Seasonal variability in spontaneous cervical artery dissection

Stylohyoid Chain Syndrome (Eagle Syndrome) in Conjunction with Carotid Artery Dissection: A Case Report of Surgical Treatment

(1) Background: "Eagle Syndrome", also known as "stylalgia" or a "stylohyoid chain anomaly", typically manifests with ipsilateral orofacial pain, a foreign body sensation in the throat, and ear-related symptoms. Despite these common presentations, its potential association with carotid artery dissection is not widely acknowledged. (2) Methods: This article presents an extremely rare case of a patient diagnosed with an ischemic stroke in the left hemisphere, followed by the dissection of the left internal carotid artery, initially with an unidentified cause. Subsequent examinations revealed elongated left styloid processes directly compressing the dissected artery. (3) Results: After initial treatment involving pharmacological and mechanical thrombectomy, styloidectomy restored blood flow to the internal carotid artery. The patient remained symptom-free during a 12-month follow-up. (4) Conclusions: This case emphasizes the importance of considering anatomical variations within the stylohyoid chain when assessing young individuals with neurological symptoms. Furthermore, it underscores the potential benefits of early surgical intervention in reducing the morbidity and mortality associated with this condition.

Genetics of spontaneous cervical and coronary artery dissections

Objectives

Spontaneous cervical artery dissections (SCeAD) and coronary artery dissections (SCoAD) are major causes of neurovascular and cardiovascular morbidity in young adults. Although multiple aspects of their etiology are still unknown, most consensuses are focused on the presence of constitutional genetic aspects and environmental triggers. Since recent evidence of genetic contribution points to a possible overlap between these conditions, we aimed to describe current information on SCeAD and SCoAD genetics and their potential shared pathological aspects.

Materials and methods

A narrative review is presented. Publications in English and Spanish were queried using database search. The articles were evaluated by one team member in terms of inclusion criteria. After collecting, the articles were categorized based on scientific content.

Results

Given that patients with SCeAD and SCoAD rarely present connective tissue disorders, other genetic loci are probably responsible for the increased susceptibility in some individuals. The common variant rs9349379 at PHACTR1 gene is associated with predisposition to pathologies of the arterial wall, likely mediated by variations in Endothelin-1 (ET-1) levels. The risk of arterial dissection may be increased for those who carry the rs9349379(A) allele, associated with lower expression levels of ET-1; however, the local effect of this vasomotor imbalance remains unclear. Sex differences seen in SCeAD and SCoAD support a role for sex hormones that could modulate risk, tilting the delicate balance and forcing vasodilator actions to prevail over vasoconstriction due to a reduction in ET-1 expression.

Conclusions

New evidence points to a common gene variation that could explain dissection in both the cervical and coronary vasculatures. To further confirm the risk conferred by the rs9349379 variant, genome wide association studies are warranted, hopefully in larger and ethnically diverse populations.

Decline in spontaneous cervical artery dissection incidence during COVID-19 public health measures: Evidence for a role of upper respiratory infections in pathogenesis

BACKGROUND

Upper respiratory infections have been suggested as a risk factor for spontaneous cervical artery dissection (sCeAD). If this is the case, public health measures implemented to contain the spread of SARS-CoV-2, which also reduced other communicable diseases such as influenza, might be associated with a reduction in cervical artery dissection incidence.

AIMS

We determined the incidence of sCeAD before, during and after the COVID-19 pandemic, and the associated public health measures.

METHODS

All patients suffering an sCeAD and seen in Innsbruck Austria, between January 2002 to December 2016 (pre-COVID comparators) and between January 2020 to August 2022 were recorded through two individual prospective cohort studies. We compared admission rates, demographic, and clinical characteristics of sCeAD patients in pre-COVID-19 and COVID-19 times.

RESULTS

In total, 249 sCeAD patients were admitted prior to the COVID-19 pandemic compared to 20 during its course. Baseline characteristics of sCeAD subjects did not differ in subjects admitted during and prior to the pandemic. Following the introduction of public health measures for the pandemic, there was a marked decrease of sCeAD admissions from 16.5 per year to 6.3 per year (p = 0.012). Since the measures were ended the number of sCeAD admissions increased again. In contrast, the number of all ischemic stroke patients treated at the Medical University of Innsbruck did not alter during the pandemic. (N per year: 633 in 2015, 687 in 2017, 684 in 2019, 731 in 2020, and 717 in 2021).

