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

AIM: This 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). METHODS: A 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. RESULTS: The 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. CONCLUSION: This 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.

Somatosensory evoked potentials and transcranial color Doppler monitoring in subarachnoid hemorrhage.

OBJECTIVES: The outcome of patients with subarachnoid hemorrhage (SAH) is broadly influenced by the complications that may result from the hemorrhage. We describe a series of subjects, in which neurophysiological monitoring executed by simultaneous recording of somatosensory evoked potentials (SEPs) and transcranial color Doppler (TCD) was performed to reveal possible, early complications following acute SAH. MATERIALS AND METHODS: We described the absolute and interhemispheric values of SEPs from the upper limb and TCD examinations of the cerebral arteries in 13 subjects with acute SAH. RESULTS: In cases with middle cerebral artery (MCA) vasospasm, N20 SEP amplitude absolute values for the hemisphere involved in the vasospasm were much lower than the contralateral ones. The N20 amplitude ratio reduction correlated with reciprocal of MCA mean flow velocity values detected within each patient. In the subjects with early ischemic damage following SAH, the affected hemisphere showed N20 amplitude drop; in addition, the relationship between SEPs and TCD findings was missing. CONCLUSION: Our findings emphasize the utility of simultaneous evaluation of SEPs and TCD in SAH follow-up, since the two methods reflect different pathomechanisms of possible secondary brain damage in aneurysmal SAH.

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.

Changing Ischemic Lesion Patterns and Hemodynamics of the Posterior Cerebral Artery in Moyamoya Disease.

OBJECTIVE: The aim of this study was to determine how hemodynamics of the posterior cerebral artery (PCA) are associated with cerebral ischemic lesions in moyamoya disease (MMD). METHODS: Thirty-six patients with ischemic MMD (Suzuki grade IV-V) were retrospectively analyzed. Hemodynamic parameters of the PCA were measured by transcranial color-coded sonography. We classified the range of ischemic lesions into 3 grades and perfusion levels into 3 grades according to computed tomography (CT) results. PCA steno-occlusion and leptomeningeal collaterals were confirmed by digital subtraction angiography. Ultrasonographic parameters in the PCA were compared with these radiographic findings. RESULTS: The velocity in the involved PCA (mean flow velocity [MFV] median, 42.00 [range, 34.50-58.00] cm/s) was significantly lower than that in the normal PCA (MFV median, 95.00 [range, 76.50-119.50] cm/s) (P < .001). The velocity in the PCA increased significantly as the leptomeningeal collateral stage advanced (MFV stage 1: median, 38.50 [range, 29.75-63.50] cm/s; stage 2: median, 55.00 [range, 44.00-96.00] cm/s; stage 3: median, 94.00 [range, 54.00-118.25] cm/s; stage 4: median, 85.50 [range, 70.50-117.75] cm/s, respectively) (P < .05). Decreased PCA velocities were associated with a larger ischemic area on CT (P ≤ .001). PCA velocity had no correlation with CT perfusion level of the temporal and frontal lobes. PCA velocity had significant correlations with perfusion level in the occipital (P < .001) and parietal lobes (P < .05). CONCLUSIONS: Our results suggest ischemic lesion patterns (as demonstrated on CT imaging) are associated with PCA velocity measurements in the advanced stage of MMD. Thus, monitoring PCA velocity in patients with advanced MMD may provide additional information to assist in managing these patients.

Comparison of transcranial color-coded real-time sonography and contrast-enhanced color-coded sonography for detection and characterization of intracranial arteriovenous malformations.

