Intracranial dissections: A pictorial review of pathophysiology, imaging features, and natural history

Parent artery occlusion for flow-related aneurysms at the proximal segment of the main feeding arteries of cerebellar arteriovenous malformations

BACKGROUND

Flow-related aneurysms (FRAs) associated with cerebellar arteriovenous malformations (AVMs) are complicated, and their management is difficult. We performed a retrospective study to explore the efficacy and outcome of parent artery occlusion (PAO) for FRAs at the proximal segment of the main feeding arteries of cerebellar AVMs.

MATERIALS AND METHODS

A retrospective study was performed for patients admitted for a cerebellar AVM between January 2015 and December 2019. Patients were included if (a) they presented with a ruptured or symptomatic FRA at the proximal segment of the main feeding arteries of the cerebellar AVM, (b) the cerebellar AVM did not bleed before admission, (c) the FRA was secured via PAO of the parent feeding artery, and (d) the cerebellar AVM was not intentionally managed or embolized through other feeding arteries during hospitalization.

RESULTS

Eight patients aged between 27 and 72 (48.6 ± 14.3) years were identified. Eight ruptured and symptomatic FRAs at the proximal segment of the main feeding arteries of the cerebellar AVMs underwent PAO with coils or Onyx while preserving the arteries distal to the aneurysms. All the patients achieved a favorable recovery after treatment in a follow-up ranged from 8 to 48 months. One patient experienced FRA recurrence and underwent a second PAO.

CONCLUSIONS

PAO for FRAs at the proximal segment of the main feeding arteries of cerebellar AVMs is a feasible option. This method is effective in preventing re-rupture of the FRAs and relieving the symptoms in the short term, allowing sufficient time for the patients to receive subsequent treatment.

Behavior of Extracranial-to-Intracranial Extended Arterial Dissections of the Vertebral Artery

BACKGROUND

Vertebral artery dissections (VADs) may extend from the extracranial to the intracranial vasculature (e+iVAD). We evaluated how the characteristics of e+iVAD differed from those of intracranial VAD (iVAD).

METHODS AND RESULTS

From 2002 to 2019, among consecutive patients with cervicocephalic dissection, those with iVAD and e+iVAD were included, and their clinical characteristics were compared. In patients with unruptured dissections, a composite clinical outcome of subsequent ischemic events, subsequent hemorrhagic stroke, or mortality was evaluated. High-resolution magnetic resonance images were analyzed to evaluate intracranial remodeling index. Among 347 patients, 51 (14.7%) had e+iVAD and 296 (85.3%) had iVAD. The hemorrhagic presentation occurred solely in iVAD (0.0% versus 19.3%), whereas e+iVAD exhibited higher ischemic presentation (84.3% versus 27.4%; P<0.001). e+iVAD predominantly presented steno-occlusive morphology (88.2% versus 27.7%) compared with dilatation patterns (11.8% versus 72.3%; P<0.001) of iVAD. The ischemic presentation was significantly associated with e+iVAD (iVAD as a reference; adjusted odds ratio, 3.97 [95% CI, 1.67-9.45]; P=0.002]). Patients with unruptured VAD showed no differences in the rate of composite clinical outcome between the groups (log-rank, P=0.996). e+iVAD had a lower intracranial remodeling index (1.4±0.3 versus 1.6±0.4; P<0.032) and a shorter distance from dural entry to the maximal dissecting segment (6.9±8.4 versus 15.7±7.4; P<0.001).

CONCLUSIONS

e+iVAD is associated with lower rates of hemorrhages and higher rates of ischemia than iVAD at the time of admission. This may be explained by a lower intracranial remodeling index and less deep intrusion of the dissecting segment into the intracranial space.

Cervical radiculopathy secondary to vertebral artery dissection: clinical features and outcomes

PURPOSE

Cervical radiculopathy due to various mechanical causes is commonly seen, however, cervical vertebral artery dissection (cVAD)-related radiculopathy is very rare with poorly characterized clinical outcomes. Thus, we conducted a systematic review of published literature and reported an institutional case to provide a better illustration of this rare entity.

METHODS

We systematically reviewed the PubMed literature and queried the clinical database at our center for cVAD-related radiculopathy. We described the baseline characteristics of patients with cVAD-related radiculopathy, the involved segment, diagnostic approach and treatment options.

