Severe Middle Cerebral Artery Stenosis Research Articles

Abstract 167: Surgical treatment for unruptured Anterior communicating artery aneurysm

Introduction We report the results of endovascular surgery as the first‐line treatment for unruptured anterior communicating artery aneurysms. Methods Fifty‐seven patients (F:M, 30:27; mean age, 65.5 years) underwent surgery for unruptured anterior communicating artery aneurysms in our hospital between January 2018 and January 2023. Results The mean aneurysm dome size was 5.29 mm (2–22 mm), and the mean aneurysm neck size was 3.2 mm (1.5–7 mm). Coil embolization was performed for fifty‐four patients using various adjunctive techniques (simple, 7; double catheter, 15; balloon neck remodeling, 7; stent‐assisted, 26 (LVIS Jr., 12; ATLAS, 14). Neck clipping was performed in 3 cases. The surgical results revealed complete coil embolization in 27, neck remnant in 26, and dome filling in 1 patient(s). The reason for 3 patients treated with neck clipping are patient's preference in one, associated with severe Middle cerebral artery stenosis needed TSA MCA anastomosis on one, and difficulty of embolization in one patient. Postoperative thrombotic complications were observed in 1 patient. The modified Rankin scale scores were 0 in 32 (96.5%) patients, 3 in 1 (1.7%) patients, and 6 in 1 (1.7%) patient. Follow‐up was performed in 55 patients, averaging 29.5 months (3–45 months). However, one patient underwent re‐aneurysm embolization for major recanalization of the aneurysm dome, and none of them suffered from rupture of the treated aneurysm. Conclusion Endovascular surgery may be the first choice of treatment for unruptured anterior communicating artery aneurysms.

Hemichorea secondary to isolated temporal infarction with severe middle cerebral artery stenosis: a case report and review of literature

BackgroundHemichorea typically results from a contralateral subthalamic nuclei (STN) lesion, although it has been reported in the cortex in a minority of cases. However, to our best knowledge, there are no documented cases in literature of hemichorea occurring as a secondary condition to an isolated temporal stroke.Case presentationWe present a case of an elderly female who sustained a sudden onset of hemichorea in her right extremities, predominantly in the distal region, lasting over a period of two days. Brain diffuse weighted image (DWI) demonstrated a high signal in the temporal region, while magnetic resonance angiography (MRA) revealed severe stenosis of the middle cerebral artery. During the symptomatic phase, computed tomography perfusion (CTP) revealed delayed perfusion in the left middle cerebral artery territory, characterized by the time-to-peak (TTP) measure. Based on the results of her medical history and laboratory tests, we were able to rule out the possibility of infectious, toxic, or metabolic encephalopathy. Her symptoms gradually improved with antithrombotic and symptomatic treatment.ConclusionsIt is important to recognize and consider acute onset hemichorea as an initial symptom of stroke to avoid misdiagnosis and delays in appropriate treatment. Further research on temporal lesion that lead to hemichorea is warranted to gain a better understanding of the underlying mechanisms.

CT Perfusion Alterations in Patients with Symptomatic and Asymptomatic Unilateral Middle Cerebral Artery Severe Stenosis or Occlusion.

To investigate the changes in CT perfusion between symptomatic and asymptomatic patients with unilateral middle cerebral artery severe stenosis or occlusion. A total of 64 consecutive patients with unilateral middle cerebral artery severe stenosis or occlusion admitted to the First Affiliated Hospital of Xinxiang Medical College from January 2019 to March 2022 were retrospectively analyzed and divided into the symptomatic group (n = 33), and the asymptomatic group (n = 31). Clinical data of the two groups were collected. Multivariate logistic regression analysis was performed to analyze the factors of symptomatic and asymptomatic MCA stenosis. A t-test was performed to compare the differences in cerebral perfusion parameters between the two groups. Multivariate logistic regression analysis indicated that glycosylated hemoglobin levels and high-density lipoprotein cholesterol levels were associated with the development of asymptomatic MCA severe stenosis or occlusion (odds ratio = 1.591 and 0.04, respectively). There were significant differences in CBV, MTT, and TTP between symptomatic and asymptomatic groups (p < 0.05). The CBF of the affected side in the symptomatic group was lower than that of the unaffected side (p < 0.05), whereas the asymptomatic group in CBF was not. Compared with the asymptomatic group, the CBF, MTT, and TTP of the affected side were significantly different (p < 0.05). In contrast, the cerebral perfusion parameters of the unaffected side were not significantly different (p > 0.05). The use of CT perfusion imaging to analyze the alterations in cerebral perfusion parameters in patients with symptomatic and asymptomatic MCA severe stenosis or occlusion was helpful in clinical diagnosis and selecting treatment strategies and judging the development of the disease.

