Multimodality Imaging of Vertebrobasilar Dolichoectasia: Clinical Presentations and Imaging Spectrum

Characterization of posterior circulation blood perfusion in patients with different degrees of basilar artery tortuosity

OBJECTIVE

The morphology of basilar artery (BA) may affect posterior circulation blood perfusion. We aimed to investigate whether different degrees of BA tortuosity could lead to the alterations of posterior circulation perfusion.

METHODS

We collected 138 subjects with different BA tortuosity scores, including 32 cases of score 0, 45 cases of score 1, 43 cases of score 2, and 18 cases of score 3. A higher score represented a higher degree of BA tortuosity. Ordered logistic regression analysis was performed to investigate the risk factors for BA tortuosity. We quantitatively measured the cerebral blood flow (CBF) in eight posterior circulation brain regions using arterial spin labeling. SPSS 25.0 was used for statistical analysis. The correlation between the CBF and BA tortuosity was corrected by the Bonferroni method. The significance level was set at 0.006 (0.05/8).

RESULTS

Hypertension (HR: 2.39; 95%CI: 1.23-4.71; P = 0.01) and vertebral artery dominance (HR: 2.38; 95%CI: 1.10-4.67; P = 0.03) were risk factors for BA tortuosity. CBF in occipital gray matter (R = -0.383, P < 0.001), occipital white matter (R = -0.377, P < 0.001), temporal gray matter (R = -0.292, P = 0.001), temporal white matter (R = -0.297, P < 0.001), and cerebellum (R = -0.328, P < 0.001) were negatively correlated with BA tortuosity degree. No significant correlation was found between the BA tortuosity degree and CBF in hippocampus (R = -0.208, P = 0.014), thalamus (R = -0.001, P = 0.988) and brainstem (R = -0.204, P = 0.016).

CONCLUSIONS

BA tortuosity could affect posterior circulation blood perfusion. CBF was negatively correlated with BA tortuosity degree. The morphology of BA may serve as a biomarker for posterior circulation and the severity of posterior circulation ischemia.

Hyperintense vessel sign in vertebrobasilar dolichoectasia

Vertebrobasilar dolichoectasia (VBD) is a rare condition characterised by ectasia, elongation and tortuosity in the vertebrobasilar arteries. VBD prevalence ranges from 0.05% to 18%. A possible interplay between vascular risk factors and a predisposing genotype could alter the balance between tunica media matrix metalloproteinases and antiprotease activity. VBD is characterised by the disruption of smooth muscle atrophy, reticular fibre degeneration and multiple gaps in the inner elastic lamina, causing thinning of the tunica media and arterial wall weakening and deformation. VBD can be asymptomatic. VBD is often characterised by ischaemic stroke, intracerebral haemorrhage, brainstem/cranial nerve compression and subarachnoid haemorrhage. Vascular events are the most common clinical manifestation. Slow arterial blood flow results in hyperintense vascular signals, which are linked with a larger infarct and a higher risk of cerebral bleeding. Treatment for VBD is difficult. Currently, there are no specific treatments for VBD, and the available treatments focus on the consequences.

Vertebrobasilar System Laterality and Idiopathic Sudden Sensorineural Hearing Loss

INTRODUCTION

The etiology of idiopathic sudden sensorineural hearing loss (ISSNHL) remains elusive, with vascular compromise as a proposed cause. This study aimed to explore the correlation between the vertebrobasilar vascular system laterality (VBVSL) and ISSNHL laterality.

METHODS

We conducted a retrospective analysis of consecutive patients diagnosed with ISSNHL from 2015 to 2020. The VBVSL pattern was established via magnetic resonance imaging scans by a neuroradiologist. ISSNHL occurring contralaterally to the basilar artery (BA) curvature or ipsilaterally to the dominant vertebral artery (VA) was designated as a "positive match," with all other scenarios classified as a "negative match."

RESULTS

Our study included 191 ISSNHL patients (median age 57 years, 89 males, 93 right ears). The majority of patients did not exhibit a positive match between ISSNHL laterality and the sides of BA curvature or dominant VA (28.8% and 36.6% for BA and VA, respectively). Notably, VA-positive match patients were significantly older than VA-negative match patients (59 vs. 53 years, p = 0.043), with a similar trend observed in BA-positive match compared to BA-negative match (59 vs. 54.5 years, p = 0.057). However, there was no significant difference in any other clinical, audiometric, or outcome factors between the positive and negative match groups.

CONCLUSION

The findings suggest no association between VBVSL and ISSNHL laterality. Furthermore, patients in the positive match group did not exhibit distinct clinical or audiometric features compared to those without a match.

Endovascular Stent Implantation in the Treatment of Vertebrobasilar Dolichoectasia

Vertebrobasilar dolichoectasia (VBD) is a rare disease in clinic, with an incidence of 0.06% and 5.8%. It is a progressive vascular disease caused by the dilatation, tortuosity, and prolongation of vertebral and basilar arteries caused by a variety of factors. VBD can lead to hemodynamic changes, ischemic stroke, compression symptoms due to vasodilation, neurological dysfunction, hydrocephalus, subarachnoid hemorrhage, and other clinical manifestations. However, because the condition of VBD is complex and changeable, the treatment of VBD is not uniform. With the development of vascular intervention, especially the development of stent technology, it may become an effective method for the treatment of VBD. Two patients with VBD were treated with endovascular stent implantation.