CONCLUSION

The incidence of sCeAD fell markedly during the pandemic and this may have resulted from the public health measures introduced and a subsequent reduction in upper respiratory infections. Our study provides indirect evidence for a role of infection in the pathogenesis of sCeAD.

DATA ACCESS STATEMENT

Anonymized data not published within this article will be made available by request from any qualified investigator.

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.

Retrospective Comparative Analysis of Clinical and Imaging Features of Craniocervical Artery Dissection: Spontaneous CAD vs. Minor Traumatic CAD

Background and Objectives

Craniocervical artery dissection (CAD) is the most common cause of ischemic stroke in young adults. The etiologies of CAD can be classified into three types, such as spontaneous (sCAD), minor traumatic (mtCAD), and genetic origin. Recent studies indicated that clinical presentations and imaging features could guide management and inform prognosis. This retrospective analysis sought to compare the clinical and imaging features of sCAD vs. mtCAD in providing evidence-based advice on medical treatment, functional rehabilitation, secondary stroke prevention, and prognosis, ultimately formulating clinical guidelines in managing CAD.

Methods

In total, 148 patients with CAD were identified from the medical records database and subdivided into sCAD and mtCAD based on the clinical presentations and imaging features. A retrospective comparative analysis was performed according to their clinical presentations and imaging features.

Results

Patients with mtCAD are significantly younger than sCAD with 120 cases of sCAD average aged 43.61 ± 12.75, while 28 cases of mtCAD average aged 35.68 ± 14.54. Patients with mtCAD had more cases of neck pain compared to sCAD. Patients with mtCAD had more cases of CAD at extracranial locations compared to sCAD. Patients with mtCAD had more cases of multiple site dissection compared to sCAD. Double lumen and intramural haematoma are the most common imaging findings with mtCAD patients having statistical significantly more cases of intramural haematoma and long tapering stenosis.

Conclusion

Patients with mtCAD were presented at a much younger age with symptoms of neck pain compared to sCAD. Patients with mtCAD predominantly presented at extracranial sites with more prominent features of multiple site dissection, intramural haematoma, and long tapering stenosis. These clinical and imaging features can translate into clinical practice guidelines for patients with CAD to improve the optimal functional outcome and reduce both morbidity and mortality.

Clinical case of successful treatment of internal carotid artery dissection during aneurysm embolization in acute period of subarachnoid hemorrhage

Artery dissection during embolization of an intracranial aneurysm is not a frequent complication. In most cases, the tactics of treatment are limited to the appointment of anticoagulants or balloon angioplasty. We present a clinical case of successful treatment of a woman of 47 years. Dissection of the internal carotid artery occurred during aneurysm embolization in the acute period of subarachnoid hemorrhage and required coronary stent implantation. The absence in the long-term period of signs of restenosis or mechanical damage to the coronary stent in the installed position indicates the possibility of implanting it in the indicated position in urgent situations. The clinical significance of the described case consists in combining sequentially rarely occurring events one after another.

Vertebral Artery Dissection in Sport: A Systematic Review

BACKGROUND

Vertebral artery dissection (VAD) is a potentially catastrophic injury that may occur during sports participation. A comprehensive review is needed to collate documented cases to improve understanding and inform future preventative approaches.

OBJECTIVE

This review aimed to understand the extent of VAD in sport and characterise trends suggestive of mechanisms of injury.

METHODS

Electronic databases were searched using terms related to VAD and sport. Records were included if they described one or more cases of VAD attributed to sport.

RESULTS

A total of 79 records described 128 individual cases of VAD in sport, of which 118 were confirmed by imaging or autopsy and included in analyses. Cases were attributed to 43 contact and non-contact sports. The median age of cases was 33 years (IQR 22-44), and 75% were male. There were 22 cases of fatal injury, of which ten involved an impact to the mastoid region and seven involved an impact to the head or neck. Non-fatal cases of VAD were attributed to impact to the head or neck (not mastoid region), movement or held position without impact, and in some cases no reported incident.

CONCLUSIONS

VAD attributed to sports participation is uncommonly reported and the mechanisms are varied. Impact to the mastoid region is consistently implicated in fatal cases and should be the focus of injury prevention strategies in sport. Efforts may also be directed at improving the prognosis of cases with delayed presentation through clinical recognition and imaging. The review was registered on the international prospective register for systematic reviews ( http://www.crd.york.ac.uk/PROSPERO ) (CRD42018090543).

