Clinical and neuroradiological features of intracranial vertebrobasilar artery dissection

Formation of a Large Fusiform Aneurysm near a Medullary Infarction Caused by Dissection of the Posterior Inferior Cerebellar Artery

Infarction of the posterior inferior cerebellar artery (PICA) can lead to ischemic stroke in the lateral medullary oblongata. PICA dissection can also elicit an ischemic event in this region, but its detection on radiological images is difficult because of the small diameter of the vessel. We report a case of Wallenberg syndrome due to PICA dissection in a 48-year-old man, which was difficult to diagnose on first admission. He reported sudden onset of sensory disturbance on the right side of his face, ataxic gait, and headache. Brain magnetic resonance imaging (MRI) revealed a fresh cerebral infarct in the right lateral medulla oblongata. Magnetic resonance angiography (MRA) performed at the time of his admission showed no cerebral vessel abnormalities. An MRI study 18 months after the event revealed a fusiform aneurysm on the lateral medullary segment of the PICA, which was extremely close to the cerebral infarct. We concluded that the infarct was due to PICA dissection because of the sudden onset of symptoms and because the infarcted territory of the occluded penetrating branch of the dissecting aneurysm was consistent with Wallenberg syndrome. The aneurysm was trapped and an occipital artery-PICA bypass was placed. At the latest follow-up, 1 year after the procedure, he had no neurological symptoms. Imaging findings at the time of his first admission indicated that the PICA was intact. However, 18 months later, MRI revealed enlargement of an aneurysm at the site of the dissection. A cerebral infarct with headache may indicate PICA dissection.

3D phase-sensitive inversion recovery sequence for intracranial vertebrobasilar artery dissection

BACKGROUND

T1-weighted 3D turbo spin echo (T1W-3D-TSE) sequences with variable refocusing flip angle are commonly used to diagnose intracranial vertebrobasilar artery dissection (iVAD). However, magnetic susceptibility artifacts of the cavernous sinus may cause loss of the basilar and vertebral arteries. This study investigated the effectiveness of a 3D phase-sensitive inversion recovery (3D-PSIR) sequence in reducing magnetic susceptibility artifacts in the cavernous sinus, and its imaging findings for iVAD.

METHODS

Twelve volunteers and eleven patients with iVAD were included. Magnetic resonance imaging (MRI) was performed using a 3.0-T MRI system. 3D-PSIR and T1W-3D-TSE sequences were used. Vessel wall defects and contrast-to-noise ratio (CNR) were evaluated. The MRI findings were visually evaluated.

RESULTS

In the 3D-PSIR images, one volunteer (8 %) had vessel wall defects, and five (42 %) had vessel wall defects (p = 0.046) in the T1W-3D-TSE images. CNR was higher in 3D-PSIR images for vessel wall-to-lumen, whereas it was higher in T1W-3D-TSE images for vessel wall-to-CSF (p < 0.001). Visual evaluation revealed similar MRI findings between the two sequences.

CONCLUSIONS

The 3D-PSIR sequence may be able to improve the vessel wall defects and achieve MRI findings comparable to those of the T1W-3D-TSE sequence in iVAD. The 3D-PSIR sequence can be a useful tool for the imaging-based diagnosis of iVAD.

Quantitative evaluation for intravascular structures of vertebral artery dissection with a novel zoomed high-resolution black-blood MR imaging

BACKGROUND

Although non-stroke vertebral artery dissection (VAD) is diagnosed using MRI, detecting the subtle intravascular structure remains challenging. This study aimed to evaluate the validity of quantitative intravascular scanning based on novel zoomed high-resolution black blood (Z-HB) MRI for distinguishing VAD from other vessel pathologies.

METHODS

Twenty-one patients with non-stroke VAD and 18 with symptomatic atherosclerotic plaques in their vertebral artery underwent Z-HB MRI and subsequent profile curve processing. Axial Z-HB imaging was obtained from dissected and normal segments in patients with VAD and atherosclerotic plaque in patients with ischemia. We investigated the qualitative categorization of the scanning patterns of the intravascular signals. We also evaluated the quantitative ability of each profile curve to discriminate multiple vessel pathologies by analyzing the receiver operating characteristics curves.

RESULTS

Profile curve processing of 140 Z-HB images categorized the intravascular signal patterns into luminal, asymmetrical, and omega types. The asymmetrical type included both dissecting and atherosclerotic vessels, and the omega type included dissecting and normal vessels. In the asymmetrical type, quantitative evaluation successfully distinguished intramural hematomas of VAD from atherosclerotic plaque with an area under the curve of 0.80. The intimal flap of the VAD was distinguished from the blood flow artifact of the normal vessel with an area under the curve of 0.93 in the omega type.

CONCLUSIONS

A combination of novel Z-HB MRI and profile curve processing provided an ultra-high-resolution analysis of the intravascular structure of non-stroke VAD and successfully distinguished VAD from normal vessels or atherosclerotic plaques.

Vessel Wall Imaging of Intracranial Arteries: Fundamentals and Clinical Applications

With the increasing use of 3-tesla MRI scanners and the development of applicable sequences, it has become possible to achieve high-resolution, good contrast imaging, which has enabled the imaging of the walls of small-diameter intracranial arteries. In recent years, the usefulness of vessel wall imaging has been reported for numerous intracranial arterial diseases, such as for the detection of vulnerable plaque in atherosclerosis, diagnosis of cerebral arterial dissection, prediction of the rupture of cerebral aneurysms, and status of moyamoya disease and cerebral vasculitis. In this review, we introduce the histological characteristics of the intracranial artery, discuss intracranial vessel wall imaging methods, and review the findings of vessel wall imaging for various major intracranial arterial diseases.