OBJECTIVES: To compare the diagnostic value of transcranial color-coded real-time sonography and contrast-enhanced color-coded sonography in detection and characterization of intracranial arteriovenous malformations. METHODS: Thirty-one patients highly suspected to have an intracranial arteriovenous malformation were imaged with real-time and contrast-enhanced sonography. With digital subtraction angiography as the reference standard, the ability to detect the malformations and accurately determine their size and location was compared between the two imaging techniques. RESULTS: One cavernous hemangioma and 30 intracranial arteriovenous malformations were imaged with real-time and contrast-enhanced sonography, which were confirmed by angiography. The detectability of contrast-enhanced sonography, especially for optimizing visualization of malformations located in the frontal, parietal, and occipital lobes, was higher than that of real-time sonography, although the overall number of malformations was too small to demonstrate significance. The sizes of the malformations (6 in the frontal lobe, 1 in the parietal lobe, and 1 in the occipital lobe) were underestimated by real-time sonography compared to angiography, whereas there was agreement in the sizes between contrast-enhanced sonography and angiography. The detection rates for the 30 arteriovenous malformations on contrast-enhanced and real-time sonography were 96.7% (29 of 30) and 70.0% (21 of 30), respectively (P = .008). Moreover, contrast-enhanced sonography was significantly superior to real-time sonography for detection of feeding arteries (59.5% [22 of 37] versus 83.7% [31 of 37]; P = .004). Although the feeding arteries showed increased peak systolic and end-diastolic velocities after contrast agent injection, there were no statistically significant differences in the velocities before and after injection. CONCLUSIONS: Transcranial contrast-enhanced color-coded sonography is superior to color-coded real-time sonography for detection of intracranial arteriovenous malformations, particularly for lesions located in the frontal, parietal, and occipital lobes of the brain.

Prevalence of intracranial stenosis in a Norwegian ischemic stroke population.

BACKGROUND: There is no data about prevalence of intracranial stenosis (IS) in Northern Europe. This study aimed to investigate the prevalence of symptomatic and asymptomatic IS in a Norwegian, community-based ischemic stroke population. METHODS: In a prospective study, all ischemic stroke or transient ischemic attack (TIA) patients were screened for IS by transcranial color-coded sonography, magnetic resonance angiography, and/or computed tomography angiography. Patients with IS and any cardiac arrhythmia or other possible causes of IS than atherosclerosis were excluded. IS was defined as symptomatic if the infarct/symptoms were related to the territory of the stenotic artery. Risk factors for cerebrovascular disease were registered on admission. RESULTS: During an 18-month study period, 607 patients had an ischemic stroke or a TIA. Out of 69 patients with IS (11.4%), 7 patients were excluded because having atrial fibrillation, and IS of possible atherosclerotic etiology was therefore diagnosed in 62 patients (10.2%). IS was symptomatic in 45 patients (7.4%). Diabetes mellitus was the only risk factor significantly associated with symptomatic IS (odds ratio 2.39, 95% confidence interval [CI] 1.03-5.54, P=.04). CONCLUSIONS: IS occurs in approximately 10% and is symptomatic in about 7% of a Norwegian ischemic stroke/TIA population. Diabetes mellitus appears to be the major risk factor for IS.

Transcranial color-coded sonography to predict recurrent transient ischaemic attack/stroke.

BACKGROUND AND PURPOSE: Patients with transient ischaemic attack (TIA) with a high risk of imminent stroke can be identified with the ABCD(2) score and findings on MRI and CT angiography. The predictive value of transcranial color-coded sonography (TCCS) has not been evaluated in this setting. METHODS: A retrospective analysis was conducted of patients consecutively treated for TIA or minor stroke in a TIA clinic within 24 h of symptom onset. Agreement between TCCS and MRI three-dimensional time-of-flight images for the diagnosis of proximal (internal carotid artery, vertebral artery, basilar artery, circle of Willis and main stem of the middle cerebral artery) >50% stenosis or occlusion of the intracranial symptomatic artery was evaluated. The sensitivity, specificity, predictive values and likelihood ratio of TCCS for predicting recurrent TIA/stroke at 7 days were calculated. RESULTS: Of 159 patients with a TIA or minor stroke within the last 24 h, 142 had a readable acoustic temporal bone window (89.3%). TCCS and MRI were performed within 4 h of each other in 116 patients. MRI showed a symptomatic proximal intracranial steno-occlusive lesion in six patients. Agreement between MRI and TCCS was perfect (κ coefficient = 1). Recurrent TIA/stroke occurred in 10 patients (eight TIA and two minor strokes). All recurrences occurred within 24 h of symptom onset. A symptomatic proximal intracranial steno-occlusive lesion was found on TCCS in 4/10 patients with recurrence and 3/132 patients without recurrence [sensitivity 40%; specificity 97.7%; likelihood ratio 18.1; odds ratio (95% CI) adjusted for ABCD(2) score 31.5 (4.5-218.6)]. CONCLUSION: Our study shows that TCCS can be used to guide triage of patients with TIA.

