Histopathologic evaluation of basilar artery atherosclerosis

Hemodynamic Impairment of Blood Pressure and Stroke Mechanisms in Symptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND

Hemodynamic impairment of blood pressure may play a crucial role in determining the mechanisms of stroke in symptomatic intracranial atherosclerotic stenosis). We aimed to elucidate this issue and assess the impacts of modifications to blood pressure on hemodynamic impairment.

METHODS

From the Third China National Stroke Registry III, computed fluid dynamics modeling was performed using the Newton-Krylov-Schwarz method in 339 patients with symptomatic intracranial atherosclerotic stenosis during 2015 to 2018. The major exposures were translesional systolic blood pressure (SBP) drop and poststenotic mean arterial pressure (MAP), and the major study outcomes were cortex-involved infarcts and borderzone-involved infarcts, respectively. Multivariate logistic regression models and the bootstrap resampling method were utilized, adjusting for demographics and medical histories.

RESULTS

In all, 184 (54.3%) cortex-involved infarcts and 70 (20.6%) borderzone-involved infarcts were identified. In multivariate logistic model, the upper quartile of SBP drop correlated with increased cortex-involved infarcts (odds ratio, 1.92 [95% CI, 1.03-3.57]; bootstrap analysis odds ratio, 2.07 [95% CI, 1.09-3.93]), and the lower quartile of poststenotic MAP may correlate with increased borderzone-involved infarcts (odds ratio, 2.07 [95% CI, 0.95-4.51]; bootstrap analysis odds ratio, 2.38 [95% CI, 1.04-5.45]). Restricted cubic spline analysis revealed a consistent upward trajectory of the relationship between translesional SBP drop and cortex-involved infarcts, while a downward trajectory between poststenotic MAP and borderzone-involved infarcts. SBP drop correlated with poststenotic MAP negatively (rs=-0.765; P<0.001). In generating hemodynamic impairment, simulating blood pressure modifications suggested that ensuring adequate blood pressure to maintain sufficient poststenotic MAP appears preferable to the reverse approach, due to the prolonged plateau period in the association between the translesional SBP drop and cortex-involved infarcts and the relatively short plateau period characterizing the correlation between poststenotic MAP and borderzone-involved infarcts.

CONCLUSIONS

This research elucidates the role of hemodynamic impairment of blood pressure in symptomatic intracranial atherosclerotic stenosis-related stroke mechanisms, underscoring the necessity to conduct hemodynamic assessments when managing blood pressure in symptomatic intracranial atherosclerotic stenosis.

Pericarotid adipose tissue computed tomography attenuation distinguishes different stages of carotid atherosclerotic disease: a cross-sectional study

Background

Carotid atherosclerotic plaque inflammation plays a critical role in guiding the prevention of secondary stroke. Increased perivascular adipose tissue attenuation observed on computed tomography angiography (CTA) may indicate local inflammation. Our objective was to investigate whether pericarotid adipose tissue (PCAT), as a local inflammation biomarker, could distinguish between different stages of carotid atherosclerotic disease plaques.

Methods

We prospectively enrolled 45 consecutive acute stroke patients with carotid artery stenosis from September 2019 to September 2021. We then matched them to non-stroke patients (n=67) and no carotid atherosclerotic disease controls (n=65) based on gender, age, and cardiovascular risk factors. We compared PCAT attenuation, carotid plaque features on CTA, clinical risk factors, and serum inflammatory factors across the different groups. To detect the association of PCAT attenuation with stage of carotid atherosclerotic disease, we used multivariable logistic regression analysis.

Results

Patients with acute stroke had a higher PCAT attenuation (-78.80±11.62 HU) than patients with non-stroke (-89.01±10.81 HU, P<0.001) and no carotid atherosclerotic disease controls (-95.24±10.81 HU, P<0.001). PCAT attenuation was significantly increased in non-stroke patients compared to non-stroke patients over no carotid atherosclerotic disease controls (P=0.004). The association between PCAT attenuation and the stage of carotid atherosclerotic disease was independent of age, gender, cardiovascular risk factors, and CTA plaque characteristics. No interaction was observed between clinical features and CTA plaque characteristics on PCAT attenuation.