Case report: Fatal ischemic stroke induced by unruptured traumatic intracranial vertebral artery dissection

Intracranial vertebral artery dissection (IVAD) is rare and potentially fatal due to the risk of secondary subarachnoid hemorrhage once ruptured. Unruptured traumatic IVAD is even rarer and can result in ischemic stroke, yet mostly benign when timely diagnosed. Herein, we present an uncommon case of a patient who underwent a fatal ischemic stroke induced by unruptured traumatic IVAD. The patient was symptomatic soon after being physically assaulted but left untreated until acute deterioration for multiple brain infarctions occurred, secondary to IVAD-induced cerebellar stroke. Fifteen days later, he died, regardless of an urgently performed thrombectomy. Multiple serial histologic examinations revealed an unruptured dissection of the intracranial vertebral artery with a slit-like tear of the intimal and medial layers, considered to be the culprit lesion. The 15-day prolonged onset of stroke was rare in traumatic IVADs. Furthermore, the slit-like tear of the intimal layer in our case may support the initial intimal laceration hypothesis for VAD pathogenesis. Since limited pathohistological information is available regarding ischemic IVAD, we believe this rare case will be beneficial in understanding the pathophysiology of ischemic IVAD.

The Role of High-Resolution Magnetic Resonance Imaging in Cerebrovascular Disease: A Narrative Review

High-resolution magnetic resonance imaging (HRMRI) is the most important and popular vessel wall imaging technique for the direct assessment of vessel wall and cerebral arterial disease. It can identify the cause of stroke in high-risk plaques and differentiate the diagnosis of head and carotid artery dissection, including inflammation, Moya Moya disease, cerebral aneurysm, vasospasm after subarachnoid hemorrhage, reversible cerebral vasoconstriction syndrome, blunt cerebrovascular injury, cerebral arteriovenous malformations, and other stenosis or occlusion conditions. Through noninvasive visualization of the vessel wall in vitro, quantified assessment of luminal stenosis and pathological features of the vessel wall can provide clinicians with further disease information. In this report, technical considerations of HRMRI are discussed, and current clinical applications of HRMRI are reviewed.

Sequential detection rates of intramural hematoma for diagnosing spontaneous intracranial artery dissection

BACKGROUND AND PURPOSE

Spontaneous intracranial artery dissection (IAD) can be definitively diagnosed by detecting intramural hematoma (IMH) on arterial wall imaging. However, evidence of a time-dependent natural history for the development of radiological findings is lacking. Therefore, this study aimed to determine when imaging detects IAD.

METHODS

We obtained data from our cohort databases between March 2011 and August 2018 on consecutive patients who had definite, probable, or possible IAD based on the multidisciplinary expert consensus criteria. We assessed IMH on initial and follow-up high-resolution three-dimensional T1-weighted imaging (HR-3D-T1WI). We retrospectively investigated the association between IMH detection and days from symptom onset to initial HR-3D-T1WI and compared the IMH detection rate with other definitive diagnostic arterial dissection findings.

RESULTS

We analyzed 106 patients (mean age = 51 ± 13 years, 31 women) with at least initial HR-3D-T1WI data. The final diagnoses were definite, probable, and possible IAD in 83, 18, and 5 patients, respectively. IMHs were observed in 63 patients (59%, 95% confidence interval [CI] = 49%-69%). Overall IMH detection rate was 55% (95% CI = 45%-64%), 20% (95% CI = 3%-60%), 40% (95% CI = 21%-64%), and 50% (95% CI = 37%-63%) on the initial HR-3D-T1WI and Days 3, 7, and 13, respectively. Among 68 patients evaluated with digital subtraction angiography and HR-3D-T1WI, IMH was confirmed more frequently than other definitive diagnostic arterial dissection findings.

CONCLUSIONS

The overall IMH detection rate on HR-3D-T1WI was >50% and peaked in 1-2 weeks. IMH was a frequently detectable finding for the diagnosis of IAD compared to other radiological findings.

Morphological changes in vertebral artery dissections observed on 4D flow magnetic resonance images: case report

The morphology of vertebral artery (VA) dissections can change in the clinical course. A 58-year-old female with a 2-week headache was diagnosed with left VA dissection. Hemodynamic stress on the right VA detected on 4D flow MRI scans resulted in increased wall shear stress but the vessel was morphologically unchanged. Subsequent MRA revealed right VA dissection. Her bilateral dissections were treated conservatively and no neurological abnormality developed. Serial 4D flow MRI may be useful for observing morphological changes in VA dissections and help to clarify the mechanism(s) underlying VA dissections.

Vertebrobasilar dissecting aneurysms: microsurgical management in 42 patients

OBJECTIVE

Vertebrobasilar dissecting (VBD) aneurysms are rare, and patients with these aneurysms often present with thromboembolic infarcts or subarachnoid hemorrhage (SAH). The morphological nature of VBD aneurysms often precludes conventional clip reconstruction or coil placement and encourages parent artery exclusion or endovascular stenting. Treatment considerations include aneurysm location along the vertebral artery (VA), the involvement of the posterior inferior cerebellar artery (PICA), and collateral blood flow. Outcomes after endovascular treatment have been well described in the neurosurgical literature, but microsurgical outcomes have not been detailed. Patient outcomes from a large, single-surgeon, consecutive series of microsurgically managed VBD aneurysms are presented, and 3 illustrative case examples are provided.

METHODS

The medical records of patients with dissecting aneurysms affecting the intracranial VA (V4), basilar artery, and PICA that were treated microsurgically over a 19-year period were reviewed. Patient demographics, aneurysm characteristics, surgical procedures, and clinical outcomes (according to modified Rankin Scale [mRS] scores at last follow-up) were analyzed.

RESULTS

Forty-two patients with 42 VBD aneurysms were identified. Twenty-six aneurysms (62%) involved the PICA, 14 (33%) were distinct from the PICA origin on the V4 segment of the VA, and 2 (5%) were located at the vertebrobasilar junction. Thirty-four patients (81%) presented with SAH with a mean Hunt and Hess grade of 3.2 at presentation. Six (14%) of the 42 patients had been previously treated using endovascular techniques. Nineteen aneurysms (45%) underwent clip wrapping, 17 (40%) were treated with bypass trapping, and 6 (14%) underwent parent artery sacrifice. The complete aneurysm obliteration rate was 95% (n = 40), and the surgical complication rate was 7% (n = 3). The 8 patients with unruptured VBD aneurysms were significantly more likely to be discharged home (n = 6, 75%) compared with 34 patients with ruptured aneurysms (n = 9, 27%; p = 0.01). Good outcomes (mRS score ≤ 2) were observed in 20 patients (48%). Eight patients (19%) died.