Wall enhancement predictive of abnormal hemodynamics and ischemia in vertebrobasilar non-saccular aneurysms: a pilot study

Objective

To analyze how wall enhancement affects hemodynamics and cerebral ischemic risk factors in vertebrobasilar non-saccular intracranial aneurysms (VBNIAs).

Materials and methods

Ten consecutive non-saccular aneurysms were collected, including three transitional vertebrobasilar dolichoectasia (TVBD). A wall enhancement model was quantitatively constructed to analyze how wall enhancement interacts with hemodynamics and cerebral ischemic factors.

Results

Enhanced area revealed low wall shear stress (WSS) and wall shear stress gradient (WSSG), with high oscillatory shear index (OSI), relative residence time (RRT), and gradient oscillatory number (GON) while the vortex and slow flow region in fusiform aneurysms are similar to TVBD fusiform aneurysms. With low OSI, high RRT and similar GON in the dilated segment, the enhanced area still manifests low WSS and WSSG in the slow flow area with no vortex. In fusiform aneurysms, wall enhancement was negatively correlated with WSS (except for case 7¹, all p values  < 0.05, r = -0.52 ~ -0.95), while wall enhancement was positively correlated with OSI (except for case 5, all p values < 0.05, r = 0.50 ~ 0.83). For the 10 fusiform aneurysms, wall enhancement is significantly positively correlated with OSI (p = 0.0002, r = 0.75) and slightly negatively correlated with WSS (p = 0.196, r = -0.30) throughout the dataset. Aneurysm length, width, low wall shear stress area (LSA), high OSI, low flow volume (LFV), RRT, and high aneurysm-to-pituitary stalk contrast ratio (CRstalk) area plus proportion may be predictive of cerebral ischemia.

Conclusion

A wall enhancement quantitative model was established for vertebrobasilar non-saccular aneurysms. Low WSS was negatively correlated with wall enhancement, while high OSI was positively correlated with wall enhancement. Fusiform aneurysm hemodynamics in TVBD are similar to simple fusiform aneurysms. Cerebral ischemia risk appears to be correlated with large size, high OSI, LSA, and RRT, LFV, and wall enhancement.

Congenital and acquired anomalies of the basilar artery: A pictorial essay

INTRODUCTION

The basilar artery is one of the two cases in our body where an arterial vessel is formed by the union of two others - the vertebral arteries. It provides vascular supply to essential structures for the main vital functions; the posterior cerebral arteries originate from it as terminal branches, and form part of the anastomotic circle of Willis.

IMAGING FINDINGS

Congenital and acquired anomalies of the basilar trunk are described. We provide a schematic and detailed representation of normal anatomical variants - mainly represented by the fenestrated basilar artery or the persistence of carotid-basilar anastomosis; course anomalies are also illustrated, with reference to neuro-vascular conflicts and dolichoectasia. Among congenital anomalies, this pictorial review also shows the variants of the basilar origin, such as in the case of basilar trunk arising from only one of the two vertebral arteries, and the calibre changes - which are represented by aneurysm and hypoplasia. The latter appears to be a risk factor for posterior circulation stroke, when associated with a bilateral posterior foetal variant.Among the acquired forms, this pictorial essay describes some clinical cases of dissections, non-congenital aneurysms, thrombosis and tumour with vascular encasing or compression of basilar artery.

CONCLUSION

CT angiography and MRI allow us to study the posterior intracranial circulation in detail, providing useful pre-treatment information. Therefore, knowledge of congenital or acquired anomalies of the basilar artery is essential for radiologists, neuroradiologists and neurosurgeons.

Incidental vascular findings on brain magnetic resonance angiography

Given the ever-increasing utilization of magnetic resonance angiography, incidental vascular findings are increasingly discovered on exams performed for unconnected indications. Some incidental lesions represent pathology and require further intervention and surveillance, such as aneurysm, certain vascular malformations, and arterial stenoses or occlusions. Others are benign or represent normal anatomic variation, and may warrant description, but not further work-up. This review describes the most commonly encountered incidental findings on magnetic resonance angiography, their prevalence, clinical implications, and any available management recommendations.

Studying the imaging features and infarction mechanism of vertebrobasilar dolichoectasia with high-resolution magnetic resonance imaging

The mechanisms underlying ischemic infarction in patients with vertebrobasilar dolichoectasia (VBD) remain unclear. In this study, we retrospectively analyzed the imaging characteristics of high-resolution magnetic resonance imaging (HR-MRI) in patients with VBD to explore the possible mechanisms of ischemic stroke (IS) in patients with VBD. Patients with VBD were recruited from the HR-MRI database between July 2017 and June 2021. HR-MRI was used to evaluate the diameter, bifurcation height, laterality, arterial dissection, and atherosclerotic plaques of the basilar artery (BA). Transcranial Doppler was used to measure the vertebrobasilar mean velocity (Vm), peak systolic velocity (Vs), end-diastolic velocity (Vd), and pulsatile index. Twenty-six patients with VBD were enrolled, of which 15 had IS and 11 did not. The incidence of classical vascular risk factors, including age, sex, hypertension, diabetes, and hypercholesterolemia, did not differ significantly between the two groups. The BA diameters of the stroke group were significantly higher than that of the nonstroke group (6.57 ± 1.00 mm vs. 5.06 ± 0.50 mm, p = 0.000). The height of the BA bifurcation in the stroke and nonstroke groups was statistically significant (p = 0.002). Compared with the nonstroke group, the Vm, Vs, and Vd of the BA in the stroke group were lower, but the difference was not significant. In the 16 patients with atherosclerotic stenosis, 30 atherosclerotic plaques were found in the BA, 18 (60%) in the greater curvature, and 12 (40%) in the lesser curvature. In addition, one artery dissection (on the lesser curvature) and two dissecting aneurysms (on the greater curvature) were found in the BA of three patients, respectively. The BA diameter and bifurcation height are factors related to IS in patients with VBD. The mechanism of stroke in patients with VBD may involve abnormal hemodynamics, artery dissection, and atherosclerosis. HR-MRI is a useful method for evaluating the risk and underlying mechanism of stroke in patients with VBD.