RESULT

14 previously published studies met the inclusion criteria and along with the case we identified in our center, our study included 17 patients total (median age: 35 years, 9 females). C5 was the most commonly affected root and ipsilateral shoulder/arm pain along with shoulder abduction weakness was most common presentation. Antiplatelet or anticoagulant therapy was the treatment of choice. Most cases managed conservatively (82%). Majority of the cases (92%) had either complete or partial resolution of their symptoms.

CONCLUSION

Despite its limitations, this study show that cVAD related radiculopathy is a relatively benign entity with excellent clinical outcomes when managed medically.

Endovascular Treatment for Intracranial Artery Dissections in Posterior Circulation

Intracranial artery dissections (IADs), although uncommon, are an important cause of cerebral infarction and subarachnoid hemorrhage (SAH). Some IADs can heal spontaneously after reconstitution of the vessel lumen with excellent prognosis. Meanwhile, others can progress to stroke that requires treatment. The incidence of IAD in the posterior circulation is higher than that in the anterior circulation. Anterior circulation dissections are more likely to develop into ischemia and posterior circulation lesions into hemorrhage. The mortality rate after IAD among patients with SAH is 19%-83%. Further, the mortality rate of IAD without SAH is 0%-3%. Patients with SAH commonly undergo surgery or receive neuroendovascular treatment (EVT) to prevent rebleeding. However, the treatment of IADs is empirical in the absence of data from randomized controlled trials. Recently, EVT has emerged and is considered for IADs because of its less invasiveness and perceived low rates of procedure-related morbidity with good efficacy. EVT strategies can be classified into deconstructive (involving sacrifice of the parent artery) and reconstructive (preserving blood flow via the parent vessel) techniques. In particular, the number of reports on reconstructive techniques is increasing. However, a reconstructive technique for ruptured IADs has not yet been established. This review aimed to provide an overview of IADs in the posterior circulation managed with EVT by performing a literature search.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review

Fusiform aneurysms of the anterior cerebral artery (ACA) are uncommon, and the natural history of this entity is poorly characterized. Along with our center experience, we conducted a systematic literature review to help shed light on the clinical course of ACA fusiform aneurysms. We queried our institutional database to identify cases with fusiform aneurysms of ACA. In addition, following the PRISMA algorithm, we identified all reported cases published in the English literature from the inception of PubMed until December 2022. We categorized clinical presentations into three categories: (i) traumatic/iatrogenic, (ii) spontaneous symptomatic ruptured/unruptured, and (iii) spontaneous asymptomatic aneurysms. We utilized descriptive statistics. We identified seven cases from our center along with 235 patients from published literature. Blunt trauma was responsible for the development of 19 aneurysms. Sixty-three percent of these aneurysms tend to rupture within 2 weeks from the initial trauma, and despite treatment, only 74% of these patients had good clinical outcomes. Spontaneous symptomatic presentation occurred in 207 patients and was often associated with previous/concomitant ACA dissection. Subarachnoid hemorrhage from ruptured aneurysms was the most common presentation. Spontaneous symptomatic fusiform aneurysm is rapidly evolving lesions, and treatment is necessary. Three of our own cases were treated with an endovascular flow diverter (pipeline) stenting with good outcomes. Spontaneous asymptomatic aneurysms were reported in nine patients. These lesions are often associated with other vascular abnormalities. Treatment included surgical clipping with good clinical outcomes. Instead, four patients from our center database were managed conservatively with equally good outcomes. Our study demonstrates good clinical outcomes when fusiform aneurysms of ACA, especially when symptomatic, are treated promptly with either reconstructive or deconstructive therapies.

Imaging investigation of cervicocranial artery dissection by using high resolution magnetic resonance VWI and MRA: qualitative and quantitative analysis at different stages

BACKGROUND

To explore the value of magnetic resonance angiography (MRA) and high resolution magnetic resonance vessel wall imaging (HRMR-VWI) in cervicocranial artery dissection (CCAD) for the disease diagnosis, course staging and treatment. On the basis of qualitative evaluation, this study also extract the changes of different stages in vessel wall in different vessel segments to identify imaging indicators for the quantitative evaluation of CCAD.