CONCLUSIONS

These data demonstrate that patients with VBD aneurysms often present after a rupture in poor neurological condition, but favorable results can be achieved with open microsurgical repair in almost half of such cases. Microsurgery remains a viable treatment option, with the choice between bypass trapping and clip wrapping largely dictated by the specific location of the aneurysm and its relationship to the PICA.

MRI and MR angiography evaluation of pulsatile tinnitus: A focused, physiology-based protocol

BACKGROUND AND PURPOSE

Pulsatile tinnitus (PT) is the subjective sensation of a pulse-synchronous sound, most often due to a cerebrovascular etiology. PT can severely impact quality of life and may indicate a life-threatening process, yet a timely and accurate diagnosis can often lead to effective treatment. Clinical assessment with a history and physical examination can often suggest a diagnosis for PT, but is rarely definitive. Therefore, PT should be evaluated with a comprehensive and targeted radiographic imaging protocol. MR imaging provides a safe and effective means to evaluate PT. Specific MR sequences may be used to highlight different elements of cerebrovascular anatomy and physiology. However, routine MR evaluation of PT must comply with economic and practical constraints, while effectively capturing both common and rarer, life-threatening etiologies of PT.

METHODS

In this state-of-the-art review, we describe our institutional MR protocol for evaluating PT.

RESULTS

This protocol includes the following dedicated sequences: time-of-flight magnetic resonance angiography; arterial spin labeling; spoiled gradient recalled acquisition in the steady state; time-resolved imaging of contrast kinetics; diffusion weighted imaging, and 3-dimensional fluid-attenuated inversion recovery.

CONCLUSIONS

We describe the physiologic and clinical rationale for including each MR sequence in a comprehensive PT imaging protocol, and detail the role of MR within the broader evaluation of PT, from clinical presentation to treatment.

A Ruptured Vertebral Artery Dissecting Aneurysm that Grew Immediately: Case Report

The etiology of the vertebral artery dissecting aneurysm (VADA) is unknown and they frequently occur in relatively healthy young men. Therefore, the pathological mechanism by which VADAs occur has not been accurately identified. In this paper, we will examine a case in which a young man complaining of a simple headache became unconscious due to the rupture of a VADA in grew immediately.

Spine artery dissection as another puzzle of Covid-19 (Clinical case)

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[Spontaneous craniocervical dissection]

Spontaneous craniocervical dissection is one of the main causes of stroke in juvenile and middle-aged patients. It is caused by intramural hematoma which may result in stenosis or even occlusion of the artery. Clinical manifestation varies from local pain to ischemic complications. The imaging modality of choice is magnetic resonance imaging (MRI) which is able to detect all characteristic signs of dissection. Intramural hematoma is detected with thin slice fat-saturated 3D black-blood images. However, with the use of special imaging techniques, questionable findings can be clarified and especially the more difficult to detect intradural dissection can be accurately diagnosed. Acute treatment depends on the severity of neurological symptoms and their duration. Factors like the location of the dissection, cerebral infarction or hemorrhage influence the choice of medication for primary and secondary prophylaxis. Resorption of the intramural hematoma often leads to spontaneous recanalization within a few months.

[Endovascular treatment of extracranial dissecting aneurysms of cervical arteries]

BACKGROUND

Dissecting aneurysms of extracranial cervical arteries are a rare vascular pathology. To date, there is no consensus on the choice of optimal surgical approach for these aneurysms.

OBJECTIVE

To evaluate the effectiveness of endovascular treatment of various extracranial dissecting aneurysms.

MATERIAL AND METHODS

There were 19 patients with 21 extracranial dissecting aneurysms for the period from January 1, 2013 to October 19, 2020. Clinical examination, ultrasound and neuroimaging data were considered to determine surgical intervention.

RESULTS

Nineteen patients underwent 20 intravascular interventions: aneurysm embolization with detachable coils with stent-assistance (n=9), flow-diverting stent implantation (n=5), arterial reconstruction with a stent for carotid stenting (n=3), aneurysm embolization with balloon assistance (n=1), aneurysm embolization with detachable coils without assistance (n=2). There were no complications. All patients were discharged without neurological impairment after 1-5 days. Long-term results of control angiography were analyzed within 1-19 months in 12 patients. All aneurysms were completely occluded. Asymptomatic occlusion of flow-diverting stent together with aneurysm occurred in 1 patient with low compliance to antiplatelet therapy. Other 6 patients are scheduled for elective angiography.

CONCLUSION

Extracranial dissecting aneurysms of cervical arteries require vigilance due to their rare occurrence and risk of severe complications. In our opinion, intravascular interventions are advisable for these patients as effective and safe procedures.

Involvement of Matrix Metalloproteinase 9 in Vertebral Arterial Dissection With Posterior Circulation Ischemic Stroke

Background

Spontaneous vertebral arterial dissection (VAD) is an important cause of posterior circulation ischemic stroke (PCS), but its pathogenesis remains elusive. Matrix metalloproteinase 9 (MMP‐9) is a gelatinase involved in inflammation process and several vascular diseases, such as aorta dissection, but its role in VBD is unclear yet. The present study aimed to determine the association between serum MMP‐9 level and VAD‐related PCS.