Multi-assessment of critical steno-occlusive middle cerebral arteries: transcranial Doppler combined with magnetic resonance angiography

BackgroundAccurate assessment of a stenotic or occluded middle cerebral artery (MCA) is essential before making optimal therapeutic decisions. However, complete occlusion is not always easy to determine for both magnetic resonance angiography (MRA) and neurologists. We aimed to study noninvasive technology using transcranial Doppler (TCD) combined with MRA to assess severe stenosis and occlusion of the MCA. MethodsWe studied consecutive patients with severe steno-occlusive MCA by digital subtraction angiography from Oct. 2011 to Mar. 2020 in our stroke center. Hemodynamic measurements of TCD, including peak velocity (PSV), mean flow velocity (MFV) and pulse index (PI), were recorded specifically at the steno-occlusive site by MRA. ResultsA total of 152 MCAs of 148 patients were enrolled (60.0 ± 11.5 y, 107 male), including 82 severe stenotic MCAs and 70 occluded MCAs (Group S & Group O) by DSA. There were 86/152 (57%) MCAs showing discontinuity in MRA, which was significantly distributed more in Group O than in Group S (84% vs. 33%, P < 0.001). The PSV and MFV in Group S were greater (264 ± 78 cm/s vs. 33 ± 34 cm/s and 182 ± 61 cm/s vs. 21 ± 23 cm/s, respectively, P < 0.001), while the PI in Group O was greater (0.98 ± 0.49 vs. 0.72 ± 0.17, P < 0.001). PSV was positively correlated with severe MCA stenosis (β = 0.036, P < 0.001, OR = 0.965, 95% confidence interval (CI): 0.952–0.978). In severe steno-occlusive MCA, using PSV and MFV to detect MCA severe stenosis yielded areas under the curve of 0.983 (CI: 0.964–1.0) and 0.982 (CI: 0.962–1.0), respectively. The cutoff points of PSV ≥ 77 cm/s and MFV ≥ 51 cm/s both yielded an optimized sensitivity of 96.3% and specificity of 98.6%. ConclusionThe critical velocity at the steno-occlusive site is reliable for distinguishing between severe MCA stenosis and occlusion.

Evaluation of collateral status and outcome in patients with middle cerebral artery stenosis in late time window by CT perfusion imaging.

ObjectivesCollateral status (CS) is a crucial determinant of outcome in patients with ischemic stroke. We aimed to test whether the cerebral blood volume (CBV) and cerebral blood flow (CBF) based on computed tomography perfusion (CTP) measurements can quantitatively evaluate CS and explore the predictive ability of CTP parameters in determining clinical outcomes in patients with MCA severe stenosis or occlusion presenting beyond 24 h.Materials and methodsIn this retrospective study, data obtained from September 2018 to March 2022 in consecutive stroke patients caused by isolated middle cerebral artery severe stenosis or occlusion were reviewed within 24–72 h after onset. Correlation between the collateral score systems assessed with CT angiography (CTA) and CTP parameters was calculated using the Spearman correlation. The optimal threshold of the CBV ratio for predicting a good outcome was determined using receiver operating characteristic curve (ROC) analysis.ResultsA total of 69 patients met inclusion criteria. Both the CBV ratio and the CBF ratio had significant correlation with collateral score systems assessed with CTA [CBV ratio and Tan score: rs = 0.702, P < 0.0001; CBV ratio and regional leptomeningeal collateral (rLMC) score: rs = 0.705, P < 0.0001; CBV ratio and Miteff score: rs = 0.625, P < 0.0001. CBF ratio and Tan score: rs= 0.671, P < 0.0001; CBF ratio and rLMC score: rs = 0.715, P < 0.0001; CBF ratio and Miteff score: rs = 0.535, P < 0.0001]. ROC analysis revealed the CBV ratio performed better than the qualitative collateral assessments and the CBF ratio in the prediction of a favorable 90-day modified Rankin scale score. The CBV ratio was a useful parameter that predicted a good functional outcome [area under the curve (AUC), 0.922; 95% CI, 0.862 ± 0.982].ConclusionsIn late time window stroke patients, the CBV and CBF ratio on CTP may be valuable parameters for quantitatively revealing the collateral status after stroke. In addition, the CBV ratio was the predictor of clinical outcomes in patients with MCA severe stenosis or occlusion.

