Spontaneous vertebral dissection: clinical, conventional angiographic, CT, and MR findings

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.

Incidence and Outcome Analysis of Vertebral Artery Injury in Posttraumatic Cervical Spine

Objective:

Vertebral artery injury (VAI) after cervical spine trauma often remains undiagnosed. Despite various clinical studies suggesting simultaneous occurrence of VAI with cervical spine trauma, guidelines regarding screening and management of posttraumatic VAI are yet to be formulated. The primary objective of the current study was to formulate a low-cost screening protocol for posttraumatic VAI, thereby reducing the incidence of missed VAI in developing countries.

Materials and Methods:

This was a single-center prospective study performed on 61 patients using plain magnetic resonance imaging (MRI) as a screening tool to assess the frequency of VAI and routine X-ray to detect morphological fracture patterns associated with the VAI in posttraumatic cervical spine cases. If the MRI study showed any evidence of vascular disruption, then further investigation in the form of computed tomography angiography was done to confirm the diagnosis.

Results:

This study showed the incidence of VAI was 14.75% (9/61). Of 61 patients, 16 had supraaxial, and 45 patients sustained subaxial cervical spine fractures. In the cohort of nine cases of VAI, eight patients had subaxial cervical spine injuries, of which seven were due to flexion-distraction injury. C5–C6 flexion-distraction injury was most commonly associated with VAI (4 cases). Of the nine cases, five succumbed to injury (mortality 55.55%), and 19 patients from the non-VAI group succumbed to injury (mortality 36.53%). From surviving four cases with VAI, two had improvement in the American Spinal Injury Association scale by Grade 1.

Conclusion:

VAI in cervical spine trauma is an underrecognized phenomenon. Plain MRI axial imaging sequence can be an instrumental low-cost screening tool in resource-deficient parts of the world. VAI has tendency to occur with high-velocity trauma like bi-facetal dislocation, which has a high mortality and poor neurological recovery.

Standard Diffusion-Weighted Imaging in the Brain Can Detect Cervical Internal Carotid Artery Dissections

BACKGROUND AND PURPOSE

The ICA is the most common site of cervical artery dissection. Prompt and reliable identification of the mural hematoma is warranted when a dissection is clinically suspected. The purpose of this study was to assess to capacity of a standard DWI sequence acquired routinely on the brain to detect dissecting hematoma related to cervical ICA dissections.

MATERIALS AND METHODS

This was a retrospective study of a cohort of 110 patients younger than 55 years of age (40 women; mean age, 46.79 years) admitted at the acute phase of a neurologic deficit, headache, or neck pain and investigated by at least a standard 3T diffusion-weighted sequence of the brain. Among them were 50 patients (14 women; mean age, 46.72 years) with subsequently confirmed ICA dissection. In the whole anonymized cohort, both a senior and junior radiologist separately assessed, on the DWI sequences only, the presence of a crescent-shaped or circular hypersignal projecting on the subpetrosal segment of the ICA arteries, assuming that it would correspond to a mural hematoma related to an ICA dissection.

RESULTS

The senior radiologist found 46 subpetrosal hyperintensities in 43/50 patients with ICA dissection and none in patients without dissection (sensitivity, 86%; specificity, 100%). The junior radiologist found 48 subpetrosal hyperintensities in 45/50 patients with dissection and none in patients without dissection (sensitivity, 90%; specificity, 100%).

CONCLUSIONS

In our cohort, a standard DWI sequence performed on the brain at the acute phase of a stroke or for a clinical suspicion of dissection detected nearly 90% of cervical ICA dissections.

Vertebral artery segment at the suboccipital dural penetration site: an anatomical study using magnetic resonance imaging

PURPOSE

The morphology of the vertebral artery (VA) segment at the suboccipital dural penetration site has little been explored with magnetic resonance imaging (MRI). Therefore, the aim of this study was to examine the structure using MRI.

METHODS

In total, 94 patients underwent thin-sliced, contrast MRI in the axial, coronal, and sagittal planes involving the atlas, axis, occipital bone, and V3 and V4 segments of the VA.

RESULTS

The VA segment at the suboccipital dural penetration site was well-delineated in 93% on the axial images and in 95% on the coronal images. The axial images showed that 82% of the VA penetration sites were located in the middle third of the dural sac. Meanwhile, the coronal images revealed that the heights of both VA penetration sites were located at the same level in 87%. The axial VA penetration angle, which is formed by the VA and tangential line of the dural sac, was 66 ± 11.9° on the right side and 61 ± 14.1° on the left side. The coronal VA penetration angle, which is formed by the tangential line of the VA and dural sac, was 111 ± 24.6° on the right side and 112 ± 19.9° on the left side.

CONCLUSIONS

The morphology of the VA segment is considerably variable at the suboccipital dural penetration site, while most penetration sites are located in the middle third of the dural sac on axial MRI. These should be assumed during surgeries around the suboccipital VA penetration site.

Pediatric Intracranial Aneurysms: Favorable Outcomes Despite Rareness and Complexity

OBJECTIVE

Pediatric intracranial aneurysms (IAs) are rare and differ from their adult counterparts in terms of their aneurysmal characteristics, presentation, treatment, and outcomes. Their treatment is often more difficult and complex compared with that of adults. However, studies outlining the clinical effect of pediatric IAs remain sparse.

METHODS

We retrospectively reviewed the data from patients aged ≤18 years admitted to our hospital from 2000 to 2017 with a diagnosis of IAs.

RESULTS

From the sample of 8207 patients with an IA diagnosis, 26 patients with 33 IAs were involved. Our cohort included 17 males and 9 females, with a mean age of 12.5 years. The mean follow-up duration was 4 years and 3 months. Seven patients (26.92%) were assumed to have a traumatic origin for their IAs. Ruptured aneurysms were more common than unruptured ones (61.53% vs. 38.46%). Complex features were observed in 14 aneurysms (42.42%). Initially, microsurgical and endovascular treatment were both performed in 10 patients (38.46%). A good recovery was obtained in 16 patients (61.54%) as determined by the Glasgow outcome scale scores at the 6-month follow-up visits. The complete obliteration of aneurysms was observed in 17 patients (65.38%). Endovascular treatment was the initial treatment in 3 patients with incomplete obliteration.