Methods and Results

We recruited 149 patients with PCS, of which 30 were VAD and 119 had other determined etiologies (non‐VAD), and 219 non‐stroke individuals. Serum MMP‐9 was measured within 14 days from stroke onset. The age of VAD group was 59.6±15.0 years, which is similar to non‐stroke group (P=0.510) but significantly younger than non‐VAD group (69.9±14.0 years, P<0.001). Males and vascular risk factors were significantly more prevalent in VAD and non‐VAD groups than non‐stroke group (P<0.001). Multivariate logistic regression analysis adjusting potential confounders revealed that every 100 ng/mL of serum MMP‐9 level increment significantly predicted VAD (versus non‐stroke group: odds ratio (OR), 4.572; 95% CI, 2.240–9.333, P<0.001; versus non‐VAD group: OR, 1.819; 95% CI, 1.034–3.200, P=0.038).

Conclusions

Patients with VAD‐related PCS had higher levels of serum MMP‐9 at the acute stage of stroke compared with non‐stroke individuals and PCS of other causes, supporting the potential involvement of extracellular matrix‐degrading protease in the mechanism of VAD, which leads to ischemic events.

Headache in cervicocerebral artery dissection

Cervicocerebral artery dissection (CAD) is one of the more frequent causes of stroke in young adults with rates of up to 25%. Predisposing and risk factors for CAD are very different, and an etiological classification is based on the presence of a previous minor or major trauma, differentiating traumatic from spontaneous CAD. Headache represents one of the main initial symptoms for this pathological condition, probably due to the release of pro-inflammatory neurotransmitters from nerve terminals near the injured vessel. For its peculiar characteristics, the headache due to CAD has been defined with specific ICHD-3 criteria. In many cases, headache is associated with other signs related to the dissection or cerebral ischemia. In this systematic review of literature, headache was reported in more than 70% of cases with CAD with a prevalence in vertebrobasilar dissections. More than half of patients suffered a severe pain that was usually located in fronto-temporal and occipito-nuchal regions in the case of dissections in the anterior and posterior circulation, respectively. For the high stroke risk, CAD has to be promptly diagnosed with MRI or CTA and treated with anticoagulants or antithrombotics.

Single-center experience with the new generation Derivo Embolization Device in ruptured dissecting and blister aneurysms

Background

Treatment of ruptured dissecting and blister aneurysms is technically challenging with potentially high morbidity and mortality. The Derivo Embolisation Device (Derivo) is a flow diverter stent designed for the treatment of intracranial aneurysms.

Purpose

To assess the safety and feasibility of the Derivo in the treatment of ruptured dissecting and blister aneurysms.

Material and Methods

We retrospectively analyzed all patients with ruptured dissecting and blister aneurysms treated with the Derivo between February 2016 and July 2018. Procedural details, complications, morbidity within 30 days, and angiographic aneurysm occlusion rates, initially and after six months, were assessed.

Results

In 10 patients 11 ruptured dissecting and blister aneurysms were treated with 12 Derivos as monotherapy. No aneurysm rebleeding was observed at follow-up. One treatment-related complication occurred including a coil perforation of an additionally treated aneurysm. One patient died due to brain edema. Initial digital subtraction angiography revealed complete (O’Kelly–Marotta [OKM] classification D) and favorable (OKM D+C) occlusion rate in three aneurysms. Six-month follow-up for digital subtraction angiography and clinical evaluation was available in 6/9 patients with complete (OKM D) occlusion in all aneurysms (6/6). Favorable (modified Rankin Scale [mRS] ≤ 2) and moderate (mRS 3) clinical outcome after a mean follow-up of 10 months was observed in six and two patients, respectively.

Conclusion

Endovascular treatment with the Derivo in ruptured dissecting and blister aneurysms revealed a sufficient initial division of aneurysms from the circulation without rebleeding. The Derivo is associated with high procedural and clinical short-term safety.

A case of severe headache attributed to vertebral artery dissection

Background

Vertebral artery dissection (VAD) sometimes has no specific symptoms and is difficult to differentiate from other forms of headache.

Case presentation

A woman in her thirties had a severe, throbbing left-sided headache. A migraine without aura was suspected and zolmitriptan was administered, which alleviated the symptoms. The woman was consequently deemed to have a migraine without aura. Despite the lack of abnormal neurological findings and showed no abnormalities on cranial computed tomography, her symptoms were not typical for migraines and showed little improvement with therapy. She therefore underwent a cranial magnetic resonance imaging (MRI) examination, which revealed VAD, for which she was transferred to the department of neurosurgery for conservative treatment.

Conclusion

The possibility of vertebral artery dissection should be considered in the differential diagnosis of severe secondary headaches, and prompt diagnosis and treatment based on detailed MRI and magnetic resonance angiography examinations should be performed.

Endovascular treatment of intracranial 'blister' and dissecting aneurysms

INTRODUCTION

Blister and dissecting aneurysms may have a different pathological background but they are commonly defined by instability of the vessel wall and bear a high risk of fatal rupture and rerupture. Lack of aneurysm sack makes treatment challenging.

PURPOSE

The purpose of this study was to assess the safety and feasibility of endovascular treatment of intracranial blister and dissecting aneurysms.

METHODS

We retrospectively analysed all patients with ruptured and unruptured blister and dissecting aneurysms treated endovascularly between 2004-2018. Procedural details, complications, morbidity/mortality, clinical favourable outcome (modified Rankin Scale ≤2) and aneurysm occlusion rates were assessed.

RESULTS

Thirty-four patients with endovascular treatment of 35 aneurysms (26 dissecting aneurysms and 9 blister aneurysms) were included. Five aneurysms were treated by parent vessel occlusion, and 30 aneurysms were treated by vessel reconstruction using stent monotherapy (n = 9), stent-assisted coiling (n = 7), flow diverting stents (n = 13) and coiling + Onyx embolization (n = 1). No aneurysm rebleeding and no procedure-related major complications or deaths occurred. There were five deaths in consequence of initial subarachnoid haemorrhage. Complete occlusion (79.2%) was detected in 19/24 aneurysms available for angiographic follow-up, and aneurysm recurrence in 2/24 (8.3%). The modified Rankin Scale ≤2 rate at mean follow-up of 15.1 months was 64.7%.

