV 47 ± 17 cm/sec (range 24-108 cm/sec) versus 40 ± 7 cm/sec (range 26-50 cm/sec) (p = 0.15); PI 1.5 ± 0.4 (range 1.0-2.5) versus 1.9 ± 0.4 (range 1.2-2.6) (p = 0.009). A retrograde blood flow in the MCA was found in 14 cases (9 in the M1 and M2 segment; 5 in the M2 segment alone), and all of them showed a good bypass function (type A, n = 10; type B, n = 4). The best parameter (cutoff value) to distinguish bypasses with higher capacity from bypasses with lower capacity was a BVF in the STA ≥ 21 ml/min (sensitivity 100%, negative predictive value 100%, specificity 91%, positive predictive value 83%). Duplex sonography is a suitable diagnostic tool to assess STA-MCA bypass function in moyamoya disease. Hemodynamic monitoring of the STA by US provides an excellent predictor of bypass patency.

Ultrasonographic Changes in Brain Hemodynamics in Patients with Parkinson's Disease and Risk Factors for Cerebrovascular Disease: A Pilot Study.

Recent epidemiological studies have revealed a correlation between atypical features and worse functional outcomes in Parkinson's disease (PD) patients with cerebrovascular disease (CVD). We aimed to evaluate the brain hemodynamics of PD patients with risk factors for CVD using Doppler ultrasonography. In this prospective pilot study, we randomly included 27 outpatients diagnosed with PD. Transcranial color-coded sonography (TCCS) examinations were performed, obtaining measurements of middle cerebral artery mean flow velocities (Vm), the resistance index (RI), and the pulsatility index (PI). The breath-holding index (BHI) was used to assess cerebrovascular reactivity (cVR). Standardized functional scales (UPDRS III, Hoehn & Yahr scale, and MoCA) were administered. The patients were divided into two groups: those with two or more vascular risk factors (PDvasc) and those with fewer than two vascular risk factors (PDnvasc). Patients in the PDvasc group showed higher PI (1.00 vs. 0.85; p=0.020), RI (0.59 vs. 0.5; p=0.05), H&Y mean (2.4 vs. 1.4; p=0.036), higher frequency of altered cVR (90.9% vs. 25.0%; p=0.001), and lower BHI (0.46 vs. 1.01; p=0.027). We also divided the patients in other two groups: one with patients with classical and another with akinetic-rigid PD clinical type. Patients with the akinetic-rigid type of PD had significantly higher RI (0.60 vs. 0.51; p=0.03), PI (0.99 vs. 0.77; p=0.03), higher frequency of altered cVR (80% vs. 35%; p=0.02), and lower BHI (0.48 vs. 0.96; p=0.05) than patients with classic-type PD. We concluded that TCCS displays impaired cerebrovascular reactivity and a more severe disease pattern in Parkinsonian patients with two or more risk factors for CVD and in the akinetic-rigid type. Doppler ultrasonography may be a useful tool in a clinical setting to investigate PD patients.

Screening and Risk Stratification Strategy Reduced Decompression Sickness Occurrence in Divers With Patent Foramen Ovale

ObjectivesThis paper sought to evaluate the occurrence of decompression sickness (DCS) after the application of a patent foramen ovale (PFO) screening and risk stratification strategy. BackgroundPFO is associated with an increased risk of DCS. Recently, transcatheter closure was reported to reduce DCS occurrence in divers with a high-grade shunt. However, to date, there are no data regarding the effectiveness of any PFO screening and risk stratification strategy for divers. MethodsA total of 829 consecutive divers (age 35.4 ± 10.0 years, 81.5% men) were screened for PFO by means of transcranial color-coded sonography in the DIVE-PFO (Decompression Illness Prevention in Divers with a Patent Foramen Ovale) registry. Divers with a high-grade PFO were offered either catheter-based PFO closure (the closure group) or advised conservative diving (high grades). Divers with a low-grade shunt were advised conservative diving (low grades), whereas those with no PFO continued unrestricted diving (controls). A telephone follow-up was performed. To study the effect of the screening and risk stratification strategy, DCS occurrence before enrollment and during the follow-up was compared. ResultsFollow-up was available for 748 (90%) divers. Seven hundred and 2 divers continued diving and were included in the analysis (mean follow-up 6.5 ± 3.5 years). The DCS incidence decreased significantly in all groups, except the controls. During follow-up, there were no DCS events in the closure group; DCS incidence was similar to the controls in the low-grade group (HR: 3.965; 95% CI: 0.558-28.18; P = 0.169) but remained higher in the high-grade group (HR: 26.170; 95% CI: 5.797-118.160; P < 0.0001). ConclusionsThe screening and risk stratification strategy using transcranial color-coded sonography was associated with a decrease in DCS occurrence in divers with PFO. Catheter-based PFO closure was associated with a DCS occurrence similar to the controls; the conservative strategy had a similar effect in the low-grade group, but in the high-grade group the DCS incidence remained higher than in all other groups.