CONCLUSIONS

The treatment of pediatric IAs is challenging and technically demanding owing to their discrete nature compared with adult IAs and the need for greater surgical skills. We found a male predominance, with internal carotid artery bifurcation as the most frequent location of the aneurysms. Despite the greater incidence of ruptured and complex aneurysm cases, many patients had experienced a good recovery at the 6-month follow-up examinations.

Arcuate foramen: "Anatomical variation shape or adaptation legacy?"

PURPOSE

The groove of the vertebral artery on the posterior arch of the atlas (sulcus arteriae vertebralis) may become a complete or partial osseous foramen: the arcuate foramen. The presence of a complete or partial arcuate foramen is a rare anatomical variant described in a minority of patients and it seems to be associated with vertigo, vertebro-basilar insufficiency, posterior circulation strokes, and musculoskeletal pain. As the number and morphology of cervical vertebrae is highly preserved, we questioned about its significance from an evolutionary point of view. We thus investigated through an extensive literature review if the arcuate foramen is a pure anatomical variation shape or if it might represent an adaptation legacy.

METHODS

We observed five atlas of an extinct species, the Late Pleistocene Mammoths (M. primigenius), and we compared them with five atlas of a closely related existent species, the African elephant (L. africana).

RESULTS

All the mammoths' atlas had an arcuate foramen through which the vertebral artery passed before turning anteriorly and becoming intradural. This foramen was not present in elephants' atlas, where only a groove was observed, such as in the majority of patients.

CONCLUSION

We would like to raise the hypothesis that this peculiar morphology of mammoths' atlas might have contributed, in association with other factors, to their precocious extinction and that the arcuate foramen might represent a disadvantage in the evolutionary process, with a low prevalence in humans being the result of a natural selection.

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.

Imaging of cervical artery dissection

Cervical artery dissection (CAD) may affect the internal carotid and/or the vertebral arteries. CAD is the leading cause of ischemic stroke in patients younger than 45 years. Specific treatment (aspirin or anticoagulants) can be implemented once the diagnosis of CAD has been confirmed. This diagnosis is based on detection of a mural haematoma on ultrasound or on MRI. The diagnosis can be suspected on contrast-enhanced MRA (magnetic resonance angiography) or CT angiography, in case of long stenosis, sparing the internal carotid bulb, or suspended, at the junction of V2 and V3 segments of the vertebral artery, in patients with no signs of atheroma of the cervical arteries. MRI is recommended as the first line imaging screening tool, including a fat suppressed T1 weighted sequence, acquired in the axial or oblique plane at 1.5T, or 3D at 3T. Complete resolution of the lumen abnormality occurred in 80% of cases, and CAD recurrence is rare, encountered in less than 5% of cases. Interventional neuroradiology (angioplasty and/or stenting of the dissected vessel) may be envisaged in rare cases of haemodynamic effects with recurring clinical infarctions in the short-term.

Clinical Characteristics of Intracranial Reversed Vertebral Artery Flow Evaluated by Transcranial Color Flow Imaging

BACKGROUND

Carotid duplex ultrasonography (CUS) has been used to identify reversed vertebral artery flow (RVAF) at the extracranial cervical artery in some patients with subclavian steal syndrome. However, the characteristics of intracranial RVAF as evaluated by transcranial color flow imaging (TC-CFI), which can examine intracranial hemodynamics in a real-time and noninvasive fashion, remain unclear. The goal of this study was to analyze the prevalence of intracranial RVAF and its associated clinical characteristics.

METHODS

Subjects were consecutive patients who underwent TC-CFI and CUS. We evaluated blood flow in both intracranial vertebral arteries (VAs) from the suboccipital echo window using TC-CFI. RVAF was defined as a flow signal directed toward the probe. We calculated the prevalence of intracranial RVAF in our subjects. Then, we investigated vascular condition (ie, site of lesion, stenosis, occlusion, and dissection) using magnetic resonance angiography, computed tomography angiography , and CUS in patients with intracranial RVAF.

RESULTS

Seven hundred twenty patients (508 men; median age, 73 years) were included in this study from September 2007 to March 2013. Intracranial RVAF was seen in 12 patients (1.7%; 11 men; median age, 61 years). Among the 12 patients with intracranial RVAF, 8 patients (67%) had ischemia of the vertebrobasilar territory with distal VA occlusion, according to CUS. Of those patients, 6 (75%) had dissection of the VA.

CONCLUSIONS

TC-CFI detected intracranial RVAF in 1.7% of consecutive examinations in our facility. In vertebrobasilar territory stroke patients with intracranial RVAF, VA dissection may contribute to the development of stroke.

Clinical and radiographic outcomes following traumatic Grade 1 and 2 carotid artery injuries: a 10-year retrospective analysis from a Level I trauma center. The Parkland Carotid and Vertebral Artery Injury Survey

OBJECT

Proper screening, management, and follow-up of Grade 1 and 2 blunt carotid artery injuries (BCIs) remains controversial. These low-grade BCIs were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction.

METHODS

A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries treated between August 2003 and April 2013 was performed and Grade 1 and 2 BCIs were identified. Grade 1 injuries are defined as a vessel lumen stenosis of less than 25%, and Grade 2 injuries are defined as a stenosis of the vessel lumen between 25% and 50%. Demographic information, radiographic imaging, number of imaging sessions performed per individual, length of radiographic follow-up, radiographic outcome at end of follow-up, treatment(s) provided, and documentation of ischemic stroke or transient ischemic attack were recorded.

RESULTS

One hundred seventeen Grade 1 and 2 BCIs in 100 patients were identified and available for follow-up. The mean follow-up duration was 60 days. Final imaging of Grade 1 and 2 BCIs demonstrated that 64% of cases had resolved, 13% of cases were radiographically stable, and 9% were improved, whereas 14% radiographically worsened. Of the treatments received, 54% of cases were treated with acetylsalicylic acid (ASA), 31% received no treatment, and 15% received various medications and treatments, including endovascular stenting. There was 1 cerebral infarction that was thought to be related to bilateral Grade 2 BCI, which developed soon after hospital admission.

CONCLUSIONS

The majority of Grade 1 and 2 BCIs remained stable or improved at final follow-up. Despite a 14% rate of radiographic worsening in the Grade 1 and 2 BCIs cohort, there were no adverse clinical outcomes associated with these radiographic changes. The stroke rate was 1% in this low-grade BCIs cohort, which may be an overestimate. The use of ASA or other antiplatelet or anticoagulant medications in these low-grade BCIs did not appear to correlate with radiographic injury stability, nor with a decreased rate of cerebral infarction. Although these data suggest that these Grade 1 and 2 BCIs may require less intensive radiographic follow-up, future prospective studies are needed to make conclusive changes related to treatment and management.