CONCLUSION

Treatment of blister and dissecting aneurysms developed from coil embolization to flow diversion with multiple stents to the usage of flow diverting stents. Results using modern flow diverting stents encourage us to effectively treat this aneurysm entity endovascularly by vessel reconstruction. Therefore, we recommend preference of vessel reconstructive techniques to parent vessel occlusion.

Stroke mechanisms and their correlation with functional outcome in medullary infarction

PURPOSE

To study the stroke mechanism of medullary infarction (MI) and their correlation with prognosis.

METHODS

We collected 81 consecutive patients with acute isolated MI including 50 patients with lateral MI (LMI), 30 with medial MI (MMI) and one with combined MI. The stroke mechanisms were defined as follows: 1. Large artery atherosclerotic occlusive disease (LAOD): with severe stenosis (>50%) or occlusion on the relevant arteries. 2. Penetrating artery disease (PAD): occlusion of penetrating arteries that arise from vertebral artery or basilar artery with no significant stenosis of the vertebro-basilar artery. 3. Dissection: angiographic findings met the criteria. 4. Cardiogenic embolism: abrupt onset with atrial fibrillation. The poor outcome was defined as a condition that includes the mRS ≥2 and/or dysphagia at one year after onset.

RESULTS

There were 20 patients with PAD (40%), 18 with dissection (36.0%) and 11 with LAOD (22.0%) in LMI and 17 with PAD (56.6%), 10 with LAOD (33.3%) in MMI. LAOD and dissection compared with PAD were independently correlated with poor outcome in LMI (OR: 12.8, p = 0.029 and OR: 14.9, p = 0.035). LAOD was significantly correlated with poor outcome in MMI (OR: 13.4, p = 0.014).

CONCLUSIONS

PAD was the most predominant stroke mechanism in MI and generally showed favorable outcome. Patients with LAOD and dissection showed worse outcome than those with PAD.

Utility of the variable flip angle 3D fast-spin echo (isoFSE) sequence on 3T MR for diagnosing vertebrobasilar artery dissection

We aimed to investigate the utility of the isoFSE sequence, one of the variable flip angle 3D fast-spin echo sequences, on 3T-MR for displaying vessel walls and diagnosing vertebrobasilar artery dissection (VAD). We retrospectively evaluated 12 initial and 28 follow-up images from 12 patients diagnosed with either intracranial VAD or carotid artery dissection. The image quality for displaying the vessel wall was scored using a five-point scale (1 poor, 5 excellent) on initial T1-weighted isoFSE images for each region of the arteries. The intracranial artery dissection findings assessed at time points after onset were evaluated on initial and follow-up T1/T2-weighted isoFSE images. For small arteries, including the anterior/posterior inferior cerebellar artery, similar high scores were obtained on both unenhanced and contrast-enhanced T1-weighted isoFSE images (average: 4.7-5.0, p > 0.2). On unenhanced images, dissected vertebral arteries showed significantly lower scores than non-dissected vertebral arteries for both readers (p = 0.017 and 0.015, respectively), but the scores were high (3.9 and 4.0, respectively). Definitive findings of VAD were observed on the initial images except in one case. For all cases, definitive findings were seen on at least one of the initial or follow-up images. Temporal changes in the findings could be observed for all cases. In conclusion, we showed favorable wall visualization on T1-weighted isoFSE images and the utility of follow-up imaging using unenhanced-T1/T2-weighted and contrast-enhanced T1-weighted isoFSE sequences with acceptable scan times, which could promote the regular use of 3D black-blood vessel wall imaging.

Spontaneous intracranial vertebral artery dissection with acute ischemic stroke: High-resolution magnetic resonance imaging findings

Background Acute ischemic stroke (AIS) more frequently develops in patients with intracranial vertebral artery dissection (VAD) than extracranial VAD, and is associated with possible poor clinical outcomes. The aim of this study is to compare high-resolution magnetic resonance imaging (HR-MRI) findings and clinical features of VAD with and without AIS. Methods Twenty-nine lesions from 27 patients (15 male and 12 female patients; age range = 28-73 years) who underwent diffusion MRI and 3T HR-MRI within seven days were included. We classified VAD according to the presence of AIS lesions on diffusion MRI. Clinical features and HR-MRI findings (angiographic patterns, presence of double lumen sign, dissecting flap, posterior inferior cerebellar artery involvement, remodeling index, length of affected vessels, T1-signal intensity, area of intramural hematoma, and grades and patterns of vessel wall enhancement) were evaluated. Results Thirteen VADs with AIS and 16 without AIS were included. There were no significant differences in the clinical parameters (sex, age, risk factors, symptoms). More VADs with AIS presented as a steno-occlusive pattern than VADs without AIS. More VADs without AIS presented with aneurysmal dilation, larger mean remodeling index and longer mean length than VADs with AIS. Presence of intramural hematoma, T1-iso-signal intensity of intramural hematoma and contrast enhancement were significantly more common in VADs with AIS than without AIS. Conclusions Our study showed some differences in HR-MRI comparing intracranial VAD patients with and without AIS. Differing findings may facilitate a better understanding of intracranial VAD and risk assessment of AIS in these patients.

Spinal Cord Infarction in the Region of the Posterior Spinal Artery After Embolization for Vertebral Artery Dissection

BACKGROUND

Endovascular surgery for vertebral artery dissections (VADs) carries the risk of spinal cord infarction (SCI). Although SCI in the region of the anterior spinal artery (ASA) has been reported, SCI in the region of the posterior spinal artery (PSA) is rare.

OBJECTIVE

To investigate PSA infarction after endovascular surgery for VAD.

METHODS

Infarction in the region of the PSA after endovascular surgery for VADs carried out in consecutive 21 cases was investigated. The variables of aneurysmal location, status, intra-aneurysmal thrombosis, antithrombotic therapy, and endovascular procedure were investigated in relation to the occurrence of spinal cord or brain stem infarction.