Effect of vertebrobasilar dolichoectasia on endovascular therapy in acute posterior circulation infarction

Background and purpose

This study aimed to analyze the feasibility and safety of endovascular therapy (EVT) in patients with acute posterior circulation stroke and vertebrobasilar dolichoectasia (VBD).

Materials and methods

BASILAR was a national prospective registry of consecutive patients with symptomatic and imaging-confirmed acute stroke in the posterior circulation within 24 h of symptom onset. We evaluated EVT feasibility and safety in patients with VBD. Primary outcomes included improvement in modified Rankin Scale scores (mRS) at 90 days and mortality within 90 days. The secondary outcome was the rate of favorable functional outcome, defined as mRS ≤ 3 (indicating independent ambulation) at 90 days. Safety outcomes included surgery-related complications and other serious adverse events.

Results

A total of 534 cases were included: 159 with VBD and 375 controls. No significant difference in mRS at 90 days was found between groups, but patients with VBD had a higher baseline National Institutes of Health Stroke Scale (NIHSS) score [30 (19–33) vs. 25 (15–32)] and were older [65 (59–74) vs. 63 (55–72) year]. After propensity score matching, there were no significant differences in baseline NIHSS score between the two groups, and the efficacy and safety of EVT were similar between patients with or without VBD. Furthermore, the prognostic effect of puncture-to-recanalization time on the probability of mortality within 90 days in EVT-treated patients with VBD was significant {adjusted odds ratio, 1.008 [95% confidence interval (1.001–1.015)]}.

Conclusion

Endovascular therapy is safe and feasible in patients with acute posterior circulation stroke and VBD. The puncture-to-recanalization time is important for predicting the prognosis of EVT-treated patients with VBD.

Triple therapy versus dual-antiplatelet therapy for dolichoectatic vertebrobasilar fusiform aneurysms treated with flow diverters

Background

Dolichoectatic vertebrobasilar fusiform aneurysms (DVBFAs) have poor natural history when left untreated and high morbimortality when treated with microsurgery. Flow diversion (FD) with dual-antiplatelet therapy (DAPT) is feasible but carries high risk of perforator occlusion and progression of brainstem compression. Elaborate antithrombotic strategies are needed to preserve perforator patency while vessel remodeling occurs. We compared triple therapy (TT (DAPT plus oral anticoagulation)) and DAPT alone in patients with DVBFAs treated with FD.

Methods

Retrospective comparison of DAPT and TT in patients with DVBFAs treated with FD at eight US centers.

Results

The groups (DAPT=13, TT=14) were similar in age, sex, clinical presentation, baseline disability, and aneurysm characteristics. Radial access use was significantly higher in the TT group (71.4% vs 15.3%; P=0.006). Median number of flow diverters and adjunctive coiling use were non-different between groups. Acute ischemic stroke rate during the oral anticoagulation period was lower in the TT group than the DAPT group (7.1% vs 30.8%; P=0.167). Modified Rankin Scale score decline was significantly lower in the TT group (7.1% vs 69.2%; P=0.001). Overall rates of hemorrhagic complications (TT, 28.6% vs DAPT, 7.7%; P=0.162) and complete occlusion (TT, 25% vs DAPT, 54.4%; P=0.213) were non-different between the groups. Rate of moderate-to-severe disability at last follow-up was significantly lower in the TT group (21.4% vs 76.9%; P=0.007).

Conclusions

Patients with DVBFAs treated with FD in the TT group had fewer ischemic strokes, less symptom progression, and overall better outcomes at last follow-up than similar patients in the DAPT group.

Large Dolichoectasia Concurrently Involving Both Anterior and Posterior Cerebral Circulation: A Case Report

Dolichoectasia is an uncommon disorder characterized by the presence of a dilated, elongated, and tortuous cerebral artery. Its main pathologic mechanism is the disruption of the internal elastic lamina. Risk factors for dolichoectasia are advanced age, chronic hypertension, and metabolic disease. It mainly involves the vertebrobasilar vasculature (or "posterior circulation"), but dolichoectasia can also be seen in the anterior circulation, particularly the anterior cerebral artery. There are no reported cases of dolichoectasia involving both anterior and posterior circulation in South Korea. Here we report an unusual case of dolichoectasia involving both anterior and posterior circulation in a young female without any underlying disease on the basis of prominent imaging findings.

Prospects and Dilemmas of Endovascular Treatment for Vertebrobasilar Dolichoectasia

Vertebrobasilar dolichoectasia (VBD) is characterized by significant expansion, elongation, and tortuosity of the basilar artery and vertebral artery. Certain highly selected cases of VBD can require intervention. Recent advances in endovascular treatment (EVT) have renewed hope for patients with VBD. However, which cases of VBD can benefit from EVT still needs to be determined. Currently, little is known regarding this matter. Therefore, we performed a review of the literature from a PubMed search and cataloged our experience regarding the classification and natural history of VBD and the prospects, prognosis and complications of EVT. The findings can be summarized as follows: for asymptomatic VBD, “wait and see” or medical management may be a reasonable strategy. EVT may only be effective in certain patients. For saccular aneurysms in VBD, especially ruptured aneurysms, EVT is reasonable. For fusiform aneurysms in VBD, EVT can carry high complication rates and should be recommended with caution. For stenting reconstruction in VBD, the effect is uncertain. For the future of EVT of VBD, randomized controlled trials and the development of neurointerventional products are worth pursuing, but EVT in VBD still has a long way to go.