High incidence and clinical characteristics of fibromuscular dysplasia in patients with spontaneous cervical artery dissection: The ARCADIA-POL study

The association between fibromuscular dysplasia (FMD) and spontaneous cervical artery dissection (SCeAD) has been recognized, but the available evidence on this relationship is scant. Therefore, the main goal of our study was to systematically evaluate FMD frequency, clinical characteristics and vascular bed involvement in patients with SCeAD. Among 230 patients referred to the ARCADIA-POL study, 43 patients (mean age 44.1 ± 8.9 years; 15 men and 28 women) with SCeAD were referred. Also, 135 patients with FMD were compared to patients with and without SCeAD. Patients underwent: ambulatory blood pressure measurements, biochemical evaluation, echocardiographic examination, and whole body computed tomographic angiography. FMD changes were found in 39.5% of patients with SCeAD. There were no differences in clinical characteristics between patients with SCeAD and FMD and those without FMD, except for a tendency towards a higher female ratio in SCeAD patients with FMD. There were no differences in other parameters describing target organ and SCeAD characteristics. Patients with SCeAD and FMD compared to those without SCeAD were characterized by a lower frequency of hypertension and a higher frequency of hyperlipidemia and history of contraceptive hormone use. Our study indicates a high incidence (39.5%) of FMD in subjects with SCeAD. Since there are no distinctive discriminating factors between patients with SCeAD and FMD and those without FMD, FMD should be suspected in all patients with SCeAD.

Spontaneous cervical artery dissection: a fluoroquinolone induced connective tissue disorder?

Background

Spontaneous cervical artery dissections more often manifest in young people and have been associated with catastrophic consequences. Some indeterminate risk factors have been identified, making the diagnosis of developing dissections quite difficult. Fluoroquinolone antibiotics have been recognized for their degradative effects on connective tissue. Recent studies have implicated fluoroquinolones in the genesis of aortic artery aneurysms. It is the purpose of this paper to provide reasoning for a testable hypothesis of whether fluoroquinolones constitute a risk factor associated with cervical artery dissections.

Methods

A PubMed search was conducted to investigate whether cervical artery dissection has been associated with fluoroquinolone use. An assessment of risk factors was made of hereditary connective tissue disorders, infection, and seasonal predisposition related to cervical artery dissection. These factors were considered in conjunction with reports of connective tissue toxicity associated with fluoroquinolone medications.

Results

It appears that no reported cases of cervical artery dissection have previously been correlated with fluoroquinolone use. Heritable connective tissue disorders, infection, seasonal predisposition and condition latencies are associated with fluoroquinolone medications. Several recent articles have implicated fluoroquinolones with aortic dissections and aneurysm.

Conclusion

A causal relationship of fluoroquinolone antibiotics to cervical artery dissection is plausible. The suppositions developed in this paper are insufficient to suggest that fluoroquinolones currently represent an established risk factor in the development of cervical artery dissections. Fluoroquinolones may indeed be a novel and previously unrecognized cause of cervical artery dissections.

Craniocervical Dissections: Radiologic Findings, Pitfalls, Mimicking Diseases: A Pictorial Review

Background:

Craniocervical Dissections (CCD) are a crucial emergency state causing 20% of strokes in patients under the age of 45. Although DSA (digital substraction angiography) is regarded as the gold standard, noninvasive methods of CT, CTA and MRI, MRA are widely used for diagnosis.

Aim:

Our aim is to illustrate noninvasive imaging findings in CCD.

Conclusion:

Emphasizing on diagnostic pitfalls, limitations and mimicking diseases.

Adverse events associated with the use of cervical spine manipulation or mobilization and patient characteristics: A systematic review