Conclusions

PCAT attenuation, which is an imaging biomarker of local inflammation, independently distinguishes patients with different stages of carotid atherosclerotic disease. Quantitative evaluation of PCAT attenuation in carotid atherosclerotic disease is expected to guide targeted surgical treatment of carotid plaque.

Incidental findings in cone beam computed tomography volumes: Calcified head-and-neck atheromas detected during dental evaluation

PURPOSE

Atheromas can be detected incidentally in routine dental cone beam computed tomography (CBCT) images. This study aims to assess prevalence and risk factors associated with these vascular lesions.

MATERIALS AND METHODS

The maxillofacial CBCTs of 458 subjects were evaluated and divided into 4 groups based on the presence of calcified atheroma: subjects with no calcified atheroma, subjects with intracranial calcified atheroma (ICA), subjects with extracranial calcified atheroma (ECA), and subjects exhibiting combined lesions. Age, sex, medical conditions, family history, and size were documented. Analysis of variance followed by a multiple comparison test was used for data satisfying parametric test assumptions. Chi-squared tests were used to assess categorical data. The Spearman Rho test was used to assess the correlation between the incidence of calcified atheroma and subjects' medical condition.

RESULTS

Of the 458 CBCTs evaluated, 29.90% presented with calcified atheroma. Calcified atheroma prevalence was significantly higher in older patients versus younger patients (p = 0.004) and in males compared to females (p = 0.004). Males were more likely to have the combination of ICA and ECA, whereas females were more likely to have ICA alone (p ≤ 0.040). Patients with calcified atheroma were significantly more likely to have a history of hyperlipidemia (p = 0.001), hypertension (p = 0.001), and myocardial infarction/coronary artery diseases (p = 0.001). Overall, patients exhibiting both intracranial and extracranial lesions were more likely to have cardiovascular risk factors (p = 0.001).

CONCLUSION

Incidentally detected calcified atheromas in CBCTs are common. Subjects with combined atheroma lesions are at higher risk for cardiovascular disease. The diagnosis of incidental calcified atheromas in CBCT's warrants early referral to medical specialists, especially if there is no medical history of existing cardiovascular disease.

CCL14 exacerbates intraplaque vulnerability by promoting neovascularization in the human carotid plaque

OBJECTIVE

To examine the role of CCL14 in the neovascularization process and vulnerability progression within carotid plaques by investigating the mechanism of CCL14 regulation of VEGF-A.

METHODS

We first performed histological analysis and immunohistochemical staining of human carotid plaque tissue to detect the expression of CCL14, JAK2, STAT3 and VEGF-A. We next examined the protein expression of CCL14, VEGF-A, JAK2, STAT3, and phosphorylation of JAK2 and STAT3 in human carotid atherosclerotic plaques by Western blotting. Finally, we performed in vitro culture of human umbilical vein endothelial cells (HUVEC). In the tube formation assay of HUVEC, we added CCL14 siRNA or VEGF-A siRNA to the culture medium using lentiviral transfection to knock down CCL14 or VEGF-A and grouped them for control assays, and detected the changes in the expression of the above proteins using Western blotting.

RESULTS

Histological and Western blotting analysis of human carotid plaque samples showed that the expression of CCL14 and VEGF-A was higher in the vulnerable plaques than in stable plaques. In the in vitro cultures of HUVEC, CCL14 was found to increase the number and length of intercellularly generated tubular structures. CCL14 increases VEGF-A expression via activating JAK2/STAT3 signaling.

CONCLUSION

In the human carotid plaques, CCL14 promotes angiogenesis by upregulation of VEGF-A via JAK2/STAT3 pathway and thus drives the progression of carotid plaques vulnerability.

