Extracranial Vertebral Artery Research Articles

Far Lateral Approach (Transcondylar, Transtubercular) for Bypass and Trapping of a Ruptured, Dissecting PICA Aneurysm

Aneurysms of the posterior circulation pose a unique challenge due to higher rupture rates, higher recurrence rates following endovascular treatment, and extended open cranial base approaches required to reach the ventrally located brainstem circulation. While endovascular therapy has made tremendous strides in successful treatment for most posterior circulation aneurysms, open microscopic approaches remain essential in specific circumstances. Here, we present a case of a patient who presented with acute, severe headache, and sixth nerve palsies, and who was found to have hydrocephalus and a dissecting aneurysm at the anterolateral medullary segment of the posterior inferior cerebellar artery (PICA). Interestingly, this patient had a history of alpha-1 antitrypsin deficiency that has been linked with spontaneous aortic and cervical arterial dissections. The fusiform geometry of the dissecting aneurysm was deemed suboptimal for endovascular treatment, so an open microsurgical approach for occipital artery to PICA bypass and aneurysm trapping was planned. Because this patient had cerebral edema in the setting of a ruptured aneurysm and hydrocephalus, a far lateral craniotomy combined with drilling of the occipital condyle and jugular tubercle was critical to enhance exposure of the first segment of the PICA and to minimize brain retraction. In this video, we highlight the key steps and nuances for harvest of the occipital artery, achieving control of the extracranial vertebral artery, performing the transcondylar and transtubercular far lateral approach, and bypass with trapping technique for these challenging posterior circulation aneurysms. The link to the video can be found at: https://youtu.be/dqgblwX6t0Q .

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.

Comparison of anticoagulation and antiplatelet therapy for treatment of blunt cerebrovascular injury in children

Blunt cerebrovascular injury (BCVI) is uncommon in the pediatric population. Among the management options is medical management consisting of antithrombotic therapy with either antiplatelets or anticoagulation. There is no consensus on whether administration of antiplatelets or anticoagulation is more appropriate for BCVI in children < 10 years of age. Our goal was to compare radiographic and clinical outcomes based on medical treatment modality for BCVI in children < 10 years. Clinical and radiographic data were collected retrospectively for children screened for BCVI with computed tomography angiography at 5 academic pediatric trauma centers. Among 651 patients evaluated with computed tomography angiography to screen for BCVI, 17 patients aged less than 10 years were diagnosed with BCVI (7 grade I, 5 grade II, 1 grade III, 4 grade IV) and received anticoagulation or antiplatelet therapy for 18 total injuries: 11 intracranial carotid artery, 4 extracranial carotid artery, and 3 extracranial vertebral artery injuries. Eleven patients were treated with antiplatelets (10 aspirin, 1 clopidogrel) and 6 with anticoagulation (4 unfractionated heparin, 2 low-molecular-weight heparin, 1 transitioned from the former to the latter). There were no complications secondary to treatment. One patient who received anticoagulation died as a result of the traumatic injuries. In aggregate, children treated with antiplatelet therapy demonstrated healing on 52% of follow-up imaging studies versus 25% in the anticoagulation cohort. There were no observed differences in the rate of hemorrhagic complications between anticoagulation and antiplatelet therapy for BCVI in children < 10 years, with a nonsignificantly better rate of healing on follow-up imaging in children who underwent antiplatelet therapy; however, the study cohort was small despite including patients from 5 hospitals.

Mechanical Thrombectomy for Tandem Vertebrobasilar Stroke: Characteristics and Treatment Outcome.

