Dissecting aneurysms of the middle cerebral artery: neuroradiological and clinical features

Middle Cerebral Artery Dissection: A Report of Two Cases With Treatments and Outcomes

In the present report, we describe two cases of right-sided M1 segment middle cerebral artery dissection in a 51-year-old Asian female and in a 28-year-old Caucasian male patient with no previous history of ischemic stroke or known intracranial atherosclerosis presenting with acute unilateral headache progressing to severe multifocal hemispheric infarction with nearly complete one-sided motor paralysis. In both patients, a middle cerebral artery dissection was detected on angiography; they were given exclusively medical therapy: patient 1 was not eligible to reperfusive therapies and was treated with a three-month course of acetylsalicylic acid and clopidogrel combined with low-dose enoxaparin, while patient 2 was initially treated with intravenous alteplase with no hemorrhagic complications and was later shifted to single antiplatelet therapy. Despite an initial worsening of clinical severity and an extensive ischemic lesion in both patients, neurologic function improved over time, eventually allowing recovery of unaided gait. Therefore, in the absence of signs of hemorrhage, intravenous thrombolysis or dual antiplatelet regimens could be considered in strokes related to middle cerebral artery dissection.

Endovascular Approach in Patients with Acute Complete Occlusion Due to Middle Cerebral Artery Dissection

Objective

Dissection of the middle cerebral artery (MCA) is less common than dissection of vessels in the vertebrobasilar system or carotid artery. Acute complete occlusion related to MCA dissection is extremely rare. We report an endovascular approach in patients with acute complete occlusion due to MCA dissection.

Methods

We reviewed retrospectively the endovascular procedure and clinical results for acute-stroke patients who underwent recanalization from October 2014 through December 2018. Initial imaging findings and the endovascular procedure were analyzed for patients with acute complete occlusion due to MCA dissection.

Results

We undertook first-line aspiration thrombectomy using a Penumbra catheter in 294 patients with acute occlusion of the M1 segment. Of these patients, seven were confirmed to have acute complete occlusion due to MCA dissection. All patients had angiographic findings of an intimal flap at the proximal occlusion site of the MCA. One patient complained of severe headache during microcatheter passage through the occluded lesion and died due to massive bleeding caused by rupture of the false lumen. The remaining patients underwent initial contact aspiration thrombectomy without microcatheter passage. After aspiration thrombectomy, six patients had delayed flow through the MCA. One patient underwent stenting of the MCA because of progressive symptoms.

Conclusion

An intimal flap at the proximal portion of an occluded MCA can suggest the possibility of MCA dissection. Contrast aspiration thrombectomy without microcatheter passage can reduce the risk of false lumen rupture in cases of MCA dissection.

Hemichorea-hemiballismus as the initial manifestation of symptomatic middle cerebral artery dissection: A case report

INTRODUCTION

Hemichorea-hemiballismus, which spans a spectrum of involuntary, continuous, nonpatterned movement involving one side of the body, can emerge as the initial manifestation of acute ischemic stroke. However, because of its rarity in the community, the diagnosis and treatment are often delayed.

PATIENT CONCERNS

We report a unique case of a 47-year-old female who presented with acute onset hemichorea-hemiballismus. No obvious focal sign apart from involuntary, continuous, nonpatterned movement of her left arm and leg was presented.

DIAGNOSIS

Initial diffusion-weighted magnetic resonance imaging (MRI) was negative but significant increase of blood flow velocity in the right middle cerebral artery (MCA) stem was revealed by transcranial doppler sonography. Repeated MRI showed acute infarction in the contralateral globus pallidus. Isolated dissection of the right MCA typified by intimal flap with double lumen was identified by digital subtraction angiography and high-resolution magnetic resonance imaging (HR-MRI).

INTERVENTIONS

The patient was initially treated with dual antiplatelet agents but the uncontrollable movement deteriorated during hospitalization. Antithrombotic therapy was then intensified with combination of tirofiban and low-molecular-weight heparin. Other symptomatic treatment included volume expansion with colloidal fluid to improve cerebral perfusion. Her involuntary movement gradually diminished and the patient was discharged with rivaroxaban 15 mg/daily.