Intracranial Arterial Calcification: Prevalence, Risk Factors, and Consequences: JACC Review Topic of the Week

Intracranial large and small arterial calcifications are a common incidental finding on computed tomography imaging in the general population. Here we provide an overview of the published reports on prevalence of intracranial arterial calcifications on computed tomography imaging and histopathology in relation to risk factors and clinical outcomes. We performed a systematic search in Medline, with a search filter using synonyms for computed tomography scanning, (histo)pathology, different intracranial arterial beds, and calcification. We found that intracranial calcifications are a frequent finding in all arterial beds with the highest prevalence in the intracranial internal carotid artery. In general, prevalence increases with age. Longitudinal studies on calcification progression and intervention studies are warranted to investigate the possible causal role of calcification on clinical outcomes. This might open up new therapeutic directions in stroke and dementia prevention and the maintenance of the healthy brain.

Characteristics of basilar artery atherosclerotic plaques in pontine infarctions: A high-resolution magnetic resonance imaging study

•

This study used a 3.0T high-resolution magnetic resonance imaging to explore basilar artery plaque characteristics in patients suffering from acute isolated pontine infarction.

•

The study also used plaque analysis software to calculate the properties of the plaques and to fully analyze and compare the differences between two types of pontine infarction.

•

The result may account for the different prognosis associated with these two types of pontine infarction.

Objective

This study used a 3.0T high-resolution magnetic resonance imaging approach to explore basilar artery plaque characteristics in patients suffering from acute isolated pontine infarction.

Materials and methods

30 consecutive patients suffering from acute isolated pontine infarction were enrolled in this study and underwent examinations including high-resolution MRI assessment of the basilar artery within 7 days following infarction.

Results

The basilar artery plaque burden of 16 patients with paramedian pontine infarction was 0.26±0.085, while the reconstruction index and enhancement rate index values in these patients were 1.097±0.133 and 1.750±0.447, respectively. In the 14 patients suffering from deep pontine infarction, these three values were 0.21±0.055, 0.896±0.223, and 1.285±0.611, respectively.These values differed significantly when comparing patients suffering from paramedian pontine infarction to those suffering from deep pontine infarction.

Conclusion

This study suggests that the characteristics of basilar artery plaques differ between the two subtypes of pontine infarctions, which may account for the differences in prognosis associated with these two infarct subtypes.

Vertebral Artery Stenoses Contribute to the Development of Diffuse Plaques in the Basilar Artery

Vertebral artery (VA) stenosis is relevant to a high early risk of recurrent stroke and basilar artery (BA) is the most common intracranial site of atherosclerotic lesions. It is important to show predictive risk factors for transient ischemic attack (TIA) or posterior infarctions. The aim of the study is to investigate morphometry and hemodynamics in intracranial vertebral and basilar arteries of health and diseased patients to enhance the risk assessment. Based on the geometrical model reconstructed from CTA images in 343 patients, a transient three-dimensional computational model was used to determine the hemodynamics. Patients were classified in symmetric, asymmetric, hypoplastic, and stenotic groups while patients in the stenotic group were divided into unilateral, bilateral, bifurcation, and tandem stenotic sub-groups. Patients in bilateral, bifurcation, and tandem stenotic sub-groups had significantly lower basilar artery diameters than other groups. Patients in the stenotic group had significantly higher surface area ratio (SAR) of high time-averaged wall shear stress gradient (TAWSSG) and higher incidence of TIAs or posterior infarctions than other groups while patients in the tandem stenotic sub-group had the highest values (SAR-TAWSSG of 57 ± 22% and TIAs or posterior infarction incidence of 54%). The high SAR-TAWSSG is predisposed to induce TIAs or posterior infarction.

Intracranial atherosclerotic disease

Intracranial atherosclerosis (ICAS) is a progressive pathological process that causes progressive stenosis and cerebral hypoperfusion and is a major cause of stroke occurrence and recurrence around the world. Multiple factors contribute to the development of ICAS. Angiography imaging techniques can improve the diagnosis of and the selection of appropriate treatment regimens for ICAS. Neither aggressive medication nor endovascular interventions can eradicate stroke recurrence in patients with ICAS. Non-pharmacological therapies such as remote ischemic conditioning and hypothermia are emerging. Comprehensive therapy with medication in combination with endovascular intervention and/or non-pharmacological treatment may be a potential strategy for ICAS treatment in the future. We summarized the epidemiology, pathophysiological mechanisms, risk factors, biomarkers, imaging and management of ICAS.