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

Background: 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. Methods: 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. Results: 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). Conclusions: 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.

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

Background: We aimed to investigate the usefulness of intracranial arterial pulsatility index to assess the prognosis of lacunar infarcts. Materials and Methods: 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. Results: 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. Conclusion: Sonography-assisted assessment of the vertebral artery blood flow during the early stage of lacunar infarct provides a reliable reference for prognosis estimation.

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.

Transcranial Color-Coded Duplex Ultrasound for Assessing Cerebrovascular Reserve in Intracranial Dissection with Aneurysm.

Intracranial artery dissection (IAD) is an uncommon cause of cerebral ischemia. It may lead to symptoms due to rupture of subadventitial aneurysms or thromboembolism from subintimal disruption. Severe stenosis may lead to reduced cerebrovascular reserve (CVR). While there are many methods of assessing CVR, we report a case of IAD with hemodynamic complications diagnosed by transcranial color-coded duplex (TCCD) ultrasonography. Our patient is a 38-year-old female who presented with a 2-month history of nausea, then feeling faint whenever she got up suddenly. On the day of admission, she had gotten up to walk, felt nauseous, and the left upper limb felt "funny," after which she lost consciousness. Clinical and neurological examination was normal. Brain magnetic resonance (MR) imaging was normal. MR angiogram and subsequent computed tomography (CT) angiogram showed flow attenuation in the M1 segment of the right middle cerebral artery (RMCA), with a possible flap. Catheter angiography was suggestive of a dissection with 2.7 mm pseudoaneurysm. TCCD showed very high velocities in the RMCA. The Breath-Holding Index (BHI) was 0.56, suggestive of reduced CVR in the RMCA territory. Acetazolamide-enhanced single-photon emission CT showed reduced right frontal CVR. She was given clopidogrel for secondary prevention, and has remained well. BHI as measured by TCCD is a new method for assessing CVR in patients with cerebral ischemia.

Intensive Lipid-Lowering Therapy Ameliorates Asymptomatic Intracranial Atherosclerosis.

Statins have proven to exert protective effects in patients with symptomatic intracranial atherosclerotic stenosis (SICAS). It is unclear whether intensive lipid-lowering therapy (ILLT) can ameliorate atherosclerosis in asymptomatic ICAS (AICAS). A single-center, prospective cohort study was performed in 71 AICAS patients with lipid-lowering therapy. Vascular stenoses were evaluated with transcranial color-coded sonography (TCCS) before and after statin treatment. With target therapeutic level of low-density lipoprotein cholesterol (LDL-C) ≤ 1.8 mmol/L or ≥ 50% reduction from baseline after the two years of follow-up, patients were divided into intensive statin treatment (IST) group and standard statin treatment (SST) group. A total of 104 stenotic intracranial arteries were detected in 51 patients belonging to the IST group and 47 arteries in 20 patients of the SST group. In the first year, LDL-C levels were significantly decreased in the IST compared with SST groups (1.48 ± 0.26 vs. 2.20 ± 0.58, P=0.000). However, the ratio of regressed ICAS in IST was not significantly higher than that in SST (26.3% vs. 5.9%, P=0.052). Forty-nine branches in 25 patients of the IST group and 16 branches in 7 patients of the SST group were followed up for two years. The LDL-C level was decreased in the IST compared with SST groups (1.55 ± 0.29 vs. 2.36 ± 0.77, P=0.048). The ratio of regressed ICAS in the IST group was significantly higher than that in SST group (34.7% vs. 6.3%, P=0.017). We concluded that the degree of stenosis in AICAS can be ameliorated with intensive lipid-lowering therapy within two years; target LDL-C level can be reached by moderate-intensity statin treatment for Chinese AICAS patients.

Transcranial color-coded sonography findings of patients with reversible cerebral vasoconstriction syndromes.