OUTCOMES

The patient had recovered with significant reduction in her hemichorea-hemiballismus. Three-month follow-up HR-MRI showed complete resolution of the MCA dissection lesions.

CONCLUSION

Prompt recognition of acute onset hemichorea-hemiballismus as the manifestation of acute ischemic stroke in appropriate clinical setting may reduce diagnostic delay. Multiple imaging techniques including cerebral digital subtraction angiography and HR-MRI can be applied to diagnosis and further clarify the mechanism of stroke, which facilitate in selection of secondary prevention therapies.

Coil and Single-Stent Placement for Ruptured Dissecting Aneurysm of Middle Cerebral Artery: A Case Report

BACKGROUND

Ruptured dissecting aneurysms located at the middle cerebral artery (MCA) are rare, and their standard treatment has not been defined. Furthermore, lenticulostriate artery involvement in the dissecting segment makes treatment extremely difficult, and no previous reports have described successful treatment for such conditions.

CASE DESCRIPTION

We herein report the case of a 74-year-old woman who presented with sudden severe headache from subarachnoid hemorrhage due to dissection in the proximal M1 segment of left MCA involving lenticulostriate arteries. Digital subtraction angiography on day 6 showed that the dissecting aneurysm had enlarged despite strict blood pressure control. On day 8, the patient was treated successfully with a self-expanding closed cell stent and coil embolization, preserving blood flow in the lenticulostriate arteries as well as the MCA.

CONCLUSIONS

Follow-up digital subtraction angiography performed 5 weeks after endovascular therapy showed healing of the dissecting lesion, and the patient was discharged neurologically intact.

Endovascular Treatment in Ruptured Middle Cerebral Artery Dissection Preservation of Arterial Continuity

Rupture of spontaneous dissecting aneurysms of the middle cerebral artery (MCA) is rare and its etiology remains obscure, although the risk of rebleeding is greater than with saccular aneurysms. Most reports concerning the treatment of a ruptured dissecting aneurysm of the anterior circulation involve surgical trapping or wrapping. Here, we report on a case of an MCA dissecting rupture treated with endovascular procedures. A 22-year-old female presented with sudden stuporous mental change following severe headache and left side hemiparesis. A computed tomography scan showed a diffuse subarachnoid hemorrhage and diffusion MR showed diffusion restriction at the right putamen and internal capsule. A 3-hour follow-up digital subtraction angiography (DSA) showed a dissecting aneurysm, which was not seen on an initial DSA. A stent assisted coil embolization was performed and double stents were applied to achieve flow diversion effects. A small remnant area of the dissecting aneurysm had disappeared at 60-day and was not observed on 12-month follow-up DSA.

Republished: Monotherapy with stenting in subarachnoid hemorrhage (SAH) after middle cerebral artery dissection

Isolated middle cerebral artery dissection is a rare clinical entity, with descriptions limited to a few case reports and case series. Symptomatic dissection in the anterior circulation can present as an ischemic stroke in a young population; however, it is rarely associated with subarachnoid hemorrhage. We describe a young patient who presented with acute headache from a subarachnoid hemorrhage that was ultimately determined to be due to a vascular dissection in the middle cerebral artery. The initial angiogram showed vascular irregularities in this area with stenosis. Repeat imaging 4 days after presentation identified a pseudoaneurysm proximal to the stenosis. The patient was successfully treated with a self-expanding nitinol stent and followed up with serial angiography during postoperative recovery in the hospital; additional angiograms were performed approximately 1 and 6 months after treatment. Serial angiograms demonstrated incremental healing of the dissection. The patient was discharged and remains neurologically intact at the 6-month follow-up.

