Magnetic resonance imaging and dynamic CT scan in cervical artery dissections

Bilateral carotid dissection due to Eagle syndrome

Eagle syndrome is defined as a collection of symptoms affecting the cervical and cranial regions, resulting from an elongated styloid process or ossified stylohyoid ligament encroaching on surrounding structures and causing a variety of symptoms. Classically, Eagle syndrome presents as neck, throat, or ear pain. Carotid artery dissection is a rare complication of Eagle syndrome. We report the case of a 40-year-old man who presented with bilateral internal carotid artery dissection secondary to pathological elongation of the styloid processes.

Cervical Artery Dissections-A Demographical Analysis of Risk Factors, Clinical Characteristics Treatment Procedures, and Outcomes-A Single Centre Study of 54 Consecutive Cases

Cervical artery dissections (CAD) are a common cause of ischemic cerebrovascular events among the younger and middle-aged population. Altogether, CAD counts for up to 15% of all causes of stroke in patients aged 50 or younger. Among the known etiological causes, especially addressing the younger population with mechanical traumas and whiplash injuries are regarded as the main culprits. However, cases of spontaneous dissection are also widespread, with risk factors such as hypertension, migraine, and lifestyle factors increasing the risk of occurrence. Clinically, the symptoms associated with a cerebrovascular event caused by CADs are highly variable and can be classified as either compressive symptoms (such as Horner's syndrome and cervical pain) or stroke syndromes attributable to cerebral ischemia. Therefore, establishing an early diagnosis might be particularly challenging as it requires particular attention and quick clinical reasoning when interviewing the patient. With these certain particularities, our main focus was to conduct a prospective study involving up to 54 patients who were diagnosed with CAD in our clinical facility between January 2015 and December 2022, with the focus of assessing certain individual parameters attributable to each patient and their influence and prognosis value for their short and long term evolution. An important emphasis was placed on parameters such as topographical localization, clinical presentation, severity of the questioned cerebrovascular event, outcomes, and causative factors. Statistical validity tools were applied when possible.

A Rare Case Report of Flexion Teardrop Cervical Fracture with Blunt Vertebral Artery Injury Leading to Stroke

Non penetrating trauma to vertebral artery is a known complication in craniovertebral trauma. They are mainly reported with facet dislocations or injuries involving the foramen transversarium. Such a type of injury is rarely seen with flexion injuries. We report such a case leading to cerebellar stroke in a young male presenting to us with hemiparesis. A 43-year-old male presented to us 1 month post trauma after a motor vehicular accident with complaint of weakness of right half of the body since the trauma. He suffered blunt trauma to head and neck and complained of a flail right upper limb since trauma and weakness of the right lower limb which had partly improved. He was conservatively managed elsewhere. Radiographic investigations revealed complete occlusion of the right vertebral injury above the level of 6^th cervical vertebra and flexion teardrop fracture of 5^th cervical vertebra. He was managed conservatively for the vertebral artery injury (VAI) and corpectomy of C5 vertebra with anterior cervical plating and fusion. Such a rare type of injury can present with unexplained neurodeficit which needs appropriate radiological investigations for diagnosis before ascribing the cause to cord trauma. Hence, all high velocity motor vehicular accidents with associated fractures and neurodeficit should be screened for blunt VAIs.

Internal Carotid Artery Dissection Presenting as Partial Horner's Syndrome and Vertigo

Distinguishing between central and peripheral causes of vertigo can be challenging not only in an acute setting but also in chronic settings. A thorough review of systems and physical exam can assist providers in differentiating central versus peripheral etiologies and the need for urgent imaging. In this case, a 47-year-old man presented with vertigo, right-sided hearing loss, right-sided headache, and right-sided facial pain that began 4 weeks before while the patient was on a cruise ship. His physical exam findings were notable for anisocoria with right pupil 3.5 and left pupil 4.5, mild ptosis on the right side, positive Romberg test to the right, and Fakuda test with deviation to the right. Urgent magnetic resonance imaging revealed dissection of the right cervical internal carotid artery with a nonocclusive intramural hematoma. This case illustrates the importance of imaging in vertigo patients in which a central etiology is suspected. It further demonstrates that isolated partial Horner's or unilateral headache may indeed be the only presenting sign in a carotid dissection.

Extracranial Cervical Artery Dissections

Cervical artery dissections (CeAD) include both internal carotid and vertebral artery dissections. They are rare but important causes of stroke, especially in younger patients. CeAD should be considered in patients with strokelike symptoms, a new-onset headache and/or neck pain, and/or other risk factors. Early imaging with computed tomography (CT) or magnetic resonance imaging (MRI) is key to making the diagnosis. Treatment may vary depending on the extent of the dissection, timing of the dissection, and other comorbidities. The overall prognosis is good, but does depend on the initial severity of symptoms.