Endoscopic third ventriculostomy for noncommunicating hydrocephalus by vertebrobasilar dolichoectasia: A case report

Background:

Vertebrobasilar dolichoectasia (VBD) is a vasculopathy characterized by the elongation, widening, and tortuosity of a cerebral artery. Rarely, hydrocephalus results when the extended basilar artery impairs communication of the cerebral ventricle and cerebrospinal fluid dynamics. We experienced such a case when a patient underwent endoscopic third ventriculostomy (ETV) for noncommunicating hydrocephalus with VBD.

Case Description:

A 54-year-old man presented with cognitive dysfunction and was diagnosed with VBD by magnetic resonance imaging (MRI). Seven years later, he exhibited subacute impaired consciousness due to acute noncommunicating hydrocephalus, undergoing external ventricular drainage (EVD) that improved consciousness. After EVD removal, the noncommunicating hydrocephalus did not recur; however, 7 months later, subacute consciousness impairment due to noncommunicating hydrocephalus was again observed. MRI showed a significant dilation of both lateral ventricles and ballooning of the third ventricle while the right posterior cerebral artery shifted slightly posteriorly. The patient underwent ETV and clinical symptoms improved. One year after the treatment, MRI observed a patent ETV fenestration and no deleterious changes in clinical symptoms were observed.

Conclusion:

ETV can be an effective treatment for the noncommunicating hydrocephalus with VBD when performed with preoperative assessment of vascular anatomy and attention to vascular injury.

Study on the Correlation between different Levels of Patients with Vertebrobasilar Dolichoectasia and Posterior Circulation Blood Perfusion

OBJECTIVE

This study investigates the differences and changing trend of posterior circulation blood perfusion between different levels of vertebrobasilar dolichoectasia(VBD) patients. The relationship between the deviation of the basilar artery(BA) in different directions and the location of pontine infarction are also investigated.

METHODS

A cohort of 106 patients(74 males and 32 females) who satisfied the diagnostic criteria for VBD were recruited for this study and classified according to the bifurcation height and the deviation position of the BA, as well as the measured blood perfusion value of the pontine, which includes rCBF, rCBV, MTT, and TTP.

RESULTS

Out of the 106 patients, 19 cases were classified as Level 1, 74 cases were classified as Level 2, and 13 cases were classified as Level 3. The different levels between the VBD groups were statistically significant (P<0.05, P<0.01), and it was found that as the level increases, rCBF and rCBV gradually decreased, while MTT and TTP gradually increased. The statistic results of different perfusion parameters were also significant, when pairwise comparisons between Level 1 and Level 3, and Level 2 and Level 3 were performed. However, when comparing Level 1 and Level 2, only the TTP showed significant result. Among 106 patients, 22 cases had brainstem infarction, 13 cases had left brainstem infarction, 8 cases had right brainstem infarction, and 1 case had brainstem infarction on both sides. Brainstem infarction generally occurs on the opposite side of the direction of BA deviation(P<0.05). Regardless of the BA was deviated to the left or right, perfusion analysis showed that there was significant difference in blood perfusion on both sides of the pontine when BA is deviated(P<0.05, P<0.01). The rCBF and rCBV on the contralateral side of deviation were lower than those on the same side, and the MTT and TTP were longer than those on the same side. There were 37 cases with vertebral artery dominance(VAD), 16 cases with left VAD, and 21 cases with right VAD. Statistical analysis showed that BA was more likely to deflect to the opposite side of the dominant artery(P<0.05), and compared with non-VAD, there was no significant difference in pontine blood perfusion (p>0.05).

CONCLUSION

As VBD level increases, rCBF and rCBV will gradually decreases while MTT and TTP showed sign of increasing. The location of brainstem infarction is opposite to the direction of the BA deviation, and BA is more likely to deviate to the opposite side of the dominant artery.

Melittin-loaded Iron Oxide Nanoparticles Prevent Intracranial Arterial Dolichoectasia Development through Inhibition of Macrophage-mediated Inflammation

Rationale: In intracranial arterial dolichoectasia (IADE) development, the feedback loop between inflammatory cytokines and macrophages involves TNF-α and NF-κB signaling pathways and leads to subsequent MMP-9 activation and extracellular matrix (ECM) degeneration. In this proof-of-concept study, melittin-loaded L-arginine-coated iron oxide nanoparticle (MeLioN) was proposed as the protective measure of IADE formation for this macrophage-mediated inflammation and ECM degeneration.

Methods: IADE was created in 8-week-old C57BL/6J male mice by inducing hypertension and elastase injection into a basal cistern. Melittin was loaded on the surface of ION as a core-shell structure (hydrodynamic size, 202.4 nm; polydispersity index, 0.158). Treatment of MeLioN (2.5 mg/kg, five doses) started after the IADE induction, and the brain was harvested in the third week. In the healthy control, disease control, and MeLioN-treated group, the morphologic changes of the cerebral arterial wall were measured by diameter, thickness, and ECM composition. The expression level of MMP-9, CD68, MCP-1, TNF-α, and NF-κB was assessed from immunohistochemistry, polymerase chain reaction, and Western blot assay.