Clinical Study of Endovascular Treatment of Severe Middle Cerebral Artery Stenosis or Occlusion and Vascular Cognitive Impairment

Objective: It is very important to study the factors affecting the incidence, progress and prognosis of patients with vascular dementia. Methods: 50 cases of severe middle cerebral artery stenosis or occlusion underwent endovascular treatment (25 cases of mild cognitive dysfunction, 25 cases of moderate cognitive dysfunction) were divided into two groups, where a medical drug treatment group and a control group established with 25 cases in each group. The cognitive function of each group of patients was evaluated before operation, 7 days after operation, 30 days after operation, and 180 days after operation. CTP was used to compare the hemodynamic changes in patients before and after operation. Results: The severe stenosis or occlusion of the middle cerebral artery in patients can be improved, and the intracranial blood supply of patients with poorly compensated medial cranial circulation and hypoperfusion can be restored to a certain extent. Meanwhile, improvement of cognitive function was definitive in some patients with cognitive dysfunction. Conclusion: To guide the formulation of treatment plans for patients with severe middle cerebral artery stenosis or occlusion.

Analysis of cerebral perfusion of leptomeningeal branch and perforating branch of unilateral middle cerebral artery with severe stenosis or occlusion based on multi-delay arterial spin labeling

Objective: To compare the cerebral perfusion differences between the symptomatic patients and the asymptomatic patients with unilateral middle cerebral artery (MCA) severe stenosis or occlusion by using three post labeling delays (PLD) of the three-dimensional pseudo-continuous arterial spin labeling (pCASL) technique. Methods: The clinical characteristics and ASL data of the 27 patients with severe stenosis or occlusion of unilateral MCA (18 symptomatic, 9 asymptomatic) were prospectively enrolled from April 2018 to November 2019 in the Department of Radiology of China-Japan Friendship Hospital. There were 16 males and 11 females, age range from 29 to 85 (55±13) years. According to the symptoms, they were divided into symptomatic group (18 cases) and asymptomatic group (9 cases). The parameters of cerebral blood flow (CBF), mean cerebral blood flow (mCBF), arterial transit time (ATT) and arterial cerebral blood volume (aCBV) were obtained using the Cereflow software. One-way multivariate analysis of variance (one-way MANOVA) was used to compare the differences of cerebral perfusion parameters between symptomatic group and asymptomatic group, and between the affected side and the control side in the two groups. Two-way ANOVA was used to evaluate the effects of symptoms, hemisphere (affected and control side), PLD times (1.5, 2.0 and 2.5 s) and the interaction between the two factors. Results: The CBF of the affected leptomeningeal branch and perforating branch of MCA in symptomatic group was lower than that in asymptomatic group [(36.8±10.2) ml·100 g-1·min-1 versus (46.6±13.9) ml·100 g-1·min-1, F(1, 75)=13.279, P=0.000 49; (32.3±8.3) ml·100 g-1·min-1 versus (36.2±7.5) ml·100 g-1·min-1, F (1, 75)=4.065, P=0.047], and there was no interaction between the symptom and PLD [F(2, 75) =0.061, P=0.940]. In the symptomatic group, the CBF of the leptomeningeal branch and perforating branch of MCA in affected side was lower than that in control side [(36.8±10.2) ml·100 g-1·min-1 versus (43.7±10.0) ml·100 g-1·min-1, F(1, 102)=12.559, P=0.000 59; (32.3±8.3) ml·100 g-1·min-1 versus (36.4±8.0) ml·100 g-1·min-1, F(1, 102)=6.493, P=0.012]. In the symptomatic group, the CBF of leptomeningeal branch of MCA when PLD was 2.5 s was 7.34 ml·100 g-1·min-1, which were higher than that when PLD of 1.5 s (95%CI: 0.72-13.9, P=0.03). There was no interaction between PLD and hemisphere [F(2, 102) =0.307, P=0.736]. Conclusions: The collateral circulation in the blood supply area of MCA in asymptomatic patients with severe unilateral MCA stenosis or occlusion is more abundant than that in symptomatic patients. ASL can be an effective technique for evaluating the cerebral perfusion of collateral circulation in patients with severe stenosis or occlusion of MCA.