RESULTS

Thirteen cases were unruptured aneurysms, and 8, ruptured aneurysms. The endovascular surgical method was internal trapping in 10 cases, stent-assisted coil embolization in 8 cases, and proximal occlusion (PO) in 3 cases. Periprocedural symptomatic infarction was detected in 4 of the 21 cases (19%): 3 SCIs and 1 lower medulla infarction, after 1 stent-assisted coil embolization and 3 PO. All 3 symptomatic SCIs were PSA infarction. On univariate analysis, the variables of posterior inferior cerebellar artery-involved-type, PO, and intraprocedural proximal flow arrest were significantly correlated with occurrence of PSA infarction.

CONCLUSION

PSA infarction after endovascular surgery for VAD seems not to be a rare potential complication. Insufficiency of collateral blood flow and artery-to-artery embolism due to intraprocedural flow stagnation of the VA seem to be the possible mechanisms of PSA infarction in addition to previously reported mechanisms such as direct obliteration by the embolic materials and extended thrombosis of the VA stump.

Association between etiology and lesion site in ischemic brainstem infarcts: a retrospective observational study

BACKGROUND AND PURPOSE

To assess the anatomical distribution of the ischemic strokes of the brainstem, the effect of anatomical distribution on clinical features and prognosis, and the association between etiology and anatomical involvement.

METHODS

A retrospective search of the patient database of our institution was performed for a total of 227 patients who were admitted to the Department of Neurology, Medical Faculty of Bezmialem Vakif University between January 2012 and September 2014. Patients with adequate diagnostic data and 3-month follow-up visit were included in the study.

RESULTS

Twenty-one (9%), 136 (60%), and 65 (29%) patients had an infarction only at the mesencephalon, pons, and medulla, respectively. However, a single patient (0.5%) had an infarction both at the mesencephalon and pons, 3 (1.5%) at the pons and medulla, and 1 (0.5%) at the mesencephalon, pons, and medulla. While anterior involvement was more common in the mesencephalon and pons, posterior and lateral involvement occurred more frequently in the medulla. Large arterial atherothrombosis was the predominant cause of the strokes in all anatomical sites, particularly in infarcts involving the pons. Cardioembolic events were more common in patients with mesencephalic infarcts. Also, ischemia due to dissection was more common in infarctions involving the medulla, especially the lateral medulla. In subjects with simultaneous infarcts at other sites in addition to the brainstem, there was a significantly higher co-occurrence of medullary infarcts with cerebellar infarcts, mesencephalic infarcts with posterior cerebral artery infarcts, and pons infarcts with anterior circulation and multiple infarcts.

CONCLUSION

Determination of risk factors and infarct localization as well as prediction of etiological parameters may assist in improving survival rates and therapeutic approaches.

Efficacy of high-resolution cone-beam CT in the evaluation of perforators in vertebral artery dissection

Introduction A major complication of internal coil trapping for vertebral artery dissection (VAD) is medullary infarction associated with perforator occlusion. Currently, higher spatial resolution imaging can be obtained with high-resolution cone-beam computed tomography (VASO CT), and the efficacy of perforator visualization adjacent to VAD was examined. Methods Eight patients who underwent internal coil trapping or stent-supported coil embolization underwent VASO CT to evaluate perforators around VAD. Visualization of perforators was compared with conventional digital subtraction angiography (DSA) and three-dimensional rotational angiography (3D-RA). Postoperative MRI was performed in all patients to investigate ischemic complications. The relationship between the perforators and the infarction was analyzed. Results Perforator visualization was much clearer on VASO CT than on 2D DSA or 3D-RA. It was sharp enough to identify each perforating artery. Medullary infarctions were detected in two cases. In these two cases, each ischemic lesion corresponded to the territory of a perforator that was well visualized on VASO CT. The axial view with adjoining tissue structures on VASO CT was useful to detect the territories of perforators. Conclusions VASO CT is an efficient modality for the detection and identification of perforators in the vicinity of VAD. It provides accurate anatomical information about the vertebrobasilar system that is useful for the treatment of unruptured VAD.

Headache in Intracranial and Cervical Artery Dissections

Dissection refers to a tear in the wall of an artery, with the two main types being intracranial or extracranial. Dissections tend to occur most commonly in the young, sometimes secondary to trauma involving the neck. To confirm a dissection, some type of vessel imaging is necessary, including magnetic resonance angiography (MRA), computed tomography angiography (CTA), or angiography. The most common presentation of a dissection (especially extracranial) is pain, usually head and neck pain along with a Horner's syndrome. Patients may also present with ischemic symptoms, including transient ischemic attack (TIA) or stroke, which may also be a complication of a dissection. Although headache is a common presentation, there is little research into phenotype or long-term outcomes. There are a number of case reports detailing the phenotypes of headaches that may be present in dissection, including a migraine-like or hemicrania-like headache. Dissections are usually treated with some type of anti-platelet or anti-coagulation, although there are only a few randomized controlled trials. In a new acute headache, dissection is an important diagnosis to keep in mind.

Stent-assisted coil embolisation for bilateral vertebral artery dissecting aneurysms presenting with subarachnoid haemorrhage

Bilateral dissecting aneurysms presenting with subarachnoid haemorrhage are rare. The treatment strategy for bilateral vertebral artery dissecting aneurysms is controversial because the contralateral vertebral artery is already dissected and can easily undergo enlargement or bleed after non-reconstructive treatment procedures such as trapping or proximal occlusion. Here, we report a case of bilateral vertebral artery dissecting aneurysm presenting with subarachnoid haemorrhage that was treated with stent-assisted coiling for the ruptured side. A 42-year-old man was admitted to our hospital with sudden headache (WFNS grade 1). Computed tomography showed a high-density region in the basal cistern and posterior fossa with more haemorrhage on the right side (Fisher group 3). Three-dimensional computed tomography and three-dimensional rotational angiography demonstrated a bilateral round protrusion on the vertebral arteries with a diameter of 5 mm just distal to the posterior inferior cerebellar artery. Stent-assisted coiling was performed for the ruptured right side and conservative therapy was selected for the contralateral side. The ruptured side was well embolised, and the contralateral side was stable over the 12-month follow-up period after treatment. The treatment strategy for bilateral vertebral artery dissecting aneurysms presenting with subarachnoid haemorrhage is different from that for unilateral vertebral artery dissecting aneurysms. Non-reconstructive treatment procedures such as trapping may cause contralateral enlargement or rupture; therefore, reconstructive treatment may be appropriate for the ruptured side.