METHODS

We retrospectively enrolled 34 patients with CCAD (38branches) with conventional MRA and HRMR-VWI examinations. Two radiologists independently analyzed imaging features of vessel wall and lumen in the different stages, and the typical sign detection of artery dissection were compared between MRA and HRMR-VWI. Then the parameters of vessel wall was quantitatively evaluated by the post-processing software (Vesselmass, Leiden University Medical Center, Leiden, The Netherlands.

RESULTS

HRMR-VWI revealed typical sign detection of artery dissection in all patients in the acute and subacute stage. Among them, the intimal flap/double lumen sign ditection were more common than the MRA, there was significant difference (P = 0.012). MRA revealed typical sign detection of artery dissection in more than half the patients, and the detection was no significant difference at the chronic stage between MRA and HRMR-VWI (P = 1.000/1.000/0.761). In the acute and subacute stage, the typical sign detection of intramural hematoma and Grade II enhancement revealed by HR-MRI was higher than the observations in the chronic stage (P = 0.000/0.000/0.016), while there was no significant difference by MRA (P = 0.902). The values of wall thickness, relative signal intensity of vessel wall enhancement, relative signal intensity of intramural hematoma (IMH), and percentage of stenosis in CCAD decreased from acute to subacute and then to chronic stages. Each quantitative parameter in patients with CCAD in the early stages (i.e., acute and subacute stages) was significantly different from that in patients with CCAD in the recovered group at chronic stage (P < 0.05). Wall thickness and relative signal intensity of vessel wall enhancement in patients with CCAD in the early stages were not significantly different from those in patients with CCAD in the incompletely recovered group at chronic stage (P > 0.05).

CONCLUSIONS

As the only noninvasive imaging technology, HRMR-VWI displays the structure of the vessel wall in vivo, showing not only excellent performance in the early diagnosis of CCAD, but also describing the changes of different stages in the qualitative and quantitative characteristics of vessel wall. It also helps to guide the diseasediagnosis, course staging and treatment of CCAD. Although the diagnostic efficacy of MRA was not as good as HRMR-VWI, it should be the first choice of method for routine examination in evaluating CCAD, especially at the chronic stage of CCAD.

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.

Early recanalization and vasospasm after endovascular treatment in a case of ruptured vertebral artery dissecting aneurysm associated with COVID-19

Background

The coronavirus disease 2019 (COVID-19) pandemic has caused significant structural changes in acute care hospitals. COVID-19-associated stroke has gained attention, with abnormal coagulation and vascular endothelial damage being recognized. While ischemic cases are commonly reported, hemorrhagic cases have also been reported. This report presents a case of ruptured vertebral artery dissection aneurysm associated with COVID-19, resulting in subarachnoid hemorrhage (SAH). The treatment course, challenges in managing cerebral vasospasm, and early recanalization achieved through endovascular therapy are described.

Case Description

A 67-year-old male patient was brought to our hospital for emergency treatment of impaired consciousness that occurred while recovering from COVID-19. He underwent endovascular internal trapping using coils, and although the rupture did not recur, he required long-term tracheal management, which resulted in a cerebral infarction caused by cerebral vasospasm. In addition, early recanalization was seen, which required retreatment.

Conclusion

This case highlights the challenges in managing COVID-19-associated SAH and emphasizes the need for infection control measures and proper postoperative care. Establishing protocols for detecting and managing cerebral vasospasm is essential.

Early ischemic recurrence in acute spontaneous cervical artery dissection

BACKGROUND AND PURPOSE

Early ischemic recurrence (EIR) following the diagnosis of acute spontaneous cervical artery dissection (CeAD) has been little investigated. We aimed to determine the prevalence and determinants on admission of EIR in a large single-center retrospective cohort study of patients with CeAD.

METHODS

EIR was defined as any ipsilateral clinical or radiological cerebral ischemia or intracranial artery occlusion, not present on admission and occurring within 2 weeks. CeAD location, degree of stenosis, circle of Willis support, presence of intraluminal thrombus, intracranial extension, and intracranial embolism were analyzed on initial imaging by 2 independent observers. Uni- and multivariate logistic regression was used to determine their association with EIR.