Early Cerebrovascular Ultrasonography as a Predictor of Hemorrhagic Transformation After Thrombectomy

ObjectivesTo determine the predictive value of early transcranial color-coded sonography (TCCS) for intracranial hemorrhage (ICH) in patients with large artery occlusion (LAO) stroke of carotid circulation, who were submitted to endovascular therapy (EVT) with successful reperfusion. Materials and MethodsRetrospective study evaluating a cohort of consecutive stroke patients with LAO of the carotid circulation that were recanalyzed with EVT. We measured angle-corrected peak systolic velocities, end-diastolic velocities and mean flow velocities (PSV, EDV and MFV) of the symptomatic and asymptomatic middle cerebral artery (MCA). The ratio between MFV of the symptomatic MCA and MFV of the asymptomatic MCA (MCA-Ra) was calculated. Parenchymal hematoma in the 24 hours control CT was considered as ICH. Univariate associations and multivariate analyses were used to identify early independent predictors for ICH among TCCS findings. ResultsWe included 234 patients, mean age 72.5 (SD 12.6) years, 52.1% male. The mean time between recanalization and TCCS was 12.3 hours (range 3-22). Patients who developed postinterventional ICH showed a higher MCA-Ra (1.02 ± 0.26 vs 1.16 ± 0,21, p = 0.036). In multivariate analysis, only higher MCA-Ra remained independently associated with postinterventional ICH (OR: 6.778, 95%CI: 1.152–39.892, p = 0.034). A value of MCA-Ra ≥ 1,05 was associated with ICH, showing a sensitivity of 81.3% and a specificity of 65.9%; the AUC based of the ROC analysis was 0.688 (95% CI 0.570-0.806). ConclusionTCCS performed within the first 24 hours after stroke onset can help to predict hemorrhagic transformation in patients with LAO.

Transcranial Color-Coded Sonography Criteria for Moderate and Severe Middle Cerebral Artery Stenosis

This study aimed to establish optimal criteria for evaluation of moderate (50%–69%) and severe (70%–99%) middle cerebral artery (MCA) stenosis with transcranial color-coded sonography (TCCS). A total of 375 cases provided 409 TCCS/digital subtraction angiography vessel pairs. Peak systolic velocity (PSV), end-diastolic velocity (EDV) and mean flow velocity (MFV) of the MCA were measured. The stenotic/distal MFV ratios (SDRs) were calculated. With digital subtraction angiography as a reference, for 50%–69% MCA stenosis, the optimal combined criteria were PSV ≥180 cm/s (sensitivity 95.7%, specificity 64.9% and overall accuracy 69.7%); EDV ≥75 cm/s (90.0%, 66.4% and 68.7%); MFV ≥110 cm/s (95.7%, 64.0% and 69.4%); and SDR ≥2.5 (88.6%, 71.3% and 76.3%). Criteria for 70%–99% MCA stenosis were PSV ≥240 cm/s (93.5%, 89.9% and 85.5%); EDV ≥100 cm/s (96.8%, 89.0% and 87.3%); MFV≥160 cm/s (91.9%, 92.8% and 92.2%); and SDR ≥4 (87.1%, 92.2% and 91.4%). Parameters of the MCA detected by TCCS, especially SDR, may increase accuracy in diagnosis of 50%–69% and 70%–99% MCA stenosis.

Assessment of Intracranial Collateral Circulation Using Novel TCCS Grading System in Patients With Symptomatic Carotid Occlusion.

Objectives: To establish a novel transcranial color-coded sonography (TCCS) grading system for collateral circulation in cases of symptomatic chronic total carotid occlusion (TCO), and to correlate this new grading system with cerebrovascular reserve capacity (CVR) measured by SPECT.Methods: Thirty-four patients with symptomatic chronic TCO recruited from the neurovascular ultrasound laboratory of the department of Neurology at Cairo University Hospital during 3 years' time period and diagnosed by color-coded duplex were subjected to: clinical assessment, grading of cerebral collaterals using a proposed TCCS criteria, Brain SPECT studies at rest and with dipyridamole stress.Results: The new grading system for cerebral collateral circulation showed a significant positive correlation with CVR (P < 0.001 and Spearman correlation coefficient 0.686).Conclusion: The current study showed that this new TCCS grading system for cerebral collaterals is a reliable indicator for cerebral perfusion and reserve capacity in cases of chronic symptomatic TCO.