Clinical and radiographic outcomes following traumatic Grade 3 and 4 carotid artery injuries: a 10-year retrospective analysis from a Level 1 trauma center. The Parkland Carotid and Vertebral Artery Injury Survey

OBJECT

Screening, management, and follow-up of Grade 3 and 4 blunt carotid artery injuries (BCAIs) remain controversial. These high-grade BCAIs were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction.

METHODS

A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries from August 2003 to April 2013 was performed, and Grade 3 and 4 BCAIs were identified. The authors define Grade 3 injuries as stenosis of the vessel greater than 50%, or the development of a pseudoaneurysm, and Grade 4 injuries as complete vessel occlusion. Demographic information, imaging findings, number of images obtained per individual, length of radiographic follow-up examination, radiographic outcome at end of follow-up period, treatment(s), and documentation of ischemic stroke or transient ischemic attack (TIA) were recorded.

RESULTS

Fifty-three Grade 3 BCAIs in 44 patients and 5 Grade 4 BCAIs in 5 patients were identified and had available follow-up information. The mean follow-up duration for Grade 3 BCAIs was 113 days, and the mean follow-up for Grade 4 BCAIs was 78 days. Final imaging of Grade 3 BCAIs showed that 53% of cases were radiographically stable, 11% had resolved, and 11% were improved, whereas 25% had radiographically worsened. In terms of treatment, 75% of patients received aspirin (ASA) alone, 5% received various medications, and 2% received no treatment. Eighteen percent of the patients in the Grade 3 BCAI group underwent endovascular intervention, and in all of these cases, treatment with ASA was continued after the procedure. Final imaging of the Grade 4 BCAIs showed that 60% remained stable (with persistent occlusion), whereas the remaining arteries improved (with recanalization of the vessel). All patients in the Grade 4 BCAI follow-up group were treated with ASA, although in 1 patient treatment was transitioned to Coumadin. There were 3 cases of cerebral infarction that appeared to be related to Grade 3 BCAIs (7% of 44 patients in the Grade 3 group), and 1 case of stroke that appeared to be related to a Grade 4 BCAI. All identified cases of stroke developed soon after hospital admission.

CONCLUSIONS

Although the posttraumatic cerebral infarction rate may be overestimated, the results of this study suggest that the Grade 3 and 4 BCAIs carry the highest stroke risk of the blunt cerebrovascular injuries, and those infarctions were identified on or shortly after hospital admission. Despite a 40% recanalization rate in the Grade 4 BCAI group and an 89% rate of persistent pseudoaneurysm in the Grade 3 BCAI group, follow-up imaging showed progressive worsening without radiographic improvement in only a small number of patients, and these findings alone did not correlate with adverse clinical outcome. Follow-up protocols may require amending; however, further prospective studies are needed to make conclusive changes as they relate to management.

Traumatic vertebral artery injury: proposal for classification of the severity of trauma and likelihood of fatal outcome

Vertebral artery injury (VAI) occurs after (blunt) trauma as well as spontaneously. The risk of incurring VAI from a blunt trauma probably parallels the severity of trauma, often referred to as major- and minor-trauma. However, the literature does not provide concrete definitions of these terms. This study aims to define minor- and major-trauma and to analyze the likelihood of fatal outcome in VAI. For this purpose, classification criteria of major- and minor-trauma were developed and a PubMed database search was performed for articles on VAI published prior to 2013. The definitions of minor- and major-trauma, derived mainly from radiological screening criteria in cervical spine injury and based on the mechanism leading to the injury, were used in the analysis of the literature. The search produced 241 VAI cases with sufficiently detailed data for the comparison of major-trauma (52 cases, 50 lethal), minor-trauma (8 cases, none lethal), and no-trauma (182 cases, 69 lethal). The numbers of lethal cases in the total study population and subgroups differed significantly between the groups (Fisher's exact test) and the likelihood ratios (LRs) of lethal outcome were substantially higher in the major-trauma group compared to the other groups. The highly significant p values show that the proposed criteria differentiate between trauma types with regard to fatal outcome. The presented results can assist in the evaluation of forensic cases of VAI.

Clinical and radiological outcomes following traumatic Grade 1 and 2 vertebral artery injuries: a 10-year retrospective analysis from a Level 1 trauma center

Object

Screening of blunt vertebral artery (VA) injuries has increased since research has shown that they occur at a higher incidence than originally reported. Grade 1 and 2 injuries are the most common form of blunt VA injury. Proper screening, management, and follow-up of these injuries remain controversial. In this report, imaging, progression, treatment, and outcomes of Grade 1 and 2 blunt VA injuries were analyzed to better define their natural history and to establish a rational management plan based upon their risk of progression and cerebral infarct.

Methods

A retrospective review of all blunt traumatic carotid artery and VA injuries from December 2003 to April 2013 was performed. For the purposes of this report, focus was given to Grade 1 and 2 VA injuries. Grade 1 injuries were defined as a vessel lumen stenosis of less than 25%, and Grade 2 injuries were defined as vessel lumen stenosis between 25% and 50%. Demographic information, radiological imaging, number of images performed per individual, length of radiological follow-up, radiological outcome at the end of follow-up, treatment provided, and documentation of stroke or transient ischemic attack were recorded.

Results

One hundred eighty-seven Grade 1 and 2 VA injuries in 143 patients were identified. Of these 143 patients, 120 with 152 Grade 1 or 2 blunt VA injuries were available for follow-up. The mean duration of follow-up was 40 days. Repeat imaging showed that 148 (97.4%) Grade 1 or 2 blunt VA injuries were stable, improved, or resolved on final follow-up imaging. Seventy-nine patients (66%) were treated with aspirin, whereas 35 patients (29%) received no treatment. The remaining patients were treated with other antiplatelet agents or anticoagulant medication. Neuroimaging demonstrated 2 cases (1.7%) with posterior circulation infarcts that were believed to be related to their blunt VA injuries, both of which occurred during the initial hospitalization and within the first 4 days after injury.