RESULTS

Two hundred thirty-three consecutive patients with 286 CeAD were included. EIR was observed in 21 patients (9%,95%CI=5-13%) with a median time from diagnosis of 1.5 days (range:0.1-14.0 days). No EIR was observed in CeAD without ischemic presentation or with less than 70% stenosis. In the remaining cases, poor circle of Willis (OR=8.5, CI95%=2.0-35.4, p = 0.003), CeAD extending to other intracranial arteries than just V4 (OR=6.8, CI95%=1.4-32.6, p = 0.017), cervical artery occlusion (OR=9.5, CI95%=1.2- 39.0, p = 0.031), and cervical intraluminal thrombus (OR=17.5, CI95%=3.0-101.7, p = 0.001) were independently associated with EIR.

CONCLUSIONS

Our results suggests that EIR is more frequent than previously reported, and that its risk might be stratified on admission with a standard workup. In particular, the presence of a poor circle of Willis, intracranial extension (other than just V4), cervical occlusion, or cervical intraluminal thrombus are associated with high risk of EIR, for which specific management should be further evaluated.

Uncommon Bilateral Carotid Artery Dissection in a Farmer: The Perils of Heavy Weight Lifting

Bilateral internal carotid artery (ICA) dissection on heavy weight lifting is a very rare cause of stroke in young patients. Arterial dissection is due to a tear in the intima and internal elastic lamina which leads to extravasation of blood into the media and subintimal plane. Clinical diagnosis of carotid artery dissection is difficult with common clinical presentations like headache and neck pain. Here we present a case of a 40-year-old young man who presented to us (tertiary referral center) with headache and quadriparesis. MRI brain showed multiple acute infarcts in bilateral centrum semiovale extending up to frontal periventricular white matter with few tiny foci in bilateral medial temporal and left gangliocapsular regions and CT cerebral angiography showed bilateral ICA dissection. He was treated with low molecular weight heparin and was discharged for follow-up with regular physiotherapy.

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.

Vascular flow limitations affecting the cervico-cranial region: Understanding ischaemia

BACKGROUND

Blood flow and brain ischaemia have been of interest to physical therapists for decades. Despite much debate, and multiple publications around risk assessment of the cervical spine, more work is required to achieve consensus on this vital, complex topic. In 2020, the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT) Cervical Framework adopted the dubious terminology 'vascular pathologies of the neck', which is misleading, on the premise that 1) not all flow limitations leading to ischaemia, are associated with observable blood vessel pathology and 2) not all blood flow limitations leading to ischaemia, are in the anatomical region of the 'neck'.

OBJECTIVE

This paper draws upon the full body of haemodynamic knowledge and science, to describe the variety of arterial flow limitations affecting the cervico-cranial region.

DISCUSSION

It is the authors' contention that to apply clinical reasoning and appropriate risk assessment of the cervical spine, there is a requirement for clinicians to have a clear understanding of anatomy/anatomical relations, the haemodynamic science of vascular flow limitation, and related pathologies. This paper describes the wide range of presentations and haemodynamic mechanisms that clinicians may encounter in practice. In cases with a high index suspicion of vascular involvement or an adverse response to assessment/intervention, appropriate referral should be made for further investigations, using consistent terminology. The term 'vascular flow limitation' is proposed when considering the range of mechanisms at play. This fits the terminology used (in vascular literature) at other anatomical sites and is understood by medical colleagues.

Headache characteristics to screen for cervicocerebral artery dissection in patients with acute onset unusual headache

OBJECTIVES

The aim of this preplanned primary analysis was to investigate the clinical manifestations of headache to screen for CAD patients with acute onset headache only.

BACKGROUND

Spontaneous cervicocerebral artery dissection (CAD) with acute onset headache is not rare in clinical practice; however, it is underdiagnosed. On the other hand, subsequent infarction or subarachnoid hemorrhage mainly occurs within 1 week of headache onset.

METHODS

Between April 2017 and January 2022, we conducted a single-center, cross-sectional retrospective study on 197 consecutive referred patients from neurosurgical outpatient clinics with acute onset unusual headache (stronger or longer headache than usual). All patients underwent magnetic resonance imaging to screen for secondary headache and were diagnosed based on the diagnostic protocol. We examined patient background data and the following headache characteristics: distribution, condition at the onset of headache, accompanying vomiting or nausea, worsening headache, and analgesic effects against headache. These factors were analyzed to identify independent diagnostic predictors of CAD. In this study, the rate of missing data was 41% for improvement of headache by analgesia and multiple imputation by chained equations was performed.

