Ultrastructural connective tissue abnormalities in patients with spontaneous cervicocerebral artery dissections

Peripheral Blood Gene Expression Profiling Reveals Molecular Pathways Associated with Cervical Artery Dissection

Cervical artery dissection (CeAD) is the primary cause of ischemic stroke in young adults. Monogenic heritable connective tissue diseases account for fewer than 5% of cases of CeAD. The remaining sporadic cases have known risk factors. The clinical, radiological, and histological characteristics of systemic vasculopathy and undifferentiated connective tissue dysplasia are present in up to 70% of individuals with sporadic CeAD. Genome-wide association studies identified CeAD-associated genetic variants in the non-coding genomic regions that may impact the gene transcription and RNA processing. However, global gene expression profile analysis has not yet been carried out for CeAD patients. We conducted bulk RNA sequencing and differential gene expression analysis to investigate the expression profile of protein-coding genes in the peripheral blood of 19 CeAD patients and 18 healthy volunteers. This was followed by functional annotation, heatmap clustering, reports on gene-disease associations and protein-protein interactions, as well as gene set enrichment analysis. We found potential correlations between CeAD and the dysregulation of genes linked to nucleolar stress, senescence-associated secretory phenotype, mitochondrial malfunction, and epithelial-mesenchymal plasticity.

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.

Treatment and Outcomes of Cervical Artery Dissection in Adults: A Scientific Statement From the American Heart Association

Cervical artery dissection is an important cause of stroke, particularly in young adults. Data conflict on the diagnostic evaluation and treatment of patients with suspected cervical artery dissection, leading to variability in practice. We aim to provide an overview of cervical artery dissection in the setting of minor or no reported mechanical trigger with a focus on summarizing the available evidence and providing suggestions on the diagnostic evaluation, treatment approaches, and outcomes. Writing group members drafted their sections using a literature search focused on publications between January 1, 1990, and December 31, 2022, and included randomized controlled trials, prospective and retrospective observational studies, meta-analyses, opinion papers, case series, and case reports. The writing group chair and vice chair compiled the manuscript and obtained writing group members' approval. Cervical artery dissection occurs as a result of the interplay among risk factors, minor trauma, anatomic and congenital abnormalities, and genetic predisposition. The diagnosis can be challenging both clinically and radiologically. In patients with acute ischemic stroke attributable to cervical artery dissection, acute treatment strategies such as thrombolysis and mechanical thrombectomy are reasonable in otherwise eligible patients. We suggest that the antithrombotic therapy choice be individualized and continued for at least 3 to 6 months. The risk of recurrent dissection is low, and preventive measures may be considered early after the diagnosis and continued in high-risk patients. Ongoing longitudinal and population-based observational studies are needed to close the present gaps on preferred antithrombotic regimens considering clinical and radiographic prognosticators of cervical artery dissection.

A Fast, Robust Method for Quantitative Assessment of Collagen Fibril Architecture from Transmission Electron Micrographs

Collagen is the most abundant protein in mammals; it exhibits a hierarchical organization and provides structural support to a wide range of soft tissues, including blood vessels. The architecture of collagen fibrils dictates vascular stiffness and strength, and changes therein can contribute to disease progression. While transmission electron microscopy (TEM) is routinely used to examine collagen fibrils under normal and pathological conditions, computational tools that enable fast and minimally subjective quantitative assessment remain lacking. In the present study, we describe a novel semi-automated image processing and statistical modeling pipeline for segmenting individual collagen fibrils from TEM images and quantifying key metrics of interest, including fibril cross-sectional area and aspect ratio. For validation, we show first-of-their-kind illustrative results for adventitial collagen in the thoracic aorta from three different mouse models.

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.

A fast, robust method for quantitative assessment of collagen fibril architecture from transmission electron micrographs

Collagen is the most abundant protein in mammals; it exhibits a hierarchical organization and provides structural support to a wide range of soft tissues, including blood vessels. The architecture of collagen fibrils dictates vascular stiffness and strength, and changes therein can contribute to disease progression. While transmission electron microscopy (TEM) is routinely used to examine collagen fibrils under normal and pathological conditions, computational tools that enable fast and minimally subjective quantitative assessment remain lacking. In the present study, we describe a novel semi-automated image processing and statistical modeling pipeline for segmenting individual collagen fibrils from TEM images and quantifying key metrics of interest, including fibril cross-sectional area and aspect ratio. For validation, we show illustrative results for adventitial collagen in the thoracic aorta from three different mouse models.

Modulation of the biophysical and biochemical properties of collagen by glycation for tissue engineering applications

The structural and functional properties of collagen are modulated by the presence of intramolecular and intermolecular crosslinks. Advanced Glycation End-products (AGEs) can produce intermolecular crosslinks by bonding the free amino groups of neighbouring proteins. In this research, the following hypothesis is explored: The accumulation of AGEs in collagen decreases its proteolytic degradation rates while increasing its stiffness. Fluorescence Lifetime Imaging (FLIM) and Fourier-transform infrared spectroscopy (FTIR) detect biochemical changes in collagen scaffolds during the glycation process. The accumulation of AGEs increases exponentially in the collagen scaffolds as a function of Methylglyoxal (MGO) concentration by performing autofluorescence measurement and competitive ELISA. Glycated scaffolds absorb water at a much higher rate confirming the direct affinity between AGEs and interstitial water within collagen fibrils. In addition, the topology of collagen fibrils as observed by Atomic Force Microscopy (AFM) is a lot more defined following glycation. The elastic modulus of collagen fibrils decreases as a function of glycation, whereas the elastic modulus of collagen scaffolds increases. Finally, the enzymatic degradation of collagen by bacterial collagenase shows a sigmoidal pattern with a much slower degradation rate in the glycated scaffolds. This study identifies unique variations in the properties of collagen following the accumulation of AGEs. STATEMENT OF SIGNIFICANCE: In humans, Advanced Glycation End-products (AGEs) are naturally produced as a result of aging process. There is an evident lack of knowledge in the basic science literature explaining the biomechanical impact of AGE-mediated crosslinks on the functional and structural properties of collagen at both the nanoscale (single fibrils) and mesoscale (bundles of fibrils). This research, demonstrates how it is possible to harness this natural phenomenon in vitro to enhance the properties of engineered collagen fibrils and scaffolds. This study identifies unique variations in the properties of collagen at nanoscale and mesoscale following accumulation of AGEs. In their approach, they investigate the unique properties conferred to collagen, namely enhanced water sorption, differential elastic modulus, and finally sigmoidal proteolytic degradation behavior.