Conclusions

Although follow-up imaging showed progressive worsening without radiological improvement in only a small number of patients with low-grade blunt VA injuries, these findings did not correlate with adverse clinical outcome. The posttraumatic cerebral infarction rate of 1.7% may be overestimated, and the use of acetylsalicylic acid or other antiplatelet or anticoagulant medication did not correlate with radiological changes or rate of cerebral infarction. While these data suggest the possibility that these low-grade VA injuries may not require treatment or follow-up, future prospective studies are needed to make conclusive changes related to management.

Imaging characteristics of symptomatic vertebral artery dissection: a systematic review

BACKGROUND

Vertebral artery dissection (VAD) is an important cause of stroke in the young. VAD can present with a range of imaging findings. We sought to summarize the diagnostic value of various imaging findings in patients with symptomatic VAD.

METHODS

We conducted a systematic review of observational studies, searching electronic databases (MEDLINE, EMBASE) for English-language manuscripts with >5 subjects with clinical or radiologic features of VAD. Two independent reviewers selected studies for inclusion; a third adjudicated differences. Studies were assessed for methodological quality and imaging data were abstracted. Pooled proportions were calculated.

RESULTS

Of 3996 citations, we screened 511 manuscripts and selected 75 studies describing 1972 VAD patients. Most studies utilized conventional angiography or magnetic resonance angiography (MRA) to diagnose VAD; computed tomographic angiography (CTA) and Doppler ultrasonography were described less frequently. Imaging findings reported were vertebral artery stenosis (51%), string and pearls (48%), arterial dilation (37%), arterial occlusion (36%), and pseudoaneurysm, double lumen, and intimal flap (22% each). In cases where conventional angiography was the reference standard, CTA was more sensitive (100%) than either MRA (77%) or Doppler ultrasonography (71%) (P=0.001).

CONCLUSIONS

Imaging findings vary widely in patients with VAD, with no single radiographic sign present in the majority of VAD patients. Nonspecific radiographic signs predominate. CTA probably has greater sensitivity for dissection than MRA or ultrasound relative to conventional angiography. Higher quality studies on imaging techniques and radiographic criteria in subjects with VAD are needed. Future studies should compare imaging techniques in well-defined, undifferentiated populations of clinical VAD suspects.

Clinical characteristics of symptomatic vertebral artery dissection: a systematic review

BACKGROUND

Vertebral artery dissection (VAD) is an important cause of stroke in the young. It can present nonspecifically and may be misdiagnosed with adverse consequences. We assessed the frequency of head/neck pain, other neurological symptoms, and cerebrovascular events in symptomatic VAD.

METHODS

We conducted a systematic review of observational studies, searching electronic databases (MEDLINE, EMBASE) for English-language manuscripts with >5 subjects with clinical or radiologic features of VAD. Two independent reviewers selected studies for inclusion; a third adjudicated differences. Studies were assessed for methodological quality, and clinical data were abstracted. Pooled proportions were calculated.

RESULTS

Of 3996 citations, we screened 511 manuscripts and selected 75 studies describing 1972 VAD patients. The most common symptoms were dizziness/vertigo (58%), headache (51%), and neck pain (46%). Stroke was common (63%), especially with extracranial dissections (66% vs. 32%, P<0.0001), whereas transient ischemic attack (14%) and subarachnoid hemorrhage (10%) were uncommon. Subarachnoid hemorrhage was seen only with intracranial dissections (57% vs. 0%, P=0.003). Fewer than half of the patients had obvious trauma, and only 7.9% had a known connective tissue disease. Outcome was good (modified Rankin scale 0 to 1) in 67% and poor (modified Rankin scale 5 to 6) in 10% of patients.

CONCLUSIONS

VAD is associated with nonspecific symptoms such as dizziness, vertigo, headache, or neck pain. Ischemic stroke is the most common reported cerebrovascular complication. VAD should be considered in the diagnostic assessment of patients presenting with dizziness or craniocervical pain, even in the absence of other risk factors. Future studies should compare clinical findings as predictors in well-defined, undifferentiated populations of clinical VAD suspects.

MR diagnosis of vertebral artery dissection: value of 3D time-of-flight and true fast imaging with steady-state precession fusion imaging

OBJECTIVES

We hypothesized that 3D time-of-flight (TOF) and true fast imaging with steady-state precession (true-FISP) fusion imaging could provide more information regarding the arterial vessel wall. The purpose of this study was to compare the accuracy of lesion detection and the diagnostic confidence of VAD between TOF images alone and fused TOF and true-FISP images.

METHODS

Fifty patients were studied: 17 had VAD and 33 had vertebral artery hypoplasia. Fusion images of the vertebral artery were reconstructed using a workstation. A receiver-operating characteristic (ROC) analysis was conducted with a continuous rating scale from 1 to 100 to compare observer performance in VAD detection. Five radiologists participated in the observer performance test, and their performances with TOF images were compared with those using fused images.

RESULT

The observers found that the mean areas under the best-fit ROC curve for TOF images alone and fused TOF images were 0.66 ± 0.05 and 0.93 ± 0.04, which were significantly different (P < 0.01).

CONCLUSION

The fusion images provided more information regarding the arterial vessel wall. Fused images aided distinction between vertebral artery dissection versus vertebral artery hypoplasia.

KEY POINTS

• New MR techniques can help to differentiate flowing blood from static blood products. • Fused TOF and true-FISP images differentiate the lumen and the arterial wall, improving diagnostic performance. • Fused images may be superior to time-of-flight MR angiography alone.

A case of traumatic intracranial vertebral artery injury presenting with life-threatening symptoms

Traumatic intracranial vertebral artery injury is a relatively rare but potentially fatal disease. We present a case of a 63-year-old man who presented with sudden onset of loss of consciousness after hitting his head. After immediate resuscitation, he showed quadriplegia and absence of spontaneous breathing. Brain and cervical spine magnetic resonance imaging revealed an atlantoaxial subluxation, fractured C2 odontoid process, left vertebral artery occlusion, and bilateral extensive ischemia in the medulla oblongata and high cervical spinal cord. Digital subtraction angiography demonstrated left vertebral artery dissection just below the level of vertebral body C2.

Dissecting aneurysms of the vertebral artery--angiographic patterns at the dissecting site on balloon test occlusion

Introduction

At present, the risk of future hemorrhage or ischemic insult from vertebral artery (VA) dissection cannot be estimated from available imaging data. We investigated the relationship between symptoms and the angiographic patterns of the dissecting site on balloon test occlusion (BTO) to develop guidelines for clinical decision-making.

