Prevalence and Characteristics of Symptomatic Intracranial Atherosclerotic Plaques in People Residing at Middle and High Altitudes: A Preliminary Study.

BACKGROUND: This study aims to determine how atherosclerotic plaque prevalence and characteristics vary between individuals residing year-round at middle and high altitudes who have intracranial atherosclerotic disease. METHODS: We conducted a retrospective analysis of patient data from our hospital, focusing on individuals with cerebrovascular symptoms who underwent high-resolution vessel wall imaging (HR-VWI). Patients who had lived at an altitude of <2500 meters for an extended period were classified in group A (n = 91), while those residing at an altitude of ≥2500 meters were placed in group B (n = 75). We examined the differences in plaque prevalence and characteristics between these two groups. RESULTS: The detection rate of basilar artery plaque was higher in group A compared to group B (16% vs. 7.6%, p = 0.036). Conversely, the detection rate of anterior cerebral artery plaque was significantly lower in group A than in group B (4% vs. 11.8%, p = 0.016). The eccentricity index (EI) was greater in group B than in group A (0.72 ± 0.11 vs. 0.68 ± 0.12, p = 0.012). The prevalence of intraplaque hemorrhage (IPH) was lower in group B than in group A (39.5% vs. 58.7%, p = 0.002). CONCLUSIONS: IPH prevalence was lower in patients residing at high altitudes than in those residing at middle altitudes. However, patients living at high altitudes had a higher EI compared to those residing at middle altitudes. These findings underscore the presence of disparities in the prevalence and characteristics of intracranial atherosclerotic plaques between individuals residing at medium and high altitudes. It is essential to account for these distinctions when diagnosing plaques.

Atherosclerosis as a Potential Cause of Deep Embolic Stroke of Undetermined Source: A 3T High-Resolution Magnetic Resonance Imaging Study.

Background The potential causes or sources of embolic stroke of undetermined source (ESUS) vary. This study aimed to investigate the main cause of deep ESUS by evaluating nonstenotic intracranial atherosclerotic plaque. Methods and Results We retrospectively screened consecutive patients with unilateral anterior circulation ESUS. After excluding the patients with possible embolism from an extracranial artery such as aortic arch plaque, carotid plaque, and so on, the enrolled patients with ESUS were categorized into 2 groups: deep ESUS and cortical with/without deep ESUS. All patients underwent intracranial high-resolution magnetic resonance imaging to assess the characteristics of nonstenotic intracranial atherosclerotic plaque. Biomarkers of atrial cardiopathy (ie, P-wave terminal force in lead V1 on ECG, NT-proBNP [N-terminal pro-brain natriuretic peptide] and left atrial diameter) were collected. A total of 155 patients with ipsilateral nonstenotic intracranial atherosclerotic plaque were found, with 76 (49.0%) in deep ESUS and 79 (51.0%) in cortical with/without deep ESUS. We found more prevalent plaque in the M1 segment of the middle cerebral artery and the ostia of the perforator, with a smaller remodeling index plaque burden, and less frequent occurrence of complicated plaque in deep ESUS versus cortical with/without deep ESUS. Higher BNP (brain natriuretic peptide) levels and a higher prevalence of atrial cardiopathy in cortical with/without deep ESUS versus deep ESUS. Moreover, the discrimination of vulnerable plaque for predicting ESUS was significantly enhanced after adjusting for or further excluding patients with deep ESUS. Conclusions The current study provides the first high-resolution magnetic resonance imaging evidence that cortical with/without deep ESUS and deep ESUS should be 2 distinct entities and that atherosclerosis, not embolism, might be the main cause of deep ESUS.

Intracranial atherosclerosis in ischemic stroke with posterior circulation: A high-resolution magnetic resonance imaging study / 中国脑血管病杂志

Objective: To explore the characteristics of intracranial atherosclerosis and possible pathogenesis of posterior circulation ischaemic stroke by 3. 0 T high-resolution magnetic resonance imaging. Methods: The imaging and clinical features of intracranial atherosclerosis in 21 patients with posterior ischemic symptoms admitted in the Department of Neurology of Hebei General Hospital from December 2016 to December 2018 were retrospectively analyzed. The recruited patients were divided into the posterior circulation ischemic stroke group(10cases and 45 plaques) and the non-stroke group(11 cases and 25 plaques) according to their clinical symptoms, signs and imaging manifestations. Clinical data of all patients were collected, and high-resolution 3D time-of-flight MR angiography was used to evaluate the degree of vascular stenosis. Also, plaque characteristics including burden, enhancement, hyperintensity and morphology were counted on high-resolution Tl weighted imaging axial images. Results: The The proportion of diabetes was significantly different between the two groups (P = 0. 024). There were no significant differences in age, sex, smoking, alcohol consumption, hypertension, hyperuricemia, hyperlipidemia, hyperhomocysteinemia, stroke history and history of coronary atherosclerotic heart disease between the two groups (all P > 0. 05). The plaque burden in the posterior circulation ischemic stroke group was higher than that in the non-stroke group ([4. 5 ±1.6] vs. [2. 3 ±1.6]) with significant difference (t = 3. 190, P = 0.005). Plaque enhancement between the two groups was significant different (40.0% [18/45] vs. 16. 0% [4/25], X2 =4. 295, P = 0. 038). There was no significant difference in plaque high signal and plaque morphology between the two groups(all P > 0. 05). Conclusion: Patients in the posterior ischemic stroke group had a higher prevalence of diabetes, and intracranial atherosclerotic plaque burden and plaque enhancement were more common, suggesting that the posterior ischemic stroke group had a higher vulnerability of plaque.