Monotherapy with stenting in subarachnoid hemorrhage (SAH) after middle cerebral artery dissection

Isolated middle cerebral artery dissection is a rare clinical entity, with descriptions limited to a few case reports and case series. Symptomatic dissection in the anterior circulation can present as an ischemic stroke in a young population; however, it is rarely associated with subarachnoid hemorrhage. We describe a young patient who presented with acute headache from a subarachnoid hemorrhage that was ultimately determined to be due to a vascular dissection in the middle cerebral artery. The initial angiogram showed vascular irregularities in this area with stenosis. Repeat imaging 4 days after presentation identified a pseudoaneurysm proximal to the stenosis. The patient was successfully treated with a self-expanding nitinol stent and followed up with serial angiography during postoperative recovery in the hospital; additional angiograms were performed approximately 1 and 6 months after treatment. Serial angiograms demonstrated incremental healing of the dissection. The patient was discharged and remains neurologically intact at the 6-month follow-up.

Pathological examination of a ruptured fusiform aneurysm of the middle cerebral artery

BACKGROUND

Little is known about the pathogenesis and clinical course of fusiform compared with saccular aneurysms. The case of a ruptured fusiform aneurysm accompanied by dissection at the M2 portion of the middle cerebral artery (MCA) is reported, along with pathological findings.

CASE DESCRIPTION

A 41-year-old female presenting with subarachnoid hemorrhage was revealed to have a ruptured fusiform aneurysm at the M2 portion of the right MCA on angiography. She was treated with superficial temporal artery-MCA anastomosis and trapping of the aneurysm. The aneurysm consisted of a whitish fusiform dilatation with a thickened wall of the MCA and two red protrusions on it. Pathological examinations revealed disruption and fragmentation of the internal elastic lamina and intimal thickening in the fusiform lesion. There were two aneurysmal protrusions on the main fusiform dilatation. In one protruded lesion, a dissection of the intima was observed.

CONCLUSION

We propose that a dissection and saccular aneurysm additionally developed on the wall of a preexisting segmental ectasia of the MCA in our case. In this report, we discuss the etiology of fusiform aneurysms of the MCA.

Management of ruptured dissecting intracranial aneurysms in infants: report of four cases and review of the literature

BACKGROUND

Intracranial cerebral aneurysms in the pediatric population are infrequent, and those occurring in infants less than 1 year old are extremely rare. Of intracranial aneurysms in children, dissecting aneurysms are the most common type seen. While spontaneous dissecting aneurysms usually present with ischemia, hemorrhage can also occur.

METHODS

A retrospective review of our patients revealed that from July 1, 2007 to June 30, 2012, four infants were treated for ruptured distal dissecting intracranial aneurysms at Texas Children's Hospital. Mycotic aneurysms and collagen vascular disorder were excluded in all four cases. All patients presented in our series presented with subarachnoid hemorrhage, and three had intraventricular hemorrhage. All patients underwent conventional catheter angiography for diagnosis. All patients in this series were managed in the acute or subacute period with surgical or endovascular trapping without distal bypass procedures. All four patients tolerated sacrifice of the parent vessels feeding these distal aneurysms well.

CASE REPORT AND REVIEW OF LITERATURE

We describe the presentation and management of these rare cases and then review the current literature on the management of these dissecting aneurysms in infants.

Peri-stent aneurysm formation following a stent implant for stenotic intracranial vertebral artery dissection: a technical report of two cases successfully treated with coil embolization

INTRODUCTION

Although stenting for stenotic vertebral artery dissection (VAD) improves compromised blood flow, subsequent peri-stent aneurysm (PSA) formation is not well-known. We report two cases with PSA successfully treated with coil embolization.

METHODS

Three patients with stenotic intracranial VAD underwent endovascular angioplasty at our institution because they had acute infarction in posterior circulation territory and clinical evidence of hemodynamic insufficiency. In two of three patients balloon angioplasty at first session failed to relieve the stenosis, and a coronary stent was implanted. Angiography immediately after stenting showed no abnormality in case 1 and minimal slit-like projection at proximal portion of the stent in case 2.