Association of severity between carotid and intracranial artery atherosclerosis

Objective

This study sought to investigate the relationship of atherosclerosis between intracranial and extracranial carotid arteries using three‐dimensional multicontrast magnetic resonance (MR) vessel wall imaging.

Methods

Patients with recent cerebrovascular symptoms in anterior circulation were recruited and underwent MR vessel wall imaging for intracranial and extracranial carotid arteries. The plaque burden, including maximum wall thickness (Max WT) and stenosis, and presence of intraplaque hemorrhage (IPH) were assessed. The correlation of the plaque characteristics between intracranial and extracranial carotid arteries was determined.

Results

In total, 107 patients (mean age: 57.0 ± 11.1 years, 69 males) were recruited. In discriminating intracranial severe stenosis (≥50% stenosis), the odds ratio (OR) of Max WT of extracranial carotid arteries was 1.41 (95% confidence interval [CI], 0.94–2.11, P = 0.095) and 1.72 (95% CI, 1.04–2.83, P = 0.034) before and after adjusting for confounding factors, respectively. The OR of stenosis of extracranial carotid arteries with increment of 10% was 1.26 (95% CI, 0.99–1.60, P = 0.054) and 1.37 (95% CI, 1.03–1.82, P = 0.033) before and after adjusting for confounding factors, in discriminating intracranial severe stenosis respectively. Receiver operating characteristic analysis revealed that the area under the curve (AUC) of Max WT, stenosis, and IPH of extracranial carotid artery plaques was 0.641, 0.605, and 0.603 in discriminating intracranial severe stenosis, respectively. After adjusting for confounding factors, the AUC of Max WT, stenosis, and presence of IPH in extracranial carotid artery plaques increased to 0.812, 0.817 and 0.781, respectively.

Interpretation

Carotid artery plaque burden is significantly associated with severe intracranial artery stenosis, suggesting that extracranial carotid plaque burden might be an independent indicator for severity of intracranial artery atherosclerosis.

Histological Characteristics of Intracranial Atherosclerosis in a Chinese Population: A Postmortem Study

Background

Anterior and posterior circulation atherosclerosis differ in vascular risk factors and stroke mechanisms. However, few studies have compared the pathological features between these lesions. Using a series of intracranial artery specimens, we characterized the intracranial atherosclerotic lesions and compared pathological features among different arteries of the intracranial vasculature.

Methods

Intracranial large arteries of 32 consecutively recruited autopsy cases of Chinese adults aged 45 years or older were examined pathologically using routine histology and immunostaining, to characterize the pathological features of the atherosclerotic lesions. We analyzed middle cerebral arteries (MCAs) (both left and right), vertebral arteries (VAs) (side more affected), and basilar arteries (BAs).

Results

Progressive atherosclerotic lesions were present in 91(71%) of the 128 arteries examined. Features of complicated plaques were infrequently detected: plaque hemorrhage was encountered in 12%, neovasculature in 12%, lumen thrombi in 13%, macrophage infiltration in 20%, and calcification in 25% of arteries. Luminal narrowing of MCA was the most severe, followed by VA; the BA least stenotic (37 ± 25 vs. 30 ± 24 vs. 20 ± 20%, all p < 0.05). MCA had more eccentric (vs. concentric) plaques than VA (69 vs. 25%, p = 0.003) and BA (69 vs. 38%; p = 0.03). Lumen thrombi were more frequent in BA, and calcification most commonly occurred in VA atherosclerotic lesions.

Conclusion

Intracranial atherosclerotic plaques were commonly present in this sample, but the lesions generally lacked features of complicated plaques. MCA lesions had demonstrable differences compared with VA and BA lesions. Further studies are needed to determine whether these characteristics indicate a distinctive atherosclerotic phenotype for the intracranial vasculature.