RESULTS

A total of 93 patients (46 men and 47 women; mean age: 48 years, range: 25-73 years) were diagnosed with CAD. Univariate logistic regression analysis showed CAD was associated with current smoking, systolic blood pressure >140 mmHg, unilateral headache, worsening headache, and no headache improvement by analgesia. Unilateral, worsening headache and no headache improvement by analgesia remained independent diagnostic predictors in multivariable logistic regression after multiple imputation. No headache improvement by analgesia had the highest sensitivity (86%), while worsening headache had the highest specificity (84%).

CONCLUSIONS

CAD needs to be considered in patients with unilateral, worsening headache and no headache improvement by analgesia.

Acute internal carotid artery occlusion due to dissection of the paraclinoid segment: Diagnostic usefulness of angiographic findings during stent retriever deployment

Intracranial artery dissection is an uncommon but possible cause of ischemic stroke, and is usually diagnosed based on imaging findings such as mural hematoma and dissection flap. However, it is challenging to recognize the underlying dissection in cases of acute large vessel occlusion. In this report, we present a case of acute internal carotid artery occlusion, in which the underlying dissection of the paraclinoid segment was found during the thrombectomy procedure. Two thrombectomy procedures failed to recanalize the acute internal carotid artery occlusion without removing any clot. Angiography performed during a Trevo stent retriever deployment in the first pass showed obscure contrast defects in the stent strut with temporary flow restoration. In the next pass, the appearance of the contrast defects changed and a parallel linear contrast appeared on the outside of the vessel wall. These angiographic findings were identified as mural hematoma and dissection flap, indicating dissection of the paraclinoid as the cause of the occlusion. During antiplatelet loading and preparation of a dedicated intracranial stent, the Trevo stent retriever was left deployed again at the occlusion site to maintain the blood flow. After permanent stenting with an Enterprise stent, angiography revealed complete recanalization. The patient recovered fully after the procedure. In the present case, stent retriever deployment revealed the hallmarks of dissection on angiography, such as mural hematoma, dissection flap, and temporal morphological changes, by restoring the blood flow temporarily. Such angiographic findings can provide useful information on the occlusion characteristics and real-time feedback for optimal treatment strategy.

Vertebral artery dissecting aneurysm rupture under severe COVID-19

Objective

We report a rare case of subarachnoid hemorrhage (SAH) caused by a ruptured vertebral artery (VA) dissecting aneurysm (DA) under severe COVID-19 treatment, and discuss the potential relationships.

Case presentation

A 58-year-old woman with COVID-19 fell into severe pneumonia needing mechanical ventilation at 10 days post-onset (day 10). The patient had no risk factors for DA or stroke other than COVID-19 infection. At day 17 when weaning ventilatory management, her systolic blood pressure was transiently elevated, and her consciousness did not recover thereafter. Computed tomography (CT) at day 21 revealed SAH with modified Fisher grade 4, and CT angiography revealed a DA in the right VA just distal to the right posterior inferior cerebellar artery (PICA). The DA was treated emergently with internal trapping by endovascular coiling, while the right PICA was preserved. Postoperative course was uneventful, and 2-time negative SARS-CoV-2 PCR results were obtained at day 45. The patient recovered to 4-month modified Rankin Scale 2.

Conclusions

Although it is not clear from the present case alone whether SARS-CoV-2 infection causes SAH by a ruptured VA DA, the accumulation of more cases and further studies are warranted to clarify the relationships between SARS-CoV-2 infection and ruptured intracranial DAs.

Trends in admissions for intracranial dissections in the United States

INTRODUCTION

Intracranial artery dissection (IAD) is rarer than cervical artery dissections (CeAD), and information is based on limited series with small cohorts. There are only several small-scale studies attempting to characterize the natural history of the disease. Herein, we analyze the prevalence of IADs in hospitalized patients using a national database.