Cervical Artery Dissections: Etiopathogenesis and Management

Cervical Artery Dissection (CeAD) is a frequent stroke etiology for patients younger than 50 years old. The most common immediate complications related to CeAD are headache and neck pain (65-95%), TIA/ischemic stroke (>50%), and partial Horner's syndrome (25%). The prevailing hypothesis regarding the pathogenesis of sCeAD is that the underlying constitutional vessel wall weakness of patients with sCeAD is genetically determined and that environmental factors could act as triggers. The stroke prevention treatment of CeAD remains controversial, involving anticoagulation or antiplatelet therapy and potentially emergent stenting and/or thrombectomy or angioplasty for selected cases of carotid artery dissection with occlusion. The treatment of headache associated with CeAD depends on the headache phenotype and comorbidities. Radiographically, more than 75% of CeAD cases present with occlusion or non-occlusive stenosis. Many patients demonstrate partial and complete healing, more commonly in the carotid arteries. One-fifth of the patients develop dissecting pseudoaneurysm, but this is a benign clinical entity with an extremely low rupture and stroke recurrence risk. Good recovery is achieved in many CeAD cases, and mortality remains low. Family history of CeAD, connective tissue disorders like Ehlers-Danlos syndrome type IV, and fibromuscular dysplasia are risk factors for recurrent CeAD, which can occur in 3-9% of the cases. This review serves as a comprehensive, updated overview of CeAD, emphasizing etiopathogenesis and management.

Postpartum reversible cerebral vasoconstriction with cortical subarachnoid hemorrhage and posterior reversible encephalopathy syndrome concomitant with vertebral artery dissection diagnosed by MRI MSDE method: A case report and review of literature

Headache is one of the most common symptoms encountered during the postpartum period. The cause may be unknown, or the following illnesses are possible: cervical artery dissection (CAD), reversible posterior cerebral encephalopathy syndrome (PRES), and reversible cerebral vasoconstrictor syndrome (RCVS). It is suggested that they are interrelated and share a similar mechanism such as small vessel endothelial dysfunction, deficiencies in self-regulation, and decreased sympathetic innervation of the posterior circulation. However, there are few reports of neuroradiological findings. We experienced a rare case of multiple postpartum vascular disease occurring at the same time. A 38-year-old woman suddenly developed thunderclap headache after giving birth. She was clear and had no neuropathy. Computed tomography revealed subarachnoid hemorrhage, including the cortical surface of the frontal lobe. Magnetic resonance image fluid-attenuated inversion recovery revealed high-intensity area in the bilateral basal ganglia and right occipital cortex. Angiography showed "string sausage" and extracranial left vertebral artery stenosis, but no aneurysm. Based on the clinical course and neuroradiological findings, we diagnosed her as postpartum vascular disease including CAD, PRES, RCVS, and cortical subarachnoid hemorrhage (SAH). Three-dimensional black blood T1-weighted images using a motion-sensitized driven equilibrium three-dimensional turbo spin echo (MSDE) sequencing method revealed an intramural hematoma consistent with the extracranial vertebral artery. After 3 months, MSDE lost its abnormal signal. Our case was rare in that multiple phenomena of postpartum vascular disease occurred at the same time. In particular, we could reveal that this speculation was reversible in the MRI MSDE sequencing.

Posttraumatic subarachnoid hemorrhage related to concomitant carotid artery dissection and ruptured basilar trunk aneurysm: A case report and literature review

Background:

Carotid artery dissections (CADs) are a relatively rare disorder, whereas intracranial aneurysms (IAs) form a common cerebrovascular pathology. Since both vascular entities share similar risk factors and associations with connective tissue and vascular disorders, a common pathogenesis has been suggested. Here, we present a case of the concomitant occurrence of a CAD and a ruptured basilar trunk aneurysm (BTA). In the discussion, we elaborate on both vascular entities and have reviewed the literature on their concomitant incidence and potential shared pathogenesis.

Case Description:

We present a case of a 40-year-old female patient who was admitted to our hospital because of subarachnoid hemorrhage following a minor head trauma. Imaging revealed a BTA and unilateral extracranial dissection of the internal carotid artery. Despite coiling of the aneurysm, stenting of the dissection, and antithrombotic therapy, the patient died due to extensive cerebral ischemia sequelae.

Conclusion:

CAD and BTAs have both been associated with a vascular vulnerability but their concomitant occurrence has not been described previously. The previous studies have suggested an increased incidence of IAs in patients with a CAD and vice versa. However, the number of studies and reports on this mutual increased incidence is limited. Therefore, a shared pathogenesis seems rather speculative. In our case, we suggest that a posttraumatic CAD-induced hemodynamic alterations resulting in rupture of the saccular BTA.