Editors' note: RCVS2 score and diagnostic approach for reversible cerebral vasoconstriction syndrome

Rocha et al. developed a discriminatory score in a cohort of 30 patients with reversible cerebral vasoconstriction syndrome (RCVS) and 80 patients with non-RCVS arteriopathy, and they validated it in a separate cohort of RCVS and its mimic, primary angiitis of the CNS (PACNS). They found that a score that evaluated for recurrent/single thunderclap headache, carotid artery involvement (less likely with RCVS), vasoconstrictive trigger, female sex, and subarachnoid hemorrhage could accurately distinguish RCVS from other intracranial arteriopathies. In response, Drs. Yuan and Hu highlight some limitations of the study, including the use of retrospective study data, limited sample size, inclusion of 2 variables relying on the patient's subjective recall (vasoconstrictive trigger and thunderclap headache), lack of a gold standard, and the need to validate the score's ability to distinguish RCVS from arteriopathies other than PACNS. They propose using additional readily available clinical variables and imaging markers such as vessel wall imaging and transcranial color-coded sonography to further refine and validate the score. Responding to these comments, Drs. Singhal and Rocha note that several of these limitations were acknowledged in the article. They counter that advanced vessel wall imaging or biomarker studies are unlikely to improve the near-perfect performance of RCVS2 scores >5 or <2 in their study but may have some utility in patients with intermediate scores. They argue that patients' recall of thunderclap headache is likely to be reliable, given the uniqueness of the experience, whereas patients may underreport vasoconstrictive triggers such as illicit drugs and over-the-counter medications. This exchange underscores the challenges and disagreements that may be encountered when developing and refining clinical scores for neurologic conditions. Rocha et al. developed a discriminatory score in a cohort of 30 patients with reversible cerebral vasoconstriction syndrome (RCVS) and 80 patients with non-RCVS arteriopathy, and they validated it in a separate cohort of RCVS and its mimic, primary angiitis of the CNS (PACNS). They found that a score that evaluated for recurrent/single thunderclap headache, carotid artery involvement (less likely with RCVS), vasoconstrictive trigger, female sex, and subarachnoid hemorrhage could accurately distinguish RCVS from other intracranial arteriopathies. In response, Drs. Yuan and Hu highlight some limitations of the study, including the use of retrospective study data, limited sample size, inclusion of 2 variables relying on the patient's subjective recall (vasoconstrictive trigger and thunderclap headache), lack of a gold standard, and the need to validate the score's ability to distinguish RCVS from arteriopathies other than PACNS. They propose using additional readily available clinical variables and imaging markers such as vessel wall imaging and transcranial color-coded sonography to further refine and validate the score. Responding to these comments, Drs. Singhal and Rocha note that several of these limitations were acknowledged in the article. They counter that advanced vessel wall imaging or biomarker studies are unlikely to improve the near-perfect performance of RCVS2 scores >5 or <2 in their study but may have some utility in patients with intermediate scores. They argue that patients' recall of thunderclap headache is likely to be reliable, given the uniqueness of the experience, whereas patients may underreport vasoconstrictive triggers such as illicit drugs and over-the-counter medications. This exchange underscores the challenges and disagreements that may be encountered when developing and refining clinical scores for neurologic conditions.

Diagnostic Yield of Early Examination for Venous Thrombosis in Patients with Cryptogenic Stroke and a Right-to-left Shunt.

Objective The presence of deep venous thrombosis (DVT) in a cryptogenic stroke (CS) patient with a right-to-left shunt (RLS) may lead to the development of paradoxical embolism. The aim of the present was to investigate the prevalence of DVT and pulmonary embolism (PE) in CS patients and the clinical features of CS in relation to DVT location and the presence of PE. Methods The medical records of 903 patients with cerebral infarction were retrospectively reviewed. For patients with a diagnosis of CS, contrast saline transcranial color-coded sonography was performed to identify an RLS. DVT and PE were assessed by duplex ultrasonography and/or contrast-enhanced computed tomography. Proximal DVT (P-DVT) was defined as DVT in the popliteal, femoral, or iliac veins, and distal DVT (D-DVT) was defined as DVT at other locations. The patients were divided into three groups: CS with P-DVT and/or PE (P-DVT/PE) group; CS with D-DVT (D-DVT) group; and CS without DVT (no DVT) group. Results Seventy-two (37%) of 194 patients with CS had an RLS. The median time to first DVT examination from stroke onset was three days. Twenty-nine percent of CS patients with an RLS had DVT. The P-DVT/PE group comprised 8.3% of the CS patients with an RLS and included a larger number of patients with multi-territory infarction than the D-DVT group. The D-DVT and P-DVT/PE groups tended to be female and older, while the P-DVT/PE group tended to have pre-stroke disability. Conclusion CS patients, especially those with multi-territory lesions, should be immediately examined for DVT and PE.

