Increased Stiffness of the Carotid Wall Material in Patients With Spontaneous Cervical Artery Dissection

Sex differences in the epidemiology of spontaneous and traumatic cervical artery dissections

BACKGROUND

Recent studies show cervical artery dissection (CeAD) is equally common between sexes, and that the incidence of CeAD has risen at a greater rate in females than males. In this population-based study, we identify sex differences in patients diagnosed with spontaneous and traumatic CeAD.

METHODS

144 patients with spontaneous or traumatic CeAD were studied for sex differences in medical comorbidities, presenting symptoms and outcomes.

RESULTS

Females were more likely to carry a diagnosis of migraine, while males were more likely to have hyperlipidaemia. Females were more likely to present with neck pain, males with stroke. Females were significantly more likely to develop recurrent dissections in the study period.

CONCLUSIONS

These findings underscore the importance of understanding CeAD through the lens of sex differences and may explain the significant rise in the diagnosis of CeAD in females. These findings support the importance of considering sex-specific risk factors and medical comorbidities with sex predilection in the diagnosis and management of CeAD. Furthermore, it emphasises the importance of female patients understanding risk factors and presenting signs that should prompt evaluation for CeAD.

Giant Dissecting Aneurysm of the Internal Carotid Artery in a 35-Year-Old Patient: A Case Report

Giant dissecting aneurysms of the internal carotid artery are extremely uncommon, particularly in young adults. In this report, we provide a case of a 35-year-old male patient who experienced severe headaches, double vision, paralysis of the left abducens nerve, trigeminal neuralgia, nausea, and vomiting. The cerebral MRI showed an intensely gadolinophilic lesion following the left internal carotid artery route from the petrous canal; it also caused an internal deviation of the cavernous route of the internal carotid artery with a fluid heterogeneous area that pushed the cavernous dura mater (including the Gasser ganglion) on the free cisternal route of the trigeminal nerve. Furthermore, the cerebral angiography revealed a giant dissecting aneurysm at the C2-C4 junction of ICA, anteriorly oriented with perilesional stenoses. The interdisciplinary medical team determined that the most optimal therapeutic strategy would involve coil embolization, and the giant left ICA aneurysm was occluded along with the left ICA, with 15 giant platinum coils. Following the successful intervention, the patient experienced a remarkable clinical outcome, characterized by an immediate reversal of the majority of the symptoms. Although we were not certain of the alleviation of symptoms after the endovascular treatment, fortunately, the results were beyond expectations.

Are There Differences between Traumatic and Spontaneous Cervical Artery Dissections?

(1) Background: Cervical arterial dissections (CeAD) are a common cause of stroke in young adults. CeAD can be spontaneous (sCeAD) or traumatic (tCeAD). Whether CeAD subtypes differ in clinical, radiological, and outcome characteristics remains unexplored. (2) Methods: Patients with CeAD were identified and divided between sCeAD and tCeAD. Demographics, clinical features, risk factors, imaging findings, treatments, and outcomes were compared between the groups. Logistic regressions were used to determine characteristics associated with favorable outcome. (3) Results: Overall, 154 patients were included (106 sCeAD and 48 tCeAD). Patients with sCeAD were significantly older (mean ± SD 46 ± 12 vs. 35 ± 14, p < 0.001) and were more likely to have hyperlipidemia (19% vs. 4%, p = 0.016), but other risk factors did not differ. Patients with tCeAD less often had signs of early infarction on imaging (21% vs. 49%, p = 0.001) and had lower stroke severity on admission (NIHSS, median, interquartile range [IQR] 0 (0-9) vs. 2 (0-4), p = 0.012), but more often had symptomatic intracranial hemorrhages (12.5% vs. 2%, p = 0.006). Patients with tCeAD less often had favorable outcomes at 90 days (78% vs. 97%, p < 0.001). In the regression analysis, the only variables associated with favorable outcome were age (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.03-1.24), initial stroke severity (OR 0.84, 95% CI 0.73-0.97), degree of vessel stenosis (OR 0.35, 95% CI 0.14-0.83), and involvement of multiple vessels on presentation (OR 0.04, 95% CI 0.02-0.70), whereas dissection subtype was not associated (OR 0.45, 95% CI 0.03-68.80). (4) Conclusions: Dissection subtype is not an independent modifier of the chances of attaining functional independence.

Association between cervicocerebral artery dissection and tortuosity - a review on quantitative and qualitative assessment

Cervicocerebral artery dissection stands out as a significant contributor to ischemic stroke in young adults. Several studies have shown that arterial tortuosity is associated with dissection. We searched Pubmed and Embase to identify studies on the association between arterial tortuosity and cervicocerebral artery dissection, and to perform a review on the epidemiology of cervicocerebral artery tortuosity and dissection, pathophysiology, measurement of vessels tortuosity, strength of association between tortuosity and dissection, clinical manifestation and management strategies. The prevalence of tortuosity in dissected cervical arteries was reported to be around 22%-65% while it is only around 8%-22% in non-dissected arteries. In tortuous cervical arteries elastin and tunica media degradation, increased wall stiffness, changes in hemodynamics as well as arterial wall inflammation might be associated with dissection. Arterial tortuosity index and vertebrobasilar artery deviation is used to measure the level of vessel tortuosity. Studies have shown an independent association between these two measurements and cervicocerebral artery dissection. Different anatomical variants of tortuosity such as loops, coils and kinks may have a different level of association with cervicocerebral artery dissection. Symptomatic patients with extracranial cervical artery dissection are often treated with anticoagulant or antiplatelet agents, while patients with intracranial arterial dissection were often treated with antiplatelets only due to concerns of developing subarachnoid hemorrhage. Patients with recurrent ischemia, compromised cerebral blood flow or contraindications for antithrombotic agents are usually treated with open surgery or endovascular technique. Those with subarachnoid hemorrhage and intracranial artery dissection are often managed with surgical intervention due to high risk of re-hemorrhage.