Systematic review of the effectiveness of carotid surgery and endovascular carotid stenting versus best medical treatment in managing symptomatic acute carotid artery dissection

Cervical artery dissection (CeAD) with an intramural haematoma can lead to stroke risk, especially in young patients. We performed comprehensive searches of the Cochrane Stroke Group Trials Register, the CENTRAL, MEDLINE and EMBASE to review the effectiveness of surgical and endovascular interventions versus best medical treatment alone for symptomatic CeAD. Furthermore, we aim to elaborate on the phenotypic individual disease manifestations of spontaneous Cervical Artery Dissection (sCAD) and how they translate into stroke and risk of dissection recurrence. Primary outcomes were ipsilateral stroke and disability. Secondary outcomes were death, any stroke, or transient ischaemic attack, residual stenosis >50%, recurrence of CeAD, expanding pseudo-aneurysm or major bleeding. Our search yielded no randomised controlled trials and/or controlled clinical trials (CCTs) comparing either carotid surgery or endovascular therapy with optimal medical management; thus there was no evidence to support the use of any specific method for management of extracranial CeAD in patients who fail antithrombotic therapy. However, despite the absence of controlled studies to compare surgery or endovascular therapy in patients who fail antithrombotic therapy, carotid surgery in young patients can be justified as a personalized precision approach given the high morbidity and mortality in this age group.

Increased Internal Carotid Artery Tortuosity is a Risk Factor for Spontaneous Cervicocerebral Artery Dissection

OBJECTIVE

Spontaneous cervicocerebral artery dissection (sCCD) is an important cause of ischaemic stroke that often occurs in young and middle aged patients. The purpose of this study was to investigate the correlation between tortuosity of the carotid artery and sCCD.

METHODS

Patients with confirmed sCCD who underwent computed tomography angiography (CTA) were reviewed retrospectively. Age and sex matched patients having CTA were used as controls. The tortuosity indices of the cervical arteries were measured from the CTA images. The carotid siphon and the extracranial internal carotid artery (ICA) were evaluated according to morphological classification. The carotid siphons were classified into five types. The extracranial ICA was categorised as simple tortuosity, coiling or kinking. Independent risk factors for sCCD were investigated using multivariable analysis.

RESULTS

The study included sixty-six patients with sCCD and 66 controls. There were no differences in vascular risk factors between the two groups. The internal carotid tortuosity index (ICTI) (25.24 ± 12.37 vs. 15.90 ± 8.55, respectively; p < .001) and vertebral tortuosity index (VTI) (median 11.28; interquartile range [IQR] 6.88, 18.80 vs. median 8.38; IQR 6.02, 12.20, respectively; p = .008) were higher in the patients with sCCD than in the controls. Type III and Type IV carotid siphons were more common in the patients with sCCD (p = .001 and p < .001, respectively). The prevalence of any vessel tortuosity, coiling and kinking of the extracranial ICA was higher in the patients with sCCD (p < .001, p = .018 and p = .006, respectively). ICTI (odds ratio [OR] 2.964; p = .026), VTI (OR 5.141; p = .009), and Type III carotid siphons (OR 4.654; p = .003) were independently associated with the risk of sCCD.

CONCLUSION

Arterial tortuosity is associated with sCCD, and greater tortuosity of the cervical artery may indicate an increased risk of arterial dissection.

Ischemic Stroke in the Young

The purpose of this article is to address several challenging questions in the management of young patients (those age 60 and under) who present with ischemic stroke. Do genetic thrombophilic states, strongly associated with venous thrombosis, independently cause arterial events in adults? Should cases of patent foramen ovale be closed with mechanical devices in patients with cryptogenic stroke? What are the optimal treatments for cerebral vein thrombosis, carotid artery dissection, and antiphospholipid syndrome and are DOACs acceptable treatment for these indications? What is the mechanism underlying large vessel stroke in patients with COVID-19? This is a narrative review. We searched PubMed and Embase and American College of physicians Journal club database for English language articles since 2000 looking mainly at randomized clinical trials, Meta analyses, Cochran reviews as well as some research articles viewed to be cutting edge regarding anticoagulation and cerebrovascular disease. Searches were done entering cerebral vein thrombosis, carotid dissection, anticoagulation therapy and stroke, antiphospholipid antibody and stroke, stroke in young adults, cryptogenic stroke and anticoagulation, patent foramen ovale and cryptogenic stroke, COVID-19 and stroke.

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.