Evaluating the Velocity and Extent of Cortical Venous Filling in Patients With Severe Middle Cerebral Artery Stenosis or Occlusion.

Objective: To investigate the velocity and extent of cortical venous filling (CVF) and its association with clinical manifestations in patients with severe stenosis or occlusion of the middle cerebral artery (MCA) using dynamic computed tomography angiography (CTA).Methods: Fifty-eight patients (36 symptomatic and 22 asymptomatic) with severe unilateral stenosis (≥70%) or occlusion of the MCA M1 segment who underwent dynamic CTA were included. Collateral status, antegrade flow, and CVF of each patient were observed using dynamic CTA. Three types of cortical veins were selected to observe the extent of CVF, and the absence of CVF (CVF-) was recorded. Based on the appearance of CVF in the superior sagittal sinus, instances of CVF, including early (CVF1), peak (CVF2), and late (CVF3) venous phases, were recorded. The differences in CVF times between the affected and contralateral hemispheres were represented as rCVFs, and CVF velocity was defined compared to the median time of each rCVF.Results: All CVF times in the affected hemisphere were longer than those in the contralateral hemisphere (p < 0.05). Patients with symptomatic MCA stenosis had more ipsilateral CVF- (p = 0.02) and more delayed CVF at rCVF2 and rCVF21 (rCVF2-rCVF1) (p = 0.03 and 0.001, respectively) compared to those with asymptomatic MCA stenosis. For symptomatic patients, fast CVF at rCVF21 was associated with poor collateral status (odds ratio [OR] 6.42, 95% confidence interval [CI] 1.37–30.05, p = 0.02), and ipsilateral CVF- in two cortical veins was associated with poor 3-month outcomes (adjusted OR 0.025, 95% CI 0.002–0.33, p = 0.005).Conclusions: Complete and fast CVF is essential for patients with symptomatic MCA stenosis or occlusion. The clinical value of additional CVF assessment should be explored in future studies to identify patients with severe MCA stenosis or occlusion at a higher risk of stroke occurrence and poor recovery.

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.

Bilaterally Asymmetric Associations Between Extracranial Carotid Artery Atherosclerosis and Ipsilateral Middle Cerebral Artery Stenosis in Symptomatic Patients: A CARE-II Study.

To determine the bilaterally asymmetrical associations between extracranial carotid artery atherosclerosis and ipsilateral middle cerebral artery (MCA) stenosis in symptomatic patients using magnetic resonance vessel wall imaging. Approach and Results: Patients with symptomatic carotid artery atherosclerosis were recruited from the Chinese Atherosclerosis Risk Evaluation, a multicenter study. All subjects underwent intracranial magnetic resonance angiography and extracranial carotid artery magnetic resonance imaging. Severe stenosis (stenosis ≥50%) of MCA, carotid moderate-to-severe stenosis (stenosis ≥50%), plaque compositions, and high-risk plaque on symptomatic side were evaluated in all subjects. Associations between ipsilateral MCA stenosis and extracranial carotid plaque features were evaluated. A total of 363 patients (mean age: 61.2±10.4 years old; 254 males) were included. In the left symptomatic cerebrovascular group (n=186), carotid moderate-to-severe stenosis (odds ratio [OR], 3.00 [95% CI, 1.03-8.79]; P=0.045), intraplaque hemorrhage (OR, 3.68 [95% CI, 1.21-11.19]; P=0.021), fibrous cap rupture (OR, 5.70 [95% CI, 1.60-20.31]; P=0.007), and high-risk plaque (OR, 2.95 [95% CI, 1.19-7.35]; P=0.020) were significantly associated with ipsilateral severe MCA stenosis, after adjusting for confounding factors. In the right symptomatic cerebrovascular group (n=177), severe MCA stenosis was significantly associated with ipsilateral carotid moderate-to-severe stenosis (OR, 3.98 [95% CI, 1.54-10.32]; P=0.004) but not with other extracranial carotid plaque features (all P>0.05), after adjusting for confounding factors. In the symptomatic arteries, vulnerable plaque features are independently associated with ipsilateral severe MCA stenosis on the left side, but this association is not found on the right side, indicating the associations of atherosclerotic disease between intracranial and extracranial carotid arteries are asymmetrical.