A narrative review on cervical artery dissection-related cranial nerve palsies

Introduction

This study aimed to emphasize the importance of cranial nerve (CN) palsies in spontaneous cervical artery dissection (sCeAD).

Methods

A search term-based literature review was conducted on "cervical artery dissection" and "cranial nerve palsy." English and German articles published until October 2023 were considered.

Results

Cranial nerve (CN) palsy in sCeAD is evident in approximately 10% of cases. In the literature, isolated palsies of CN II, III, VII, IX, X, and XII have been reported, while CN XI palsy only occurs in combination with other lower cranial nerve palsies. Dissection type and mural hematoma localization are specific to affected CN as CN palsies of II or III are solely evident in those with steno-occlusive vessel pathologies located at more proximal segments of ICA, while those with CN palsies of IX, X, XI, and XII occur in expansive sCeAD at more distal segments. This dichotomization emphasizes the hypothesis of a different pathomechanism in CN palsy associated with sCeAD, one being hypoperfusion or microembolism (CN II, III, and VII) and the other being a local mass effect on surrounding tissue (CN IX, X, XI, and XII). Clinically, the distinction between peripheral palsies and those caused by brainstem infarction is difficult. This differentiation is key, as, according to the reviewed cases, peripheral cranial nerve palsies in sCeAD patients mostly resolve completely over time, while those due to brainstem stroke do not, making cerebrovascular imaging appraisal essential.

Discussion

It is important to consider dissections as a potential cause of peripheral CN palsies and to be aware of the appropriate diagnostic pathways. This awareness can help clinicians make an early diagnosis, offering the opportunity for primary stroke prevention.

The influence of aortic stiffness on carotid stiffness: computational simulations using a human aorta carotid model

Increased aortic and carotid stiffness are independent predictors of adverse cardiovascular events. Arterial stiffness is not uniform across the arterial tree and its accurate assessment is challenging. The complex interactions and influence of aortic stiffness on carotid stiffness have not been investigated. The aim of this study was to evaluate the effect of aortic stiffness on carotid stiffness under physiological pressure conditions. A realistic patient-specific geometry was used based on magnetic resonance images obtained from the OsiriX library. The luminal aortic-carotid model was reconstructed from magnetic resonance images using 3D Slicer. A series of aortic stiffness simulations were performed at different regional aortic areas (levels). By applying variable Young's modulus to the aortic wall under two pulse pressure conditions, one could examine the deformation, compliance and von Mises stress between the aorta and carotid arteries. An increase of Young's modulus in an aortic area resulted in a notable difference in the mechanical properties of the aortic tree. Regional deformation, compliance and von Mises stress changes across the aorta and carotid arteries were noted with an increase of the aortic Young's modulus. Our results indicate that increased carotid stiffness may be associated with increased aortic stiffness. Large-scale clinical validation is warranted to examine the influence of aortic stiffness on carotid stiffness.

Long-Term Course of Circulating Elastin, Collagen Type I, and Collagen Type III in Patients with Spontaneous Cervical Artery Dissection: a Prospective Multicenter Study

An impaired integrity of vascular elements and the extracellular matrix (ECM) has been discussed to play a critical role in the pathophysiology of spontaneous cervical artery dissection (sCAD). This study aimed to explore the temporal course of circulating elastin, collagen type I, and collagen type III in patients with sCAD and evaluated their eligibility as diagnostic biomarkers. Patients with sCAD were prospectively enrolled in four German stroke centers. Blood samples were collected at baseline (acute phase), at day 10 ± 3 (subacute phase), and after 6 ± 1 months (chronic phase). Patients with acute ischemic stroke not related to sCAD, healthy probands, and patients undergoing thromboendarterectomy of the carotid artery served as control groups. Serum levels of elastin and collagen types I and III were determined by ELISAs. Fifty-seven patients with sCAD were enrolled. Compared to all three control groups, patients with sCAD had significantly lower levels of elastin and collagen type III at baseline and after 6 months. Compared to healthy probands, patients with sCAD showed similar collagen type I levels at baseline and in the subacute phase, but significantly increased levels after 6 months. As serum levels of elastin, collagen types I and III were not elevated in the acute phase, they do not appear eligible as biomarkers for the diagnosis of sCAD. Persisting low serum levels of elastin and collagen type III towards the chronic phase of sCAD strengthens the hypothesis of a subtle, in most cases clinically inapparent affection of the ECM in patients with sCAD.

Spontaneous cervical artery dissection: is it really a connective tissue disease? A comprehensive review

Background

Spontaneous cervical artery dissection (sCeAD) is an important cause of stroke in young adults. The underlying pathophysiology remains unclear, without validated biomarkers to identify subjects at risk. Previous studies suggested the role of abnormalities in the connective component of the arterial wall.

Purpose

To assess dermal ultrastructural aberrations of connective tissue by skin biopsy and genetic variations in sCeAD patients.

Method

We searched the PubMed and Scopus databases until August 2023 with PRISMA guidelines. Original articles assessing skin biopsy in sCeAD patients were included. Two reviewers independently conducted the screening.

Findings

We included 16 studies compromising 459 patients. Thirteen studies assessed ultrastructural changes and found aberrations of collagen and elastic fibers, described as irregular contours and calibers of collagen fibrils, composite flower-like fibrils, fragmented moth-eaten elastin, and microcalcifications, cumulatively in 50.5% of patients. Seven studies showed no causative mutations in collagen type I, III, V, or elastin genes. One study showed linkage between connective tissue alterations and mutation on chromosomes 15q2 and 10q26 using genome-wide linkage analysis, while another study found significant copy number variant enrichments in genes involved in extracellular matrix (COL5A2/COL3A1/SNTA1) and collagen fibril organizations (COL5A2/COL3A1). Finally, differential expression of extracellular proteins was linked to connective tissue disorder in patients with recurrent sCeAD using a quantitative proteomics approach.