Collagen fibril abnormalities in human and mice abdominal aortic aneurysm

Vascular diseases like abdominal aortic aneurysms (AAA) are characterized by a drastic remodeling of the vessel wall, accompanied with changes in the elastin and collagen content. At the macromolecular level, the elastin fibers in AAA have been reported to undergo significant structural alterations. While the undulations (waviness) of the collagen fibers is also reduced in AAA, very little is understood about changes in the collagen fibril at the sub-fiber level in AAA as well as in other vascular pathologies. In this study we investigated structural changes in collagen fibrils in human AAA tissue extracted at the time of vascular surgery and in aorta extracted from angiotensin II (AngII) infused ApoE^-/- mouse model of AAA. Collagen fibril structure was examined using transmission electron microscopy and atomic force microscopy. Images were analyzed to ascertain length and depth of D-periodicity, fibril diameter and fibril curvature. Abnormal collagen fibrils with compromised D-periodic banding were observed in the excised human tissue and in remodeled regions of AAA in AngII infused mice. These abnormal fibrils were characterized by statistically significant reduction in depths of D-periods and an increased curvature of collagen fibrils. These features were more pronounced in human AAA as compared to murine samples. Thoracic aorta from Ang II-infused mice, abdominal aorta from saline-infused mice, and abdominal aorta from non-AAA human controls did not contain abnormal collagen fibrils. The structural alterations in abnormal collagen fibrils appear similar to those reported for collagen fibrils subjected to mechanical overload or chronic inflammation in other tissues. Detection of abnormal collagen could be utilized to better understand the functional properties of the underlying extracellular matrix in vascular as well as other pathologies. STATEMENT OF SIGNIFICANCE: Several vascular diseases including abdominal aortic aneurysm (AAA) are characterized by extensive remodeling in the vessel wall. Although structural alterations in elastin fibers are well characterized in vascular diseases, very little is known about the collagen fibril structure in these diseases. We report here a comprehensive ultrastructural evaluation of the collagen fibrils in AAA, using high-resolution microscopy techniques like transmission electron microscopy (TEM) and atomic force microscopy (AFM). We elucidate how abnormal collagen fibrils with compromised D-periodicity and increased fibril curvature are present in the vascular tissue in both clinical AAA as well as in murine models. We discuss how these abnormal collagen fibrils are likely a consequence of mechanical overload accompanying AAA and could impact the functional properties of the underlying tissue.

Connective Tissue Abnormalities in Patients with Ruptured Intracranial Aneurysms and No Known Systemic Connective Tissue Disorder

BACKGROUND

Defect in internal elastic lamina, defect in tunica media, and the amount of collagen and elastin play a role in vessel wall weakening leading to aneurysm formation. A similar picture may be found in connective tissue disorders, such as Marfan syndrome, Ehlers-Danlos syndrome (EDS), neurofibromatosis type 1, and Loeys-Dietz syndrome (LDS), where there is a predominant disorder of collagen formation/maturation.

METHODS

Histopathology of skin and the superficial temporal artery (STA) was done. All specimens were obtained during craniotomy for ruptured aneurysm clipping or other indicated procedures (for control subjects). Parameters in skin biopsy seen were epithelial thickness, dermal collagen thickness, and so forth. For the STA, parameters such as intimal thickness, intimal proliferation, thickness of media, and so forth were studied.

RESULTS

Twenty cases and twenty control subjects were studied. The mean age of the study population was 40.5 years. Salient findings on skin biopsy in patients of intracranial aneurysms (IAs) (cases) were haphazard orientation of collagen, inflammation in the subepidermal layer, increased dermal collagen thickness, and reduced and/or fragmented elastic fibers. Prominent findings on vessel wall biopsy were intimal proliferation, reduplication of internal elastic lamina, reduced and/or fragmented elastin, and vacuolation of smooth muscle cells. The average number of aberrations per patient was significantly higher in cases than control subjects.

CONCLUSIONS

The histologic changes seen in skin and the STA in cases of IAs signify a weak connective tissue. Some of these findings are also seen in known connective tissue disorders such as Marfan syndrome, EDS, neurofibromatosis type 1, and LDS. The connective tissue abnormalities found in patients with IAs may be congenital, which gets further accentuated by known risk factors leading to weak vessel wall and subsequent aneurysm formation.

Isolated hypoglossal nerve palsy from internal carotid artery dissection related to PKD-1 gene mutation

Background

Internal carotid artery dissection has been well recognized as a major cause of ischaemic stroke in young and middle-aged adults. However, internal carotid artery dissection induced hypoglossal nerve palsy has been seldom reported and may be difficult to diagnose in time for treatment; even angiography sometimes misses potential dissection, especially when obvious lumen geometry changing is absent.

Case presentation

We report a 42-year-old man who presented with isolated hypoglossal nerve palsy. High-resolution MRI showed the aetiological dissected internal carotid artery. In addition, a potential genetic structural defect of the arterial wall was suggested due to an exon region mutation in the polycystic-kidney-disease type 1 gene.

Conclusions

Hypoglossal nerve palsy is a rare manifestations of carotid dissection. High-resolution MRI may provide useful information about the vascular wall to assist in the diagnosis of dissection. High-throughput sequencing might be useful to identify potential cerebrovascular-related gene mutation, especially in young individuals with an undetermined aetiology.

Internal carotid and vertebral artery dissection: morphology, pathophysiology and provoking factors

The causes of internal carotid artery (ICA) and vertebral artery (VA) dissection, as well as its provoking factors, remain understudied. The aim of this paper was to explore morphological changes in the ICA/VA walls, factors provoking dissection, clinical signs and biomarkers of connective tissue (CT) damage. A total of 271 patients were examined, of whom 54% were women. The mean age of the participants was 37.0 ± 10 years. Clinical signs and biomarkers of CT damage (matrix metalloproteinase 9, tissue inhibitor of metalloproteinase 1, hydroxyproline, sulphated glycosaminoglycans) were analyzed in 82 patients and 40 healthy volunteers. Histologic examination of dissected and seemingly intact arteries conducted in 5 cases revealed signs of arterial wall dysplasia similar to those characteristics of fibromuscular dysplasia: thinning and splitting of the internal elastic membrane, areas of fibrosis, irregular orientation of myocytes, and their necrosis in the tunica media. Clinical signs and biomarkers of CT dysplasia (CTD) were more pronounced in patients with arterial dissection than in the controls. The major provoking factors were head turns and physical activity (42%), minor head injury (10%), and acute respiratory infection in the month preceding arterial dissection (14%). We conclude that arterial wall dysplasia is a predisposing factor for ICA/VA dissection, both spontaneous and provoked. The analysis of CTD biomarkers and clinical signs suggests connective tissue pathology in patients with ICA/VA dissection.