Results: MeLioN prevented morphologic changes of cerebral arterial wall related to IADE formation by restoring ECM alterations and suppressing MMP-9 expression. MeLioN inhibited MCP-1 expression and reduced CD68-positive macrophage recruitments into cerebral arterial walls. MeLioN blocked TNF-α activation and NF-κB signaling pathway. In the Sylvian cistern, co-localization was found between the CD68-positive macrophage infiltrations and the MeLioN distributions detected on Prussian Blue and T2* gradient-echo MRI, suggesting the role of macrophage harboring MeLioN.

Conclusions: The macrophage infiltration into the arterial wall plays a critical role in the MMP-9 secretion. MeLioN, designed for ION-mediated melittin delivery, effectively prevents IADE formation by suppressing macrophage-mediated inflammations and MMP activity. MeLioN can be a promising strategy preventing IADE development in high-risk populations.

Assessment of cerebrovascular disease with computed tomography in COVID-19 patients: correlation of a novel specific visual score with increased mortality risk

PURPOSE

Cerebrovascular disease (CVD) is considered a major risk factor for fatal outcome in COVID-19. We aimed to evaluate the possible association between computed tomography (CT) signs of chronic CVD and mortality in infected patients.

MATERIALS AND METHODS

We performed a double-blind retrospective evaluation of the cerebral CT scans of 83 COVID-19 patients looking for CT signs of chronic CVD. We developed a rapid visual score, named CVD-CT, which summarized the possible presence of parietal calcifications and dolichosis, with or without ectasia, of intracranial arteries, areas of chronic infarction and leukoaraiosis. Statistical analysis was carried out with weighted Cohen's K test for inter-reader agreement and logistic regression to evaluate the association of in-hospital mortality with CVD-CT, chest X-ray (CXR) severity score (Radiographic Assessment of Lung Edema-RALE) for radiological assessment of pulmonary disease, sex and age.

RESULTS

CVD-CT (odds ratio 1.6, 95% C.I. 1.2-2.1, p = 0.001) was associated with increased risk of mortality. RALE showed an almost significant association (odds ratio 1.05, 95% C.I. 1-1.1, p 0.06), whereas age and sex did not.

CONCLUSION

CVD-CT is associated with risk of mortality in COVID-19 patients. The presence of CT signs of chronic CVD may be correlated to a condition of fragility of the circulatory system, which constitutes a key risk factor for death in infected patients.

Imaging of Non-atherosclerotic Vasculopathies

Non-atherosclerotic vasculopathies (NAVs) may present with various neurological symptoms ranging from headache, stroke, visual symptoms, and various types of intracranial hemorrhage. NAVs result from different etiologies which include collagenopathies, immunological, hematological, and infection mechanisms, and other rarer unidentifiable or idiopathic causes. NAV etiologies account for about 10–15% and 20–25% of adult and pediatric stroke cases, respectively, and therefore, diagnosing the underlying cause of NAV becomes clinically very important. Clinical diagnosis of NAV is challenging because the clinical presentation is very non-specific and overlapping with various other central nervous system disorders. Before the advent of non-invasive techniques, making a diagnosis of non-atherosclerotic vasculopathy as a cause of the stroke was very challenging. Today with newer techniques such as high-resolution magnetic resonance (MR), MR and computed tomography perfusion, and angiogram, there are number of pointers which can give us a lead about the non-atherosclerotic causes. Imaging may provide the first lead to the clinician regarding the diagnosis or possible differential diagnosis so that the targeted and focused biomarkers (blood, cerebrospinal fluid, or/and in some cases biopsies) may be obtained to clinch the diagnoses. The purpose of the article is to enumerate the causes, clinical features, and illustrate the imaging findings of the various non-atherosclerotic vasculopathic disorders and discuss “pearls” to their diagnosis. In this article, we have also discussed the latest advances in vascular imaging and elaborated on few uncommon non-atherosclerotic vasculopathies. These are very relevant clinically in the day-to-day practice for the radiologist, neurologist, and the neurointerventionalist.

Vertebrobasilar Dolichoectasia as a Rare Cause of Simultaneous Abducens and Vestibulocochlear Nerve Symptoms: A Case Report and Literature Review

Vertebrobasilar dolichoectasia (VBD) can lead to cranial nerve symptoms. However, multiple cranial nerve symptoms associated with VBD in one case remain extremely rare. We here present the case of a 33-year-old male with VBD diagnosed by multimodality imaging, who developed simultaneous abducens and vestibulocochlear nerve symptoms and subsequently improved after blood pressure control treatment. To our knowledge, this is the first report of such a vascular disorder resulting in simultaneous symptoms of the abducens and vestibulocochlear nerves. This study highlights that such a vascular anomaly should be considered when cranial nerve symptom is encountered, especially when multiple cranial nerves involved. Meanwhile, radiological evalurrrrrrrrrrrrrrrrrrration of such neurovascular conflict using three-dimensional constructive interference in steady-state imaging is recommended.

Basilar artery tortuosity as a predictive factor for the efficacy of heparin adjuvant therapy in unilateral idiopathic sudden sensorineural hearing loss

Introduction

Cochlear ischemia is hypothesized as one of the major etiologies of idiopathic sudden sensorineural hearing loss. Therefore, anticoagulant therapies are designed to be beneficial in certain patients with this condition.

Objective

This study aimed to determine which patients with idiopathic sudden sensorineural hearing loss would benefit from heparin treatment as adjuvant therapy.