The Prevalence of and Factors Related to Vascular Hyperintensity on T1-Weighted Imaging in Acute Ischemic Stroke

BACKGROUND

Thrombus visualization in patients with acute ischemic stroke has been detected and reported using various imaging modalities. T1-weighted imaging (T1-WI) can depict thrombi as hyperintense signals within vessels. Moreover, in addition to thrombi, T1-WI hyperintensities in arteries may suggest arterial dissection. However, the frequency of and factors related to the T1-hyperintense vessel sign (T1-HVS) are not fully known. The aim of this study was to clarify the prevalence of and related factors for the T1-HVS in patients with acute ischemic stroke.

METHODS

From September 2014 through December 2015, consecutive acute ischemic stroke patients who were admitted to our stroke unit within 7 days from symptom onset were retrospectively recruited from the prospective registry. A T1-HVS was defined as the presence of a hyperintense signal, with intensity higher than surrounding brain, within the vessel lumen. Moreover, T1-HVSs were separated into filled T1-HVSs (hyperintensity fills whole vessel lumen) and non-filled T1-HVSs. The frequency of the T1-HVS and the timing of emersion and the relationship between the presence of the T1-HVS and arterial occlusion were assessed.

RESULTS

A total of 399 patients (139 women; median age 73 years; National Institutes of Health Stroke Scale score 3) were enrolled in the present study. Of these, 327 (82%) patients had T1-WI on admission. Two hundred and sixty-seven (67%) subjects had at least one follow-up T1-WI (median 6 days after admission), and 134 (34%) cases had ≥2 follow-up T1-WI examinations. The T1-HVS was observed in 18 patients during admission; therefore, the frequency of the T1-HVS in acute ischemic stroke patients was 4.5% (95% CI 2.5-6.5%). All but one (94%) of the T1-HVSs were first observed on follow-up imaging, and the median number of days from onset to T1-HVS appearance was 9. For patients having initial major artery occlusion and follow-up MRI (n = 95), sensitivity and specificity of the T1-HVS for persistent arterial occlusion on follow-up MR angiography were 22 and 100%, respectively. T1-HVS persisted for a few months and then normalized. Although there were no significant differences between filled and non-filled T1-HVS, more patients with non-filled T1-HVS had arterial dissection (43%) than those with filled T1-HVS (9%, p = 0.245).

CONCLUSION

The T1-HVS was observed in 4.5% of acute ischemic stroke patients. T1-HVSs appeared in the subacute phase in arteries with persistent occlusion and remained for a few months.

CT versus MR Techniques in the Detection of Cervical Artery Dissection

BACKGROUND

Spontaneous cervical artery dissection (sCAD) is an important etiology of juvenile stroke. The gold standard for the diagnosis of sCAD is convential angiography. However, magnetic resonance imaging (MRI)/MR angiography (MRA) and computed tomography (CT)/CT angiography (CTA) are frequently used alternatives. New developments such as multislice CT/CTA have enabled routine acquisition of thinner sections with rapid imaging times. The goal of this study was to compare the capability of recent developed 128-slice CT/CTA to MRI/MRA to detect radiologic features of sCAD.

METHODS

Retrospective review of patients with suspected sCAD (n = 188) in a database of our Stroke center (2008-2014), who underwent CT/CTA and MRI/MRA on initial clinical work-up. A control group of 26 patients was added. All Images were evaluated concerning specific and sensitive radiological features for dissection by two experienced neuroradiologists. Imaging features were compared between the two modalities.

RESULTS

Forty patients with 43 dissected arteries received both modalities (29 internal carotid arteries [ICAs] and 14 vertebral arteries [VAs]). All CADs were identified in CT/CTA and MRI/MRA. The features intimal flap, stenosis, and lumen irregularity appeared in both modalities. One high-grade stenosis was identified by CT/CTA that was expected occluded on MRI/MRA. Two MRI/MRA-confirmed pseudoaneurysms were missed by CT/CTA. None of the controls evidenced specific imaging signs for dissection.

CONCLUSIONS

CT/CTA is a reliable and better available alternative to MRI/MRA for diagnosis of sCAD. CT/CTA should be used to complement MRI/MRA in cases where MRI/MRA suggests occlusion.