Craniocervical Arterial Dissection in Children: Pathophysiology and Management

BACKGROUND

Craniocervical arterial dissection is a commonly reported arteriopathy associated with stroke in children. It is characterized by a high stroke recurrence rate and variable outcomes. Here we review the pathophysiology, clinical presentation, and diagnostic neuroimaging approaches that are helpful in accurate diagnosis and follow-up of children with arterial dissection.

METHODS

MEDLINE searches (2000 to 2018) for articles that contained patients aged less than 18 years with craniocervical arterial dissection was performed, with the goal of analyzing their presenting features, pathophysiological mechanisms, and imaging characteristics and interventions.

RESULTS

Sixteen articles met the study criteria and reported 182 cases of craniocervical arterial dissection, 68% male, average age 8.6 years. Dissection was associated with head and neck trauma in 56% of the cases and frequently involved the posterior (61%) and extracranial locations (64%); the vertebral artery was the most commonly involved artery (60%). The most common clinical presentation was hemiparesis (80/160, 50%), followed by headache (64/164, 39%). Magnetic resonance imaging was the preferred neuroimaging method, followed by cerebral catheter angiography as a gold standard definitive neurovascular imaging modality when the initial vascular imaging revealed nondiagnostic findings.

CONCLUSIONS

The diagnosis of arterial dissection requires a high index of suspicion and consideration for detailed neurovascular imaging, including both the cranial and cervical regions. Neurovascular imaging challenges, especially visualization of arterial abnormalities, highlight the importance of appropriate and timely use of specific neurovascular imaging techniques. Magnetic resonance imaging appears to be the preferred neurovascular imaging modality in children with arterial dissection and may obviate the need for invasive cerebral catheter angiography.

Spontaneous bilateral internal carotid and vertebral artery dissections with dominant-hemisphere circulation maintained by external carotid artery–ophthalmic artery anastomoses

Spontaneous cervical artery dissection (sCAD) is a major cause of stroke in young adults. Multiple sCAD is a rarer, more poorly understood presentation of sCAD that has been increasingly attributed to cervical trauma such as spinal manipulation or genetic polymorphisms in extracellular matrix components. The authors present the case of a 49-year-old, otherwise healthy woman, who over the course of 2 weeks developed progressive, hemodynamically significant, bilateral internal carotid artery and vertebral artery dissections. Collateral response involved extensive external carotid artery–internal carotid artery anastomoses via the ophthalmic artery, which were instrumental in maintaining perfusion because circle of Willis and leptomeningeal anastomotic responses were hampered by the dissection burden in the corresponding collateral vessels. Endovascular intervention by placement of Pipeline embolization devices and Atlas stents in bilateral internal carotid arteries was successfully performed. No syndromic or systemic etiology was discovered during a thorough workup.

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.

Non-Atherosclerotic Vascular Disease in Women

OPINION STATEMENT

Takayasu arteritis, fibromuscular dysplasia (FMD), spontaneous arterial dissection, Raynaud's phenomenon, and chilblains are vascular conditions that are associated with an increased predisposition in women and are often underdiagnosed. Takayasu arteritis has an incidence rate of 2.6 cases per million individuals per year in the USA and predominantly affects women of childbearing age. HLA-B5 genetic locus is linked with Takayasu arteritis susceptibility. Methods to determine active disease are limiting; currently utilized clinical and imaging findings and laboratory tests are of limited value for this purpose. Pregnancy poses risks for maternal and fetal complications, and these patients need additional monitoring and care before and after conception. Controlling hypertension and immunosuppression using steroids, biological and non-biological immunosuppressants, are key components of managing patients with this arteritis. FMD commonly affects middle-aged, white females. Its true prevalence is unknown. Renal and cerebrovascular beds are the most frequently involved vascular beds. Its clinical presentation varies from no symptoms to catastrophic events. Controlling vascular risk factors, periodic surveillance, and revascularization when indicated are important factors in FMD management. Spontaneous arterial dissections are less common, but are an important cause of morbidity and mortality in specific populations. Cervicocephalic dissection causes 10-20% of the strokes in young adults, and coronary artery dissection is the culprit in almost one fourth of young women presenting with acute myocardial infarction. Early diagnosis is key to improving prognosis in these patients, as the majority of patients have spontaneous resolution of the dissection with conservative management alone. Increased clinician awareness of the presentation features and angiographic findings are imperative for early diagnosis. Raynaud's phenomenon and chilblains are cold- or stress-induced cutaneous lesions, commonly involving distal extremities. Secondary causes such as connective tissue diseases and malignancies must be thoroughly excluded during evaluation of these conditions. Cold avoidance, systemic and local warming, and oral vasodilator therapy are the mainstays of therapy.

Direct visualization of the arterial wall water permeability barrier using CARS microscopy

The artery wall is equipped with a water permeation barrier that allows blood to flow at high pressure without significant water leak. The precise location of this barrier is unknown despite its importance in vascular function and its contribution to many vascular complications when it is compromised. Herein we map the water permeability in intact arteries, using coherent anti-Stokes Raman scattering (CARS) microscopy and isotopic perfusion experiments. Generation of the CARS signal is optimized for water imaging with broadband excitation. We identify the water permeation barrier as the endothelial basolateral membrane and show that the apical membrane is highly permeable. This is confirmed by the distribution of the AQP1 water channel within endothelial membranes. These results indicate that arterial pressure equilibrates within the endothelium and is transmitted to the supporting basement membrane and internal elastic lamina macromolecules with minimal deformation of the sensitive endothelial cell. Disruption of this pressure transmission could contribute to endothelial cell dysfunction in various pathologies.