High-Degree Middle Cerebral Artery Stenosis

PurposeEndovascular treatment in severe middle cerebral artery (MCA) stenosis is controversial owing to high rates of periprocedural complications, especially occlusion of the lenticulostriate arteries (LSA). The characteristics of LSAs and the spatial relationships between MCA plaques and LSAs using the fusion of three-dimensional (3D) digital subtraction angiography (DSA) and magnetic resonance imaging (3D DSA-MRI fusion) were investigated.MethodsWe retrospectively analyzed data from 32 ischemic stroke or transient ischemic attack patients with severe MCA stenosis, who underwent MRI and DSA within 2 weeks after symptom onset. The patients were divided into culprit and non-culprit MCA stenosis groups. The 3D DSA-MRI fusion was performed on dedicated workstations, which allowed automated overlays of the target vessels. The characteristics of LSAs, plaque distribution and lesion patterns, and their relationships were evaluated.ResultsThe 3D DSA-MRI fusion image was able to illustrate the spatial relationships between MCA plaques and LSA orifices. Of 42 LSA stems in 32 patients, 10 had MCA plaque over the LSA orifice and were all found in the culprit MCA stenosis group. Over half (51.9%) of the LSA stems in patients with culprit MCA stenosis originated from the stenotic MCA segment. The MCA plaque-LSA orifice spatial relationships were classified into four types, which were significantly different between the two groups (p = 0.016).ConclusionThe 3D DSA-MRI fusion technique enables visualization of the LSA orifice and MCA plaque and their spatial relationships. This classification of the type of spatial relationships can provide insights into the pathogenesis of MCA stroke and useful guides for treatment strategies.

Association Between Steno-Occlusive Middle Cerebral Artery and Basal Ganglia Perivascular Spaces.

Objectives: Enlarged perivascular spaces in the basal ganglia (BG-EPVS) share common vascular risk factors with atherosclerosis. However, little is known about the relationship between steno-occlusive middle cerebral artery (MCA) and BG-EPVS. In this cross-sectional study, we aimed to test the hypothesis that severe MCA stenosis or occlusion is associated with increased MRI-visible BG-EPVS.Methods: We retrospectively reviewed 112 patients with a steno-occlusive MCA from Fujian Medical University Union Hospital between January 2014 and December 2018. We rated BG-EPVS, white matter hyperintensities (WMH), and lacunes as markers of cerebral small vessel disease (CSVD) on magnetic resonance image (MRI). The severity of steno-occlusive MCA was assessed by computed tomography angiography (CTA) and was classified into moderate (50–69%), severe (70–99%), and occlusion (100%). We evaluated the association of steno-occlusive MCA for >10 BG-EPVS using logistic regression model adjusted for age, gender, hypertension, MR-visible WMH, and lacunes. We also compared the number of BG-EPVS between the affected side and unaffected side in patients with only unilateral steno-occlusive MCA.Results: In multivariable logistic regression analysis, age (OR = 1.07, 95%CI: 1.03–1.13, p = 0.003), hypertension (OR = 2.77, 95%CI: 1.02–7.51, p = 0.046), severe MCA stenosis (OR = 3.65, 95%CI: 1.12–11.87, p = 0.032), or occlusion (OR = 3.67, 95%CI: 1.20–11.27, p = 0.023) were significantly associated with >10 BG-EPVS. The number of BG-EPVS in the affected side was higher than the unaffected side in patients with severe MCA stenosis (12 [9−14] vs. 8 [6−11], p = 0.001) or occlusion (11 [7−14] vs. 8 [5−11], p = 0.028).Conclusions: BG-EPVS were more prevalent in patients with severe MCA atherosclerosis. Our findings suggest a biological link between severe steno-occlusive MCA and increased BG-EPVS. These results need confirmation in prospective studies.