Background and Purpose- Tandem vertebrobasilar strokes are not well-known causes of posterior circulation stroke. The purpose of this study was to investigate the characteristics and outcome of mechanical thrombectomy in patients with tandem vertebrobasilar stroke. Methods- Acute basilar artery occlusion patients with tandem vertebral artery (VA) stenosis/occlusion who underwent mechanical thrombectomy were retrospectively analyzed. Concomitant tandem VA steno-occlusion was defined as severe stenosis/occlusion of the extracranial VA with impaired flow. Clinical/angiographic characteristics, recanalization rate, procedure time, and clinical outcome were evaluated with comparisons according to the treatment strategy. Results- Tandem vertebrobasilar occlusion was identified in 24.6% (55 of 224) of the acute basilar artery occlusion patients. Overall successful recanalization and good clinical outcome was achieved in 87.2% (48 of 55) and 30.9% (17 of 55) of the patients. There were no significant differences in procedure time, recanalization rate, and clinical outcome in comparisons of the VA access route selection or angioplasty of the tandem VA lesion. Two patients developed short-term recurrent basilar artery occlusion when angioplasty of the tandem VA lesion was not performed. Good clinical outcome was more likely with lower baseline National Institutes of Health Stroke Scale score (odds ratio, 0.87 [95% CI, 0.787-0.961]; P=0.006) and short onset-to-recanalization time (odds ratio, 0.993 [95% CI, 0.987-0.999]; P=0.03). Conclusions- Tandem vertebrobasilar occlusion may be a frequent pathological mechanism of posterior circulation stroke. Good outcome may be achieved by strategic choice of the access route and selective angioplasty of the tandem VA lesion.

A case of bow hunter’s syndrome due to bilateral extracranial vertebral artery dissection in the craniovertebral junction caused by neck rotation

A case of bow hunter’s syndrome due to bilateral extracranial vertebral artery dissection in the craniovertebral junction caused by neck rotation

Holding up under pressure: a complex interplay between cerebral blood flow and ventilatory responses to alterations in carbon dioxide.

Holding up under pressure: a complex interplay between cerebral blood flow and ventilatory responses to alterations in carbon dioxide.

Stroke and Death Rate in Patient Cohort Studies of Extracranial Vertebral Artery Stenosis: A Systematic Review (5188)

Stroke and Death Rate in Patient Cohort Studies of Extracranial Vertebral Artery Stenosis: A Systematic Review (5188)

New ischemic lesions on brain magnetic resonance imaging in patients with blunt traumatic cerebrovascular injury.

Patients with blunt cerebrovascular injuries are at risk of thromboembolic stroke. Although primary prevention with antithrombotic therapy is widely used in this setting, its effectiveness is not well defined and requires further investigation. The aim of this study was to evaluate the utility of magnetic resonance imaging (MRI)-detected ischemic brain lesions as a possible future outcome for randomized clinical trials in this patient population. This prospective observational study included 20 adult blunt trauma patients admitted to a level I trauma center with a screening neck CTA showing extracranial carotid or vertebral artery injury. All subjects lacked initial evidence of an ischemic stroke and were managed with antithrombotic therapy and observation and then underwent brain MRI within 30 days of the injury to assess for ischemic lesions. The MRI scans included diffusion, susceptibility, and Fluid-attenuated Inversion Recovery (FLAIR) sequences, and were reviewed by two neuroradiologists blinded to the computed tomography angiography (CTA) findings. Eleven CTAs were done in the emergency department upon admission. There were 12 carotid artery dissections and 11 unilateral or bilateral vertebral artery injuries. Median interval between injury and MRI scan was 4 days (range, 0.1-14; interquartile range, 3-7 days). Diffusion-weighted imaging evidence of new ischemic lesions was present in 10 (43%) of 23 of the injured artery territories. In those injuries with ischemic lesions, the median number was 8 (range, 2-25; interquartile range, 5-8). None of the lesions were symptomatic. Blunt cerebrovascular injury was associated with a higher mean ischemic lesion count (mean count of 3.17 vs. 0.14, p < 0.0001), with the association remaining after adjusting for injury severity score (p < 0.0001). In asymptomatic blunt trauma patients with CTA evidence of extracranial cerebrovascular injury and treated with antithrombotic therapy, nearly half of arterial injuries are associated with ischemic lesions on MRI. Therapeutic/care management, level IV.