High-resolution vessel wall MRI for the evaluation of intracranial atherosclerotic disease

High-resolution vessel wall MRI (vwMRI) of the intracranial arteries is an emerging diagnostic imaging technique with the goal of evaluating vascular pathology. vwMRI sequences have high spatial resolution and directly image the vessel wall by suppressing blood signal. With vwMRI, it is possible to identify distinct morphologic and enhancement patterns of atherosclerosis that can provide important information about stroke etiology and recurrence risk. We present a review of vwMRI research in relation to intracranial atherosclerosis, with a focus on the relationship between ischemic stroke and atherosclerotic plaque T1 post-contrast enhancement or plaque/vessel wall morphology. The goal of this review is to provide readers with the most current understanding of the reliability, incidence, and importance of specific vwMRI findings in intracranial atherosclerosis, to guide their interpretation of vwMRI research, and help inform clinical interpretation of vwMRI. We will also provide a translational perspective on the existing vwMRI literature and insight into future vwMRI research questions and objectives. With increased use of high field strength MRI, powerful gradients, and improved pulse sequences, vwMRI will become standard-of-care in the diagnosis and prognosis of patients with cerebrovascular disease, making a firm grasp of its strengths and weakness important for neuroimagers.

Intracranial Atherosclerosis: From Microscopy to High-Resolution Magnetic Resonance Imaging

Intracranial atherosclerosis is one of the leading causes of ischemic stroke and occurs more commonly in patients of Asian, African or Hispanic origin than in Caucasians. Although the histopathology of intracranial atherosclerotic disease resembles extracranial atherosclerosis, there are some notable differences in the onset and severity of atherosclerosis. Current understanding of intracranial atherosclerotic disease has been advanced by the high-resolution magnetic resonance imaging (HRMRI), a novel emerging imaging technique that can directly visualize the vessel wall pathology. However, the pathological validation of HRMRI signal characteristics remains a key step to depict the plaque components and vulnerability in intracranial atherosclerotic lesions. The purpose of this review is to describe the histological features of intracranial atherosclerosis and to state current evidences regarding the validation of MR vessel wall imaging with histopathology.

Pathological Characteristics

Within the intracranial vasculature, atherosclerosis occurs in two distinctive patterns: (1) in Western populations who have severe extracranial and systemic atherosclerosis, the severity of intracranial involvement is consistently less than that within extracranial arteries; and (2) in Asians, Africans, and Hispanics, who often have isolated intracranial arterial disease that is found to be more often accompanied by brain infarction than comparable extracranial atherosclerotic disease. Compared to coronary and extracranial carotid atherosclerosis, intracranial atherosclerosis has distinct pathological characteristics compared to that of extracranial arteries. Intracranial atherosclerosis (ICAS) had been understudied due to the relative inaccessibility of cerebral artery specimens under current treatment strategies. Acquiring post-mortem cerebral vessel specimens for histology processing is the most direct method to analyze the pathological characteristics of ICAS, in order to analyze both lumen stenosis and plaque components contributing to brain infarctions. The developments in high resolution magnetic resonance imaging (HRMRI) make it feasible to assess human ICAS in vivo. It is nevertheless challenging to understand vessel wall changes within brain vasculature demonstrated on HRMRI, as well as to identify biomarkers for stroke risk stratification and treatment strategy modification. Knowledge about intracranial atherosclerosis remains limited due to lack of human arterial specimens, and the development of proper animal models of human cerebral atherosclerosis is necessary to explore the pathogenesis of intracranial atherosclerosis and to assess various strategies preventing or treating ICAS-related stroke.

Evaluation of basilar artery atherosclerotic plaque distribution by 3D MR vessel wall imaging

PURPOSE

Basilar artery (BA) atherosclerosis is an important cause of perforator stroke in the brainstem due to plaque involvement of the perforator ostia in BA dorsal or lateral walls. Therefore, to acquire information on plaque distribution is important to better understand and prevent the perforator stroke. This study aimed to comprehensively evaluate BA plaque distribution with 3D magnetic resonance imaging (MRI) vessel wall imaging.

MATERIALS AND METHODS

Consecutive patients with cerebrovascular symptoms and stenosis or irregular luminal surface of BA were recruited and underwent BA 3D proton density-weighted volume isotropic turbo spin echo acquisition (VISTA) imaging at 3T. The cross-sectional and longitudinal distribution of BA plaque were analyzed with a custom-developed tool.