METHODS

The National Inpatient Sample was queried from 2016-2019 for patients with a diagnosis of unruptured intracranial dissection (uIAD) using ICD-10-CM codes (I67.0). Moreover, patients with acute ischemic stroke (AIS) and CeAD were extracted to compare its prevalence among patients with concomitant AIS (+/-dissections). The Cochrane-Armitage test was conducted to assess trends in the prevalence of uIADs among those with concomitant AIS or among all craniocervical dissections.

RESULTS

There were 725 hospitalizations involving uIAD, while there were 62,220 involving CeADs. uIADs represented 5.1 per million hospitalizations across 2016-2019. The average age of presentation was 56.9 years (SE: 1.62), while it was 54.4 (SE: 0.17) for CeADs (p = 0.13). Females were represented among 44.8% (n = 325) of uIADs, a similar proportion compared to CeADs (44.3%%, n = 27,530; p = 0.89). Compared to CeADs, AIS and motor deficits were more common in uIAD (71.72% vs. 47.0%; p < 0.001). There were 18.6 uIAD with concomitant AIS per 100,000 with AIS. uIADs represented 1.75% of all dissections with concomitant AIS (n = 520/29,750). There was no trend in the average age of presentation for uIADs. Proportion of females among those with uIADs increased from 36.8% in 2016 to 59.5% in 2019 (trend: +9.46% per year; 95% CI: 3.13 to 15.8; p = 0.004). There was no trend in the proportion of races among those with uIADs.

CONCLUSION

The prevalence of uIADs among hospitalized patients is very low, and only 1.75% of craniocervical dissection-related AIS is due to uIAD. Compared to CeADs, patients were more likely to be male, and uIAD more commonly led to acute ischemic stroke and motor deficits. The trend in age remained stable across the four years analyzed, while the proportion of females increased. There was no trend in the proportion of races among uIADs, however.

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.

Unruptured cerebral aneurysm risk stratification: Background, current research, and future directions in aneurysm assessment

Background:

The optimal management of unruptured cerebral aneurysms is widely debated in the medical field. Rapid technology advances, evolving understanding of underlying pathophysiology, and shifting practice patterns have made the cerebrovascular field particularly dynamic in recent years. Despite progress, there remains a dearth of large randomized studies to help guide the management of these controversial patients.

Methods:

We review the existing literature on the natural history of unruptured cerebral aneurysms and highlight ongoing research aimed at improving our ability to stratify risk in these patients.

Results:

Landmark natural history studies demonstrated the significance of size, location, and other risk factors for aneurysm rupture, but prior studies have significant limitations. We have begun to understand the underlying pathophysiology behind aneurysm formation and rupture and are now applying new tools such as flow dynamics simulations and machine learning to individualize rupture risk stratification.

Conclusion:

Prior studies have identified several key risk factors for aneurysmal rupture, but have limitations. New technology and research methods have enabled us to better understanding individual rupture risk for patients with unruptured cerebral aneurysms.

Potential hemorrhagic risk of endovascular revascularization therapy due to recanalization of the dissected perforator in intracranial internal carotid artery dissection: A case report

Background:

Intracranial internal carotid artery (ICA) dissection manifesting as ischemic stroke is rare. Although endovascular revascularization therapy is effective in preventing the progression of stroke, little is known about the potential risk of this therapeutic approach.

Case Description:

We report a case of a 38-year-old woman who presented with acute ischemic infarcts in the territory of the left anterior choroidal artery (AChA) due to intracranial ICA dissection. She underwent balloon angioplasty, resulting in the complete resolution of the stenosis. The AChA, which was nearly occluded preoperatively, was unexpectedly recanalized after the procedure. Four hours later, she developed a parenchymal hemorrhage in the left basal ganglia without subarachnoid hemorrhage. The AChA, suspected as the hemorrhagic source during surgical hematoma removal, was revealed to have a disrupted internal elastic lamina on pathological examination, suggesting that the dissection of the ICA extended to the AChA.

Conclusion:

To the best of our knowledge, this is the first case report demonstrating that the intracranial ICA dissection extends to the associated perforator. Considering the potential risk of subsequent hemorrhagic complications by recanalization of the dissected perforator, prudent postoperative management, including strict blood pressure control, is advisable following endovascular revascularization therapy against intracranial artery dissection involving perforators.