Duplex Ultrasound Recognition of Spontaneous Carotid Dissection

Spontaneous dissection of the internal carotid artery is an uncommon entity with a variable clinical presentation. A high index of suspicion is required to make the diagnosis, and prompt diagnosis and treatment with anticoagulation are essential for improved patient outcomes. Duplex ultrasound provides a safe and reliable imaging modality for early diagnosis and followup. The authors present a case of spontaneous internal carotid artery dissection with duplex ultrasound findings and a review of the literature.

Vascular Tortuosity May Be Associated With Cervical Artery Dissection

BACKGROUND AND PURPOSE

Dissection is an increasingly recognized cause of ischemic stroke, which occurs spontaneously or after trauma, in relatively young patients. We hypothesized that there might be a predisposing factor weakening the vascular wall and that arterial tortuosity might be higher in patients with dissection.

METHODS

We consecutively enrolled cervical artery dissection (CerAD) patients who had undergone magnetic resonance angiography. Age- and sex-matched healthy subjects who underwent magnetic resonance angiography in a routine health examination were used as controls. The tortuosity was measured semiautomatically from the carotid artery and vertebral artery (VA) arteries. Tortuosity index was defined as: [(arc/chord)-1×100] in each arteries. Independent risk factors associated with CerAD were investigated using multivariable analysis. Subgroup analysis according to the dissected artery was performed.

RESULTS

There were no differences in vascular risk factors between the 75 CerAD patients and the 75 controls. The tortuosity indexes of the contralesional VA (16.3±6.8 versus 12.1±4.5, respectively; P<0.001) and carotid artery (8.8±4.0 versus 7.3±2.9, respectively; P=0.01) were higher in patients with CerAD compared with those of control subjects. VA tortuosity (odds ratio, 1.175; P=0.001) was independently associated with the presence of CerAD. In subgroup analysis, VA tortuosity was significantly higher in 57 patients with VA dissection than in controls (P<0.001), and carotid artery tortuosity was marginally higher in 18 patients with carotid artery dissection (P=0.05).

CONCLUSIONS

CerAD is associated with tortuous cervical arteries, which may implicate weakened cervical vascular structure in these patients.

Neurovascular manifestations of connective-tissue diseases: A review

Patients with connective tissue diseases are thought to be at a higher risk for a number of cerebrovascular diseases such as intracranial aneurysms, dissections, and acute ischemic strokes. In this report, we aim to understand the prevalence and occurrences of such neurovascular manifestations in four heritable connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome, Neurofibromatosis Type 1, and Loeys-Dietz syndrome. We discuss the fact that although there are various case studies reporting neurovascular findings in these connective tissue diseases, there is a general lack of case-control and prospective studies investigating the true prevalence of these findings in these patient populations. Furthermore, the differences observed in the manifestations and histology of such disease pathologies encourages future multi-center registries and studies in better characterizing the pathophysiology, prevalence, and ideal treatment options of neurovascular lesions in patents with connective tissue diseases.

State-of-art in surgical treatment of dissecting posterior circulation intracranial aneurysms

Vertebrobasilar (VB) intracranial dissecting aneurysms (IDAs) pose difficult therapeutic issues and are especially among the most difficult to manage surgically. There are, however, some cases where selective aneurysm obliteration by endovascular approach is impossible or is associated with an unacceptable risk of morbidity. This is particularly true when the aneurysm is dissecting, giant, or has a large neck. In such cases, surgical treatment may be the only alternative. Optimal management of these lesions is therefore challenging and treatment decisions have to be made on a case-by-case basis. Ideal treatment should be a complete surgical excision of the lesion; however, this procedure might only be possible after distal and proximal vessel wall occlusion which might not be tolerated by the patient depending on the location of the aneurysm. Therefore, formulation of recommendations concerning the surgical strategy remains still difficult due to inconsistency of surgical outcomes. The literature describing surgical strategy of VB IDAs is varying in quality and content, and many studies deal with only a few patients. In the presented review, the authors summarize the current knowledge on the incidence, pathogenesis, clinical presentation, and diagnostic procedures with special emphasis on surgical treatment of IDAs in posterior circulation.

TGFBR2 mutation and MTHFR-C677T polymorphism in a Mexican mestizo population with cervico-cerebral artery dissection

Spontaneous cervico-cerebral artery dissection (CCAD) is a common condition found among young patients with ischemic stroke. We examined the possible association between the polymorphism of methylenetetrahydrofolate reductase (MTHFR)-C677T and the gene mutation in transforming growth factor beta receptor II (TGFBR2) in a cohort of CCAD patients. One-hundred CCAD cases (65 males; mean age: 38.08 ± 10.68 years) and 100 matching controls were included. Ancestry informative markers (AIMs) were used to increase internal validity of the genetic analysis. Genotypes of the C677T polymorphism in the MTHFR gene were determined by polymerase chain reaction and restriction fragment length polymorphism; direct sequencing was used for a mutation analysis of the TGFBR2 gene. Associations were evaluated using a multivariate statistics, and Hardy-Weinberg equilibrium was analyzed. We also incorporated our data into a meta-analysis of the MTHFR-C677T. Sixty-three patients presented with vertebral and 37 with carotid artery dissection. Ancestry markers found a call rate on each over 95 %. All AIMs did not deviate from Hardy-Weinberg equilibrium (p > 0.05). The homozygous TT genotype was more frequent in cases (OR 2.04, CI 95 % 1.53-2.72, p = 0.005), whereas no significant difference was found on heterozygous CT genotype. TGFBR2 mutation was not present in our samples. In the meta-analysis of MTHFR/C677T variant, a total 613 cases and 1547 controls were analyzed; we found a moderate association for the recessive model genotype (OR 2.04, CI 95 % 1.53-2.72; p = 0.342; Z = 4.83; I (2) = 11.3). This study supports a positive association between the MTHFR-C677T polymorphism and genetically confirmed Mexican mestizo CCAD patients.