RESULTS

Angiography obtained 16 months after the stenting revealed PSA in case 1. In case 2, angiography performed 3 months later showed that the projection at proximal portion enlarged and formed an aneurysm outside the stent. Because follow-up angiographies showed growth of the aneurysm in both cases, endovascular aneurysmal embolization was performed. We advanced a microcatheter into the aneurysm through the strut of existing stent and delivered detachable coils into the aneurysm lumen successfully in both cases. The post-procedural course was uneventful, and complete obliteration of aneurysm was confirmed on angiography in both cases.

CONCLUSION

Stenting for stenotic intracranial VAD may result in delayed PSA; therefore, follow-up angiographies would be necessary after stenting for stenotic intracranial arterial dissection. Coil embolization through the stent strut would be a solution for enlarging PSA.

Management of middle cerebral artery dissecting aneurysm

BACKGROUND

Dissecting aneurysms of the intracranial carotid circulation were previously thought to occur primarily in young people presenting with cerebral infarction caused by arterial stenosis and occlusion. The appropriate management of dissecting aneurysms in the anterior circulation remains controversial, especially in patients who also present with cerebral infarction. However, recent studies have reported better outcomes for patients with middle cerebral artery (MCA) dissecting aneurysms involving surgically treated subarachnoid hemorrhage (SAH). The purpose of this study is to describe a case of spontaneous SAH from rupture of a dissecting aneurysm in the M2 segment observed in a 79-year-old man with no sign of an ischemic neurological deficit, and also to review the clinical and radiological features of cases reported since 1990.

METHODS

Our review of the literature identified 24 cases of MCA dissecting aneurysms after 1990.

RESULTS

Of the patients in these cases, 15 (63%) presented with pure bleeding and 7 (29%) with ischemia, and two were detected incidentally. Our review also found that the outcome of patients presenting with pure bleeding differed from those with ischemia. Patients with an MCA dissecting aneurysm who presented with pure bleeding showed better outcomes if they had surgery than if they did not. In contrast, the appropriate management of patients with a dissecting aneurysm who present with ischemia remains controversial.

CONCLUSION

Our review found that the clinical course of patients presenting with ischemia differed from that of patients presenting with pure bleeding. Most of the patients with ischemia underwent progressive deterioration. However, while the outcome for patients with ischemia treated surgically was relatively good, it remained poor compared to the outcome for patients who had been bleeding.

The new MRI modalities "BPAS and VISTA" for the diagnosis of VA dissection

OBJECTIVE

Recently VA dissection has drawn attention as a relatively common cause of stroke because of the introduction of MRI as a diagnostic technique. Basiparallel anatomic scanning (BPAS) was designed to visualize the surface appearance of the vertebrobasilar artery within the cistern. Volumetric isotropic TSE acquisition (VISTA) is a sort of black blood imaging method to evaluate the arterial wall and lumen. In this study, we aimed to evaluate the efficacy of the new MRI modalities "BPAS and VISTA," and to present a retrospective analysis of our experience with the diagnosis.

MATERIALS AND METHODS

Between1995 and 2010, we experienced 24 cases of VA dissection at our institution. In our cases, we could obtain images of 15 in BPAS and VISTA in addition to MRA. The mean age of the 15 patients (12 male and 3 female) was 51 years old (range 18-80). Ten of fifteen patients presented with ischemia, and 5/15 with only headache. There were no cases of SAH. In BPAS, we evaluated dilatation of the external diameter of the affected artery. We compared the findings in BPAS with MRA to evaluate the discrepancy. In VISTA, we evaluated its capability to distinguish intramural hematoma.

RESULT

Thirteen of fifteen patients presented with dilatation of the external diameter on BPAS. By comparing the findings in BPAS with MRA, we found a discrepancy in 8/15 cases (53%). We could detect intramural hematoma by using VISTA in 9/15 cases (60%). Thirteen of fifteen patients received follow-up MRI. Temporal change of the arterial shape was confirmed in 7/13 cases (53.8%).

CONCLUSION

Dilatation of the external diameter was shown highly frequently in VA dissections. In addition, a discrepancy between BPAS and MRA as well as the intramural hematoma on VISTA was found comparatively frequently. BPAS and VISTA are minimally invasive and useful methods as screening tests.