Methods

In total, 134 patients who underwent magnetic resonance imaging for unilateral idiopathic sudden sensorineural hearing loss at a tertiary referral hospital between January 2014 and December 2018 were included in this retrospective study. All patients received Intratympanic steroid injections or heparin therapy plus oral corticosteroids. Radiological parameters of the vertebrobasilar system and clinical data from pre- and post-treatment assessments were analyzed.

Results

Most patients (71.6%) had a tortuous basilar artery The 65 patients with severe-to-profound idiopathic sudden sensorineural hearing loss showed a significant relationship between idiopathic sudden sensorineural hearing loss laterality and basilar artery displacement to the opposite side (p = 0.036), while the 69 patients with mild-to-moderate idiopathic sudden sensorineural hearing loss did not (p = 0.950). Additionally, the degree of basilar artery tortuosity was significantly associated with the degree of hearing impairment in the severe-to-profound idiopathic sudden sensorineural hearing loss group (p = 0.015). When idiopathic sudden sensorineural hearing loss occurred on the opposite side to basilar artery displacement, the improvement of hearing was significantly greater in patients treated with heparin than in those treated with intratympanic steroids (p =  0.041).

Conclusion

In a subset of patients with severe-to-profound idiopathic sudden sensorineural hearing loss, basilar artery tortuosity had a significant directional relationship with idiopathic sudden sensorineural hearing loss laterality. In these selected patients, a significant effect of heparin therapy on improving hearing was observed.

Change in basilar artery length and bending according to aging and vertebral artery dominance: A longitudinal study

This study aimed to investigate the basilar artery (BA) geometric changes in a longitudinal study. 154 subjects with normal vertebrobasilar arterial systems on magnetic resonance angiography were assigned into two groups: 1) non-dominant vertebral artery (VA) and 2) VA dominance. We defined the dominant VA as either that the VA is 3 millimeters larger in diameter or the VA is connected to BA in a more straight angle. BA imaging was segmented to obtain BA bending length (BABL) and BA length (BAL). A mixed model ANOVA was conducted to investigate the impact of aging and VA dominance on the change of BABL and BAL after 123.6 ± 16.2 months. There was a significant main effect of VA dominance on the change of BABL after about 10 years, F (1,152) = 39.78, p < 0.01. On the other hand, there was a significant main effect of aging on the change of BAL during the same period of time, F (1,152) = 6.64, p = 0.01. Most subjects had an opposite directional relationship between the dominant VA and BA bending (71.3%; p < 0.01). Our study supported the hypothesis that the bending of the BA depends on the dominance of the VA, whereas the increased length of the BA depends on aging.

Evaluation of hemodynamic characteristics in posterior circulation infarction patients with vertebral artery dominance by color doppler flow imaging and transcranial doppler sonography

PURPOSE

The aim of this study was to investigate the hemodynamic characteristics of posterior circulation infarction (PCI) patients with the vertebral artery dominance (VAD) using Color Doppler flow imaging (CDFI) and Transcranial Doppler sonography (TCD) and to explore the pathogenesis of PCI caused by VAD.

MATERIALS AND METHODS

A total of 186 consecutive PCI patients were enrolled. All the patients underwent magnetic resonance (MR) examination and the clinical data were collected. According to the brain magnetic resonance angiography (MRA), the patients were divided into VAD and non-VAD groups. CDFI and TCD were performed to identify the hemodynamic parameters of the vertebral artery (VA) and basilar artery (BA).

RESULTS

The male population was significantly more frequent in the VAD group (71.3%) as compared to the non-VAD group (53.1%). The significant difference in hemodynamic parameters was observed between VAD and non-VAD groups. Resistance index (RI) of extracranial and intracranial VA was different as well. There were also differences in the VA side-to-side diameter difference-value, peak velocity (Vp), mean velocity (Vm) and pulsatility index (PI) with varying degrees of BA curvature.

CONCLUSIONS

VA and BA hemodynamic changes caused by VAD may be an important risk factor in the process of occurrence of PCI. The combination of CDFI and TCD can help to detect the hemodynamic changes in the intracranial and extracranial segments of VA and BA. This can have important clinical value in understanding the pathogenesis of PCI.

Vestibulocochlear Symptoms Caused by Vertebrobasilar Dolichoectasia

OBJECTIVES

Vertebrobasilar dolichoectasia (VBD), an elongation and distension of vertebrobasilar artery, may present with cranial nerve symptoms due to nerve root compression. The objectives of this study are to summarize vestibulocochlear manifestations in subjects with VBD through a case series and to discuss the needs of thorough oto-neurotologic evaluation in VBD subjects before selecting treatment modalities.

METHODS

Four VBD subjects with vestibulocochlear manifestations were reviewed retrospectively. VBD was confirmed by either brain or internal auditory canal magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). Patient information, medical history, MRI/MRA findings, and audiometry or vestibular function tests were reviewed according to patient's specific symptom.

RESULTS

Of the four subjects, three presented with ipsilesional sensorineural hearing loss (SNHL), three with paroxysmal recurrent vertigo, and two with typewriter tinnitus. The MRI/MRA of the four subjects revealed unilateral VBD with neurovascular compression of cisternal segment or the brainstem causing displacement, angulation, or deformity of the cranial nerve VII or VIII that corresponded to the symptoms.