Features of branch occlusive disease-type intracranial atherosclerotic stroke in young patients

BackgroundYoung ischemic stroke patients are common while classification and analysis based upon imaging characteristics are rarely reported. We intend to compare the clinical and MRI characteristics of cerebral stroke induced by intracranial atherosclerosis between young patients with branch occlusive disease (BOD) and those with non-branch occlusive disease (non-BOD) or small artery disease (SAD).MethodsA total of 151 subjects with acute infarction within the middle cerebral artery (MCA) territory were included and patients with ipsilateral internal carotid artery stenosis or cardioembolism were excluded. Based on the distribution characteristics of infarction and the presence of ipsilateral MCA stenosis, the patients were divided into three groups: BOD-striatocapsular area infarction with ipsilateral MCA stenosis; non-BOD -infarction size exceeds the striatocapsular area and accompanied by ipsilateral MCA stenosis; SAD. The clinical and MCA stenosis characteristics of the three groups were compared.ResultsThe number of BOD patients with hypertension was significantly higher than that of SAD (92.9% vs 53.7%, p = 0.000) and non-BOD (92.9% vs 57.1%, p = 0.001); subjects with smoking history significantly exceeded that of SAD (50% vs 26.9%, p = 0.03) and subjects with family history of cardiovascular disease was significantly less than that of non-BOD (14.3% vs 41.1%). Baseline NIHSS scores and mRS scores at discharge in patients with BOD were significantly lower than those with non-BOD (p = 0.000, p = 0.001). Majority of patients in non-BOD group displayed severe MCA stenosis (39 cases, 69.6%) while that in BOD group displayed mild stenosis (26 cases, 92.9%), and the difference was statistically significant (p = 0.000). Compared with non-BOD group, the stenosis in BOD group located at a relatively distal end in the M1 segment of MCA (S/M1, 58% vs 40%, p = 0.000) and was more localized (stenosis level/ (SL/M1), 1.86 (1.35–2.6) vs 2.9 (2.0–5.0), p = 0.002).ConclusionBOD in young patients with ischemic stroke induced by intracranial atherosclerosis is not rare (33.3%) and its clinical manifestations and prognosis are similar to those of SAD. This may be related to the mild localized stenosis at the distal end in the M1 segment of MCA. Control of hypertension might play a positive role in secondary prevention.

Fewer peripheral asymmetrical cortical veins is a predictor of favorable outcome in MCA infarctions with SWI-DWI mismatch.

Outcome prediction of asymmetrical prominent cortical veins (APCVs) on infarction is still debated and may help in selecting patients for reperfusion treatment. To explore the relationship between fewer peripheral APCVs and the outcome in the patients of acute/subacute middle cerebral artery (MCA) infarctions as well as the relationship between this sign and stenosis of ipsilateral MCA. Retrospective case-control study. We enrolled 41 patients with MCA acute/subacute infarction. Compared to the low sign of cortical veins of contralateral hemisphere on susceptibility-weighted imaging (SWI), these patients were divided into fewer (n = 28) and prominent APCVs (n = 13) groups. 3.0T conventional stroke sequences, including T1 -weighted imaging, T2 -weighted imaging, fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI) (b = 0 and 1000 s/mm2 ), MR angiography (MRA), and SWI. We explored the relationships between fewer peripheral APCVs sign and clinical outcome, as well as the relationship between this sign and the degree of ipsilateral MCA stenosis. Fisher's exact analysis, logistical regression, as well as Cohen's kappa coefficient were used for statistical analysis. Fewer and prominent peripheral APCVs were detected in 28 (56.10%) and 13 (43.90%) patients. In 28 patients with fewer peripheral APCVs, 23 patients (82.14%) had a favorable outcome (modified Rankin Scale [mRS] ≤2), and five patients (17.76%) had an unfavorable outcome (mRS >2) (P = 0.010). In terms of MCA stenosis, the rate of normal and mild to moderate stenosis of MCA in the fewer APCVs group (82.14%) was higher than that in the prominent APCVs group (23.08%) (P < 0.001). More severe stenosis of ipsilateral MCA was found in patients with prominent APCVs group (76.92%) than that of fewer APCVs group (17.86%). The peripheral APCVs was positively correlated with the degree of MCA stenosis (r = 0.538, P < 0.001). Fewer peripheral APCVs may suggest a favorable outcome in unilateral MCA infarction. The patency of ipsilateral MCA may correlate to fewer APCVs and favorable outcome. 3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;48:964-970.