Evaluation of Cerebral Hemodynamics with Color-Coded Duplex Sonography: Normative Values with Correction of Insonation Angles

Background: Transcranial color-coded sonography (TCCS) allows direct observation of arteries and the possibility of correcting the insonation angle for reliable evaluation of hemodynamics. We obtained TCCS reference values of the cerebral hemodynamics after correction of insonation angles. Methods: We studied 195 healthy adults equally allocated into 3 age groups: 18-40, 41-60, and greater than or equal to 61 years. The middle (MCA), anterior (ACA), and posterior cerebral arteries (PCA) were evaluated through the temporal acoustic window using conventional pulsed transcranial Doppler and TCCS. Peak systolic, end diastolic, and mean blood flow velocities were registered, as well as pulsatility and resistance indices at 0° and with correction by alignment of insonation angle parallel to the blood flow vector. We derived normative values assuming both the parametric and nonparametric distributions. Results: We excluded 33 participants due to inadequate acoustic window (10.3%), carotid disease (2.1%), and embryonic variants (4.6%), leaving out 162 for final analysis (50% female, median age 48 years). The 2.5th-97.5th percentiles of the corrected angle for MCA was 0°-60°, ACA 0°-44°, and PCA 30°-60°. After angle correction, 2.5th-97.5th percentiles for flow velocity of MCA, ACA, and PCA were 37.7-112.5 cm/s, 25.6-71.2 cm/s, and 29.2-80.8 cm/s, respectively. There were wide discrepancies between hemodynamics values obtained with insonation angles at 0° and after angle correction. No differences were found between ultrasound methods at exactly 0° or between hemispheres, however, there were differences according to age and sex. Conclusions: Specific normative tables should be used in TCCS when the corrected angle is greater than 0° since the hemodynamics values greatly differ after correction of the insonation angle. Further studies are necessary to determine critical cutoffs indicating disease.

Pattern of Activated Pathways and Quality of Collateral Status in Patients with Symptomatic Internal Carotid Artery Occlusion

Background: Internal carotid artery occlusion (ICAO) is an important risk factor for stroke. Cerebral hemodynamics in patients with ICAO depends on the individual capacity to activate sufficient collateral pathways. Therefore, the assessment of intracranial collaterals is essential for the acute and long-term management of these patients and accurate estimation of further stroke risk. Methods: Acute stroke patients with unilateral ICAO were prospectively enrolled. We assessed the following collaterals by transcranial color-coded sonography (TCCS): the anterior and posterior communicating artery (ACoA, PCoA), the ophthalmic artery (OA), and leptomeningeal collaterals of the posterior cerebral artery (LMC). We subdivided the flow pattern of the Doppler spectrum in the middle cerebral artery (MCA) into 3 categories: (1) good, (2) moderate, and (3) bad according to the hemodynamic effects on the ipsilateral MCA flow. Finally, we compared the individual TCCS results with the stroke pattern detected on CT or MRI scan. Results: One hundred thirteen patients (age 66 ± 12 years; ­female 24) were included. The collateral status was good, moderate, and bad in 59 (52%), 37 (33%), and 17 (15%) patients, respectively. The ACoA collateral was most frequently activated (81%), followed by the OA (63%), the PCoA (53%), and the LMC (22%). The quality of the collateral status was determined by the type (p = 0.0003) but not by the number (p = 0.19) of activated collateral pathways. Good collateral function was highly associated with primary collaterals (ACoA > PCoA). Best parameter for a good collateral status was an antegrade flow in the OA, indicating a high blood supply via the communicating arteries. Conclusions: TCCS allows the assessment of intracranial collaterals and their hemodynamic capacity. Prevalence of collateral sufficiency in ICAO seems to be higher than previously reported. ACoA cross flow is essential for the optimal hemodynamic compensation of ICAO. Antegrade OA flow indicates good collateral status.