Reversible cerebral vasoconstriction syndromes (RCVS) have been well recognized recently as one cause of cerebrovascular disease, but the time course of vessel vasoconstriction remains uncertain. We report herein 2 cases with RCVS in which we clarified temporal changes in vessel vasoconstriction in detail using transcranial color-coded sonography (TCCS). The first case involved a 27-year-old woman who developed intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) after severe headache. TCCS showed peak systolic velocity (PSV) in the left middle cerebral artery (MCA) peaked at 212 cm/s on day 6 and gradually decreased, whereas PSV of the left posterior cerebral artery (PCA) and left anterior cerebral artery (ACA) re-elevated to 190 cm/s on day 15. The second case involved a 53-year-old woman who developed cerebral infarction in the PCA territory 9 days after severe headache. TCCS study showed PSV elevation in the right MCA. Although TCCS seemed to normalize 7 days after admission, PSV of the left PCA, left ACA, and left MCA re-elevated at day 17. Both cases showed bimodal PSV peaks, with the posterior circulation peak preceded by the anterior circulation peak. These findings may be important in clarifying the mechanisms underlying vasoconstriction in patients with RCVS.

Transcranial Color-Coded Sonography for the Detection of Cerebral Veins and Sinuses and Diagnosis of Cerebral Venous Sinus Thrombosis.

This study aimed to determine the detection rate of transcranial color-coded sonography (TCCS) of cerebral veins and sinuses and to explore the diagnostic accuracy of TCCS for straight sinus (SS) and transverse sinus (TS) thromboses. The detection rates of cerebral veins and sinuses using TCCS and contrast-enhanced TCCS (CE-TCCS) were analyzed. The diagnostic accuracy of CE-TCCS was evaluated. Median time from symptoms to CE-TCCS was 10 (range, 1-150) d. The detection rate of bilateral basal veins of Rosenthal was 100% by CE-TCCS, followed by right TS (91.89%), SS (88.12%), left TS (74.59%) and vein of Galen (70.27%). Compared with magnetic resonance imaging/magnetic resonance venography, CE-TCCS showed 100% sensitivity and 96.3% specificity for SS thrombosis, 100% and 100% for right TS thrombosis and 100% and 94.4% for left TS thrombosis. In conclusion, CE-TCCS shows high identification rates of cerebral veins and sinuses and a high diagnostic accuracy for SS and TS thrombosis.

The Assessment of Diagnostic Accuracy for Basilar Artery Stenosis by Transcranial Color-Coded Sonography.

This study aimed to determine the optimal criteria for evaluating basilar artery stenosis (BAS) by transcranial color-coded sonography (TCCS). A total of 403 cases with both TCCS and digital subtraction angiography (DSA) were enrolled. Peak systolic velocity (PSV), end diastolic velocity (EDV) and mean flow velocity (MFV) of the basilar artery (BA), intracranial vertebral artery (IVA) and posterior cerebral artery (PCA) were measured. The ratios PSVBA/PSVIVA and PSVBA/PSVPCA were calculated. With DSA as the reference, the optimal criteria for grading BAS were determined by receiver operating characteristic analysis. They were as follows: PSV ≥110 cm/s, MFV ≥70 cm/s and PSVBA/PSVIVA ≥1.5 for <50% BAS; PSV ≥150 cm/s, MFV ≥90 cm/s and PSVBA/PSVIVA ≥2.0 for 50%-69% BAS; PSV ≥210 cm/s, MFV ≥120 cm/s and PSVBA/PSVIVA ≥3.0 for 70%-99% BAS. The combination of PSV, MFV and PSVBA/PSVIVA may increase the accuracy for diagnosing 70%-99% BAS.

Changes in Blood Flow Velocity of the Middle Cerebral Artery After Carotid Endarterectomy: Daily Assessment with Transcranial Color-Coded Sonography.

BACKGROUND: Hyperperfusion syndrome (HPS) is a well-known complication of carotid endarterectomy (CEA) warranting repeatable inexpensive monitoring. Transcranial color-coded sonography (TCCS) may provide a potential modality for such monitoring, but little is known about TCCS trends after CEA. METHODS: Between January 2016 and February 2017, we prospectively included patients with CEA at our institute in this study. TCCS was performed preoperatively and repeated daily from the operation day until postoperative day (POD) 7. Daily trends in mean flow velocity (MFV) at the M1 portion of the middle cerebral artery were compared between patients with and without HPS. RESULTS: Among 35 patients with CEA, daily TCCS monitoring was performed in 18 patients (mean age ± SD, 72 ± 7 years; male/female, 17:1). Among these 18 patients, 3 had probable HPS. On POD 0, MFV of the 18 patients showed a 32% increase from the initial preoperative value (from 52.5 to 69.4 cm/s, P = 0.0013). This increased MFV lasted for several days and recovered gradually by POD 7. Patients with probable HPS demonstrated a trend to higher MFV than those without; however, the difference was below the significance level. CONCLUSIONS: We used daily TCCS after CEA to depict cerebral blood flow changes after CEA in our cohort. This technique may be useful both for the detection and prevention of HPS.