Conclusion

Current literature supports the hypothesis that an underlying, subclinical connective tissue disorder, likely genetically determined, may predispose to arterial wall weakness and sCeAD. Further studies with larger sample sizes and robust methodology are needed to better define the role of connective tissue in sCeAD pathogenesis.

Genetic Insights on the Relation of Vascular Risk Factors and Cervical Artery Dissection

BACKGROUND

The association between vascular risk factors and cervical artery dissections (CeADs), a leading cause of ischemic stroke (IS) in the young, remains controversial.

OBJECTIVES

This study aimed to explore the causal relation of vascular risk factors with CeAD risk and recurrence and compare it to their relation with non-CeAD IS.

METHODS

This study used 2-sample Mendelian randomization analyses to explore the association of blood pressure (BP), lipid levels, type 2 diabetes, waist-to-hip ratio, smoking, and body mass index with CeAD and non-CeAD IS. To simulate effects of the most frequently used BP-lowering drugs, this study constructed genetic proxies and tested their association with CeAD and non-CeAD IS. In analyses among patients with CeAD, the investigators studied the association between weighted genetic risk scores of vascular risk factors and the risk of multiple or early recurrent dissections.

RESULTS

Genetically determined higher systolic BP (OR: 1.51; 95% CI: 1.32-1.72) and diastolic BP (OR: 2.40; 95% CI: 1.92-3.00) increased the risk of CeAD (P < 0.0001). Genetically determined higher body mass index was inconsistently associated with a lower risk of CeAD. Genetic proxies for β-blocker effects were associated with a lower risk of CeAD (OR: 0.65; 95% CI: 0.50-0.85), whereas calcium-channel blockers were associated with a lower risk of non-CeAD IS (OR: 0.75; 95% CI: 0.63-0.90). Weighted genetic risk scores for systolic BP and diastolic BP were associated with an increased risk of multiple or early recurrent CeAD.

CONCLUSIONS

These results are supportive of a causal association between higher BP and increased CeAD risk and recurrence and provide genetic evidence for lower CeAD risk under β-blockers. This may inform secondary prevention strategies and trial design for CeAD.

Cervical Artery Dissection

OBJECTIVE

Cervical artery dissection is a common cause of stroke in young adults. This article reviews the pathophysiology, etiology and risk factors, evaluation, management, and outcomes of spontaneous cervical artery dissection.

LATEST DEVELOPMENTS

Cervical artery dissection is believed to be a multifactorial disease, with environmental factors serving as possible triggers in patients who have a genetic predisposition to dissection formation. Cervical artery dissection can cause local symptoms or ischemic events, such as ischemic stroke or transient ischemic attack. Neuroimaging is used to confirm the diagnosis; classic findings include a long tapered arterial stenosis or occlusion, dissecting aneurysm, intimal flap, double lumen, or intramural hematoma. Patients with cervical artery dissection who present with an acute ischemic stroke should be evaluated for IV thrombolysis, endovascular therapy eligibility, or both. Antithrombotic therapy with either anticoagulation or antiplatelet treatment is used to prevent stroke from cervical artery dissection. The risk of recurrent ischemia appears low and is mostly limited to the first two weeks after symptom onset.

ESSENTIAL POINTS

Cervical artery dissection is a known cause of ischemic strokes. Current data show no difference between the benefits and risks of anticoagulation versus antiplatelet therapy in the acute phase of symptomatic extracranial cervical artery dissection, thereby supporting the recommendation that clinicians can prescribe either treatment. Further research is warranted to better understand the pathophysiology and long-term outcomes of cervical artery dissection.

Arterial Stiffness Assessment in Healthy Participants Using Shear Wave Elastography

BACKGROUND

Arterial stiffness is an important biomarker for cardiovascular disease. Shear wave elastography (SWE) provides quantitative estimates of tissue stiffness.

OBJECTIVE

This study aimed to provide reference values for arterial wall, assessing the suitability of SWE to quantify elasticity of the common carotid artery (CCA) and evaluating inter- and intra-observer reproducibility.

METHODS

A Supersonic Aixplorer ultrasound system with L15-4 probe was used to scan longitudinal sections of the CCA. Young's modulus (YM) was measured within 2-mm regions of interest. Reproducibility was assessed within a subgroup of 16 participants by two operators (one novice and one experienced) during two sessions >one week apart.

RESULTS

This study involves seventy-three participants with a mean age of 40±10 years and body mass index of 26 ±6 kg/m2. YM estimates were 59 kPa ±19 in men and 56 kPa ±12 in women. The average YM of the CCA walls was 58 kPa ±15 (57 ±15 kPa for the anterior wall and 58 ±20 kPa for the posterior wall, p=0.75). There was no significant difference in the mean of YM estimates of the CCA between the observers (observer: one 51 ±14 kPa and observer two: 55 ±17 kPa [p=0.46]). inter- and intra-observer reproducibility was fair to good (Intra-class correlations, ranging from 0.46 to 0.71). Inter-frame variability was 28%.

CONCLUSION

In healthy individuals, SWE provided an estimate of YM of the CCA (58 kPa) with fair to good reproducibility. This study demonstrated the potential of using SWE for assessing biomechanical properties of blood vessels.

Ultrasound shear wave elastography imaging of common carotid arteries in patients with Spontaneous Coronary Artery Dissection (SCAD)

BACKGROUND

Shear wave elastography (SWE) is emerging as a valuable clinical tool for a variety of conditions. The aim of this pilot study was to assess the potential of SWE imaging of the common carotid arteries (CCA) in patients with spontaneous coronary artery dissection (SCAD), a rare but potentially life-threatening condition, hypothesized to be linked to changes in vessel wall elasticity.