Bilateral spontaneous internal carotid artery dissection managed with endovascular stenting - A case report

Carotid artery dissection (CAD) is a frequent cause of stroke, accounting for up to 25% of all ischemic strokes in young and middle-aged patients.1,2 It may be traumatic or spontaneous, with multi-factorial etiology. A tear in the arterial wall causes intrusion of blood within its layers, producing intra-luminal stenosis, or aneurysmal dilatation.3 Thrombo-embolism arising from this anatomic disruption has been postulated as the essential stroke mechanism in CAD.4 Bilateral internal carotid artery dissection (ICAD) has been rarely reported.1,4 Antiplatelets and anticoagulation remain standard therapy for CAD.5 However, in patients with either expanding pseudoaneurysms, severe flow compromise, worsening symptoms despite anticoagulation or contraindication to anticoagulation, endovascular stenting is beneficial.6 We describe a patient with ischemic stroke from spontaneous bilateral ICAD with completely occluded left ICA. Having failed medical therapy with antiplatelets and anticoagulants due to extensive loss of carotid vascular supply, he was managed successfully with endovascular stenting with good neurological recovery.

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.

Intracranial vertebral artery dissections: evolving perspectives

Intracranial vertebral artery dissection (VAD) represents the underlying etiology in a significant percentage of posterior circulation ischemic strokes and subarachnoid hemorrhages. These lesions are particularly challenging in their diagnosis, management, and in the prediction of long-term outcome. Advances in the understanding of underlying processes leading to dissection, as well as the evolution of modern imaging techniques are discussed. The data pertaining to medical management of intracranial VADs, with emphasis on anticoagulants and antiplatelet agents, is reviewed. Surgical intervention is discussed, including, the selection of operative candidates, open and endovascular procedures, and potential complications. The evolution of endovascular technology and techniques is highlighted.

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.

Cervical carotid artery dissection: current review of diagnosis and treatment

Carotid artery dissection is a cause of stroke, especially in young and middle-aged patients. A dissection occurs when there is an intimal tear or rupture of the vasa vasorum, leading to an intramural hematoma, which is thought to result from trauma or can occur spontaneously, and is likely multifactorial, involving environmental and intrinsic factors. The clinical diagnosis of carotid artery dissection can be challenging, with common presentations including pain, partial Horner syndrome, cranial nerve palsies, or cerebral ischemia. With the use of noninvasive imaging, including magnetic resonance and computed tomography angiography, the diagnosis of carotid dissection has increased in frequency. Treatment options include thrombolysis, antiplatelet or anticoagulation therapy, endovascular or surgical interventions. The choice of appropriate therapy remains controversial as most carotid dissections heal on their own and there are no randomized trials to compare treatment options.

Evaluation of luminal and vessel wall abnormalities in subacute and other stages of intracranial vertebrobasilar artery dissections using the volume isotropic turbo-spin-echo acquisition (VISTA) sequence: a preliminary study

OBJECTIVE

To evaluate the utility of 3D variable refocusing flip-angle volume isotropic turbo-spin-echo acquisition (VISTA) imaging, using a 1.5-T MRI unit, which can minimize flow artifacts, due to its sequence-endogenous flow-void capability, in the diagnosis of intracranial vertebrobasilar artery dissection (VAD).

MATERIAL AND METHODS

The presence of intimal flaps, intramural hematomas, vessel dilatations and abnormal vessel enhancements were evaluated on T1-weighted VISTA images from 18 VAD patients with 20 dissected arteries (15 subacute and five at other stages). Additional gadolinium-enhanced T1VISTA images were available for 13 patients. The frequency of flow artifacts on T1VISTA imaging in 70 non-dissected arteries in VAD patients and 12 control subjects was also evaluated. Furthermore, in 13 and eight patients, contrast-enhanced three-dimensional (CE3D) imaging with spoiled gradient-recalled (SPGR) acquisition in steady state and electrocardiographically gated black-blood (BB) T1-weighted imaging (T1WI) were evaluated to compare visualization of false lumens.

RESULTS

Intimal flaps, intramural hematomas and dilatations were identified on T1VISTA images in 65% (13/20), 55% (11/20) and 90% (18/20) of VADs, respectively. Abnormal vessel enhancement was recognized in 100% (15/15) of VADs on contrast-enhanced T1VISTA images. Only four normal arteries showed small, thin, linear artifacts. Compared with CE3D-SPGR imaging, T1VISTA imaging depicted false lumens more conspicuously in seven VADs (P=0.02). T1VISTA also revealed intimal flaps and hematomas as did BB T1WI.