Methods

We retrospectively reviewed 18 patients with unilateral VA dissection who presented with subarachnoid hemorrhage (SAH) or cerebral infarction. We analyzed the angiographic findings at the dissecting site on contralateral VA angiograms during BTO of the affected VA, classified the angiographic patterns into two types, and compared the symptoms they presented.

Results

Patients with dissection opacified from the distal to the proximal side are more likely to present with cerebral infarction than SAH. Conversely, patients with dissection opacified from the proximal to the distal side had a significantly higher incidence of SAH.

Conclusions

Angiographic findings at the dissecting site on contralateral VA angiograms during BTO of the affected VA are helpful for considering the treatment and prognosis of patients with VA dissecting aneurysms.

Strategy for Treating Unruptured Vertebral Artery Dissecting Aneurysms

BACKGROUND

The natural course of unruptured vertebral artery dissecting aneurysms (VADAs) remains unclear.

OBJECTIVE

The purpose of this retrospective study was to develop a strategy for treating unruptured VADAs based on long-term follow-up.

METHODS

Our study population consisted of 100 patients with unruptured VADAs; in 66, the initial symptom was headache only, 30 presented with ischemic symptoms and 4 with mass effect. All underwent magnetic resonance imaging and magnetic resonance angiography at the time of admission and 2 weeks and 1, 3, 6, 12, and 24 months after the onset. If the dissection site was demonstrated to be enlarged on magnetic resonance imaging and magnetic resonance angiography without the manifestation of new symptoms, the patients received additional treatment to prevent bleeding.

RESULTS

Of the 100 patients, 4 underwent early intervention because of symptom exacerbation. The other 96 were initially treated conservatively; during follow-up, 5 manifested lesion enlargement on magnetic resonance angiography. Nine patients received additional treatment; 1 underwent direct surgery with trapping of the dissection site, and 8 underwent coil embolization. The other 91 patients continued to be treated conservatively; the dissection site remained unchanged in 70, improved or healed in 18, and disappeared in 3 patients. We treated 38 patients with recurrent ischemic attacks with antiplatelet therapy. No patients experienced bleeding or permanent neurological deficits during follow-up.

CONCLUSION

The nature of an unruptured VADA is not highly aggressive. However, if the dissection site enlarges without the manifestation of new symptoms, it should be occluded. In patients with recurrent ischemic attacks antiplatelet therapy should be considered.

Is it possible to recognize cervical artery dissection on stroke brain MR imaging? A matched case-control study

BACKGROUND AND PURPOSE

Extracranial CAD accounts for nearly 20% of cases of stroke in young adults. The mural hematoma frequently extends cranially to the petrous carotid segment in cCAD or is distally located in vCAD. We hypothesized that standard brain MR imaging could allow the early detection of CAD of the upper portion of carotid and vertebral arteries.

MATERIALS AND METHODS

Our prospectively maintained stroke data base was retrospectively queried to identify all patients with the final diagnosis of CAD. In the 103 consecutive patients studied, analysis of cervical fat-suppressed T1-weighted sequences demonstrated that the mural hematoma was located in the FOV of brain MR imaging in 77 patients. Subsequent to enrollment of a patient, a control patient was extracted from the same data base, within a similar categories for sex, age, NIHSS score, and stroke on DWI. Two blinded observers independently reviewed the 5 brain MR sequences of each examination and determined whether a CAD was present.

RESULTS

Fifty-nine of the 77 patients with CAD (76.6%) and 73 of the 77 patients without CAD (94.8%) were correctly classified. Brain MR imaging demonstrated cCAD more frequently than vCAD in 54/58 (93.1%) and 5/19 (26.3%) patients, respectively, (P < .0001).

CONCLUSIONS

Initial brain MR imaging can correctly suggest CAD in more than two-thirds of patients. This may have practical implications in patients with stroke with delayed cervical MRA or in those who are not initially suspected of having CAD.

Cerebrovascular Dissections—A Review Part I: Spontaneous Dissections

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

Quality of life in survivors after cervical artery dissection

BACKGROUND AND PURPOSE

Little data exists about longterm outcome, quality of life (QOL) and its predictors after spontaneous cervical artery dissections (sCAD).

METHODS

Clinical and radiological data of 114 patients with sCAD were collected prospectively. Six patients died within 3 months, the remaining 108 were contacted after a mean of 1498 days (range: 379-3455), 99 survivors (92 %) replied. QOL, assessed with the stroke-specific QOL scale (SSQOL), and functional abilities, measured with modified Rankin Scale (mRS) were compared, and predictors of QOL were analyzed. Subgroup analyses were performed for patients with ischemic stroke, those with isolated local symptoms or transient ischemic symptoms and those without significant disabilities (mRS 0-1) at follow-up.

RESULTS

Seventy-one of 99 patients (72 %) had no significant disability, but only 53 (54 %) reported a good QOL (SS-QOL > or = 4). Compared to the self-rated premorbid QOL of all patients, SS-QOL was impaired after sCAD (p < 0.001); impairment of QOL was observed in patients with ischemic stroke (p < 0.001), in patients with isolated local or transient ischemic symptoms (p < 0.038) and those without significant disabilities at follow-up (p = 0.013). Nevertheless, low mRS was associated with better overall QOL (Kendall's tau > 0.5). High National Institute of Health Stroke Scale score on admission and higher age were independent predictors of impaired QOL (p < 0.05).

CONCLUSION

QOL is impaired in almost half of long-term survivors after sCAD, even in patients with local or transient symptoms or without functional disability. Impairment of QOL is a surprisingly frequent long-term sequela after sCAD and deserves attention as an outcome measure in these patients.

Vertebral artery dissection with a normal-appearing lumen at multisection CT angiography: the importance of identifying wall hematoma

BACKGROUND AND PURPOSE

CT angiography (CTA) is widely used and may be the only vascular imaging technique ordered for emergent evaluation of neurovascular disease. With thin-section multisection CTA, the resolution of vessel wall imaging has improved. We describe cases of acute vertebral artery dissection (VAD) in which the only abnormality on CTA was a characteristic thickening of the wall of the V3 portion of the vertebral artery (VA). The arterial lumen at the dissection site was normal in caliber. This type of dissection is easily overlooked if only lumen-opacifying studies such as contrast MR angiography (MRA) or conventional angiography are performed. We highlight the importance of recognizing this finding, the "suboccipital rind" sign, in the V3 portion, a segment commonly affected in VAD. The purpose of our study was to review the CTA imaging characteristics of patients with VAD in the V3 portion compared with normal controls.