Vocal Cord Paralysis as the First Sign of Spontaneous Carotid Dissection in a Patient With Extracranial Internal Carotid Artery Aneurysm

INTRODUCTION

Spontaneous dissection of supra-aortic arteries is an exceptionally rare cause of vocal cord dysfunction. We are reporting a case of spontaneous carotid dissection and internal carotid artery aneurysm presenting as vocal cord paralysis.

CASE REPORT

A 44-year-old female was admitted with hoarseness and swallowing disorders. Diagnostic imaging revealed dissection and obliteration of the right internal carotid artery (ICA) 23 mm from the carotid bifurcation. Electromyography revealed unilateral paralysis/paresis of the right vocal cord. Genetic analyses for thrombophilia, methylenetetrahydrofolate reductase, and plasminogen activator inhibitor 1 were found to be at high risk. The patient was discharged after 5 days without any neurological findings, and control angiography revealed complete restitution of the flow in the right ICA one month later. However, a fusiform aneurysm of the distal part of the extracranial right ICA was detected and excluded with endovascular procedure.

CONCLUSION

Connective tissue systemic disorders and even mild trauma could initiate the dissection process of neck arteries. Precise diagnosis might be difficult even for an experienced neurologist, however, the final outcome is favorable.

Cervical Artery Dissection: A Review of the Epidemiology, Pathophysiology, Treatment, and Outcome

CONTEXT

Cervical artery dissection (CAD) is a common cause of stroke in young adults. There is controversy over whether anticoagulation is superior to antiplatelet therapy in preventing stroke in patients with CAD, although meta-analyses to date have not shown any difference between the two treatments.

EVIDENCE ACQUISITION

We performed a PubMed search using each of the keywords: "Cervical artery dissection", "Dissection", "Carotid dissection", and "Vertebral dissection" between January 1^st, 1990 and July 1^st 2015. We identified evidence-based peer-reviewed articles, including randomized trials, case series and reports, and retrospective reviews that encompass the epidemiology, clinical manifestations, pathophysiology, treatment, and outcome of cervical artery dissection.

RESULTS

This paper highlights the mechanisms of cervical artery dissection and stroke in patients with dissection as well as the natural history and treatment.

CONCLUSION

Given the relatively rare incidence of this disease, multicenter studies with collaborative effort among stroke centers worldwide should be considered to enroll patients with cervical artery dissection in a randomized trial comparing the two treatments.

Familial occurrence and heritable connective tissue disorders in cervical artery dissection

OBJECTIVE

In a large series of patients with cervical artery dissection (CeAD), a major cause of ischemic stroke in young and middle-aged adults, we aimed to examine frequencies and correlates of family history of CeAD and of inherited connective tissue disorders.

METHODS

We combined data from 2 large international multicenter cohorts of consecutive patients with CeAD in 23 neurologic departments participating in the CADISP-plus consortium, following a standardized protocol. Frequency of reported family history of CeAD and of inherited connective tissue disorders was assessed. Putative risk factors, baseline features, and 3-month outcome were compared between groups.

RESULTS

Among 1,934 consecutive patients with CeAD, 20 patients (1.0%, 95% confidence interval: 0.6%-1.5%) from 17 families (0.9%, 0.5%-1.3%) had a family history of CeAD. Family history of CeAD was significantly more frequent in patients with carotid location of the dissection and elevated cholesterol levels. Two patients without a family history of CeAD had vascular Ehlers-Danlos syndrome with a mutation in COL3A1. This diagnosis was suspected in 2 additional patients, but COL3A1 sequencing was negative. Two patients were diagnosed with classic and hypermobile Ehlers-Danlos syndrome, one patient with Marfan syndrome, and one with osteogenesis imperfecta, based on clinical criteria only.

CONCLUSIONS

In this largest series of patients with CeAD to date, family history of symptomatic CeAD was rare and inherited connective tissue disorders seemed exceptional. This finding supports the notion that CeAD is a multifactorial disease in the vast majority of cases.

Cervical arterial dissections and association with cervical manipulative therapy: a statement for healthcare professionals from the american heart association/american stroke association

PURPOSE

Cervical artery dissections (CDs) are among the most common causes of stroke in young and middle-aged adults. The aim of this scientific statement is to review the current state of evidence on the diagnosis and management of CDs and their statistical association with cervical manipulative therapy (CMT). In some forms of CMT, a high or low amplitude thrust is applied to the cervical spine by a healthcare professional.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association's Manuscript Oversight Committee. Members were assigned topics relevant to their areas of expertise and reviewed appropriate literature, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge.

RESULTS

Patients with CD may present with unilateral headaches, posterior cervical pain, or cerebral or retinal ischemia (transient ischemic or strokes) attributable mainly to artery-artery embolism, CD cranial nerve palsies, oculosympathetic palsy, or pulsatile tinnitus. Diagnosis of CD depends on a thorough history, physical examination, and targeted ancillary investigations. Although the role of trivial trauma is debatable, mechanical forces can lead to intimal injuries of the vertebral arteries and internal carotid arteries and result in CD. Disability levels vary among CD patients with many having good outcomes, but serious neurological sequelae can occur. No evidence-based guidelines are currently available to endorse best management strategies for CDs. Antiplatelet and anticoagulant treatments are both used for prevention of local thrombus and secondary embolism. Case-control and other articles have suggested an epidemiologic association between CD, particularly vertebral artery dissection, and CMT. It is unclear whether this is due to lack of recognition of preexisting CD in these patients or due to trauma caused by CMT. Ultrasonography, computed tomographic angiography, and magnetic resonance imaging with magnetic resonance angiography are useful in the diagnosis of CD. Follow-up neuroimaging is preferentially done with noninvasive modalities, but we suggest that no single test should be seen as the gold standard.