CONCLUSION

T1VISTA imaging may be useful for diagnosing VAD at subacute stages, as it can reveal vessel wall and lumen abnormalities with a minimum of flow artifacts.

Identification of internal carotid artery dissection by transoral carotid ultrasonography

BACKGROUND AND PURPOSE

Conventional transsurface carotid ultrasonography (TSCU) via the cervical surface often fails to detect dissection of the extracranial internal carotid artery (ICA). The role of transoral carotid ultrasonography (TOCU) in the detection of ICA dissection was examined.

METHOD

Patients with unilateral extracranial ICA dissection identified by digital subtraction angiography (DSA) from our database of patients with ischemic stroke or transient ischemic attack (TIA) were reviewed. Findings of dissection were compared between TSCU and TOCU.

RESULTS

Eight patients (7 men, 37-69 years old), including 7 with ischemic stroke and 1 with TIA, had ICA dissection. By DSA, dissection was identified between the first and third vertebrae in 4 patients and from the third cervical vertebra to the intracranial level in the remaining 4. TOCU images revealed an intimal flap as definite evidence of dissection in all patients. In 7 patients, color flow signals were not seen in false lumens, indicating thrombosed lumens. Four patients showed morphological changes of dissection on follow-up TOCU, including a patient with recovery of color flow signals in false lumens. The diameter of the dissected ICA was 7.3 ± 0.7 mm and that of the contralateral ICA was 4.9 ± 0.6 mm (p = 0.008). In contrast, TSCU did not enable any conclusive findings of ICA dissection to be made in any patient. Six patients had intramural hematoma on T(1)-weighted MRI, and 2 had an intimal flap with a double lumen on magnetic resonance angiography.

CONCLUSION

TOCU has advantages over TSCU in achieving an accurate diagnosis and follow-up evaluation of ICA dissection.

Basi-parallel anatomical scanning magnetic resonance imaging in patients with bilateral vertebrobasilar artery dissections

A 31-year-old man presented with bilateral unruptured vertebral artery (VA) dissections. The temporal course of the dissected arteries was successively evaluated using brain surface imaging modality basi-parallel anatomical scanning (BPAS) magnetic resonance (MR) imaging in combination with the conventional modalities of MR angiography and three-dimensional computed tomography (3D-CT) angiography. Initially, BPAS-MR imaging clearly demonstrated bilateral fusiform dilatations of the arterial wall, whereas MR angiography and 3D-CT angiography showed irregular, dilated, or interrupted inner contour of the arteries. Finally, BPAS-MR imaging demonstrated resolution of both aneurysms, and MR angiography demonstrated obstruction of the left VA and normal contours of the right VA. Combination of diagnostic tools such as BPAS-MR imaging and MR angiography is useful for evaluating the exact nature of dissected arteries and determining the temporal course.

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.

Comparison of test performance characteristics of MRI, MR angiography, and CT angiography in the diagnosis of carotid and vertebral artery dissection: a review of the medical literature

OBJECTIVE

Initial assessment of patients with suspected dissection of the carotid or vertebral arteries typically is made by MRI, alone or in combination with MR angiography (MRA) or CT angiography (CTA). We reviewed the medical literature to determine, based on test performance characteristics such as sensitivity, specificity, positive predictive value, and negative predictive value, whether evidence could be found to support routine use of one imaging technique over the other for assessment of suspected dissection.

CONCLUSION

Test characteristics for MR techniques such as MRI and MRA were relatively similar to those for CTA in diagnosis of carotid and vertebral artery dissection.

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.

Sensitivity of neurovascular ultrasound for the detection of spontaneous cervical artery dissection

The reported sensitivity of neurovascular ultrasound (nUS) for detecting spontaneous cervical artery dissection (sCAD) varies from 80% to 96% in the internal carotid artery (ICA) and from 70% to 86% in the vertebral arteries (VA). The aim of this study was to assess the sensitivity of nUS compared to MRI of the neck and MR angiography for the detection of sCAD. Forty consecutive patients with sCAD proven by 1.5T MRI were investigated by nUS within 48 hours of admission. A total of 52 cases of sCAD were detected by MRI, equally distributed (n=26, 50%) in the ICA and VA territories. Two sCADs affecting the ICA (n=2, 8%) and two sCADs of the VA (n=2, 8%) had normal initial nUS findings. The sensitivity of nUS in detecting sCAD is high, about 92% for both vascular territories. However, intramural hematomas may be missed either when they are located outside the arterial segments directly visible by nUS or if they are too small to cause hemodynamically significant stenosis.