Cervical spinal manipulation (CSM) and cervical mobilization are frequently used in patients with neck pain and headache. Pre-manipulative cervical instability and arterial integrity tests appear to be unreliable in identifying patients at risk for adverse events. It would be valuable if patients at risk could be identified by specific characteristics during the preliminary screening. Objective was to identify characteristics of 1) patients, 2) practitioners, 3) treatment process and 4) adverse events (AE) occurring after CSM or cervical mobilization. A systematic search was performed in PubMed, Embase, CINAHL, Web-of-science, AMED, and ICL (Index Chiropractic Literature) up to December 2014. Of the initial 1043 studies, 144 studies were included, containing 227 cases. 117 cases described male patients with a mean age of 45 (SD 12) and a mean age of 39 (SD 11) for females. Most patients were treated by chiropractors (66%). Manipulation was reported in 95% of the cases, and neck pain was the most frequent indication. Cervical arterial dissection (CAD) was reported in 57% (P = 0.21) of the cases and 45.8% had immediate onset symptoms. The overall distribution of gender for CAD is 55% (n = 71) for female and therefore opposite of the total AE. Patient characteristics were described poorly. No clear patient profile, related to the risk of AE after CSM, could be extracted. However, women seem more at risk for CAD. There seems to be under-reporting of cases. Further research should focus on a more uniform and complete registration of AE using standardized terminology.

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.

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.

MR in hypertension

Hypertension is a common systemic disorder affecting the cardiovascular system and kidneys with important morbidity and mortality. However, hypertension is often thought of by radiologists as an "invisible" disease. The aim of this article is to first review hypertension first in terms of its diagnosis, epidemiology and clinical importance. Second, those causes of secondary hypertension that may be diagnosed with MRI techniques are described along with the effects of hypertension on the cardiovascular system and kidneys that are demonstrable with MRI with particular emphasis on renovascular disease. Lastly the use of integrated MRI protocols to evaluate the hypertensive patient and areas for future research are considered.

Vertebral artery dissection complicating occipital injection of heparin for treatment of thoracic outlet syndrome

A 38-year-old woman with a 2-year history of chronic neck pain radiating down her right arm underwent radiological and neurological evaluations, which revealed no anatomical cause for her pain. She sought alternative therapies including intramuscular heparin injections. Following a right occipital injection of heparin, cyanocobalamin, and lidocaine, she had a sudden cardiorespiratory arrest and was successfully resuscitated, but did not regain consciousness.Computed tomography of the head and neck and subsequent autopsy revealed a right vertebral artery dissection, but at autopsy, no significant subarachnoid hemorrhage was noted at the base of the brain. This is the first case report where heparin (a potent anticoagulant) used in an occipital injection was documented to cause a vertebral artery dissection. It is also the first reported case where radiographically and histologically documented vertebral artery dissection did not present with overwhelming subarachnoid hemorrhage at the base of the brain. The subtle gross anatomical findings in this case highlight the importance of evaluating the cervical spinal cord in any case of sudden cardiorespiratory arrest following even apparently minor neck injury.

[Factors predisposing to cervical artery dissection]

INTRODUCTION

Cervical artery dissection is a major cause of cerebral ischemia in young adults and can lead to various clinical symptoms, some of which are benign (e.g. headache, neck pain, Horner's syndrome, and cranial nerve palsy). However, most patients have a stroke or transient ischemic attack.

EPIDEMIOLOGY

The incidence of cervical artery dissection is low and is estimated to be around 2.6 per 100,000 inhabitants. Mortality and short-term recurrence rates are low: however; they may have been underestimated.

PATHOPHYSIOLOGY

Although the pathophysiology is still unclear constitutional and partly genetic susceptibility of the arterial wall has been proposed as a causal factor; triggered by infection or minor trauma. PREDISPOSING FACTORS: In addition to the trauma to the neck, other risk fractors have been suggested, such as infection, migraine, hyperhomocisteinamia, and the 67TT genotype of the 5,10-methylene-tetrahydrofolate reductase gene although evidence is sparse.

GENETIC FACTORS

Cervical artery dissection is now considered a multifactorial disease caused by several genetic abnormalities and environmental factors acting synergistically.

CONCLUSION

Research aimed at improving our understanding of the environmental and genetic factors predisposing to cervical artery dissection and assessment of long-term outcomes of this disease is needed. Better understanding of the underlying pathophysiology and the natural history of the disease through large prospective multicentre cohorts could also be helpful to improve therapeutic and preventive strategies. Several mutlticentre efforts are already under way to meet these needs.