Intracranial atherosclerotic plaque enhancement associated with ischemic stroke: a study with three-dimensional high-resolution magnetic resonance vessel wall imaging / 复旦学报（医学版）

Objective To evaluate the reproducibility of three-dimensional high-resolution magnetic resonance imaging (HR-MRI) for vessel wall in demonstration of intracranial atherosclerotic plaque enhancement and to explore the relationship between plaque enhancement and ischemic stroke.Methods Fifty-two patients with ischemic stroke underwent traditional head MRI,three-dimensional time of flight magnetic resonance angiography and HR-MRI on a 3.0 T MRI scanner.Each identified intracranial plaque was classified as either culprit (the only or most stenotic lesion upstream from a stroke) or non-culprit (not the most stenotic lesion upstream from a stroke or not within the vascular territory of a stroke).The degree of plaque enhancement was graded by two independent radiologists.The degree of plaque enhancement and luminal stenosis were compared between the culprit group and the non-culprit group by using Mann-Whitney U test.Binary logistic regression analysis was performed to assess the relation between the degree of plaque enhancement and culprit plaques.Results Total 118 plaques were identified in 52 patients with ischemic stroke (52 culprit plaques and 66 non-culprit plaques).The degree of enhancement was rated as strong,moderate and none in 40,9 and 3 culprit plaques,and in 4,24 and 38 non-culprit plaques.Both intra-observer and inter-observer agreement were high for identification of plaque enhancement (kappa＞ 0.75).For culprit plaques group,the degree of plaque enhancement(Z =-7.787,P＜0.01) and luminal stenosis (Z =-5.327,P＜0.01) were significantly higher than those in the non-culprit group.Binary logistic regression analysis revealed that strong enhancement of plaques was independently associated with culprit plaques (OR:74.3,95％CI:15.0-367.1,P＜0.01).Conclusions Three-dimensional HR-MRI detects enhancement of intracranial plaques with high reproducibility.Enhancement is more common in culprit plaques and is associated with the likelihood of ischemic stroke.

Evaluating the relationship between intracranial atherosclerotic plaque stability and stroke recurrence risk with high-resolution MRI / 中国脑血管病杂志

Objective To investigate the relationship between intracranial atherosclerotic plaque stability and stroke recurrence risk.Methods Forty-eight patients with acute ischemic stroke caused by intracranial atherosclerosis in Guangdong Province Hospital of TCM were analyzed retrospectively.After the Essen Stroke Risk Scale (ESRS) was used to assess the risk factors for the patients,they were divided into either an ESRS ≥3 group (n=21 in the high-risk recurrence group) or an ESRS <3 group (n=27 in the low-risk recurrence group).Both groups of patients underwent high-resolution MR imaging (HR-MRI) examinations of the intracranial guilty vessels (basilar artery or unilateral middle cerebral artery).According to the signal intensity of HR-MRI on the T1-weighted imaging,T2-weighted imaging,and T1 fat suppression sequences,the intracranial atherosclerotic stable plaques and unstable plaques were distinguished.The stabilization of intracranial atherosclerotic plaques was compared in patients of both groups.Results There were significant differences in the age and incidences of hypertension,diabetes mellitus,and unstable plaques in patients of both groups (P<0.05).Further multivariate logistic regression analysis of the four factors showed that the age,hypertension,diabetes,and intracranial atherosclerotic unstable plaques were the high-risk factors for recurrent ischemic stroke (ORs,87.114,159.423,8.942,and 11.551,respectively;95%CIs 4.218-1 799.078,3.235-7 855.957,1.054-75.857,and 1.011-132.043,respectively;all P<0.05).Conclusion In addition to the traditional risk factors such as age,hypertension,and diabetes,the intracranial atherosclerotic unstable plaque is an independent risk factor for high-risk recurrence of ischemic stroke.