Comparison of multidetector CT angiography and MR imaging of cervical artery dissection

BACKGROUND AND PURPOSE

Conventional angiography has been historically considered the gold standard for the diagnosis of cervical artery dissection, but MR imaging/MR angiography (MRA) and CT/CT angiography (CTA) are commonly used noninvasive alternatives. The goal of this study was to compare the ability of multidetector CT/CTA and MR imaging/MRA to detect common imaging findings of dissection.

MATERIALS AND METHODS

Patients in the data base of our Stroke Center between 2003 and 2007 with dissections who had CT/CTA and MR imaging/MRA on initial work-up were reviewed retrospectively. Two neuroradiologists evaluated the images for associated findings of dissection, including acute ischemic stroke, luminal narrowing, vessel irregularity, wall thickening/hematoma, pseudoaneurysm, and intimal flap. The readers also subjectively rated each vessel on the basis of whether the imaging findings were more clearly displayed with CT/CTA or MR imaging/MRA or were equally apparent.

RESULTS

Eighteen patients with 25 dissected vessels (15 internal carotid arteries [ICA] and 10 vertebral arteries [VA]) met the inclusion criteria. CT/CTA identified more intimal flaps, pseudoaneurysms, and high-grade stenoses than MR imaging/MRA. CT/CTA was preferred for diagnosis in 13 vessels (5 ICA, 8 VA), whereas MR imaging/MRA was preferred in 1 vessel (ICA). The 2 techniques were deemed equal in the remaining 11 vessels (9 ICA, 2 VA). A significant preference for CT/CTA was noted for VA dissections (P < .05), but not for ICA dissections.

CONCLUSION

Multidetector CT/CTA visualized more features of cervical artery dissection than MR imaging/MRA. CT/CTA was subjectively favored for vertebral dissection, whereas there was no technique preference for ICA dissection. In many cases, MR imaging/MRA provided complementary or confirmatory information, particularly given its better depiction of ischemic complications.

Cervicocranial arterial dissection

Cervicocranial arterial dissection (CCAD) occurs when there is a tear in the intimal layer of the carotid or vertebral arteries with subsequent extravasation of blood into the subintimal layers. The dissection may be extradural, intradural, or extend over both segments. The contents of the subintimal layers are highly thrombogenic, and thus, embolism, vessel stenosis, or occlusion may follow. Symptoms of dissection may be caused by local injury to the blood vessel or by ischemia to the retina or brain. Thus, dissection should always be considered in patients who present with Horner syndrome associated with ipsilateral headache, carotidynia, ocular pain, or amaurosis fugax. Rare neuro-ophthalmologic presentations of dissection include anterior and posterior ischemic optic neuropathy; central retinal artery occlusion; ophthalmic artery occlusion; transient ophthalmoparesis; and third, fourth, or sixth cranial nerve palsy. The most common serious complication of dissection is ischemic stroke. No randomized controlled trials have evaluated therapies for patients presenting with CCAD. Thus, treatment is essentially empiric and often varies by region. Medical management is first line in most patients. Given the propensity for thrombus formation and early embolization or occlusion, acute anticoagulation using intravenous heparin or low-molecular-weight heparinoids followed by short-term, dose-adjusted warfarin is the treatment of choice for most patients with extradural CCAD who present early after symptom onset. The risk of cerebral ischemia is greatest in the first few weeks after dissection; thus, it is reasonable to recommend antiplatelet agents for patients who present late and have not had evidence of ischemia. Intradural dissection is rare but is associated with a meaningful risk of subarachnoid hemorrhage (SAH). As a result, anticoagulants and antiplatelet agents should not be used if SAH is suspected or confirmed. Endovascular intervention may be necessary in a small minority of cases with recurrent events despite anticoagulation or SAH due to intradural dissection. Of special note, CCAD is not considered a contraindication for tissue plasminogen activator use in acute stroke patients who are otherwise eligible for treatment.

Duplex Scanning Diagnosis of Internal Carotid Artery Dissections

BACKGROUND

The reliability of duplex scanning (DS) for the diagnosis of internal carotid artery dissections (ICAD) is not clear.

METHODS

Nine DS signs known to be suggestive for the diagnosis of ICAD were compared between 70 patients with ICAD and 70 matched patients without dissection.

RESULTS

Visible internal tapering occlusion, regular eccentric narrowing channel, ectasia beyond the carotid bulb, resistive index asymmetry, blood flow slowdown, ophthalmic artery blood flow inversion, and biphasic flow are more frequent in cases than in controls (p < 0.001). Atheroma plaques were absent in 80% of ICAD. When DS direct signs and hemodynamic signs were studied, sensitivity was 90% and specificity 60%.