Cerebrovascular Dissections—A Review Part I: Spontaneous Dissections

Spontaneous cerebrovascular dissections are subintimal or subadventitial cervical carotid and vertebral artery wall injuries and are the cause of as many as 2% of all ischemic strokes. Spontaneous dissections are the leading cause of stroke in patients younger than 45 years of age, accounting for almost one fourth of strokes in this population. A history of some degree of trivial trauma is present in nearly one fourth of cases. Subsequent mortality or neurological morbidity is usually the result of distal ischemia produced by emboli released from the injury site, although local mass effect produced by arterial dilation or aneurysm formation also can occur. The gold standard for diagnosis remains digital subtraction angiography. Computed tomography angiography, magnetic resonance angiography, and ultrasonography are complementary means o evaluation, particularly for injury screening or treatment follow-up. The annual rate of stroke after injury is approximately 1% or less per year. The currently accepted method of therapy remains antithrombotic medication, either in the form of anticoagulation or antiplatelet agents; however, no class I medical evidence exists to guide therapy. Other options for treatment include thrombolysis and endovascular therapy, although the efficacy and indications for these methods remain unclear.

Common infections and the risk of stroke

The occurrence of stroke in populations is incompletely explained by traditional vascular risk factors. Data from several case-control studies and one large study using case series methodology indicate that recent infection is a temporarily acting, independent trigger factor for ischemic stroke. Both bacterial and viral infections, particularly respiratory tract infections, contribute to this association. A causal role for infection in stroke is supported by a graded temporal relationship between these conditions, and by multiple pathophysiological pathways linking infection and inflammation, thrombosis, and stroke. Furthermore, observational studies suggest that influenza vaccination confers a preventive effect against stroke. Case-control and prospective studies indicate that chronic infections, such as periodontitis, chronic bronchitis and infection with Helicobacter pylori, Chlamydia pneumoniae or Cytomegalovirus, might increase stroke risk, although considerable variation exists in the results of these studies, and methodological issues regarding serological results remain unresolved. Increasing evidence indicates that the aggregate burden of chronic and/or past infections rather than any one single infectious disease is associated with the risk of stroke. Furthermore, genetic predispositions relating to infection susceptibility and the strength of the inflammatory response seem to co-determine this risk. Here, we summarize and analyze the evidence for common acute and chronic infectious diseases as stroke risk factors.

Cervical artery dissection: emerging risk factors

Cervical artery dissection (CAD) represents an increasingly recognized cause of stroke and the most common cause of ischemic stroke in young adults. Many factors have been identified in association with CAD such as primary disease of arterial wall (fibrodysplasia) and other non-specific diseases related to CAD like Ehlers Danlos-syndrome IV, Marfan's syndrome, vessel tortuosity. Moreover, an underlying arteriopathy which could be in part genetically determined, has been suspected. The rule of emerging risk factors for CAD such as recent respiratory tract infection, migraine and hyperhomocysteinemia are still a matter of research. Other known risks factors for CAD are major head/neck trauma like chiropractic maneuver, coughing or hyperextension injury associated to car. We examined emerging risks factors for CAD detected in the last years, as CAD pathogenesis is still not completely understood and needs further investigations.

Spontaneous arterial dissection: phenotype and molecular pathogenesis

Arterial dissection (AD) is defined as the longitudinal splitting up of the arterial wall caused by intramural bleeding. It can occur as a spontaneous event in all large and medium sized arteries. The histological hallmark of AD is medial degeneration. Histological investigations, gene expression profiling and proteome studies of affected arteries reveal disturbances in many different biological processes including inflammation, proteolytic activity, cell proliferation, apoptosis and smooth muscle cell (SMC) contractile function. Medial degeneration can be caused by various rare dominant Mendelian disorders. Genetic linkage analysis lead to the identification of mutations in different disease-causing genes involved in the biosynthesis of the extracellular matrix (FBN1, COL3A1), in transforming growth factor (TGF) beta signaling (FBN1, TGFBR1, TGFBR2) and in the SMC contractile system (ACTA2, MYH11). Genome wide association studies suggest that the CDKN2A/CDKN2B locus plays a role in the etiology AD and other arterial diseases.

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.

Extracranial and intracranial vertebral artery dissection: long-term clinical and duplex sonographic follow-up

PURPOSE

To determine the value of color Doppler sonography (CDUS) in the diagnosis and follow-up of patients with extracranial and intracranial vertebral artery (VA) dissection.

METHOD

Thirty-three patients aged 42 +/- 12 years with 40 VADS confirmed via digital subtraction angiography (DSA) (n = 37) and magnetic resonance angiography (MRA) (n = 3) were included in the study. All patients were investigated with extracranial CDUS and transcranial CDUS (TCCDUS) over a mean +/- SD follow-up period of 42 +/- 24 months and occurrence of new ischemic symptoms was assessed. Sonographic results were compared with initial and follow-up angiographic results.