CONCLUSIONS

CD is an important cause of ischemic stroke in young and middle-aged patients. CD is most prevalent in the upper cervical spine and can involve the internal carotid artery or vertebral artery. Although current biomechanical evidence is insufficient to establish the claim that CMT causes CD, clinical reports suggest that mechanical forces play a role in a considerable number of CDs and most population controlled studies have found an association between CMT and VAD stroke in young patients. Although the incidence of CMT-associated CD in patients who have previously received CMT is not well established, and probably low, practitioners should strongly consider the possibility of CD as a presenting symptom, and patients should be informed of the statistical association between CD and CMT prior to undergoing manipulation of the cervical spine.

The Association Between Cervical Spine Manipulation and Carotid Artery Dissection: A Systematic Review of the Literature

OBJECTIVE

Controversy surrounds the safety of cervical spine manipulation. Ischemic stroke secondary to cervical spine manipulation is a hypothesized adverse event. In Canada, the seriousness of these events and their perceived association to cervical spine manipulation has led some members of the public to call for a ban of the procedure. The primary objective of this study was to determine the incidence of internal carotid artery (ICA) dissection after cervical spine manipulation in patients who experience neck pain and its associated disorders. The secondary objective was to determine whether cervical spine manipulation is associated with an increased risk of ICA dissection in patients with neck pain, upper back pain, or headaches.

METHODS

We systematically searched MEDLINE, CINAHL, Alternative Health, AMED, Index to Chiropractic Literature, and EMBASE from 1970 to November 2012. Two independent reviewers used standardized criteria to screen the eligibility of articles. We considered cohort studies, case-control studies, and randomized clinical trials that addressed our objectives. We planned to critically appraise eligible articles using the Scottish Intercollegiate Guideline Network methodology.

RESULTS

We did not find any epidemiologic studies that measured the incidence of cervical spine manipulation and ICA dissection. Similarly, we did not find any studies that determined whether cervical spine manipulation is associated with ICA dissection.

CONCLUSIONS

The incidence of ICA dissection after cervical spine manipulation is unknown. The relative risk of ICA dissection after cervical spine manipulation compared with other health care interventions for neck pain, back pain, or headache is also unknown. Although several case reports and case series raise the hypothesis of an association, we found no epidemiologic studies that validate this hypothesis.

Management of ruptured dissecting intracranial aneurysms in infants: report of four cases and review of the literature

BACKGROUND

Intracranial cerebral aneurysms in the pediatric population are infrequent, and those occurring in infants less than 1 year old are extremely rare. Of intracranial aneurysms in children, dissecting aneurysms are the most common type seen. While spontaneous dissecting aneurysms usually present with ischemia, hemorrhage can also occur.

METHODS

A retrospective review of our patients revealed that from July 1, 2007 to June 30, 2012, four infants were treated for ruptured distal dissecting intracranial aneurysms at Texas Children's Hospital. Mycotic aneurysms and collagen vascular disorder were excluded in all four cases. All patients presented in our series presented with subarachnoid hemorrhage, and three had intraventricular hemorrhage. All patients underwent conventional catheter angiography for diagnosis. All patients in this series were managed in the acute or subacute period with surgical or endovascular trapping without distal bypass procedures. All four patients tolerated sacrifice of the parent vessels feeding these distal aneurysms well.

CASE REPORT AND REVIEW OF LITERATURE

We describe the presentation and management of these rare cases and then review the current literature on the management of these dissecting aneurysms in infants.

Risk factors and clinical presentation of craniocervical arterial dissection: a prospective study

Background

Craniocervical arterial dissection is a major cause of ischaemic stroke in young adults. The pathogenesis is not fully understood but is thought to be related to a combination of an intrinsic weakness in the arterial wall and an external trigger. Intrinsic susceptibility is thought to be a generalised arteriopathy, vascular anomaly or genetic predisposition. Proposed extrinsic factors include recent viral infection and minor mechanical trauma to the neck, including neck manipulation, which has raised concerns amongst manual practitioners in particular as to the appropriate screening of patients and avoidance of more vigorous therapeutic techniques. The presenting features of dissection may mimic a musculoskeletal presentation, creating a diagnostic dilemma for primary care practitioners. Early recognition is critical so that appropriate management can be commenced.

The aims of this study are to prospectively investigate young patients ≤55 years admitted to hospital with radiologically diagnosed craniocervical arterial dissection compared to matched controls with stroke but not dissection, to identify risk factors and early presenting clinical features, so these may be more readily identified by primary care practitioners.

Methods

Patients ≤ 55 years presenting to hospital with craniocervical arterial dissection and controls will have their medical records reviewed and be interviewed and questioned about possible risk factors, preceding events to admission such as recent neck trauma, and presenting clinical features including any preceding transient ischaemic features. Clinical assessment will include a connective tissue screening examination to identify subclinical connective tissue disorders. Radiology and blood screening will be reviewed for typical features and inflammatory markers. Functional outcome will be reviewed to determine the burden of the stroke.

Discussion

This study will provide descriptive and comparative data on intrinsic and extrinsic risk factors for craniocervical arterial dissection and outline the typical clinical presentation, including the nature of early presenting features which might assist practitioners to identify those patients for whom vigorous manual therapy of the neck is inappropriate and alert them to those for whom immediate urgent medical care should be sought.