Abstract TP444: New Ischemic Lesions on Brain MRI in Patients With Blunt Traumatic Cerebrovascular Injury

Introduction: Patients admitted after high energy blunt trauma with extracranial cerebrovascular injuries on screening neck computed tomography angiography (CTA) represent a unique group of patients at risk of thromboembolic stroke. These arterial dissections account for &gt;1,000 ischemic strokes in the United States per year. Although stroke prophylaxis with antithrombotics is widely used in this setting, the risk of ischemic brain injury is unknown. Methods: This prospective observational study included 20 adult blunt trauma patients admitted with a screening CTA showing extracranial carotid or vertebral artery injury. All subjects had no initial clinical evidence of ischemic stroke, were managed with antiplatelets and observation and had brain magnetic resonance imaging (MRI) within 14 days of admission. The MRIs included diffusion, susceptibility, and FLAIR sequences to distinguish acute ischemic lesions from contusions and chronic infarctions and were read by two neuroradiologists blind to the findings of the neck CTA. A negative binomial regression adjusted for age and Injury Severity Score (ISS) was used to assess association between artery injury and lesion counts. Results: There were 12 carotid injuries and 11 unilateral or bilateral vertebral artery injuries. Mean interval between injury and MRI scan was 6.9 days. New ischemic lesions in the territory of the affected artery were present in 10 (43%) of the injured artery territories. The mean number of ischemic lesions was 7.8 (range 2-25), which was higher for territories with artery injury (mean=3.17) than those without injury (mean=0.14). None of the lesions were symptomatic. Adjusted for age and ISS, those with artery injury had a 23-fold higher average count of lesions (p=0.0004). In a sensitivity analysis excluding lesion counts &gt;1.5 standard deviation units, the association remained 11-fold higher count for artery injury (p=0.0107). Conclusions: In blunt trauma patients with CTA evidence of extracranial cerebrovascular injury and treated with antiplatelets, &gt;40% of arterial injuries are associated with ischemic lesions on MRI. Ischemic lesions on MRI may be a useful endpoint for future clinical trials of antithrombotic strategies in patients with blunt cerebrovascular injury.

Canine Assault with Blunt Trauma to the Chest Causing Acute Ischemic Stroke

Ischemic stroke occurs in a significant subset of patients with blunt traumatic cerebrovascular injury (TCVI). The patients are most often victims of motor vehicle crashes or assaults, and suffer ischemic stroke due to injury of the extracranial carotid or vertebral arteries. A 60 year old male described walking in a park when a large dog jumped up striking him in the chest and causing forceful rotation of the neck, but no head injury was reported. Immediately after the incident the patient complained of dizziness, clumsiness of the left arm, and difficulty seeing to the left. Computed tomography angiography of the neck demonstrated 50% stenosis of the proximal right internal carotid artery secondary to mural thrombus. Prior to the event the patient had no known history of carotid disease. Magnetic resonance imaging of the brain showed numerous subcentimeter foci of acute ischemia in the right cerebral hemisphere within the right middle and posterior cerebral artery distributions. Most literature about TCVI and stroke has been published in trauma, general surgery, and neurosurgery journals because these patients are generally primarily managed by trauma surgeons. Because of the increasing prevalence and awareness of TCVI, it is important to bring this clinical entity to the attention of all medical providers.

Correlation between the hemodynamic parameters of extracranial vertebral artery and the severity and location of intracranial vertebral artery stenosis

Objective To analyze the effects of the degree and location of intracranial vertebral artery(VA) lesions on the hemodynamic parameters of extracranial VA. Methods A total of 275 consecutive patients who were diagnosed as posterior circulation ischemic stroke or transient ischemic attack (TIA) with unilateral intracranial VA stenosis or occlusion in the Department of Neurology and Neurosurgery of Capital Medical University Xuanwu Hospital from January 2015 to December 2017 were enrolled. All patients were examined by head and neck vascular ultrasound, CT angiography (CTA) and/or digital subtraction angiography (DSA) within one week. According to the results of DSA or CTA, the patients were divided into mild stenosis group(53 patients), moderate stenosis group(62 patients), severe stenosis group(58 patients) and occlusion group(102 patients). The inner diameter (D), peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) of the extracranial segment (V2 segment) of the VA were recorded and analyzed. Results The PSV and EDV in the severe stenosis group and the occlusion group were significantly lower than those in the mild stenosis group and the moderate stenosis group (P=0.000), and the PSV and EDV in the occlusion group were significantly lower than those in the severe stenosis group[ (31±10) cm/s vs (46±12)cm/s, (5±4)cm/s vs (15±7)cm/s; all P=0.000], RI was significantly higher than the other three groups (0.85±0.12, 0.70±0.10, 0.66±0.07, 0.64±0.06, respectively; all P=0.000); RI in the severe stenosis group were not significantly different from those in the mild to moderate stenosis groups (P=0.044, 0.223). There were no significant differences in the inner diameter, PSV, EDV and RI between the subgroups in the severe stenosis group before or after the PICA (posterior inferior cerebellar artery)(P=0.130, 0.322, 0.865, 0.227). However, the EDV decreased and RI increased in the occlusive subgroup before the PICA when compared the subgroup after the PICA (all P=0.000). Conclusions The location and degree of intracranial VA lesions directly affect the changes of blood flow velocity and vascular resistance of extracranial VA, and the changes of low-speed and high-resistance hemodynamics of extracranial VA may indicate the existence of occlusive lesions in intracranial VA. Key words: Ultrasonography; Vertebral artery stenosis; Occlusive diseases; Hemodynamics; Extracranial segment; Intracranial segment