METHODS

Ultrasound shear wave elastography (SWE) estimates of artery wall elasticity were obtained from the left and right CCAs of 89 confirmed SCAD patients and 38 non-dissection controls. SWE images obtained over multiple cardiac cycles were analysed by a blinded observer to estimate elasticity in the form of a Young's Modulus (YM) value, across regions of interest (ROI) located within the anterior and posterior CCA walls.

RESULTS

YM estimates ranged from 17 to 133 kPa in SCAD patients compared to 34 to 87 kPa in non-dissection controls. The mean YM of 55 [standard deviation (SD): 21] kPa in SCAD patients was not significantly different to the mean of 57 [SD: 12] kPa in controls, p = 0.32. The difference between groups was 2 kPa [95% Confidence Interval - 11, 4].

CONCLUSIONS

SWE imaging of CCAs in SCAD patients is feasible although the clinical benefit is limited by relatively high variability of YM values which may have contributed to our finding of no significant difference between SCAD patients and non-dissection controls.

Traumatic and Spontaneous Vertebral Artery Dissections: An Analysis of Tertiary-Center 310 Patient Cohort

BACKGROUND

Vertebral artery dissections (VADs) are rare yet potentially devastating events. While the etiology of these events is either traumatic or spontaneous, there is a paucity of quantitative literature comparing the two.

OBJECTIVE

To identify differences in predisposing factors, event characteristics, and clinical outcomes between traumatic VADs (tVADs) and spontaneous VADs (sVADs).

METHODS

We retrospectively identified patients with VADs presenting to our institution at VAD onset with at least a 3-mo follow-up. Demographics, event characteristics, treatment details, and neurological outcomes as modified Rankin scale (mRS) scores were collected.

RESULTS

Of the 310 patients sustaining 366 VADs total, 187 (60.3%) patients experienced a total of 221 (60.4%) sVADs and 123 (39.7%) patients experienced a total of 145 (39.6%) tVADs. sVADs were more likely to occur in the intracranial course of the artery (P = .042) and have a lower mRS at discharge, 3-month, and last clinical follow-up (P = 003, .002, and .001, respectively). tVADs were more likely associated with concomitant fractures (P < .001).

CONCLUSION

Despite similar patient populations, tVADs are associated with higher mRS scores at all time points. Although further study is needed, this may suggest other concomitant trauma rather than the VAD itself is contributing to worse neurological status in patients with tVADs.

Extracellular matrix protein signature of recurrent spontaneous cervical artery dissection

OBJECTIVE

To assess whether connective tissue disorder is evident in patients with spontaneous cervical artery dissection and therefore identify patients at risk of recurrence using a cutting-edge quantitative proteomics approach.

METHODS

In the ReSect study, all patients with spontaneous cervical artery dissection treated at the Innsbruck University Hospital since 1996 were invited to attend a standardized clinical follow-up examination. Protein abundance in skin punch biopsies (n = 50) was evaluated by a cutting-edge quantitative proteomics approach (liquid chromatography-mass spectrometry) that has hitherto not been applied to such patients.

RESULTS

Patients with 1-time single-vessel (n = 19) or multiple-vessel (n = 13) dissections did not differ between each other or compared to healthy controls (n = 12) in protein composition. Patients with recurrent spontaneous cervical artery dissection (n = 6), however, showed significantly different expression of 25 proteins compared to the other groups combined. Literature review and Gene Ontology term annotation check revealed that 13 of the differently expressed proteins play a major role in the structural integrity of connective tissue or are linked to connective tissue disorders. These proteins showed clustering to a collagen/elastin cluster and one consisting of desmosome related proteins.

CONCLUSION

This study unravels an extracellular matrix protein signature of recurrent spontaneous cervical artery dissection. In the long run and after large-scale validation, our findings may well assist in identifying patients at risk of recurrent spontaneous cervical artery dissection and thus guide therapy.

Association between Pregnancy and Cervical Artery Dissection

OBJECTIVE

We wanted to determine whether pregnancy is associated with cervical artery dissection.

METHODS

We performed a case-control study using claims data from all nonfederal emergency departments and acute care hospitals in New York and Florida between 2005 and 2015. Cases were women 12-42 years of age hospitalized with cervical artery dissection, defined using validated diagnosis codes for carotid/vertebral artery dissection. Controls were women 12-42 years of age with a primary diagnosis of renal colic. Cases and controls were matched 1:1 on age, race, insurance, income, state, and visit year. The exposure variable was pregnancy, defined as labor and delivery within 90 days before or 6 months after the index visit. Logistic regression was used to compare the odds of pregnancy between cases and controls. We performed a secondary cohort-crossover study comparing the risk of cervical artery dissection during pregnancy versus the same time period 1 year later.

RESULTS

Pregnancy was twice as common among 826 women with cervical artery dissection compared with the 826 matched controls with renal colic (odds ratio, 2.5; 95% confidence interval [CI], 1.3-4.7). In our secondary analysis, pregnancy was associated with a higher risk of cervical artery dissection (incidence rate ratio [IRR], 2.2; 95% CI, 1.3-3.5), with the heightened risk limited to the postpartum period (IRR, 5.5; 95% CI, 2.6-11.7).

INTERPRETATION

Pregnancy, specifically the postpartum period, was associated with hospitalization for cervical artery dissection. Although these findings might in part reflect ascertainment bias, our results suggest that arterial dissection is one mechanism by which pregnancy can lead to stroke. ANN NEUROL 2020;88:596-602.