RESULTS

In all, 85 BA plaques were detected in 61 recruited patients. For cross-sectional distribution, the prevalence of plaque involvement in the ventral, left, dorsal, and right quadrant of BA wall was 74.1%, 70.6%, 67.1%, and 62.4%, respectively. Of the 85 plaques, 17.7% involved one quadrant and 82.3% involved two or more quadrants. The most severe plaque region was more commonly situated at lateral walls (66.1%) as compared to ventral (23.2%, P < 0.001) and dorsal walls (10.6%, P < 0.001). Longitudinally, plaques were more frequently found to occur at BA segment distal than proximal to anterior inferior cerebellar artery (AICA) (63.5% vs. 36.5%).

CONCLUSION

Taking advantage of 3D MR vessel wall imaging, BA plaques were found to more likely affect lateral walls and form in BA distal to AICA, where most perforators originate, suggesting that it might be useful to characterize BA plaque distribution before aggressive treatment for prevention of perforator stroke. J. Magn. Reson. Imaging 2016;44:1592-1599.

Intracranial atherosclerosis: correlation between in-vivo 3T high resolution MRI and pathology

BACKGROUND

High-resolution MRI (HRMRI) is a promising tool for studying intracranial atherosclerotic disease (ICAD) in-vivo, but its use to understand the pathophysiology of ICAD has been limited by a lack of correlation between MRI signal characteristics and pathology in intracranial arteries.

DESCRIPTION OF CASE

A patient with symptomatic left cavernous carotid stenosis underwent 3T HRMRI and died 4 days later. In-vivo HRMRI and postmortem histopathology images were compared. MRI signal characteristics consistent with atherosclerotic plaque composed of lipid and loose matrix, fibrous tissue, and calcium were correlated with pathology findings. Intraplaque hemorrhage was not present on HRMRI or pathology.

CONCLUSIONS

This report demonstrates correlation between atherosclerotic plaque components visualized on 3T HRMRI images obtained in-vivo and pathological specimens of a symptomatic ICAD plaque, providing an important step in developing HRMRI as an in-vivo research tool to understand ICAD pathology.

Intracranial atherosclerosis

Atherosclerotic disease often involves the intracranial arteries including those encased by cranial bones and dura, and those located in the subarachnoid space. Age, hypertension, and diabetes mellitus are independent risk factors for intracranial atherosclerosis. Intracranial atherosclerosis can result in thromboembolism with or without hypoperfusion leading to transient or permanent cerebral ischaemic events. High rates of recurrent ischaemic stroke and other cardiovascular events mandate early diagnosis and treatment. Present treatment is based on a combination of antiplatelet drugs, optimisation of blood pressure and LDL cholesterol values, and intracranial angioplasty or stent placement, or both, in selected patients.

Intracranial plaque enhancement in patients with cerebrovascular events on high-spatial-resolution MR images

PURPOSE

To characterize intracranial plaque inflammation in vivo by using three-dimensional (3D) high-spatial-resolution contrast material-enhanced black-blood (BB) magnetic resonance (MR) imaging and to investigate the relationship between intracranial plaque inflammation and cerebrovascular ischemic events.

MATERIALS AND METHODS

The study was approved by the institutional review board and was HIPAA compliant. Twenty-seven patients (19 men; mean age, 56.8 years ± 12.4 [standard deviation]) with cerebrovascular ischemic events (acute stroke, n = 20; subacute stroke, n = 2; chronic stroke, n = 3; transient ischemic attack, n = 2) underwent 3D time-of-flight MR angiography and contrast-enhanced BB 3-T MR imaging for intracranial atherosclerotic disease. Each identified plaque was classified as either culprit (the only or most stenotic lesion upstream from a stroke), probably culprit (not the most stenotic lesion upstream from a stroke), or nonculprit (not within the vascular territory of a stroke). Plaque contrast enhancement was categorized on BB MR images (grade 0, enhancement less than or equal to that of normal arterial walls seen elsewhere; grade 1, enhancement greater than grade 0 but less than that of the pituitary infundibulum; grade 2, enhancement greater than or equal to that of the pituitary infundibulum), and degree of contrast enhancement was calculated. Associations of the likelihood of being a culprit lesion with both plaque contrast enhancement and plaque thickness were estimated with ordinal logistic regression.