Abstract WMP110: Improvement in Cortical Versus Subcortical Perfusion After Superficial Temporal Artery- Middle Cerebral Artery (MCA) Bypass in Patients With Severe Stenosis of Intracranial Carotid and MCA

Background and Objective: The role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We have recently reported the improvement in clinical and various cerebral hemodynamic parameters after STA-MCA bypass surgery for severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR). Using acetazolamide challenged hexamethylpropyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT), we evaluated the differential improvement in metabolic perfusion in cortical and subcortical structures after STA-MCA bypass surgery. Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) for CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged SPECT and STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent SPECT at 4±1 months. Using automated image analyzer, we evaluated differences in metabolic perfusion in cortical and subcortical regions. Results: Of the 126 patients (80 male, mean age 56yrs; range 23-78yrs) that fulfilled our inclusion criteria, 84 (67%) showed impaired CVR on SPECT. Fifty (60%) of them underwent STA-MCA bypass surgery. HMPAO-SPECT repeated 4±1 months after surgery showed significant improvement in all cases. Significantly better improvement (14.5%) in cerebral perfusion was noted in the cortical regions as compared to the subcortical regions (4.5%, p&lt;0.005). Conclusion: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in cerebral perfusion, especially in the cortical regions.

Dynamic Cerebral Autoregulation in Asymptomatic Patients With Unilateral Middle Cerebral Artery Stenosis.

The aim of the study was to assess the capacity of dynamic cerebral autoregulation (dCA) in asymptomatic patients with unilateral middle cerebral artery (MCA) stenosis.Fifty-seven patients with asymptomatic mild, moderate, and severe unilateral MCA stenosis and 8 patients with symptomatic severe unilateral MCA stenosis diagnosed by transcranial Doppler were enrolled. Twenty-four healthy volunteers served as controls. The noninvasive continuous cerebral blood flow velocity and arterial blood pressure were recorded simultaneously from each subject in the supine position. Transfer function analysis was applied to determine the autoregulatory parameters (phase difference [PD] and gain).The PD values in the severe stenosis groups were significantly lower than those of the control group (60.71 ± 18.63°), the asymptomatic severe stenosis group was impaired ipsilaterally (28.94 ± 27.43°, P < 0.001), and the symptomatic severe stenosis group was impaired bilaterally (13.74 ± 19.21°, P < 0.001; 19.68 ± 14.50°, P = 0.006, respectively). The PD values in the mild and moderate stenosis groups were not significantly different than the controls (44.49 ± 27.93°; 48.65 ± 25.49°, respectively). The gain values in the mild and moderate groups were higher than in the controls (1.00 ± 0.58 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, and 1.20 ± 0.59 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, respectively). The gain values in the severe stenosis groups were significantly lower than that in the control group: the asymptomatic severe stenosis group was lower bilaterally (0.56 ± 0.32 cm/s/mm Hg, P = 0.003; 0.60 ± 0.32 cm/s/mm Hg, P < 0.05, respectively), whereas the symptomatic severe group was lower unilaterally (on the contralateral side) (0.53 ± 0.43 cm/s/mm Hg, P < 0.05).In asymptomatic patients with unilateral MCA stenosis, only the dCA of the severe stenosis was ipsilaterally impaired. Acute stroke may aggravate the impaired dCA and even spread contralaterally.

Superficial temporal artery-to-middle cerebral artery bypass surgery for middle cerebral artery stenosis in a patient with cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy

Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy is a rare hereditary small vessel disease. Ischemic events are the main clinical manifestation of this condition. Here, we present a case in which superficial temporal artery-to-middle cerebral artery anastomosis was performed in a patient with cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy who developed cerebral infarctions caused by severe middle cerebral artery stenosis. Cerebral blood flow and cerebrovascular reactivity were effectively improved using double anastomoses. To our knowledge, surgical revascularization for patients with this condition has not yet been described in the literature. Superficial temporal artery-to-middle cerebral artery anastomosis is effective for patients with cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy who show marked regional cerebral hypoperfusion.

Hemodynamic alterations in unilateral chronic middle cerebral artery stenosis patients and the effect of percutaneous transluminal angioplasty and stenting: a perfusion-computed tomography study.