CONCLUSION

Vestibulocochlear symptoms such as SNHL, recurrent paroxysmal vertigo, or typewriter tinnitus can be precipitated from a neurovascular compression of the vestibulocochlear nerve by VBD. Because proper medical or surgical treatments may stop the disease progression or improve audio-vestibular symptoms in subjects with VBD, a high index of suspicion and meticulous radiologic evaluation are needed when vestibulocochlear symptoms are not otherwise explainable, and if VBD is confirmed to cause audiovestibular manifestation, a thorough oto-neurotologic evaluation should be performed before initial treatment.

Ultrasound Findings Disclose the Mutual Impact of Vertebrobasilar Dolichoectasia and Vertebral Artery Hypoplasia

OBJECTIVES

Vertebrobasilar dolichoectasia (VBD) and vertebral artery hypoplasia (VAH) are known predisposing factors of posterior circulation stokes. These vascular conditions have unique hemodynamic patterns in neuroimaging studies; however, they have been presented as a single entity in some reports. The aim of this retrospective study was to clarify the relationship between these conditions with regard to ultrasound (US) findings.

METHODS

A total of 465 patients with strokes were recruited. Brain magnetic resonance imaging of vertebrobasilar arteries and differences in extracranial side-to-side vertebral artery (VA) flow were recorded by US and compared in groups.

RESULTS

The mean age of the 465 patients ± SD was 67.23 ± 12.13 years; 296 were men. The prevalence of VBD was 13.5% (n = 63), and 10.8% (n = 50) of the patients had coexisting VAH and VBD. These patients also had the highest prevalence of posterior circulation strokes (58% [n = 29]). A cutoff value of 55.65 mL/min and a ratio discrepancy of 5.28 (group median) for the side-to-side extracranial VA flow volume as detected by conventional US were also observed in the patients with both VAH and VBD.

CONCLUSIONS

Our study revealed a higher prevalence of posterior circulation strokes in the patients with both VBD and VAH. Chronic asymmetric hemodynamic shear force in extracranial VAs leading to deformity of the vertebrobasilar system may explain our observations. Accordingly, the blood flow volume and the ratio difference could potentially be used to detect patients at risk of VBD and reduce stroke risk factors.

Basilar Artery Tortuosity Is Associated With White Matter Hyperintensities by TIMP-1

Background and Purpose

To test the hypothesis that the imbalance between matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) may play a potential role in bridging vertebrobasilar dolichoectasia (VBD) with lacunar infarction (LI) and white matter hyperintensities (WMH).

Methods

We studied 212 patients with vertigo who underwent multimodal magnetic resonance imaging (MRI) tests for VBD, LI, and WMH identification. We investigated biomarkers of VBD with magnetic resonance angiography (MRA) via various physical characteristics of the vertebrobasilar arteries (VBAs). Similarly, LI and WMH biomarkers were extracted using T2-weighted and fluid attenuated inversion recovery (FLAIR) images. We first determined which of these neuroimaging markers were significant identifiers of VBD, LI and the different grades of WMH. We then sought to draw potential mechanistic conclusions from these MRI-derived parameters, by associating the aforementioned biomarkers with MMP and TIMP serum levels in patient blood samples using non-parametric statistical tests.

Results

MMP-9 serum level was significantly higher in vertigo patients with VBAs dilation and basilar artery (BA) elongation compared to those with healthy arterial size, and the ratio of MMP-9/TIMP-1 level were higher in those patients. TIMP-1 level was also markedly higher in vertigo patients with BA tortuosity than those without BA tortuosity. The bending length (BL) of the BA was positively correlated with TIMP-1. The length, BL, and tortuosity index of the BA, as well as serum levels of TIMP-1 were greater in patients with higher WMH grades compared to those with low WMH grades. The vertebral artery and BA diameters, and the levels of MMP-2, -3, -9, TIMP-2 and cathepsin L were similar in patients with different WMH grades.

Conclusion

In vertigo patients, we found various probably associations between MMP-9 and TIMP-1 with arterial alterations linked to both VBD and WMH that may help with the diagnosis and treatment of such diseases in the future.

Deletion of 6p25.3 Is Associated with Cerebrovascular Dolichoectasia: Report of 2 Cases

Developmental dolichoectasia of the intracranial vessels is a rare occurrence. The authors report 2 sibling pediatric patients who were born with 6p25.3 deletion, associated with carotid and vertebrobasilar dolichoectasia. MRI imaging of both children showed asymptomatic elongation and dilation of the vertebrobasilar system and "kissing" carotid arteries. A microarray analysis was also performed for both patients, which identified a 1.5-Mb deletion of 6p25.3 covering 15 genes including FOXC1, which has been implicated in defects in vascular morphogenesis.

Clinical and imaging features of vertebrobasilar dolichoectasia combined with posterior circulation infarction: A retrospective case series study

This study aims to analyze the clinical and imaging features of vertebrobasilar dolichoectasia (VBD) combined with posterior circulation infarction, and to explore risk factors for the occurrence of posterior circulation infarction in VBD patients.VBD patients were divided into 2 groups, according to the results of the imaging examination: posterior circulation infarction group and nonposterior circulation infarction group. The demographics, vascular risk factors, imaging, and other clinical data of the VBD patients were collected and retrospectively compared, and the risk factors for the occurrence of posterior circulation infarction in VBD patients were analyzed. The relationship between imaging features of the VBD blood supply artery and the infarct site was also analyzed.A total of 56 VBD patients were included into the analysis. Among these patients, 26 patients had posterior circulation infarction. Infarction occurred in the blood supply area of the posterior cerebral artery in 14 patients. The difference in the height of the basilar artery bifurcation between patients with vertebrobasilar artery blood supply area infarction and patients with posterior cerebral artery supply area infarction was statistically significant. Hypertension and posterior circulation intracranial atherosclerosis were the risk factors for posterior circulation infarction in VBD patients.Elevated basilar artery bifurcation is a risk factor for infarction in the posterior cerebral artery supply area in VBD patients. Posterior circulation infarction in VBD may be the comprehensive result of multiple factors, such as congenital defects of the basilar artery wall, hypertension, and atherosclerotic lesions.