Vessel Wall Magnetic Resonance Imaging in Cerebrovascular Diseases

Cerebrovascular diseases are a leading cause of disability and death worldwide. The definition of stroke etiology is mandatory to predict outcome and guide therapeutic decisions. The diagnosis of pathological processes involving intracranial arteries is especially challenging, and the visualization of intracranial arteries’ vessel walls is not possible with routine imaging techniques. Vessel wall magnetic resonance imaging (VW-MRI) uses high-resolution, multiparametric MRI sequences to directly visualize intracranial arteries walls and their pathological alterations, allowing a better characterization of their pathology. VW-MRI demonstrated a wide range of clinical applications in acute cerebrovascular disease. Above all, it can be of great utility in the differential diagnosis of atherosclerotic and non-atherosclerotic intracranial vasculopathies. Additionally, it can be useful in the risk stratification of intracranial atherosclerotic lesions and to assess the risk of rupture of intracranial aneurysms. Recent advances in MRI technology made it more available, but larger studies are still needed to maximize its use in daily clinical practice.

Cervical and intracranial artery dissections

This review summarizes recent therapeutic advances in cervical (CeAD) and intracranial artery dissection (IAD) research. Despite unproven benefits, but in the absence of any signal of harm, in patients, with acute ischemic stroke attributable to CeAD, intravenous thrombolysis and, in case of large-vessel occlusion, endovascular revascularization should be considered. Future research will clarify which patients benefit most from either treatment modality. For stroke prevention, the recently published randomized controlled TREAT-CAD study showed that, against the initial hypothesis, aspirin was not shown non-inferior to anticoagulation with vitamin K antagonists (VKAs). With the results of two randomized controlled trials (CADISS and TREAT-CAD) available now, the evidence to consider aspirin as the standard therapy of CeAD is weak. Further analyses might clarify whether the assumption supports, in particular, that patients presenting with cerebral ischemia, clinical or subclinical with magnetic resonance imaging surrogates, might benefit most from VKA treatment. In turn, it remains to be shown, whether in CeAD patients presenting with pure local symptoms and without hemodynamic compromise, antiplatelets are sufficient, and whether a dual antiplatelet therapy during the first weeks of treatment is recommendable. The observation that ischemic strokes occurred (or recurred) very early after CeAD diagnosis, consistently across randomized and observational studies, supports the recommendation to start antithrombotic treatment immediately, whatever antithrombotic agent is chosen in each individual case. The lack of a license for the use in CeAD patients and the paucity of data are still arguments against the use of direct oral anticoagulants in CeAD. Nevertheless, due to their beneficial safety and efficacy profile proven in atrial fibrillation, these agents are a worthwhile treatment option to be tested in further CeAD treatment trials. In IAD, the experience with the use of antithrombotic agents is limited. As the risk of suffering intracranial hemorrhage is higher in IAD than in CeAD, the use of antithrombotic therapy in IAD remains controversial.

Intracranial Fusiform and Circumferential Aneurysms of the Main Trunk: Therapeutic Dilemmas and Prospects

Intracranial fusiform and circumferential aneurysms (IFCAs), especially those located on the main trunk, are uncommon and difficult to manage. Currently, literature focused on IFCAs on the main trunk of cerebral arteries is lacking. The treatment of IFCAs is still under debate. Therefore, in this review, we further explore the treatment of this complicated entity. In addition, we also present some interesting cases. Based on the literature review and our experience, we found that IFCAs are often located in the vertebrobasilar system and that ruptured or large symptomatic IFCAs are associated with increased mortality and higher rebleeding rates. The treatment strategies for IFCAs can be classified as deconstructive and reconstructive methods via open surgery and/or endovascular treatment (EVT). Currently, EVT is a popular method and the main therapeutic choice. In particular, flow diversion has revolutionized the treatment of IFCAs. Parent artery occlusion (PAO) with or without revascularization may still be considered a suitable choice. Complex IFCAs that cannot be resolved by EVT can also be treated via open surgery with or without extracranial–intracranial bypass. Targeted embolization for the weak points of IFCAs is a temporary or palliative choice that is rarely used. In summary, despite complications, both surgical treatment and EVT are effective options for appropriately selected cases. Due to the development of endovascular implants, EVT will have better prospects in the future.