Endovascular Revascularization of Nonacute Symptomatic Proximal Extracranial Vertebral Artery Occlusion

To evaluate the feasibility, success rate, and safety of endovascular revascularization of nonacute symptomatic proximal extracranial vertebral artery occlusion (PEVAO). In a retrospective, single-center study, we analyzed clinical and imaging data from consecutive patients with PEVAO who underwent endovascular revascularization from June 2011 to March2018. The study enrolled 23 patients (mean age, 59 years; range, 42-77 years; 17 men). The rate of successful technical revascularization was 91.3% (n= 21), and the rate of complications was 4.3% (n= 1). At 3-month follow-up, the patients with successful endovascular revascularization of nonacute symptomatic PEVAO did not present any neurologic symptoms and computed tomography angiography did not show restenosis of the stent. Endovascular revascularization of nonacute symptomatic PEVAO is feasible and associated with a high rate of procedural success and low rate of procedural complications. A large, multicenter, randomized study is warranted to confirm the findings.

Assessment of Cerebral Vasodilatory Capacity as Part of Catheter-Based Cerebral Angiography.

Cerebral vasodilatory capacity assessment for risk stratification in patients with extracranial arterial stenosis or occlusion may be useful. We describe a new method that assesses cerebral vasodilatory capacity as part of catheter-based cerebral angiography. We prospectively assessed regional cerebral blood volume (rCBV) in the arterial distribution of interest using a controlled contrast injection in the common carotid or the subclavian arteries. rCBV maps were created using a predefined algorithm based on contrast distribution in the venous phase (voxel size: .466 mm3 ). rCBV maps were acquired again after selective administration of intra-arterial nicardipine (2.0 mg) distal to the stenosis. Two independent observers graded the change in rCBV in 10 predefined anatomical regions within the tributaries of the artery of interest (0 = reduction, 1 = no change, 2 = increase) and total rCBV change scores were summated. Twenty-five patients with internal carotid artery stenosis (n = 18; 0-90% in severity) or extracranial vertebral artery stenosis (n = 7; 0-100% in severity) were assessed. There was an increase in rCBV in a tributary of the artery of interest in 18 of 25 after intra-arterial nicardipine (mean score: 11.98; range 0-19.5). There was no change or decrease in rCBV in 7 of 25 patients. The mean rCBV change score was similar in patients with an assessment of internal carotid artery or vertebral artery distributions (12.2 ± 5.3; 11.4 ± 2.5; P = .68). Selective vasodilatory response to intra-arterial nicardipine in the affected arterial distribution during catheter-based cerebral angiography may provide new data for risk stratification.

Association between the posterior part of the circle of Willis and the vertebral artery hypoplasia.