Changes in internal carotid and vertebral arterial wall stiffness with head movement can be detected with shear wave elastography

Background: Safe practice is important for patients with neck pain, with the potential for injury to cervical arteries. Cervical manipulation or end range techniques/positions may place considerable strain on the arteries. Altered integrity of the arterial wall may render them more susceptible to minor trauma, particularly in the upper cervical region. Screening of blood flow velocity is limited for predicting those at risk. Examining properties of the cervical arterial wall (stiffness characteristics) and their response to head movement may provide an alternate measure of arterial susceptibility.Objectives: To investigate whether shear wave ultrasound elastography can detect any changes in internal carotid (ICA) and vertebral (VA) arterial wall stiffness in neutral compared with contralateral head rotation.Design: Observational studyMethods: Shear wave ultrasound elastography was used to measure the stiffness of the ICA and VA. Shear wave velocity (m/s), indicative of arterial stiffness, was measured in both arteries proximally (C3-4) and distally (C1-2) in neutral and contralateral head rotation as were intimal thickness (mm) and flow velocity (cm/s).Results: Thirty participants (20-62 years) were successfully imaged. The VA was stiffer than ICA and it became significantly stiffer in contralateral rotation (p = 0.05). The ICA became significantly less stiff (p = 0.01). Effects were more apparent at C1-2 but significant in the ICA only (p = 0.03). Flow velocity and intimal thickness were unchanged in rotation.Conclusions: Changes in VA and ICA arterial wall stiffness can be measured with shear wave ultrasound elastography. This measure may ultimately help identify arteries with greater vulnerability to rotational stresses.

Shear wave elastography of the cervical arteries: A novel approach to the assessment of cervical arterial wall stiffness. An investigation of psychometric properties and intra-rater reliability

BACKGROUND

Cervical arterial dissection, can occur spontaneously and is a rare but catastrophic adverse event associated with neck manipulation. Pathophysiology involves altered integrity of the arterial wall increasing its vulnerability to minor trauma. Those at risk are difficult to detect. Previous screening investigated blood flow but altered mechanical properties as stiffness of cervical arterial wall could provide a more valid indication of arterial integrity or even early dissection.

OBJECTIVES

To investigate suitability and intra-rater reliability of shear wave ultrasound elastography to measure mechanical properties of the cervical arterial wall. Suitability was assessed by ability to track arteries along their length and measurement accuracy.

DESIGN

Observational and intra-rater reliability study.

METHODS

Internal carotid (ICA) and vertebral arteries (VA) of healthy participants were examined with shear wave elastography. Shear wave velocity (m/s) indicative of wall stiffness was measured with the head in the neutral position: proximally (C3-4) and distally (C1-2) where injuries have been more commonly reported. Proximal measures were repeated to assess intra-rater reliability.

RESULTS

Thirty healthy participants (13 female), mean age of 29 (±12.8) years were imaged. Mean VA wall stiffness (3.4 m/s) was greater than ICA (2.3 m/s) (p < 0.000). Intra-rater reliability for ICA was ICC 0.81 (CI 0.52 to 0.92) and for VA ICC 0.76 (CI 0.38 to 0.9). Standard error of measurement was 0.16 for ICA and 0.34 for VA.

CONCLUSIONS

Shear wave ultrasound elastography appears a suitable and reliable method to measure cervical arterial wall stiffness, justifying further research into its use for screening arterial integrity.

The potential dangers of neck manipulation & risk for dissection and devastating stroke: An illustrative case & review of the literature

Chiropractic cervical manipulation is a common practice utilized around the world. Most patients are never cleared medically for manipulation, which can be devastating for those few who are at increased risk for dissections. The high velocity thrust used in cervical manipulation can produce significant strain on carotid and vertebral vessels. Once a dissection has occurred, the risk of thrombus formation, ischemic stroke, paralysis, and even death is drastically increased. In this case report, we highlight a case of a 32-year-old woman who underwent chiropractic manipulation and had vertebral artery dissection with subsequent brainstem infarct. She quickly deteriorated and passed away shortly after arrival to the hospital. Although rare, one in 48 chiropractors have experienced such an event. We utilize this case to highlight the risk associated with cervical manipulation and urge open dialogue between chiropractors and physicians. Receiving medical clearance prior to cervical manipulation in potential at risk patients would drastically reduce morbidity and mortality.

Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection

Isolated spontaneous common carotid artery (CCA) dissection is rare. So far, surgical or medical treatment have only been reported in a few cases in the literature. We report a 39-year-old man, diagnosed as isolated spontaneous CCA dissection one year ago, who experienced a new minor stroke despite medical treatment. Because of the presence of new ischemic lesions on new magnetic resonance imaging despite medical treatment, and critical narrowing of internal carotid artery (ICA) orifice with jet and turbulence flow pattern at the bulbar portion of the ICA, endovascular management was performed with carotid stent deployment. To the best of our knowledge, this is the first case of spontaneous isolated CCA dissection treated with stenting of the carotid artery reported in literature.

Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection

Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69-0.82; P = 4.46 × 10(-10)), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10(-3); combined P = 1.00 × 10(-11)). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions.

Pathophysiology and risk factors of cervical artery dissection: what have we learnt from large hospital-based cohorts?

PURPOSE OF REVIEW

Cervical artery dissection (CeAD) is a major cause of ischemic stroke in young and middle-aged adults, although relatively uncommon in the community. Recent large collaborative projects have provided new insights into mechanisms and risk factors of CeAD.