RESULTS

Seventy-eight plaques were identified in 20 patients with acute stroke (21 [27%] culprit, 12 [15%] probably culprit, and 45 [58%] nonculprit plaques). In these patients, grade 2 contrast enhancement was associated with culprit plaques (odds ratio 34.6; 95% confidence interval: 4.5, 266.5 compared with grade 0) when adjusted for plaque thickness. Grade 0 was observed in only nonculprit plaques. Culprit plaques had a higher degree of contrast enhancement than did nonculprit plaques (25.9% ± 13.4 vs 13.6% ± 12.3, P = .003).

CONCLUSION

Contrast enhancement of intracranial atherosclerotic plaque is associated with its likelihood to have caused a recent ischemic event and may serve as a marker of its stability, thereby providing important insight into stroke risk.

Advanced intimal hyperplasia without luminal narrowing of leptomeningeal arteries in CADASIL

BACKGROUND AND PURPOSE

Leptomeningeal artery abnormalities in Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) have not been extensively characterized. We quantified substructure and diameter of leptomeningeal arteries in CADASIL compared with age-matched controls and the very old; in addition, we characterized intimal thickening in CADASIL using immunohistochemistry.

METHODS

Frontal and temporal cortex of 6 genetically proven CADASIL brains (average age, 66 years), 6 controls without symptoms of cerebrovascular disease, and 6 very old brains (average age, 89 years) were examined for leptomeningeal artery intimal, medial, and adventitial thickness; inner diameter; and sclerotic index and for smooth muscle markers.

RESULTS

The intima of CADASIL arteries was thickened 5-fold compared with controls and the very aged (P<0.0001). Medial thickness was lower in CADASIL compared with controls and the very old (P<0.01). The adventitia was not significantly increased in CADASIL compared with age-matched controls. Arterial diameters were not smaller in CADASIL compared with controls. Sclerotic index was significantly increased in CADASIL compared with other groups (P<0.00001). Intimal cells in CADASIL expressed smooth muscle actin, S100A4, and vimentin but not desmin.

CONCLUSIONS

Principle changes of leptomeningeal arteries in CADASIL include intimal thickening and medial thinning, but not luminal narrowing. Smooth muscle-like cells participate in neointimal thickening of CADASIL arteries.

Isoform-specific immunolocalization of 14-3-3 proteins in atherosclerotic lesions of human carotid and main cerebral arteries

14-3-3 proteins are now recognized to have a wide range of potential functions and pathological relevance, such as regulating the intercellular signal processes of differentiation, the development and growth of cells, or preventing or mediating cell apoptosis and survival by controlling the localization of potential signaling molecules. We investigated the immunolocalization of 14-3-3 proteins in atherosclerotic lesions of human cerebral and carotid arteries using 14-3-3 isoform-specific antibodies to distinguish 7 isoforms, and confirmed the cell type localization using double immunofluorolabeling. 14-3-3 common (COM)-like immunoreactivity (IR) was intense, mainly in the foam cells and multinucleated giant cells of the carotid artery. The beta, gamma, epsilon, tau, eta, and zeta (6/7) isoform-specific antibodies showed similar results to those with anti-14-3-3 COM antibody. However, among these isoform-specific antibodies, the anti-eta isoform antibody most intensely immunolabeled multinucleated giant cells and foam cells, and the anti-zeta isoform antibody most intensely immunolabeled infiltrating vascular smooth muscle cells (VSMCs), in carotid plaques. Zeta IR was also observed in one part of the mural thrombus and in the nuclei of foam cells. Gamma isoform-like IR was relatively limited in cell components, but extracellular lesions were partly positive for this isoform. In the main cerebral arteries, the anti-epsilon isoform antibody most intensely immunolabeled infiltrating VSMCs in the intima of thickened fibrous cap plaques. Endothelial cells were also positive for the epsilon isoform. These findings may provide a basis for understanding the isoform-specific role associated with atherosclerotic lesions of the cerebral and carotid arteries.