BackgroundIt is not clear whether the configuration of the posterior part of the circle of Willis (CW) depends on the proximal part of the vertebrobasilar system. Our aim is to evaluate the posterior part of CW in association with different size of vertebral arteries (VA) in healthy volunteers.Materials and methodsThe present study was based on a sample of 923 healthy volunteers who were examined from 2013 through 2018. The duplex ultrasonographic examination of the extracranial vertebral (VA) and carotid arteries was performed. VA was defined as hypoplastic (VAH) when VA diameter in the entire course was less than 2.5 mm. All the participants underwent magnetic resonance angiography (MRA) examination. All the component vessels of the circle of Willis were assessed in each individual. We classified the posterior communicating artery (PCoA) as presence PCoA, absence/hypoplastic PCoA and fetal-type posterior circle of Willis (FCW) in which the major stem of the posterior cerebral artery (PCA) arises from ipsilateral internal carotid artery (ICA). The comparison of the posterior part of CW was made in subjects with normal VA and VAH of a different degree (communicating with basilar artery (VAH-BA) and not communicating with the basilar artery (VAH-PICA)).ResultsFCW was found in 15.9% of subjects, bilaterally–in 2.3%. FCW was more frequent in individuals with VAH than in those with normal VA (accordingly, 28.8% vs. 13.5%, p<0.001. Moreover FCW was recorded in 50% of the subjects with VA—PICA in comparison with 13.5% of those with normal VA and 22.8% with VAH—BA, p<0.005. On the contrary, absence/hypoplasia of both PCoA was mostly found in the group with normal VA in comparison with VAH-BA and VAH-PICA (accordingly, 50.7%, 38.6% and 12.5%, p<0.01).ConclusionIndividuals with VAH have a different pattern of the posterior part of CW in comparison with those with normal VA. With the increasing degree of VAH, the proportion of FCW increases, while the proportion of absence/hypoplastic of both PCoA decreases.

Letter to the Editor Regarding “Flow Diverter for the Treatment of Pseudoaneurysms of the Extracranial Vertebral Artery: Report of 2 Cases and Review of the Literature”

Letter to the Editor Regarding “Flow Diverter for the Treatment of Pseudoaneurysms of the Extracranial Vertebral Artery: Report of 2 Cases and Review of the Literature”

Vertebral artery stenting to prevent recurrent stroke in symptomatic vertebral artery stenosis: the VIST RCT.

Symptomatic vertebral artery (VA) stenosis has been associated with a markedly increased early risk of recurrent stroke. VA stenosis can be treated with stenting; however, there are few data from randomised controlled trials evaluating the efficacy of this treatment, and recent studies in intracranial stenosis have suggested that stenting may be associated with increased risk. The Vertebral artery Ischaemia Stenting Trial (VIST) was established to compare the risks and benefits of vertebral angioplasty and stenting with best medical treatment (BMT) alone for recently symptomatic VA stenosis. VIST was a prospective, randomised, open, parallel, blinded end-point clinical trial. The trial was performed in 14 hospitals in the UK. Recruitment began on 23 October 2008 and follow-up ended on 1 March 2016, by which time every patient had been followed up for at least 1 year. Participants had to have symptomatic vertebral stenosis of at least 50% resulting from presumed atheromatous disease. Both patients and clinicians were aware of treatment allocation; however, an independent adjudication committee, masked to treatment allocation, assessed all primary and secondary end points. Participants were randomly assigned (1 : 1) to either vertebral angioplasty/stenting plus BMT (n = 91) or BMT alone (n = 88). A total of 182 patients were initially enrolled; however, three patients (two who withdrew after randomisation and one who did not attend after the initial randomisation visit) did not contribute any follow-up data and were excluded. None of these three patients had outcome events. The primary end point was the occurrence of fatal or non-fatal stroke in any arterial territory during follow-up. The median follow-up was 3.5 (interquartile range 2.1-4.7) years. Of the 61 patients who were stented, 48 (78.7%) had extracranial stenosis and 13 (21.3%) had intracranial stenosis. No perioperative complications occurred with extracranial stenting; two strokes occurred during intracranial stenting. The primary end point occurred in five patients (including one fatal stroke) in the stent group and in 12 patients (including two fatal strokes) in the medical group (giving a hazard ratio of 0.40, 95% confidence interval 0.14 to 1.13; p = 0.08), with an absolute risk reduction of 25 strokes per 1000 person-years. The study was underpowered because it failed to reach target recruitment. The high rate of non-confirmation of stenosis in the stented group of the trial was a second limitation. The trial found no difference in risk of the primary end point between the two groups. Post hoc analysis suggested that stenting could be associated with a reduced recurrent stroke risk in symptomatic VA and further studies are now required to confirm these findings, particularly in extracranial VA stenosis where complication rates with stenting were confirmed to be very low. Current Controlled Trials ISRCTN95212240. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 41. See the NIHR Journals Library website for further project information. In addition, funding for the pilot phase was provided by the Stroke Association.