RECENT FINDINGS

Pathologic changes observed at the media-adventitia border in temporal arteries of CeAD patients suggest a predisposing arterial wall weakness. In large multicenter series of CeAD patients, compared to age-matched healthy controls and patients with an ischemic stroke of another cause, hypertension and migraine, especially without aura, were confirmed as risk factors for CeAD, in addition to cervical trauma and recent infection. Hypercholesterolemia and being overweight were shown to be inversely associated with CeAD. Differences in risk factor profile and structural features between carotid and vertebral dissection suggest that their pathophysiology may partly differ. An association of CeAD with fibromuscular dysplasia and reversible cerebral vasoconstriction syndrome was described. Genetic risk factors of CeAD are still poorly understood.

SUMMARY

Large cohorts of CeAD patients have refined our understanding of the pathophysiology and risk factors of CeAD, but the molecular mechanisms are still poorly understood. Ongoing high-throughput genetic projects will hopefully provide novel insight into the biological substrate of CeAD.

Large-vessel correlates of cerebral small-vessel disease

OBJECTIVE

Our aim was to investigate the relationship of carotid structure and function with MRI markers of cerebral ischemic small-vessel disease.

METHODS

The study comprised 1,800 participants (aged 72.5 ± 4.1 years, 59.4% women) from the 3C-Dijon Study, a population-based, prospective cohort study, who had undergone quantitative brain MRI and carotid ultrasound. We used multivariable logistic and linear regression adjusted for age, sex, and vascular risk factors.

RESULTS

Presence of carotid plaque and increasing carotid lumen diameter (but not common carotid artery intima-media thickness) were associated with higher prevalence of lacunar infarcts: odds ratio (OR) = 1.60 (95% confidence interval [CI]: 1.09-2.35), p = 0.02 and OR = 1.24 (95% CI: 1.02-1.50), p = 0.03 (by SD increase). Carotid plaque was also associated with large white matter hyperintensity volume (WMHV) (age-specific top quartile of WMHV distribution): OR = 1.32 (95% CI: 1.04-1.67), p = 0.02, independently of vascular risk factors. Increasing Young elastic modulus and higher circumferential wall stress, reflecting augmented carotid stiffness, were associated with increasing WMHV (effect estimate [β] ± standard error: 0.0003 ± 0.0001, p = 0.024; β ± standard error: 0.005 ± 0.002, p = 0.008). Large WMHV was also associated with increasing Young elastic modulus (OR = 1.22 [95% CI: 1.04-1.42], p = 0.01) and with decreasing distensibility coefficient (OR = 0.83 [95% CI: 0.69-0.99], p = 0.04), independently of vascular risk factors. Associations of carotid lumen diameter with lacunar infarcts and of carotid stiffness markers with WMHV were independent of carotid plaque.

CONCLUSIONS

In addition to and independently of carotid plaque, increasing carotid lumen diameter and markers of carotid stiffness were associated with increasing prevalence of lacunar infarcts and increasing WMHV, respectively.

Dolichoectatic vertebrobasilar dissecting aneurysm originating from atherosclerosis: an autopsy case

We herein report an unusual case of profound brain infarction of the posterior circulation due to a dolichoectatic vertebrobasilar dissecting aneurysm (DVDA) originating from atherosclerosis. On autopsy, diffuse atherosclerosis was observed with a multi-fusiform aneurysm measuring 1 to 2 cm in diameter ranging from the left vertebral artery to the basilar artery. The microscopic findings of the aneurysm revealed severe stenosis of the artery caused by intimal thickening, intimal flap formation and thrombosis, indicating the presence of a dissecting aneurysm originating from atherosclerosis. The DVDA observed in this case was considered to be slowly progressive and associated with the development of atherosclerosis. The etiology of structural destabilization in patients with DVDA involves rupture of the internal elastic lamina, which is dislodged by massive hematomas that form atheromatous lesions.

Traumatic and spontaneous carotid and vertebral artery dissection in a level 1 trauma center

This study aimed to compare traumatic and spontaneous carotid artery dissection (CAD) and vertebral artery dissection (VAD) with respect to age, pre-morbid risk factors, and site of dissection. Chart review was performed for 49 patients with CAD and VAD admitted to Westchester Medical Center, a level 1 trauma center, from 1999 to 2007. Presentation was categorized into traumatic (n=28, 57%) or spontaneous dissection (n=21, 43%). Pre-morbid risk factors were analyzed. Location of dissection was identified and categorized into four possible segments. Patients with spontaneous dissection were likely to be over the age of 50 years (p<0.05), and had significantly higher proportions of coronary artery disease (33% compared to 7%, p<0.05), hypertension (57% compared to 18%; p<0.01), and hypercholesterolemia (29% compared to 0%; p<0.01). Of the 49 patients, 42 had imaging studies available for segmental analysis. In both traumatic CAD and VAD, dissection at Segment III (corresponds with the first and second cervical vertebrae), was the most common site (37.5% and 50%, respectively, p<0.05). In contrast, Segment I (origin of the vessel to the fifth cervical vertebrae) was the most common site for spontaneous CAD and VAD (55% and 77%, respectively, p<0.05). This cross-sectional study suggests that etiology plays an important role in the location of dissection. Traumatic CAD and VAD occur most commonly in Segment III. Spontaneous CAD and VAD occur most commonly in Segment I and are associated with increasing age and premorbid cerebrovascular risk factors.

Cervical carotid artery dissection: current review of diagnosis and treatment

Carotid artery dissection is a cause of stroke, especially in young and middle-aged patients. A dissection occurs when there is an intimal tear or rupture of the vasa vasorum, leading to an intramural hematoma, which is thought to result from trauma or can occur spontaneously, and is likely multifactorial, involving environmental and intrinsic factors. The clinical diagnosis of carotid artery dissection can be challenging, with common presentations including pain, partial Horner syndrome, cranial nerve palsies, or cerebral ischemia. With the use of noninvasive imaging, including magnetic resonance and computed tomography angiography, the diagnosis of carotid dissection has increased in frequency. Treatment options include thrombolysis, antiplatelet or anticoagulation therapy, endovascular or surgical interventions. The choice of appropriate therapy remains controversial as most carotid dissections heal on their own and there are no randomized trials to compare treatment options.