CONCLUSION

Diagnosis of ICAD by DS could be improved if direct signs were combined with hemodynamic signs, giving a high sensitivity and a rather good specificity.

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.

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.

[Cervical arteries dissection: diagnostic Color Doppler US criteria at the acute phase]

PURPOSE

To estimate the value of duplex color-coded ultrasonography in the initial diagnosis of acute cervical artery dissection.

MATERIAL AND METHOD

Retrospective study of 31 patients, mean age 45, sex ratio=1, referred for clinical suspicion of cervical artery dissection, confirmed by MRI. 46 dissected arteries were imaged. Ten patients presented multiple dissections. The evaluated sonographic diagnostic criteria were the direct signs of intra-mural hematoma: localized increased diameter of the artery, narrowed lumen, hypo and/or isoechoic intra-mural hematoma, intimal flap. The associated criteria studied were: the location of intra-mural hematoma and in case of an occlusion, the dissection of an other artery.

RESULTS

We analyzed separately the arterial segments visualized in B-mode ultrasound (supra-bulbar internal carotid artery, vertebral artery from V0 to V3) and the arterial segments evaluated only by pulsed Doppler (intrapetrosal carotid artery, V3-V4 of the vertebral artery). With the above criteria, on arterial segments visualized in B-mode ultrasound, the diagnosis of dissection was done in 83% of cases during the initial examination but in only 30% of the arterial segments non visualized on ultrasonography.

CONCLUSION

The direct signs of intra-mural hematoma on internal carotid and vertebral segments imaged by B-mode ultrasonography have a good sensitivity. Because results were compared to MRI, the specificity could not be assessed. In case of occlusion of an artery, multiple dissections are a strong argument for the diagnosis.

Spontaneous intracranial arterial dissection in the young: diagnosis by CT angiography

Background

Spontaneous carotid artery dissections have been rarely reported in children. Diagnosis has traditionally been confirmed by catheter arteriography. More recently diagnosis has been made by magnetic resonance imaging and magnetic resonance angiography; however the sensitivity of these techniques has yet to be determined. The authors are unaware of reports of carotid dissection confirmed by dynamic computed tomography (computerized tomographic arteriography) in the young.

Case presentation

We recently evaluated a fourteen year-old male following the development of transient neurologic symptoms. There was no antecedent illness or trauma. Dynamic computed tomography revealed an intracranial dissection involving the supraclinoid segment of the left internal carotid artery (confirmed by catheter arteriography). Studies for vasculitis, pro-thrombotic states, and defects of collagen were negative.

Conclusion

Spontaneous carotid artery dissection is a potential cause of transient neurological symptoms and ischemic stroke in the pediatric population. Dynamic computed tomography appears to be a reliable diagnostic tool which can lead to early diagnosis.

Dissection of the Extracranial Vertebral Artery: Clinical Findings and Early Noninvasive Diagnosis in 24 Patients

Dissection of cervical arteries causes ischemic stroke in young adults. This reports the clinical, ultrasonographic, and neuroradiological findings in 24 patients with 28 vertebral artery dissections in the neck (4 occurring bilaterally). In 20 patients (83%), the dissection was temporally related to trauma. No patients had an underlying vascular disease, for example, atherosclerosis or fibromuscular dysplasia. In all, the major initial manifestation was pain in the occipital or neck region. The next most common symptoms were vertigo and nausea (in 17 patients). Clinical manifestations were vertebrobasilar transient ischemic attack (TIA) (5 patients: in 2 patients vestibulocerebellar TIA, in 1 patient visual TIA, in 1 patient motor TIA, and in 1 patient brain stem TIA with perioral paresthesia), cerebellar infarction (10 patients, in 4 patients bilateral), brainstem infarction (5 patients), posterior cerebral artery territory infarction (1 patient), and multiple vertebrobasilar ischemic lesions (3 patients). Typical angiographic findings were irregular narrowing of the vessel lumen or a tapering stenosis with distal occlusion. Magnetic resonance imaging showed a thickened vessel wall with hematoma signal at the site of the dissection. Duplex color-flow imaging was valuable for the early diagnosis of extracranial vertebral artery dissection and for follow-up examinations. The distal V1- and the proximal V2-segment (at the level of C6 vertebra) was the most frequent localization of dissections (in 43%). The outcome was favorable except for 2 patients with basilar artery occlusion. Embolism to the basilar artery may be avoided by early administration of anticoagulants.