MATERIALS AND METHODS

Our imaging data base was reviewed for cases of acute VAD and the presence of a "suboccipital rind" sign. A control group of 50 patients was randomly recruited from a group of patients undergoing CTA. The VA luminal diameter, the wall thickness (total diameter-luminal diameter), and the ratio of luminal diameter/total diameter were measured along 5 adjacent V3 segments and were compared between the 2 groups.

RESULTS

There was no evidence of luminal tapering or narrowing in the dissected VAs compared with controls (P = .1). The average wall thickness of the dissection group was 2.96 mm greater than that for the control group (P < .001; 95% confidence interval, 2.6-3.3). There was a significant difference in the ratio of lumen diameter/lumen+wall diameter in dissected segments compared with controls (P < .001).

CONCLUSIONS

Cross-sectional vascular imaging is often performed with multisection helical CTA for a variety of concerns, some without neurologic symptoms. Our study confirms that in cases of the "suboccipital rind" sign, the lumen appears normal in caliber, with wall thickening as the only imaging sign of VAD. In our center, this clinically occult VAD would influence management, with patients usually treated with antiplatelet agents. We caution against using only luminal-opacifying techniques such as contrast-enhanced MRA or conventional angiography to exclude VAD because they are limited in the evaluation of mural hematoma.

Craniocervical arterial dissection: spectrum of imaging findings and differential diagnosis

Craniocervical artery dissection is a potentially disabling yet probably underrecognized condition that often occurs in young and middle-aged adults. Accurate and prompt diagnosis of this condition is crucial because timely and appropriate therapy can significantly reduce the risk of stroke and long-term sequelae. Because of the great diversity in the clinical features of craniocervical artery dissection, imaging plays a primary role in its diagnosis. The increased diagnosis of this disorder in the past two decades can be attributed to an increased awareness of the clinical manifestations of internal carotid artery and vertebral artery dissection and to use of noninvasive diagnostic imaging techniques. To achieve an accurate diagnosis of craniocervical artery dissection, it is important to be familiar with its pathologic features (intimal tear, intramural hematoma, and dissecting aneurysm); the spectrum of imaging findings at color duplex ultrasonography, computed tomographic angiography, magnetic resonance (MR) imaging with MR angiography, and conventional angiography; and potential pitfalls in image interpretation.

Symptomatic spontaneous intracranial carotid artery dissection treated with a self-expanding intracranial nitinol stent: a case report

BACKGROUND

Although extracranial carotid dissection with stroke is common, intracranial dissection with stroke is rare. Stenting has been used to treat extracranial carotid dissections. Intracranially, however, it is only recently that stents have become a feasible option for this disease. We present a case of a spontaneous intracranial CAD with progressive symptoms despite medical management treated with a self-expanding intracranial micronitinol stent.

CASE DESCRIPTION

A 47-year-old, right-handed woman presented to the emergency department after noticing left-sided face and arm weakness and numbness, along with slurred speech. The patient was started on aspirin 325 mg/d orally and lovenox 40 mg/d subcutaneously. On hospital day 2, the patient was noted to have repeated episodes of weakness and numbness on the left side and MRI evidence of a new stroke. A diagnostic cerebral angiogram from a selective right internal carotid injection revealed a flow-limiting stenosis secondary to a dissection of the supraclinoid internal carotid artery with severe flow limitation to the hemisphere. Endovascular management was decided on, and a Neuroform stent measuring 4.5 x 20 mm (Boston Scientific Corporation, Natick, Mass) was deployed across the dissection with significant improvement of flow to that hemisphere on the poststent angiogram.

CONCLUSIONS

This case illustrates the successful off-label use of a self-expanding intracranial nitinol stent to treat a symptomatic intracranial internal CAD in the setting of failure of traditional medical management. This is a promising application of novel endovascular technology.

Spontaneous parapharyngeal haematoma caused by a leaking vertebral artery pseudoaneurysm

We describe an unusual case of spontaneous parapharyngeal haematoma, in a patient with haemophilia. The cause was a leaking extracranial vertebral artery pseudoaneurysm eroding through the atlas at the level of the skull base. The leaking pseudoaneurysm was successfully controlled with embolisation of the vertebral artery. The haematoma caused a cerebral infarct and vocal cord paralysis, requiring external drainage and tracheostomy. This is the first reported case of a parapharyngeal haematoma originating from a vertebral artery pseudoaneurysm where imaging demonstrated a causal link.

Spontaneous dissecting aneurysm of the intracranial vertebral artery: management strategies

PURPOSE

Pathogenesis and treatment of spontaneous dissecting aneurysm of the intracranial vertebral artery (VA) remain controversial. This study was designed to provide management strategies and to improve management outcome in patients with these aneurysms.

MATERIALS AND METHODS

Among a total of 1,990 patients treated for intracranial aneurysms from February 1992 to June 2005, 28 patients (1.4%) were treated either by surgery (8 patients) or neurointervention (20 patients) for spontaneous dissecting aneurysms of the intracranial VA. Twenty-two patients had ruptured aneurysms. We analyzed indications of surgery or neurointervention for each case, and assessed the management outcome at a 6-month follow-up.

RESULTS

For selection of therapeutic options, patients were initially evaluated as possible candidates for neurointervention using the following criteria: 1) poor clinical grade; 2) advanced age; 3) medical illness; 4) unruptured aneurysm; 5) equal or larger opposite VA; 6) anticipated surgical difficulty due to a deep location of the VA-posterior inferior cerebellar artery (PICA) junction. Surgery was considered for patients with: 1) high-risk aneurysms (large or irregular shaped); 2) smaller opposite VA; 3) failed neurointervention; or 4) dissection involving the PICA. Management outcomes were favorable in 25 patients (89.3%). Causes of unfavorable outcome in the remaining 3 patients were the initial insult in 2 patients, and medical complications in one patient.

CONCLUSION

Ruptured aneurysms must be treated to prevent rebleeding. For unruptured aneurysms, follow-up angiography would be necessary to detect growth of the aneurysm. Treatment modality should be selected according to the clinical characteristics of each patient and close collaboration between neurosurgeons and neurointerventionists is essential.