The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial indicated that most patients with symptomatic intracranial atherosclerosis are not good candidates for percutaneous transluminal angioplasty and stenting (PTAS) because of a higher complication risk than with conservative treatment. However, enrollment of SAMMPRIS patients was based on lesion severity only, without functional imaging. To determine whether perfusion computed tomography (PCT) can effectively evaluate hemodynamic compromise in unilateral chronic middle cerebral artery stenosis and the alterations of hemodynamics after PTAS. In this prospective study, 89 patients with unilateral middle cerebral artery (MCA) stenosis/occlusion were enrolled and classified into four groups according to the degree of stenosis. Cerebral hemodynamics was evaluated by measuring cerebral blood flow (CBF), cerebral blood volume (CBV), and time to peak (TTP) in the ipsilateral and contralateral hemispheres by PCT before and after intervention with PTAS. Differences in hemodynamic parameters before and after intervention were analyzed. Three different hemodynamic patterns were observed in these patients. Patients with severe MCA stenosis (70-99%) or MCA occlusion demonstrated a significant increase of ipsilateral CBV and TTP, indicating hemodynamic compromise. Ten severe stenosis patients with recurrent ischemic symptoms despite of maximal conservative therapy were selected for PTAS. PTAS induced a rapid recovery of cerebral hemodynamics (especially TTP) at 1 week post intervention. PCT appears to be a valuable noninvasive technique to evaluate hemodynamic compromise in unilateral chronic MCA stenosis and the improvements after PTAS.

Specific Shrinkage of Carotid Forks in Moyamoya Disease: A Novel Key Finding for Diagnosis.

This study was aimed to analyze the outer diameter of the involved arteries in moyamoya disease, using three-dimensional (3D) constructive interference in steady state (CISS) and direct surgical inspection. Radiological evaluation was performed in 64 patients with moyamoya disease. As the controls, six patients with severe middle cerebral artery (MCA) stenosis and 17 healthy subjects were also recruited. On 3D-CISS, the outer diameter was quantified in the supraclinoid portion of internal carotid artery (C1), the horizontal portions of MCA (M1) and anterior cerebral artery (A1), and basilar artery. The involved carotid fork was directly observed during surgery in another series of three adult patients with moyamoya disease. In 53 adult patients with moyamoya disease, the outer diameters of C1, M1, and A1 segments were 2.3 ± 0.7 mm, 1.3 ± 0.5 mm, and 1.0 ± 0.4 mm in the involved side (n = 91), being significantly smaller than the control (n = 17), severe M1 stenosis (n = 6), and non-involved side in moyamoya disease (n = 15, P < 0.01). There were significant correlations between Suzuki’s angiographical stage and the outer diameters of C1, M1, and A1 (P < 0.001). The laterality ratio of C1 and M1 was significantly smaller in unilateral moyamoya disease (n = 20) than the controls and severe MCA stenosis (P < 0.01). Direct observations revealed a marked decrease in the outer diameter of the carotid fork (n = 3). These findings strongly suggest specific shrinkage of the involved arteries in moyamoya disease, which may provide essential information to distinguish moyamoya disease from other intracranial arterial stenosis and shed light on the etiology and novel diagnosis cue of moyamoya disease.

Mechanism of Acute Ischemic Stroke in Patients with Severe Middle Cerebral Artery Atherosclerotic Disease

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of ischemic stroke worldwide. Although the pathogenesis of cerebral infarct in ICAD has been reported from autopsy series, the mechanism of stroke is not well known. This study used baseline perfusion imaging and diffusion-weighted imaging (DWI) or computerized tomography (CT) imaging to help identify the mechanism of stroke in ICAD involving the middle cerebral artery (MCA). We retrospectively reviewed baseline CT or magnetic resonance (MR) perfusion studies and diffusion-weighted MR imaging or CT scans in patients with severe symptomatic MCA stenosis. Perfusion scans were classified according to stage of perfusion deficit, and the acute stroke patterns were categorized as borderzone, cortical, or perforating artery infarcts according to DWI or noncontrast CT. Fifteen patients were included in this analysis. All 15 patients had some type of borderzone infarct. Six had borderzone infarct only, 4 had borderzone and cortical infarcts, and 5 had borderzone, cortical, and perforating artery infarcts. Thirteen of the 15 patients had baseline perfusion deficits. In patients with severe MCA ICAD, the mechanism of stroke is multifactorial, but hemodynamic insufficiency plays a significant role. This finding is important in selecting a subgroup of patients who may benefit from revascularization.