Utility of Screening for Blunt Vascular Neck Injuries with Computed Tomographic Angiography

PURPOSE

To prospectively study the impact of implementing a computed tomographic angiography (CTA)-based screening protocol on the detected incidence and associated morbidity and mortality of blunt vascular neck injury (BVNI).

METHODS

Consecutive blunt trauma patients admitted to a single tertiary trauma center and identified as at risk for BVNI underwent admission CTA using an eight-slice multi-detector computed tomography scanner. The detected incidence, morbidity, and mortality rates of BVNI were compared with those measured before CTA screening. A logistic regression model was also applied to further evaluate potential risk factors for BVNI.

RESULTS

A total of 1,313 blunt trauma patients were evaluated. One hundred seventy screening CTAs were performed, of which 33 disclosed abnormalities. Twenty-three were evaluated angiographically, of which 15 were considered to have significant BVNIs, as were 4 of the 10 patients with abnormal CTAs and no angiogram. The incidence of angiographically proven BVNIs in our series was 1.1%. If four patients who were treated for BVNIs based on CTA alone are included, the incidence rises to 1.4%. This is significantly higher than the 0.17% incidence before screening (p < 0.001). In addition, the delayed stroke rate and injury-specific mortality fell significantly from 67% to 0% (p < 0.001) and 38% to 0% (p = 0.002), respectively. Overall mortality also fell significantly, from 38% to 10.5% (p = 0.049). Univariate logistic regression identified the presence of cervical spine injury as a significant predictor of BVNI (p < 0.001).

CONCLUSION

CTA screening increases the detected incidence of BVNI 8-fold, with rates similar to angiographically based screening protocols. CTA screening significantly decreases BVNI-related morbidity and mortality in an efficient manner, underlying its utility in the early diagnosis of this injury.

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.

Non-Atherosclerotic Vascular Disease in the Young

There are a large variety of non-atherosclerotic causes of ischemic stroke in the young. Arterial dissection, most commonly associated with non-traumatic causes, is among the most common. Both the carotid and vertebrobasilar circulations can be affected. The vasculitidies represent a rare, but potentially treatable series of conditions that can lead to stroke through diverse mechanisms. Moyamoya is a nonatherosclerotic, noninflammatory, nonamyloid vasculopathy characterized by chronic progressive stenosis or occlusion of the distal internal carotid arteries and/or proximal portions of the middle and/or anterior cerebral arteries. Moyamoya can be idiopathic (moyamoya disease) or the result of other conditions. An appreciation of the unusual causes of stroke in the young is important when considering secondary prevention measures.

Pediatric oropharyngeal trauma: what is the role of CT scan?

OBJECTIVES/HYPOTHESIS

Pediatric oropharyngeal trauma (OPT) is a common injury in children with rare, but at times severe complications including carotid injury and dissection of air/micro-organisms into the deep tissues of the neck or chest. Cervical CT scan with contrast (CT angiography (CTA)) is nearly universally available and may enhance the evaluation of OPT patients by screening for these potentially devastating complications.

STUDY DESIGN

Retrospective record review, systematic review of the literature.

METHODS

Twenty-three patients diagnosed with OPT from 1997 to 2003 at Boston Children's Hospital were identified by database review. Records were reviewed for site and mechanism of injury, use of diagnostic studies, management, and outcomes. Results were compared to previously published reports. The current literature was reviewed to assess the level of evidence pertaining to the evaluation of OPT patients with CT scan. An extrapolation was made to the general trauma literature to further evaluate the ability of CT angiography to detect carotid injury.

RESULTS

Demographics and mechanism of injury in the current series were unchanged from previous reports. CT demonstrated superior detection and localization of free air. Systematic review of OPT literature revealed data on the use of CT scan as evaluation tool were lacking. Extrapolations to the trauma literature strongly indicate helical CTA has high sensitivity and specificity in detecting carotid injury.

CONCLUSIONS

Pediatric oropharyngeal trauma is a common injury with rare, but severe complications. The routine use of CT scan with contrast may assist in the evaluation of these patients to detect injuries that could lead to severe complications. Collection of prospective data on the ability of CT scan to detect carotid injuries is needed but may not be feasible.

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.