Mild Mechanical Traumas Are Possible Risk Factors for Cervical Artery Dissection

BACKGROUND AND PURPOSE

Cervical artery dissection (CAD) is a common cause of ischemic stroke in younger aged subjects. Retrospective studies suggest cervical manipulative therapy (CMT) and preceding infections as extrinsic risk factors for CAD. In a case-control study, we assessed a questionnaire with 7 mild mechanical traumas as potential trigger factors for CAD, including CMT and recent infections.

PATIENTS AND METHODS

Forty-seven consecutive patients with CAD were compared with 47 consecutive patients of similar age with ischemic stroke due to etiologies other than CAD. Patients underwent a standardized face-to-face interview. We assessed head or neck pain and recent infection <7 days before symptom onset, as well as the following mechanical trigger factors <24 h and <7 days prior to symptom onset: (1) heavy lifting, (2) sexual intercourse, (3) mild direct or (4) indirect neck trauma, (5) jerky head movements, (6) sports activity, and (7) CMT.

RESULTS

We found no association between any single one of the above risk factors and CAD. CMT (CAD, n = 10; non-CAD, n = 5) and recent infections (CAD, n = 18; non-CAD, n = 10) were more frequent in the CAD group but failed to reach significance. However, the cumulative analysis of all mechanical trigger factors revealed a significant association of mechanical risk factors as a whole in CAD <24 h prior to symptom onset (p = 0.01).

CONCLUSION

Mild mechanical stress, including CMT, plays a role as possible trigger factor in the pathogenesis of CAD. CMT and recent infections alone failed to reach significance during the present investigation, presumably due to the relatively small sample size of the study cohort.

Vertebral Artery Dissection

Background and Purpose— Few data exist about clinical, radiologic findings, clinical outcome, and its predictors in patients with spontaneous vertebral artery dissection (sVAD).

Methods— Clinical characteristics, imaging findings, 3-month outcomes, and its predictors were investigated in consecutive patients with sVAD.

Results— One hundred sixty-nine patients with 195 sVAD were identified. Brain ischemia occurred in 131 patients (77%; ischemic stroke, n=114, 67%; transient ischemic attack, n=17, 10%). Three patients with ischemic stroke showed also signs of subarachnoid hemorrhage (SAH); 3 (2%) had SAH without ischemia. The 134 patients with brain ischemia or SAH had head and/or neck pain in 118 (88%) and pulsatile tinnitus in seven (5%) patients. The remaining 35 patients (21%) had isolated head and/or neck pain in 21 (12%) cases, asymptomatic sVAD in 13 (8%), and cervical radiculopathy in one case (1%). Location of sVAD was more often in the pars transversaria (V2; 35%) or atlas loop (V3; 34%) than in the prevertebral (V1; 20%) or intracranial (V4; 11%) segment ( P =0.0001). Outcome was favorable (modified Rankin scale score 0 or 1) in 88 (82%) of 107 ischemic stroke patients with follow up. Two (2%) patients died. Low baseline National Institutes of Health Stroke Scale score ( P <0.0001) and younger age ( P =0.007) were independent predictors of favorable outcome.

Conclusions— sVAD is predominantly located in the pars transversaria (V2) or the atlas loop (V3). Most patients show posterior circulation ischemia. Favorable outcome is observed in most ischemic strokes and independently predicted by low National Institutes of Health Stroke Scale score and younger age.

Pain as the only symptom of cervical artery dissection

BACKGROUND

Headache or neck pain is a frequent symptom of spontaneous cervical artery dissection (sCAD).

PATIENTS AND METHODS

Patients were drawn from an ongoing hospital-based registry of consecutive cases diagnosed with sCAD. Only patients with isolated pain were included in this series. Pain topography, dynamics, severity and quality, imaging findings and outcome were analysed.

RESULTS

20 of 245 (8%) patients with sCAD presented with pain as the only symptom (mean (SD) age 39 (8) years; 14 (70%) women). Of them, 12 had vertebral artery dissection, 3 had internal carotid dissection and 5 had multiple dissections. The median delay from symptom onset to diagnosis was 7 days (range 4 h to 29 days). 6 patients presented with headache, 2 with neck pain and 12 with both. Onset of headache was progressive in 6, acute in 8 and thunderclap-type in 4 patients; neck pain was progressive in 7 and acute in 7. Headache was throbbing in 13 and constrictive in 5 patients; neck pain was throbbing in 4 and constrictive in 10. Pain was unilateral in 11 and bilateral in 9. Pain was different from earlier episodes in all but one case. All patients were pain free at 3 months.

CONCLUSION

Pain may be the only symptom in sCAD, even when multiple arteries are dissected. Pain topography, dynamics, quality and intensity were heterogeneous. Data from this study lend support to recommendations favouring imaging studies of the cervical arteries in patients with new-onset unexplained headache or neck pain.

Carotid and vertebral artery dissections: clinical aspects, imaging features and endovascular treatment

Extracranial arterial dissections are a recognised cause of stroke, particularly in young adults. Clinical diagnosis may be difficult, and the classical triad of symptoms is uncommon. Imaging plays a pivotal role in the diagnosis of extracranial arterial dissections, and this review provides a detailed discussion of the relative merits and limitations of currently available imaging modalities. Conventional arteriography has been the reference standard for demonstrating an intimal flap and double lumen, which are the hallmarks of a dissection, and for detecting complications such as stenosis, occlusion or pseudoaneurysm. Noninvasive vascular imaging methods, such as ultrasound (US), magnetic resonance angiography (MRA) and computed tomography angiography (CTA) are increasingly replacing conventional angiography for the diagnosis of carotid and vertebral dissections. Ultrasound provides dynamic and "real-time" information regarding blood flow. Source data of MRA and CTA and additional cross-sectional images can provide direct visualisation of the mural haematoma and information about the vessel lumen. Anticoagulation to prevent strokes is the mainstay of medical treatment, but randomised trials to define the optimal treatment regime are lacking. Surgery has a limited role in management of dissections, but endovascular procedures are gaining importance for treatment of complications and if medical management fails.