Reduced Cerebrovascular Reserve Capacity as a Biomarker of Microangiopathy in Alzheimer's Disease and Mild Cognitive Impairment.

BACKGROUND: Cerebral microangiopathy in Alzheimer's disease (AD) causes chronic hypoperfusion and probably accelerates neurodegenerative changes. OBJECTIVE: We hypothesize microvascular impairment could be present already in mild cognitive impairment (MCI) and can be revealed using transcranial color-coded sonography (TCCS) and the breath-holding maneuver. METHODS: Three groups of subjects (AD in the stage of dementia, MCI, and cognitively normal controls) with detailed neuropsychological testing and low cerebrovascular burden (no history of stroke, no intra- or extracranial artery stenoses, and no severe vascular lesions on brain MRI), underwent a TCCS assessment of peak systolic (PSV), mean flow (MFV), and end diastolic velocities (EDV) and resistance and pulsatility indices (RI, PI) in large intracranial vessels bilaterally. Cerebrovascular reserve capacity was assessed using the breath-holding index (BHI) in middle cerebral artery (MCA) bilaterally. The ultrasound parameters were compared between the groups, correlated with neuropsychological tests, and compared between amnestic and non-amnestic MCI subtypes. RESULTS: Fourteen AD (3 males, 67.9±11.1 years, MMSE 18.0±4.6), 24 MCI (13 males, 71.9±7.3 years, MMSE 28.0±1.6), and 24 risk factor-matched controls (14 males, 67.8±6.4 years, MMSE 29.1±1.2) were enrolled. Significant differences were found between AD and controls in MFV, EDV, RI, PI in right MCA after breath holding, in PSV, MFV, EDV in left MCA after breath holding, and in BHI on the left side. The left BHI correlated positively with verbal memory test. CONCLUSION: Results show decreased cerebrovascular reserve capacity in AD as a sign of impaired cerebral hemodynamic status without severe underlying atherosclerosis. This can be identified using TCCS and BHI.

Assessment of intracranial venous blood flow after subarachnoid hemorrhage: a new approach to diagnose vasospasm with transcranial color-coded duplex sonography.

OBJECTIVETranscranial color-coded duplex sonography (TCCS) is a reliable tool that is used to assess vasospasm in the M1 segment of the middle cerebral artery (MCA) after subarachnoid hemorrhage (SAH). A distinct increase in blood flow velocity (BFV) is the principal criterion for vasospasm. The MCA/internal carotid artery (ICA) index (Lindegaard Index) is also widely used to distinguish between vasospasm and cerebral hyperperfusion. However, extracranial ultrasonography assessment of the neck vessels might be difficult in an intensive care unit. Therefore, the authors evaluated whether the relationship of intracranial arterial to venous BFV might indicate vasospasm with similar or even better accuracy.METHODSPatients who presented between 2008 and 2015 with aneurysmal SAH were prospectively enrolled in the study. Digital subtraction angiography (DSA) and TCCS were performed within 24 hours of each other to assess vasospasm 8-10 days after SAH. The following different TCCS parameters were analyzed to assess vasospasm in the MCA and were compared with the gold-standard DSA parameters: 1) mean time-averaged maximum BFV (Vmean) of the MCA, 2) peak systolic velocity (PSV) of the MCA, 3) the Lindegaard Index using Vmean as well as PSV, and 4) a new arteriovenous index (AVI) between the MCA and the basal vein of Rosenthal using Vmean and PSV. The best cutoff values for these parameters to distinguish vasospasm from normal perfusion or hyperperfusion were calculated using receiver operating characteristic curve analysis. Sensitivity, specificity, positive predictive value, and negative predictive value as well as the overall accuracy for each cutoff value were analyzed.RESULTSA total of 102 patients (mean age 52 ± 12 years) were evaluated. Bilateral MCA assessment by TCCS was successful in all patients. In 6 cases (3%), the BFV of the basal vein of Rosenthal could not be analyzed. The AVI could not be calculated in 50 of 204 cases (25%) because the insonation quality was very low in one of the ICAs. An AVI > 10 for Vmean and an AVI > 12 for systolic velocity provided the highest accuracies of 87% and 86%, respectively. Regarding the Lindegaard Index, the accuracy was highest using a threshold of > 3 for the mean BFV (84%) as well as systolic BFV (80%). BFVs in the MCA of ≥ 120 cm/sec (Vmean) and ≥ 200 cm/sec (PSV) predicted vasospasm with accuracies of 84% and 83%, respectively. A combined analysis of the MCA BFV and the AVI led to a slight increase in specificity (Vmean, 94%; PSV, 93%) and positive predictive value (Vmean, 88%; PSV 86%) without further improvement in accuracy (Vmean, 88%; PSV, 84%).CONCLUSIONSThe intracranial AVI is a reliable parameter that can be used to assess vasospasm after SAH. Its reliability for differentiating vasospasm and hyperperfusion is slightly higher than that for the established Lindegaard Index, and this method has the additional advantage of a remarkably lower failure rate.