Intracranial Vessel Wall MRI: Principles and Expert Consensus Recommendations of the American Society of Neuroradiology

Intracranial vessel wall MR imaging is an adjunct to conventional angiographic imaging with CTA, MRA, or DSA. The technique has multiple potential uses in the context of ischemic stroke and intracranial hemorrhage. There remain gaps in our understanding of intracranial vessel wall MR imaging findings and research is ongoing, but the technique is already used on a clinical basis at many centers. This article, on behalf of the Vessel Wall Imaging Study Group of the American Society of Neuroradiology, provides expert consensus recommendations for current clinical practice.

Management of Cervical Arterial Dissection

Background

Clinical, pathological and radiological advances in recent years have considerably advanced our understanding of the incidence and underlying mechanisms producing dissection of the cervical arteries, which should have implications for medical and, surgical therapy in the near future. This review is a summary of progress to date.

Summary of review

Numerous published studies, primarily over the last decade, have generated a rapidly evolving data base especially in the areas of etiology, neuroimaging and more recently, arterial pathology and its genetic basis.

Conclusion

Dissection of the carotid and vertebral arteries, both intracranially and extracranially, is a major and frequently underdiagnosed cause of stroke, especially in the young. These advances in clinical epidemiological observations, and new radiological and pathological data, are gradually providing an evidence-based rationale for future trials of therapeutic interventions, using both drugs and devices.

Ipsilateral hemiparesis in lateral medullary infarction: Clinical investigation of the lesion location on magnetic resonance imaging

BACKGROUND

In 1946, Opalski reported two cases of Wallenberg syndrome with ipsilateral hemiparesis (IH). His hypothesis seems to be based on the view that IH is caused by post-decussating pyramidal tract damage. Afterwards, other researchers proposed a different hypothesis that ipsilateral sensory symptoms of limbs (ISSL) or ipsilateral limb ataxia (ILA) caused by lateral medullary infarction (LMI) might lead to ipsilateral motor weakness. The present study is aimed to clarify whether IH in LMI patients is attributable mainly to ISSL/ILA or disruption of ipsilateral post-decussating pyramidal tract.

METHODS

Thirty-two patients with acute LMI admitted during the last 13years were divided to IH Group (n=7) and Non-IH Group (n=25). Lesion location/distribution on MRI and neurological findings were compared between the two groups.

RESULTS

LMI involved the lower medulla in all seven IH patients and 12 of 25 Non-IH patients. The lower medullary lesion extended to the cervico-medullary junction (CMJ) in four of seven IH patients and one of 12 Non-IH patients. Definitive extension to upper cervical cord (UCC) was confirmed in none of the patients. ISSL was found in two IH and three Non-IH patients all showing only superficial sensory impairments. ILA or hypotonia was observed in 57% of IH and 60% of Non-IH patients.

CONCLUSION

IH in LMI appears to be due mainly to post-decussating pyramidal tract damage at the lower medulla instead of ILA or ISSL participation.

Diagnosis of Intracranial Artery Dissection

Cerebral arterial dissection is defined as a hematoma in the wall of a cervical or an intracranial artery. Cerebral arterial dissection causes arterial stenosis, occlusion, and aneurysm, resulting in acute infarction and hemorrhage. Image analysis by such methods as conventional angiography, computed tomography, magnetic resonance imaging, and so on plays an important role in diagnosing cerebral arterial dissection. In this study, we explore the methods and findings involved in the diagnosis of cerebral arterial dissection.

Radical surgical treatment for recurrent giant fusiform thrombosed vertebral artery aneurysm previously coiled

Background:

Fusiform aneurysms are rare (<1%) and the underlying pathophysiology is not well known. Endovascular coiling is the standard of treatment; however, a surgical procedure with vascular reconstruction by excluding the pathological segment of the vessel and restoring the blood flow, seems to be the most effective and definitive treatment.

Case Description:

We report a patient who presented a fusiform vertebral artery aneurysm previously coiled which developed a giant enlargement and a new contralateral fusiform aneurysm. Hemodynamic changes resulting in the formation of contralateral aneurysm might be the result of aneurysm occlusion without revascularization. In addition, continued blood flow to the aneurysmal wall through the vasa vasorum might result in aneurysm recanalization or regrowth. In order to account for these possible sources of complications, we performed a vascular reconstruction with high and low flow bypasses after trapping the aneurysm.

Conclusions:

We hypothesize that, in this and similar cases, surgical vascular reconstruction should be the first and definitive treatment under experienced cerebrovascular surgeons.

Evaluation of the Arterial Wall in Vertebrobasilar Artery Dissection Using High-Resolution Magnetic Resonance Vessel Wall Imaging

BACKGROUND

High-resolution magnetic resonance vessel wall imaging (HRMR-VWI) has been used to explore vascular diseases such as vasculitis and vulnerable plaque of intracranial arteries. Although vessel wall inflammation is suspected as one of the causes of cerebral arterial dissection, there have been few reports regarding the application of HRMR-VWI to arterial dissection. We have therefore evaluated the efficacy of HRMR-VWI in patients with vertebrobasilar artery dissection.

METHODS

HRMR-VWI was performed on 5 patients who had been diagnosed with nonhemorrhagic vertebrobasilar artery dissection.

RESULT

Four patients exhibited vessel wall enhancement on HRMR-VWI, the range of which corresponded with the dissection sites identified by cerebral angiogram, magnetic resonance imaging, or magnetic resonance angiography. The enhancements observed in all cases were extensive as compared with the findings of conventional angiography.

CONCLUSION

HRMR-VWI is thought to elucidate the condition of the affected vessel wall more in detail as compared with conventional methods.