Magnetic Resonance Imaging of Suspected Cervicocranial Arterial Dissections

The authors propose that the optimal screening protocol for evaluation of suspected cervicocranial arterial dissections is magnetic resonance imaging (MRI) that includes three components: 1) contrast-enhanced three-dimensional time-of-flight magnetic resonance angiography (MRA) through the superior mediastinum, neck, and skull base; 2) three-dimensional multiple overlapping thin-section acquisition MRA of the skull base and Circle of Willis region; and 3) axial non-contrast, non-fat-suppressed T1-weighted, fat-suppressed T1-weighted, and T2-weighted spin-echo MRI from the level of the aortic arch through the level of the circle of Willis. MRA permits visualization of vascular luminal narrowing or obliteration, which can suggest vascular dissection but can also be caused by congenital variation, dysplasia, intraluminal thrombus, vasospasm, or extramural compression by tumor. By directly visualizing the blood vessel wall, axial T1-weighted and T2-weighted spin-echo MRI can identify the intramural hemorrhage of vascular dissection. This protocol is designed to maximize the sensitivity of a noninvasive technique and may eliminate the need for conventional endovascular angiography.

A child with isolated Horner's syndrome after blunt neck trauma

Horner's syndrome is the triad of miosis, ptosis, and anhidrosis that results from disruption of the sympathetic pathways between the brain and the eye. Although the individual signs of Horner's syndrome do not constitute an emergency, their presence makes any Horner's syndrome a potential vascular emergency due to the proximity of the internal carotid artery to the sympathetic ganglia. We present a case of Horner's syndrome in a 5-year-old child after blunt trauma to the neck, and discuss the management and implications of a potential carotid artery injury.

MR angiography of the extracranial circulation

In this article, the authors present a brief history of MR angiography (MRA) of the neck with emphasis on the techniques developed, particularly recent ones, to improve image quality. The goal of MRA is to eventually replace catheter angiography. The use of MRA, particularly contrast enhanced MRA with regards to pathology (atherosclerotic disease/plaque formation, dissection and post-traumatic aneurysm) involving the extra-cranial carotid and vertebral arteries is addressed. The authors also comment on computed tomographic angiography and sonography and how they compare with contrast enhanced MRA when pertinent.

A patient with Wallenberg’s syndrome induced by severe cough

A 45-year-old man developed severe cough with cervical pain. The patient was unable to hold an upright position. The origin of the right posterior inferior cerebellar artery was not enhanced by angiography. MRI showed a high signal intensity string-like structure of the right vertebral artery. In young patients, Wallenberg's syndrome related to mild head trauma has been reported. However, none of the previous studies related to vertebral arterial dissection was induced by severe cough. When cervical pain is present in young patients with severe cough, MRI should be performed to evaluate the possibility of vertebral arterial dissection.

The diagnostic accuracy of computed tomography angiography for traumatic or atherosclerotic lesions of the carotid and vertebral arteries: a systematic review

INTRODUCTION

Helical computed tomography angiography (CTA) has become an established technique for evaluating atherosclerosis of the cerebrovascular arteries. However, the role of CTA in penetrating and blunt trauma to the carotid and vertebral arteries is not well defined. We conducted a systematic literature review to determine the diagnostic accuracy of CTA for atherosclerotic, penetrating and blunt lesions in the carotid and vertebral arteries.

METHODS

We searched MEDLINE and EMBASE databases to identify studies evaluating the diagnostic accuracy of CTA of the carotid and vertebral arteries published between January 1, 1992 and December 31, 2002. Two reviewers independently assessed abstracts and full text to determine study eligibility. Information on methodological quality, imaging technique and diagnostic accuracy was abstracted from all eligible studies by three independent reviewers. We pooled sensitivity and specificity data from diagnostic accuracy studies of high methodological quality.

RESULTS

Forty-three articles met the inclusion criteria and were included in the review. Thirty studies examined atherosclerotic disease, two blunt trauma, two penetrating trauma and nine examined patients with other pathology. Pooled data from 15 higher quality studies demonstrated that CTA had a sensitivity of 95% (91-97% CI) for detecting severe (>70%) atherosclerotic stenosis of the carotid artery. The specificity of CTA for severe stenosis was also high 98% (96-99% CI). CTA remained a sensitive technique (95%; 93-97% CI) when the criterion for a positive result is relaxed to moderate or greater (>30%) stenosis. Two studies raised concerns about the use of CTA in the blunt trauma setting, suggesting that CTA may not be sensitive for detecting small intimal injuries, although both of these studies used older technologies for either obtaining or viewing images. Conversely, two penetrating trauma studies concluded that the sensitivity of CTA was high.

CONCLUSIONS

Our findings demonstrate that CTA is both a sensitive and specific imaging technique for identifying severe atherosclerotic stenosis and occlusion of the carotid arteries. However, there is currently not enough high quality evidence to accurately estimate the sensitivity and specificity of CTA in the setting of blunt or penetrating trauma.