Age-dependent differences in cervical artery dissection

The goal of this work was to explore age-dependent differences in cervical artery dissection (CeAD). This study is based on the Cervical Artery Dissection and Ischemic Stroke Patients population comprising 983 consecutive CeAD patients and 658 control patients with a non-CeAD ischemic stroke (IS), frequency-matched for age and gender. Patients were divided into three age categories: ≤33 (for CeAD, n = 150), 34-54 (n = 688), and ≥55 (n = 145) years, and the youngest and oldest groups were compared. The youngest patients were mostly women and the oldest men. The frequency of internal carotid artery dissection (ICAD) versus vertebral artery dissection (VAD) increased with age from 44 to 75 %. This age-related shift remained significant after adjustment for sex. The frequency of a transient ischemic event as the CeAD symptom declined from 33 % in the youngest age group, to 19 % in the oldest. Vascular risk factors increased in frequency with advancing age in both groups, but for hypertension the increase was steeper for non-CeAD IS patients. For CeAD patients, but not for patients with non-CeAD IS, preceding infection was more common in the oldest group. The youngest non-CeAD IS patients had better functional outcome (modified Rankin Scale 0-1) than the oldest, while the similar trend was not statistically significant among CeAD patients. Younger age seems to be associated with VAD and female gender, and older age with ICAD and male gender. Age-related changes in the frequencies of hypertension and recent infection were different between the CeAD and non-CeAD IS groups. Age does not seem to be an important outcome predictor in CeAD strokes.

Cervical-artery dissections: predisposing factors, diagnosis, and outcome

Cervical-artery dissection (CAD) is a major cause of cerebral ischaemia in young adults and can lead to various clinical symptoms, some of which are benign (eg, headache, neck pain, Horner's syndrome, and cranial-nerve palsy), but most patients have a stroke or transient ischaemic attack. In addition to trauma to the neck, other risk factors have been suggested, such as infection, migraine, hyperhomocysteinaemia, and the 677TT genotype of the 5,10-methylenetetrahydrofolate reductase gene (MTHFR 677TT), although evidence is sparse. An underlying arteriopathy, which could in part be genetically determined, is believed to have a role in the development of CAD. Importantly, both research on and optimum management of CAD strongly rely on diagnostic accuracy. Although the functional outcome of CAD is good in most patients, socioprofessional effects can be important. Incidence of the disorder in the general population is underestimated. Mortality and short-term recurrence rates are low but possibly also underestimated. Further research is warranted to improve our understanding of the underlying pathophysiology, to assess the long-term outcome, and ultimately to provide treatment and prevention strategies.

Vertebral artery dissection after direct laryngoscopy: case report and literature review

OBJECTIVE

We report a case of vertebral artery dissection following direct laryngoscopy, and we provide an update on current knowledge regarding this condition and its relationship to movements of the neck.

METHOD

A case report and review of the world literature are presented.

RESULTS

Vertebral artery dissection is an uncommon event leading to stroke. It has been associated with many risk factors, particularly extreme movement of the cervical spine. The pathogenesis of the condition and the true aetiological significance of neck movement are not known.

CONCLUSION

To our knowledge, we present the first case of vertebral artery dissection following direct laryngoscopy. We highlight the need for caution when considering neck pain in patients after direct laryngoscopy.

Vasomotion in Multiple Spontaneous Cervical Artery Dissections

Background and Purpose— The etiology of spontaneous cervical artery dissection (sCAD) is still unknown, even though an underlying arteriopathy impairing vasomotion has often been suspected. This study was undertaken to investigate: (1) spontaneous, (2) endothelial-dependent, and (3) endothelial-independent vasodilation in patients with multiple sCAD.

Methods— In 19 consecutive patients with multiple carotid or vertebral artery dissections high-resolution ultrasound was used to assess spontaneous and endothelial-independent dilations (isosorbide dinitrate-mediated) in the common carotid, vertebral and brachial arteries, and endothelial-dependent dilation (flow-mediated arterial dilation) in the brachial arteries alone. The same parameters were measured in 19 healthy subjects matched for age, sex, and height (controls). Ultrasound studies were performed by one investigator, and off-line analysis by another investigator who was blinded to the clinical data and study status (patient or control).

Results— Spontaneous and endothelial-independent dilations were significantly impaired in the carotid ( P =0.0006 and P <0.0001, respectively) and vertebral arteries ( P =0.0121 and P =0.0047, respectively) of patients as compared with controls, whereas no statistically significant differences were found in the brachial arteries; conversely, endothelial-dependent dilation of the brachial arteries was significantly lower in patients as compared with controls ( P <0.0001).

Conclusions— Patients with multiple sCADs have a significantly impaired vasomotion, which may predispose to dissection.

Influence of pravastatin on carotid artery structure and function in dyslipidemic HIV-infected patients receiving antiretroviral therapy

Forty-two pravastatin-treated HIV-positive patients and 42 sex, age, and smoking status-matched hypercholesterolemic HIV-positive patients not under lipid-lowering treatment were compared for differences in intima-media thickness (IMT) of the common carotid artery (CCA) and aortic stiffness. Pravastatin had no influence on carotid artery structure and function, or aortic stiffness. Age and body mass index were independent determinants of IMT of the CCA. Mean arterial pressure, age, duration of HIV infection and protease inhibitor exposure determined aortic stiffness.