Chronic basilar artery dissection with an associated symptomatic aneurysm presenting with massive subarachnoid hemorrhage

Basilar artery dissection (BAD) is a rare condition with a worse prognosis than a dissection limited to the vertebral artery. We report a rare case of chronic BAD with an associated symptomatic aneurysm presenting with massive subarachnoid hemorrhage (SAH) in a 54-year-old woman. The diagnosis of acute BAD could only be made retrospectively, based on clinical and neuroradiological studies from a hospital admission 10months earlier. Angiography performed after her SAH showed unequivocal signs of imperfect healing; she was either post-recanalization of a complete occlusion or post-dissection. Residual multi-channel intraluminal defects led to the development of a small aneurysm, which was responsible for the massive hemorrhage. The occurrence of an associated aneurysm, and wall disease, but not an intraluminal process, reinforces the diagnosis of dissection. The patient was fully recovered at 90day follow-up. This case reinforces the need for long-term neuroradiological surveillance after non-hemorrhagic intracranial dissections to detect the development of de novo aneurysms.

Flow diverter placement for management of dissecting ruptured aneurysm in a non-fused basilar artery

Intracranial vertebral artery dissection can be associated with subarachnoid hemorrhage (SAH) and pseudoaneurysm formation. Dissecting aneurysms have a high risk of rebleeding in the acute phase. To our knowledge, the management of an acute vertebrobasilar junction dissecting aneurysm associated with a basilar non-fusion has not been previously reported. We report here a case of SAH due to rupture of a dissecting aneurysm involving the vertebrobasilar junction and extending to involve the right limb and proximal junction of a non-fused basilar artery, managed by insertion of a flow-diverting stent with excellent clinical outcome and long-term patency of the flow diverter.

Endovascular management of fusiform aneurysm of anterior temporal artery: Technical report

Background:

The treatment of a rare, nontraumatic, fusiform aneurysm of the anterior temporal artery (ATA) via endovascular techniques is presented, and procedural nuances are highlighted.

Methods:

We performed a retrospective chart review and collected demographic and clinical data on the patient presented here; procedural details were extracted from operative notes.

Results:

Following successful balloon test occlusion (BTO) of the ATA, complete coil embolization of the ATA, and its associated fusiform aneurysm was performed. Postprocedurally, the patient did not suffer any adverse neurological sequelae.

Conclusion:

Selective BTO of intracranial branch vessels is safe, technically feasible, and could serve as a useful technical tool in the treatment of complex, fusiform intracranial aneurysms.

Progressive Intracranial Vertebral Artery Dissection Presenting with Isolated Trigeminal Neuralgia-Like Facial Pain

Intracranial vertebral artery dissection (IVAD) is a potentially life-threatening disease, which usually presents with ischemic stroke or subarachnoid hemorrhage. IVAD presenting with isolated facial pain is rare, and no case with isolated trigeminal neuralgia- (TN-) like facial pain has been reported. Here, we report the case of a 57-year-old male with IVAD who presented with acute isolated TN-like facial pain that extended from his left cheek to his left forehead and auricle. He felt a brief stabbing pain when his face was touched in the territory of the first and second divisions of the left trigeminal nerve. There were no other neurological signs. Magnetic resonance imaging (MRI) of the brain 7 days after onset revealed dissection of the left intracranial vertebral artery without brain infarction. The pain gradually disappeared in approximately 6 weeks, and the patient remained asymptomatic thereafter, except for a brief episode of vertigo. Follow-up MRI revealed progressive narrowing of the artery without brain infarction. This case indicates that IVAD can present with isolated facial pain that mimics TN. IVAD should be considered in the differential diagnosis of acute facial pain or TN.

Usefulness of R2* maps generated by iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation sequence for cerebral artery dissection

INTRODUCTION

Acute intramural hematoma resulting from cerebral artery dissection is usually visualized as a region of intermediate signal intensity on T1-weighted images (WI). This often causes problems with distinguishing acute atheromatous lesions from surrounding parenchyma and dissection. The present study aimed to determine whether or not R2* maps generated by the iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation sequence (IDEAL IQ) can distinguish cerebral artery dissection more effectively than three-dimensional variable refocusing flip angle TSE T1WI (T1-CUBE) and T2*WI.

METHODS

We reviewed data from nine patients with arterial dissection who were assessed by MR images including R2* maps, T2*WI, T1-CUBE, and 3D time-of-flight (TOF)-MRA. We visually assessed intramural hematomas in each patient as positive (clearly visible susceptibility effect reflecting intramural hematoma as hyperintensity on R2* map and hypointensity on T2*WI), negative (absent intramural hematoma), equivocal (difficult to distinguish between intramural hematoma and other paramagnetic substances such as veins, vessel wall calcification, or hemorrhage) and not evaluable (difficult to determine intramural hematoma due to susceptibility artifacts arising from skull base).

RESULTS

Eight of nine patients were assessed during the acute phase. Lesions in all eight patients were positive for intramural hematoma corresponding to dissection sites on R2* maps, while two lesions were positive on T2*WI and three lesions showed high-intensity on T1-CUBE reflected intramural hematoma during the acute phase.

CONCLUSION

R2* maps generated using IDEAL IQ can detect acute intramural hematoma associated with cerebral artery dissection more effectively than T2*WI and earlier than T1-CUBE.

Rapid progression of symptomatic vertebrobasilar artery dissection on magnetic resonance imaging: a case report

Spontaneous intracranial vertebrobasilar dissection can manifest with various clinical symptoms, including subarachnoid hemorrhage or ischemic symptoms from impaired posterior circulation. A 29-year-old woman came to our emergency department with a sudden onset of left sided mild motor weakness and headache. Initial magnetic resonance imaging (MRI) showed mild luminal irregularities in the vertebrobasilar arteries with an eccentric periluminal hematoma. Follow-up MRI obtained 3 days later showed a progression of vertebrobasilar dissection to multifocal stenoses with an increased intramural hematoma.