RESULTS

At presentation, 24/33 (73%) patients had suffered an ischemic stroke, 5/33 (15%) had a transient ischemic attack (TIA), and 4/33 (12%) were asymptomatic. Two patients had a recurrent vertebrobasilar TIA; there was no recurrent stroke. The initial DSA findings consisted of 14 stenoses, 20 tapered occlusions, and 6 pseudoaneurysms. During follow-up, 63% of the vessels recanalized. Sonographic findings were consistent with angiographic findings in 80% at the initial examination and in 86% during follow-up. The main reason for discordant results was the failure of CDUS to detect pseudoaneurysms. No recurrence occurred in the vertebral arteries (VA), but 1 patient had an asymptomatic carotid artery dissection during follow-up.

CONCLUSION

Recurrent TIA or stroke after VAD appears to be extremely rare, independent of recanalization or persistent occlusion of the affected artery. CDUS and TCCDUS provide reliable follow-up of VAD in all patients presenting with stenosis or occlusion, but do not allow for detection of pseudoaneurysms of the VA.

A narrative review of pathophysiological mechanisms associated with cervical artery dissection

OBJECTIVE

The purpose of this narrative review was to describe pathophysiological risk factors that have been reported in association with cervical artery dissection (CAD) and to discuss the strength of those associations.

DATA SOURCES

MEDLINE, PubMed, Manual Alternative and Natural Therapy System (MANTIS), and CINAHL databases were searched for the years 1966 through September 2006. Additionally, the literature generated by the searches was culled for relevant citations incorporated within the articles.

RESULTS

The search strategy generated a total of 130 distinct citations, of which 49 were determined to be relevant after applying the study's selection criteria. An additional 6 references were harvested from the reference lists of the included articles.

SUMMARY

The most compelling pathophysiological risk factors have to do with connective tissue abnormalities, which may contribute to a weakening of the vascular wall making it more susceptible to tearing. However, the exact pathogenesis of CAD is uncertain, especially in cases that occur spontaneously, are related to trivial trauma, or occur in the absence of discernable risk factors.

Familial Cervical Artery Dissections

Background and Purpose— Genetic risk factors are thought to play a role in the etiology of spontaneous cervical artery dissections (CAD). However, familial CAD is extremely rare. In this study we analyzed patients with familial CAD and asked the question whether familial CAD has particular features.

Methods— Seven families with 15 CAD patients were recruited. All patients were carefully investigated by a neurologist, a neuroradiologist, and a dermatologist for clinical characteristics. From 11 patients a skin biopsy was performed to study the morphology of the connective tissue and to analyze the coding sequences of COL3A1, COL5A1, COL5A2, and part of COL1A1.

Results— The mean age of the patients (n=15, 9 women) at their first dissection was 36.2 years (median age 32 years, range 18 to 59). Two patients had bilateral CAD. One patient had a right and a left internal carotid artery dissection in successive weeks, another patient had 5 dissections over a period of 8 years. A high intrafamilial correlation was found between the affected vessels (ie, the carotid and the vertebral arteries) and between ages at the first dissection. In 1 patient we found clear and reproducible ultrastructural abnormalities in the skin biopsy, but the second patient from the family was not studied, because he died as a result of CAD before this study. The dermal connective tissue aberrations in the examined patient were similar to mild findings in patients with vascular Ehlers-Danlos syndrome (EDS type IV), but might be iatrogenic and related to long-term corticosteroid inhalation therapy. All other analyzed patients showed normal connective tissue morphology. In patients from 6 families we analyzed the whole coding sequence of COL3A1, COL5A1, and COL5A2, and from part of COL1A1. A missense mutation in the COL3A1 gene (leading to a G157S substitution in type III procollagen) was detected in both patients from 1e family. Two patients from another family carried a rare nonsynonymous coding polymorphism in COL5A1 (D192N); 1 of them carried also a rare variant in COL5A2 (T12337).

Conclusions— Familial CAD patients are young and probably are at high risk for recurrent or multiple CAD. Ultrastructural alterations of the dermal connective tissue might not be an important risk factor for familial CAD. However, the finding of a COL3A1 mutation revealed the presence of an inherited connective tissue disorder in 1 family.