EFFECTS OF ROSUVASTATIN AND ATORVASTATIN ON BLOOD PRESSURE, CEREBRAL BLOOD FLOW, ENDOTHELIAL FUNCTION, ANGIOTENSIN II IN PATIENTS WITH ISCHEMIC STROKE-COMPLICATED HYPERTENSION

Objective: To study the dose-dependent effect of rosuvastatin (R) and atorvastatin (A) on blood pressure (BP) profile, cerebral blood flow (CBF), endothelial functional activity and level of angiotensin II (ATII) in patients (pts) with hyperlipidemia (HLP) and arterial hypertension (AH) after cerebral ischemic stroke (CIS). Design and method: 68 pts were randomized to 4 groups: 1)R10 mg, 2)R20 mg, 3)A10 mg, 4)A40 mg. The study lasted 12 weeks (wks). 24-hour ABPM was performed according to standard protocol, CBF was assesed by Doppler ultrasonography of extracranial carotid arteries (CA) and vertebral arteries (VA). We evaluated the blood levels of end-metabolites of NOx, endothelin-1 (ET-1), ATII. Results: 24-hour ABPM showed reduction of SBP variability of night time (by 16,1%, p < 0,05) on A10 mg, SBP time index at night (by 15,5%, p < 0,05) and DBP day/night difference (by 32,7%, p < 0,05) on A40 mg. Therapy R 20 mg observed increase SBP variability of daytime (by 13,9%, p < 0,05). After 12 wks there were some improvement of CBF: peak systolic velocity (Vps) to end diastolic velocity (Ved) ratio and pulsatility index (PI) decreased by 6% (p < 0,05) and 8.4% (p < 0.05), respectively, in pts on A10 mg end-diastolic velocity (Ved) increased by 10,5% (p < 0,05) in pts on A 40 mg. The R20 mg increase of Ved by 4,1% (p < 0.01), decrease of resistive index (RI) of CA by 3,1% (p < 0,05) and increase of Ved in V2/V3 segments of VA by 7,3% (p < 0,05). Assessment of CBF showed improvement of flow parameters after 12 wks of treatment only from «non-ischemic» sites. After 6 wks of treatment of A40 mg and R20 mg concentrations of NOx metabolites significantly increased by 7.7 and 8.1 % (p < 0.05), respectively, and after 12 months we observed maximal effect in all pts. Levels of ET-1 significantly decreased after 12 wks of A40 mg (by 4,8%, p < 0.05) and R10 mg (by 9,5%, p < 0,05). The levels of AT II were decreased after 12 wks therapy with A40 mg only (by 7.1%, p < 0.05). Conclusions: The different doses of R and A showed dose-depended antiatherogenic and pleiotropic effects in the post-CIS pts with HLP and hypertension.

Intracranial Extension of Extracranial Vertebral Dissection Is Associated With an Increased Risk of Ischemic Events.

Background and Purpose- Intracranial artery dissection can eventually lead to subarachnoid or intracerebral hemorrhage. Little is known about the clinical features and risks associated with extracranial vertebral artery dissection that extends intracranially. The clinical and imaging characteristics of extracranial vertebral artery dissection (eVAD) with (e+iVAD) or without (eVAD) intracranial extension were analyzed. Methods- The frequency of ischemic events, including ischemic strokes and transient ischemic attacks, was compared between e+iVAD and eVAD patients from a monocentric cohort study. Results- Among 328 patients with cervical artery dissection, vertebral artery dissection was diagnosed in 153 individuals. Twenty-nine patients had e+iVAD (19%) and 124 patients had only eVAD (81%). Cardiovascular risk factors did not differ between these 2 groups, but ischemic events were more frequent in patients with e+iVAD than in patients with eVAD (86% versus 48%, P=0.0002). Subarachnoid hemorrhage occurred in 1 patient with e+iVAD and in 9 with eVAD (6% versus 3%, P=0.53). Intracranial extension was an independent factor associated with ischemic stroke at admission (odds ratio, 6.43; 95% CI, -1.96 to 21.08; P=0.002) after adjustment for cardiovascular risk factors and imaging findings. Conclusions- In a large cohort of patients with vertebral artery dissection, intracranial extension of the vessel dissection appears associated with an increased risk of ischemic stroke.

57-Year-Old Man With Vertigo

57-Year-Old Man With Vertigo

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

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. 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. 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. 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.