Dissection of cervicocephalic arteries: early diagnosis and follow-up with magnetic resonance imaging

Evaluate Magnetic Resonance (MR) and Magnetic Resonance Angiography (MRA) sensibility in the diagnosis and follow-up of dissection of Internal Carotid and Vertebral Artery (ICA/VA). We revalued MR examination of 36 patients, 24 men, 12 women, aged 18-69 years. All patients underwent brain TC and MR (GE 1 Tesla); in 16 subjects 3D Time-of-Flight (TOF-3D) MRA was performed and in 20 subjects a Contrast-Enhanced MRA (CEMRA) of neck and head arteries. Thirty-one patients underwent a MRA follow-up. Dissection involved ICA in 30 and VA in 8. MR showed ischemic signs in 25 cases, wall hematoma in 19, and was normal in 11. MRA showed 25 vessels stenosis, 12 occlusions, and 9 aneurysm. Follow-up MRA showed 6 cases of complete resolution of stenosis, 17 partial resolution, 2 aneurysmal dissecanting, 6 luminal alteration unchanged, 1 aneurysma enlarged. MRA represented a non-invasive technique as investigation in suspected cervicocephalic arteries dissection.

The emerging role of multidetector row CT angiography in the diagnosis of cervical arterial dissection: preliminary study

INTRODUCTION

Cervical artery dissection is an important cause of ischemic stroke, particularly in young patients. The diagnosis can be made with invasive catheter angiography or non-invasive imaging, either with MRI in conjunction with MR angiography (MRA) or CT angiography (CTA). Both modalities have been shown to have a high specificity and sensitivity. New developments such as multi-slice CTA (MSCTA) are emerging as an alternative methods for imaging the cervical and intracranial arteries. However, the contribution of modern MSCTA to carotid artery dissection has not been reported.

METHODS

We present a retrospective series of seven patients in whom both MSCTA and cervical axial T1 MRI and MRA were performed in the acute to subacute setting of internal carotid artery dissection.

RESULTS

Carotid artery dissection was identified in all seven patients by MSCTA. The combination of MRI and MRA identified dissection in five of the seven patients. Additionally, a pseudoaneurysm was identified by MSCTA that was missed by MRI and MRA.

CONCLUSION

Our findings confirm that MSCTA is a complementary technique in comparison to cervical axial T1 MRI and cervical MRA for diagnosing carotid artery dissection, and at times may provide additional information that can impact patient management.

Negative ultrasound findings in patients with cervical artery dissection

BACKGROUND

Cervical artery dissection (CAD) is a common cause of ischemic stroke in the younger age group. Modern imaging techniques allow the depiction of the mural hematoma, even in CADs with only subtle vessel alterations. The aim of this retrospective study was (1) to characterize the angiological features in CAD and (2) to determine the frequency of initially normal ultrasonography (US) findings.

METHODS

86 patients aged 44 +/- 11 years with CAD of the internal carotid (ICA), (n = 55) or the vertebral artery (VA), (n = 31), admitted to our hospital within 8 days (mean 1.6 days) of symptom onset, were included. CAD was confirmed either by CT-angiography, MRI of the neck, MR-angiography or digital substraction angiography (DSA) and was compared with the results of the initial as well as repeated US examinations of the arteries supplying the brain.

RESULTS

In 75 patients (81.2 %) signs of vessel stenosis or occlusion were found while 11 patients (12.8%) with CAD of the ICA (n = 9) and the VA (n = 2) had normal US findings. The site of dissection in the US negative patients was highly variable without a predilection site. In 2 of 7 patients with repeated US examinations, complete vessel occlusion was found on follow-up, while in 5 patients again normal results were found. In four patients, there were changing findings in two alternative confirming imaging methods (MRI/DSA, CT/MRI) and in one patient conflicting findings (CT/MRI). Brain infarctions had occurred in 7 of the initially sonographically normal patients while the other 4 had suffered from transient (n = 2) or local (n = 2) symptoms only.

CONCLUSION

Approximately 1 out of 8 patients with subsequently proven CAD has negative initial neurovascular US findings despite comprehensive examination. In patients with suspected CAD and negative US examination, repeated US examinations and further diagnostic imaging, especially MRI is necessary.

Treatment of Intra- and Extracranial Arterial Dissections Using Stents and Embolization

PURPOSE

To evaluate the safety and efficacy of stent placement for extracranial and intracranial arterial dissections.

METHODS

Eighteen patients underwent endovascular treatment of carotid and vertebral dissections using intraluminal stent placement. Five patients with arterial dissection were treated, 2 using one insertion of a single stent and 3 using placement of two stents. Patients with a dissecting aneurysm were treated as follows: 7 patients with insertion of one stent, 4 with placement of two stents, and 2 by stent-assisted Guglielmi detachable coil embolization. In the 18 patients in whom stenting was attempted, the overall success in reaching the target lesion was 94.4%. Of the 17 patients treated with stents, stent release and positioning were considered optimal in 16 (94%) and suboptimal in one (6%). In patients who underwent a successful procedure, all parent arteries were preserved. There were no instances of postprocedural ischemic attacks, new neurologic deficits, or new minor or major strokes prior to patient discharge. In follow up, all patients were assessed, using the modified Rankin scale, as functionally improved or of stable clinical status. The reduction in dissection-induced stenosis or pseudoaneurysm, the patency rate obtained at follow-up, and the lack of strokes (ischemic or hemorrhagic) suggest that stent placement offers a viable alternative to complex surgical bypass or reconstructive procedures. The long-term efficacy and durability of stent placement for arterial dissection remain to be determined in a larger series.

Imaging the vertebral artery

Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed.

Bilateral spontaneous vertebral artery dissection: management during labor and vaginal delivery

We report the successful management of labor and delivery of a parturient with a history of spontaneous bilateral vertebral artery dissection. We also outline the reasons why the obstetric anesthetist should be aware of this condition as well as other cranio-cervical dissections.

Simultaneous bilateral internal carotid and vertebral artery dissection following chiropractic manipulation: case report and review of the literature

Single-vessel cervical arterial dissections typically occur in young adults and are a common cause of cerebral ischemia and stroke. Although the pathogenesis of multivessel dissection is unclear, it is thought to be a consequence of underlying collagen vascular disease. We present a 34-year-old previously healthy man who developed bilateral internal carotid and vertebral artery dissection following chiropractic manipulation.

Spontaneous renal artery dissection: treatment with coil embolization

A 47-year-old man presented with nonspecific left flank pain and severe hypertension as a result of a spontaneous dissection of an accessory renal artery. Because of the progressive increase in the size of the dissection flap and uncontrollable hypertension, treatment with segmental embolization of the true and false lumen of the accessory renal artery was performed with successful clinical outcome. This case report will address the salient clinical features of spontaneous renal artery dissections and treatment options.