Comparison between Brain Computed Tomography Scan and Transcranial Sonography to Evaluate Third Ventricle Width, Peri-Mesencephalic Cistern, and Sylvian Fissure in Traumatic Brain-Injured Patients.

INTRODUCTION: Transcranial color-coded duplex sonography (TCCS) may help guide multimodal monitoring in the neurocritical setting. It may provide indirect information about intracranial hypertension, such as midline shift, third ventricle width, and peri-mesencephalic cistern obliteration. We aim to assess the agreement between brain computed tomography scan (CT scan) and TCCS in traumatic brain injury (TBI) patients. METHODS: In this retrospective cross-sectional observational study, TCCS was performed within 6 h before a brain CT scan. Only the first CT and TCCS after ICU admission were included. The agreement between the CT scan and TCCS was assessed by Bland-Altman plots and evaluating the intraclass correlation coefficient. RESULTS: Overall, 15 consecutive patients were included (80% male, 42 ± 23 years of age, Glasgow Coma Score 5 [4,6]). The mean difference between the brain CT scan and TCCS in measuring the midline shift was 0.30 ± 2.1 mm (intraclass correlation coefficient: 0.93; p < 0.01). An excellent correlation was also observed between the methods in assessing the third ventricle width (intraclass correlation coefficient: 0.88; p < 0.01). Bland-Altman plots did not show any systematic bias in either agreement analysis. TCCS showed good accuracy in predicting non-compressed peri-mesencephalic cisterns (AUC: 0.83, 95% CI 0.46-1.0) and the presence of the Sylvian fissure (AUC: 0.91, 95% CI 0.73-1.0) on CT scan. CONCLUSION: TCCS is a promising tool and may be an alternative to CT scans for evaluating TBI patients.

Influence of smoking cigarettes on cerebral blood flow parameters.

INTRODUCTION: While chronic cigarette smoking can lead to increased risk of stroke, the acute effects of smoking have not been established. We studied the changes in blood flow parameters in the major cerebral arteries caused by smoking one cigarette. METHOD: Using transcranial color-coded sonography (TCCS), we studied the anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA), and the internal carotid artery (ICA) of 36 healthy male volunteers before and after they smoked one cigarette. RESULTS: Blood flow velocity increased to a different degree in all but one of the arteries examined after participants smoked a single cigarette: The end diastolic velocity increased significantly by 7.8% in the PCA, 8% in the ACA, and 14.4% in the MCA. The peak systolic velocity increased significantly by 7.5% in the MCA. Blood flow velocity remained unchanged in the ICA only. Blood pressure and heart rate increased as did the flow velocity ratio for the MCA/ICA. The pulsatility index decreased after smoking from 0.92 ± 0.13 to 0.87 ± 0.14 in the MCA, 0.93 ± 0.15 to 0.87 ± 0.13 in the ACA, and 0.95 ± 0.17 to 0.89 ± 0.16 in the PCA. CONCLUSIONS: The results suggest that the direct effect of smoking on cerebral circulation includes peripheral vasodilatation with possible constriction of the main trunk of the basal cerebral arteries.