Perfusion by delayed time to peak in vertebrobasilar dolichoectasia patients with vertigo

Objective

To investigate the association between the perfusion magnetic resonance imaging (MRI) and vertebrobasilar dolichoectasia (VBD) in vertigo patients and at least one vascular risk factor.

Methods

We studied 289 patients with vertigo (spinning, swaying, nausea, vomiting, and unsteady gait) who performed multimode MRI. Maximum diameter and tortuous parameters of the basilar artery and vertebral arteries were calculated using magnetic resonance angiography. Relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), mean transit time (MTT), and time to peak (TTP) maps were evaluated by dynamic susceptibility contrast‐enhanced perfusion imaging. Association of perfusion MRI and VBD was evaluated by nonparametric tests and receiver‐operating characteristic curve was constructed to predict posterior ischemic stroke in VBD patients.

Results

The prevalence of VBD was 26.6% (n = 77/289) in our study. Male gender was the risk factor of VBD by multivariate analysis. BA diameter was significant statistics between ischemic stroke and nonischemic stroke patients. TTP in bilateral lower cerebellum, superior cerebellum, bilateral pons, and occipital and temporal lobes region of interests was significantly delayed in VBD versus non‐VBD patients, while rCBF, rCBV, and MTT parameters were not significant differences. TTP in the right temporal lobe delayed by 21.96 ms was the best predictive value and the mean TTP predictive threshold value in all ROIs was 22.67 ± 1.48 ms.

Interpretation

VBD leads to the hypoperfusion of posterior circulation territory characterized by delayed TTP. Delayed TTP in cerebellum, pons, and occipital and temporal lobes fed by vertebrobasilar arteries predicted the occurrence of posterior ischemic stroke in VBD patients.

Why does my patient's basilar artery continue to grow? A four-year case study of a patient with symptoms of vertebrobasilar dolichoectasia

BACKGROUND

Vertebrobasilar dolichoectasia (VBD) is a clinical entity associated with ischemic stroke, compression of cranial nerves or brainstem, and hydrocephalus. There have been relatively few studies following the progression of VBD in patients presenting with a variety of diverse clinical features.

CASE PRESENTATION

Here, we report a case study of a male with progressive VBD who was followed from November 2012 to December 2016. The patient had diagnosed hypertension for several years and suffered from left peripheral facial paralysis, recurrent ischemic attacks in the brainstem and cerebellum, obstructive hydrocephalus and frequent pneumonia. A series of cranial CT and multi-modal MRI scans were performed to explore the brain imaging features of the patient during follow-up.

CONCLUSIONS

The presented case study suggests that aging, uncontrolled hypertension, arterial dissection and infection may contribute to the exacerbation of VBD and recurrent ischemic stroke.

Decreased outlet angle of the superior cerebellar artery as indicator for dolichoectasia in late onset Pompe disease

BACKGROUND

Lysosomal α-glucosidase deficiency (Pompe disease) not only leads to glycogen accumulation in skeletal muscle, but also in the cerebral arteries. Dolichoectasia of the basilar artery (BA) has been frequently reported. Therefore progression of BA dolichoectasia in late onset Pompe patients (LOPD) was studied.

METHODS

BA length, diameter and volume, and cerebral lesions were analysed by MRI/TOF-MR angiography or CT/CT angiography in 20 LOPD patients and 40 controls matching in age, sex- and cardiovascular risk factors. The height of BA bifurcation was assessed semi-quantitatively using the Smoker's criteria and quantitatively by measuring the outlet angle of the superior cerebellar artery (SUCA). Nine patients were followed over 5 years.

RESULTS

The height of the BA bifurcation was abnormal in 12/20 (60%) LOPD patients and in 12/40 (30%) matched controls. The SUCA outlet angle was reduced in LOPD patients compared to controls (127 ± 33° vs. 156 ± 32°, p = 0.0024). The diameter, length and volume of the BA were significantly increased in LOPD patients compared to controls. 12/20 (60%) LOPD patients and 27/40 (68%) controls presented white matter lesions. During 5 years 2/9 LOPD patients developed an abnormal height of BA bifurcation according to the Smoker's criteria and in all patients the SUCA outlet angle decreased (138 ± 34° vs. 128 ± 32°, p = 0.019). One patient with prominent basilar dolichoectasia experienced a thalamic hemorrhage.

CONCLUSION

Pompe disease is associated with BA dilation, elongation and elevated bifurcation height of the BA which might result in cerebrovascular complications. The SUCA outlet angle seems to be useful for monitoring the progression of BA dolichoectasia.

Vertebrobasilar Dolichoectasia Causing An Optic Tract Syndrome

Vertebrobasilar dolichoectasia (VBD) is characterized by significant dilation, elongation, and tortuosity of the vertebrobasilar system. We present a unique case of VBD, confirmed by neuroimaging studies, showing vascular compression of the right optic tract and lower cranial nerves leading to an incongruous left homonymous inferior quadrantanopia and glossopharyngeal neuralgia.