Dilated outer diameter of the dissected artery: acute bilateral anterior cerebral artery dissection evaluated by repeat magnetic resonance cisternography. Case report

A 42-year-old male patient presented with an anterior cerebral artery (ACA) dissection manifesting as sudden onset of severe headache. Initial computed tomography revealed faint subarachnoid hemorrhage in the frontal region. Initial angiography showed tapering stenosis at the A(2) segment of right ACA. The patient was admitted to our hospital and treated conservatively. Magnetic resonance (MR) imaging and angiography did not detect intramural hematoma, intimal flap, or double lumen at the stenotic right A(2) segment. The ACA dissection was difficult to confirm based on the findings on day 0. ACA dissection was confirmed by improvement of the right ACA stenosis on follow-up angiography on day 14. On the other hand, MR cisternography revealed a fusiform dilatation of the vascular outer contour at the right A(2) on day 0, which had resolved on day 14. Cerebral angiography and MR cisternography similarly suggested asymptomatic contralateral (left) A(2) dissection on day 14. Fusiform dilatation of the vascular outer contour at the affected segment on MR cisternography may be indicative of arterial dissection in the acute phase.

Spontaneous intra-cranial arterial dissection frequently causes anterior cerebral artery infarction

BACKGROUND AND PURPOSE

Spontaneous intra-cranial arterial dissection (SICAD) without history of head and neck injury is now recognized as an important cause of stroke. However, the frequency of SICAD involving the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) territories remains unclear. This study therefore investigated the distribution of SICAD.

METHODS

Subjects comprised 194 patients (126 men, 68 women; median age, 68.0 years) with infarct isolated to the ACA, MCA or PCA territories who underwent conventional angiography. Diagnosis of SICAD was based on clinical and neuroradiological findings. Frequency of SICAD was compared among ACA, MCA, and PCA infarcts. All patients were divided into SICAD and non-SICAD groups, and clinical characteristics were compared between groups.

RESULTS

Infarcts involved the ACA in 14 cases (7.2%), MCA in 165 cases (85.1%), and PCA in 15 cases (7.7%). SICAD was diagnosed in 17 of 194 cases (8.8%), with cerebral angiography showing main findings of the string sign in 11 patients (64.7%), the pearl and string sign in 6 patients (35.3%), and pseudoaneurysm formation in 2 patients (11.7%). SICAD most frequently involved the ACA (ACA, 64.3%; MCA, 4.2%; PCA, 6.7%; P<0.001).

CONCLUSION

SICAD was seen in 64.3% of patients with ACA infarct. The mechanisms of ACA infarction may thus differ from those of MCA and PCA infarction.

Ruptured dissecting cerebral aneurysms in young people: report of three cases

Intracranial arterial aneurysms in the pediatric population are rare. Among these, dissecting aneurysms are the most frequent, followed by saccular, infectious, and posttraumatic. It is widely known that aneurysmal rupture is uncommon in the first two decades of life. Spontaneous dissecting aneurysms (SDAs) of the middle cerebral artery (MCA) affecting young individuals most frequently present as occlusive syndrome with ischemia, although bleeding and subarachnoid hemorrhage can also occur. Between March 2006 and January 2008, three young patients (20 months, 8 and 20 years old) were surgically treated for MCA SDA in the Neurosurgical Department of "12 de Octubre" Hospital of Madrid. These patients showed hemorrhage as primary radiological finding, and all of them underwent surgical operation. Aneurysms were always treated by trapping, with aneurysmectomy in one case, but no distal extra-intracranial (EC-IC) bypass was performed. In two cases, the histological examination of the aneurysm's wall evidenced signs of subintimal dissection with widespread disruption of the internal elastic lamina and media with neointima formation and intramural hemorrhage. Although bleeding is an uncommon presenting sign of SDAs, they should be suspected in young people showing hemorrhage at CT scan. Early surgical treatment and, if possible, preoperative neuroimaging evaluation of intracranial vessels should be performed to reduce the mortality in these patients despite a higher postoperative morbidity. From a technical point of view, surgical trapping of the aneurysm seems to be a reasonable treatment strategy especially in an emergency basis. However, whenever possible, an EC-IC bypass could help diminish the ischemic morbidity associated with these aneurysms.