Common carotid arterial stiffness and the risk of ischaemic stroke

In the present case-control study we aimed to investigate the association of common carotid arterial (CCA) stiffness with ischaemic stroke (IS) and to determine whether this relationship was independent of conventional risk factors including CCA intima-media thickness (CCA-IMT). CCA distensibility, defined as the change of CCA-diameter during the cardiac cycle, and CCA-IMT were evaluated by means of high-resolution B-mode carotid ultrasound examination in consecutive, first-ever IS patients (n=193) and in age- and sex-matched control subjects (n=106). The CCA distensibility (inverse of CCA stiffness) was significantly (P=0.007) lower in IS (0.353 mm, 95% CI: 0.326-0.379) than in control subjects (0.415 mm, 95% CI: 0.378-0.451) even after adjusting for blood pressure values, diastolic CCA-diameter and height. The multivariate logistic regression procedure selected CCA-IMT and CCA distensibility as the only independent predictor variables of IS. Each 1 SD increase in the CCA-IMT and each 1 SD decrease in the CCA distensibility independently increased the likelihood of IS by 167.0% (OR: 2.67, 95% CI: 1.80-3.96, P<0.001) and 59.0% (OR: 1.59, 95% CI: 1.22-2.07, P=0.001) respectively. Increased CCA stiffness is associated with IS independent of conventional risk factors and CCA-IMT. The causal interrelationship between the elastic properties of the CCA and the risk of stroke deserves further investigation by longitudinal studies.

Elevated inflammatory laboratory parameters in spontaneous cervical artery dissection as compared to traumatic dissection

Several studies have reported infection as a possible risk factor for cervical artery dissection (CAD). We retrospectively analyzed several inflammatory parameters of CAD patients with the aim of detecting differences between spontaneous (n = 25) and traumatic (n = 18) CAD. In this case-control study, we observed significantly higher absolute leucocyte values (10.3 versus 8.1 G/L; p = 0.02) as well as an elevated frequency of leucocytosis (64% versus 28%; p = 0.02) and elevated CRP (60% versus 28%; p = 0.04) in patients without a history of trauma ("spontaneous" CAD) compared with patients with trauma-related CAD. As the elevated inflammatory laboratory parameters were not associated with an elevated infection rate, these findings imply a role of an acute inflammation as a pathogenetic factor in spontaneous CAD. The cause and mechanism of the inflammatory process remain unknown.

Carotid and aortic stiffness: determinants of discrepancies

Several studies have shown that aortic stiffness was an independent predictor for cardiovascular events. However, data are less consistent concerning carotid stiffness. We analyzed the determinants of the discrepancies between aortic and carotid stiffness in different populations with contrasting cardiovascular risk factors: 94 healthy normotensives (NT), 243 nondiabetic hypertensives (HT), and 126 patients with hypertension and type 2 diabetes (T2D). Aortic stiffness was measured with carotid-femoral pulse wave velocity. Common carotid stiffness was determined from the relative stroke change in diameter (measured with a high-resolution echotracking system) and carotid pulse pressure (measured with applanation tonometry) and was expressed in the same dimensions as pulse wave velocity (m/s). We identified the various factors explaining the discrepancies between aortic and carotid stiffness by multivariate analysis of the residuals of the correlation between aortic and carotid stiffness. The strength of the correlation between aortic and carotid stiffness became weaker as the number of cardiovascular risk factors increased (NT, r2=0.41; HT, r2=0.16; and T2D, r2=0.11), whereas we observed the opposite for the discrepancies (residuals) between aortic and carotid stiffness, of which an increasing part was explained (11% in NT, 22% in HT, and 45% in T2D) primarily by aging. In conclusion, although carotid-femoral pulse wave velocity and carotid stiffness provided similar information on the impact of aging on large artery stiffness in normal subjects, this was not the case for high blood pressure and/or diabetes. In these cases, the aorta stiffened more than the carotid artery with age and other cardiovascular risk factors.

A systematic review of the risk factors for cervical artery dissection

BACKGROUND AND PURPOSE

Cervical artery dissection (CAD) is a recognized cause of ischemic stroke among young and middle-aged individuals. The pathogenesis of dissections is unknown, although numerous constitutional and environmental risk factors have been postulated. To better understand the quality and nature of the research on the pathogenesis of CAD, we performed a systematic review of its risk factors.

METHODS

PubMed [MEDLINE (1966 to February 22, 2005)] and Embase (1980 to February 22, 2005) were searched to identify studies fulfilling the inclusion criteria. Two reviewers independently assessed methodological quality of the primary studies. Relevant data were extracted, including the risk factor(s) investigated, characteristics of the study population, and strength of the association(s).

RESULTS

Thirty-one case-control studies were included for analysis. Selection bias, lack of control for confounding, and inadequate method of data analysis were the most common identified methodological shortcomings. Strong associations were reported from individual studies for the following risk factors: aortic root diameter >34 mm (odds ratio [OR=14.2; 95% confidence interval [CI], 3.2 to 63.6), migraine (ORadj, 3.6; 95% CI, 1.5 to 8.6), relative diameter change (>11.8%) during the cardiac cycle of the common carotid artery (ORadj, 10.0; 95% CI, 1.8 to 54.2), and trivial trauma (in the form of manipulative therapy of the neck) (ORadj, 3.8; 95% CI, 1.3 to 11). A weak association was found for homocysteine (2 studies: ORcrude, unknown; 95% CI, 1.05 to 1.52; ORcrude, 1.3; 95% CI, 1.0 to 1.7), and recent infection (ORadj, 1.60; 95% CI, 0.67 to 3.80). Two studies had conflicting findings for low levels of alpha1-antitrypsin, with the methodologically stronger study suggesting no association with CAD.

CONCLUSIONS

CAD is a multi-factorial disease. Many of the reviewed studies contained 2 or more major sources of bias commonly found in case-control studies. Only one study (of homocysteine) used healthy controls, a robust sample size, and had a low risk of biased results. The relationship between atherosclerosis and CAD has been insufficiently examined.