Diagnostic characteristics and management of intracranial aneurysms in children

Childhood aneurysms have special characteristics different from adults' aneurysms. Their features were found to significantly differ from aneurysms in adults especially in their gender prevalence, location, morphology and underlying etiology. Treatment options include both surgical and endovascular methods. Whenever possible, endovascular treatment for pediatric aneurysms is the recommended approach, since it offers both reconstructive and deconstructive techniques, durable results and better clinical outcome.

3T MRI - 3D DSA Fusion Technique on Posterior Cerebral Artery Dissecting Aneurysm: Understanding a Potential Pathophysiologic Mechanism

SUMMARY

We aimed to show the anatomical relationship between a dissecting aneurysm of the posterior cerebral artery (PCA) and tentorial free edge to understand the pathophysiologic mechanism. A 52-year-old woman with a history of head trauma presented with dizziness and numbness in her left fingers. 3D DSA showed a dissecting aneurysm of the right P2-P3 segment of PCA. The fusion of 3D DSA and 3T MRI was performed at the dedicated workstation using three pairs of landmarks including the ICA termination, MCA bifurcation and A1-A2 junction of the right ACA. Fusion of 3D DSA and 3T MRI clearly demonstrated the dissected segment of PCA crossed the tentorial free edge twice. The fusion images support the direct trauma hypothesis of dissecting aneurysm of the P2-P3 segment of PCA. This novel imaging technique shows future potential to be used to understand the anatomical relationships between various vascular lesions and surrounding structures.

Two cases of spontaneous middle cerebral arterial dissection causing ischemic stroke

Spontaneous middle cerebral arterial dissection (MCAD) is a rare cause of ischemic stroke. We report two cases of isolated spontaneous MCAD causing ischemic stroke. MCAD should be considered when a young patient has a middle cerebral artery territory infarct with stenosis at the origin of the middle cerebral artery. We discuss noninvasive radiological techniques for the diagnosis of MCAD.

The role of endovascular treatment for pediatric aneurysms

OBJECTIVES

To review all cases of pediatric aneurysms, we treated and evaluated their characteristics. The objective of the study is to compare between surgical and endovascular approaches regarding treatment and outcome.

METHODS

All cases of pediatric intracranial aneurysms diagnosed and managed by our team in the last 12 years were prospectively collected in our vascular malformation data base and reviewed.

CONCLUSION

Pediatric aneurysms differ in their features when compared to adult aneurysms. Over the last years, there has been a gradual shift from traditional surgical approaches towards endovascular treatment of pediatric aneurysms. In our experience, patients treated by endovascular means had a better outcome than when treated by surgery. Whenever possible, endovascular treatment for pediatric aneurysms is the recommended approach. This offers both constructive and deconstructive techniques. Improved understanding with respect to the etiology of pediatric aneurysms will be the next step that will likely lead us to even better treatment decisions.

Aneurysms in Twig-Like Middle Cerebral Artery

BACKGROUND

We report a vascular abnormality of the middle cerebral artery (MCA) that has not been described in the literature before.

METHODS

Two patients (1 male and 1 female; age 44 and 67 years, respectively) were found to have a vascular abnormality in which the main trunk of the MCA had a twig-like form. Both patients presented with intracranial hemorrhage.

RESULTS

In these 2 patients, the abnormality was seen before the genu of the MCA. They had an intracranial hemorrhage due to an associated aneurysm inside the twigs. The twig appeared to be a network between the bifurcation of internal carotid artery and insular segment of MCA, and it was different from the collateral circulation due to acquired occlusion or moyamoya disease.

CONCLUSION

This new type of vascular lesion of the MCA is not benign. It appears to be associated with the occurrence of an aneurysm, an important clinical aspect.