Symptomatic spontaneous vertebrobasilar dissections in children: review of 29 consecutive cases

Vessel Wall Imaging Features of Spontaneous Intracranial Carotid Artery Dissection

BACKGROUND AND OBJECTIVES

Intracranial dissection is an important cause of stroke often with nonspecific angiographic features. Vessel wall imaging (VWI) can detect dissections, but intracranial applications remain unvalidated by pathologic specimens. We sought to determine the ability of VWI to identify the rarely reported spontaneous intracranial carotid dissection (sICD) guided by postmortem validation.

METHODS

VWI features of sICD, validated by postmortem specimen analysis in 1 patient, included luminal enhancement within a hypoenhancing outer wall, narrowing the mid to distal ophthalmic (C6) segment, relatively sparing the communicating (C7) segment. VWI examinations were reviewed to identify patients (1) with matching imaging features, (2) no evidence of other vasculopathies (i.e., inflammatory, intracranial atherosclerotic disease [ICAD]), and (3) adequate image quality. These sICD VWI features were compared with those in patients with known ICAD causing similar narrowing of C6 and relative sparing of C7 by a Fisher exact test accounting for multiple samples.

RESULTS

Among 407 VWI examinations, 8 patients were identified with 14 sICDs, all women aged 30-56 years, 6 (75%) bilateral. All patients with sICD had risk factors of dissection (e.g., recently postpartum, fibromuscular dysplasia, and hypertension) and 3 (37.5%) had intracranial dissections elsewhere. Seven (87.5%) were diagnosed as moyamoya syndrome on initial angiography. Enhancing lesions varied from thin flap-like defects (n = 6) to thick tissue along the superolateral wall of the internal carotid artery, within the hypoenhancing outer wall. Compared with 10 intracranial carotid plaques in 8 patients with ICAD, sICD demonstrated stronger (84.6% vs 20.0%, p = 0.003-0.025) and more homogeneous (61.5% vs 0.0%, p = 0.005-0.069) enhancement and less positive remodeling (0.0% vs 60.0%, p = 0.004-0.09). T1 hyperintensity was identified in 5 sICDs in 3 patients but not identified in ICAD. Three patients with serial imaging (8- to 39.8-month maximum intervals) revealed little to no changes in stenosis, wall thickening, or enhancement.

DISCUSSION

sICD is distinguishable on VWI from ICAD by enhancement characteristics, less positive remodeling, and clinical parameters. These VWI features should raise suspicion especially in young women with risk factors of dissection. Temporal stability and a lack of T1 hyperintensity should not discourage diagnosing sICD.

Imaging of Vertebral Artery Dissection in Children: An Underrecognized Condition with High Risk of Recurrent Stroke

Vertebral artery dissection (VAD) is a common cause of a rare condition, pediatric posterior circulation arterial ischemic stroke (PCAIS). VAD is clinically important due to the risk of multifocal and continuing infarcts from artery-to-artery thromboembolism, with the potential for occlusion of arteries that perfuse the brainstem. Early diagnosis is important, as recurrent stroke is a common effect of VAD in children. Although the relative efficacies of different treatment regimens for VAD in children remain unsettled, early initiation of treatment can mitigate the risk of delayed stroke. Clinical diagnosis of PCAIS may be delayed due to multiple factors, including nonspecific symptoms and the inability of younger patients to express symptoms. In fact, subacute or chronic infarcts are often present at initial imaging. Although the most common cause of isolated PCAIS is VAD, imaging of the cervical arteries has been historically underused in this setting. Cervical vascular imaging (MR angiography, CT angiography, and digital subtraction angiography) for VAD must be optimized to detect the sometimes subtle findings, which may be identified at initial or follow-up imaging. Osseous variants of the craniocervical junction and upper cervical spine and other extrinsic lesions that may directly injure the vertebral arteries or lead to altered biomechanics have been implicated in some cases. The authors review characteristic imaging features and optimized imaging of VAD and associated PCAIS and related clinical considerations. Identification of VAD has important implications for evaluation, treatment, and imaging follow-up, as this condition may result in progressive arteriopathy and recurrent stroke. © RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Vertigo and dizziness in children: When to consider a neurological cause

Vertigo is common in childhood and adolescence. Although children and adults share common causes of vertigo, epidemiology changes with aging. For instance, ischemic stroke is less frequent in childhood, whereas audiovestibular disorders, such as vestibular neuritis and the migraine equivalent, are the leading causes of vertigo. However, even if severe causes of vertigo are rare, clinicians must not miss them. In this review, we discuss the neurological causes of central vertigo in children. The diagnostic approaches reviewed here are focused on the search for signs of severity, such as an abrupt onset, infectious context, or intracranial hypertension, which may subsequently require brain imaging.

Complete functional recovery in a child after endovascular treatment of basilar artery occlusion caused by spontaneous dissection: a case report

Stroke caused by dissection of arteries of the vertebrobasilar system in children is still poorly investigated in terms of etiology, means of treatment, course of disease, and prognosis. The aim of this report was to describe the unusual course of a spontaneous dissection of the basilar artery (BA) in a child treated with endovascular techniques and to point out that the plasticity of the brain stem can fully compensate for structural damage caused by stroke. We report the case of a 15-year-old boy who suffered a wake-up stroke with BA occlusion caused by spontaneous dissection. A blood clot was aspirated from the false lumen and the true lumen re-opened, but the patient deteriorated a few hours later, and repeated angiography revealed that the intimal flap was detached, occluding the BA again. The lumen of BA was then reconstructed by a stent. Despite a large pons infarction, the patient was completely recovered 11 months after the onset. The case was analyzed with angiograms and magnetic resonance imaging, macroscopic and microscopic pathological analysis, computed tomographic angiography, magnetic resonance-based angiography, and diffusion tensor imaging. This case illustrates that applied endovascular techniques and intensive care measures can alter the course of potentially fatal brain stem infarction. Our multimodal analysis gives new insight into the anatomical basis for the plasticity mechanism of the brain stem.

Craniocervical Arterial Dissection in Children: Pathophysiology and Management

BACKGROUND

Craniocervical arterial dissection is a commonly reported arteriopathy associated with stroke in children. It is characterized by a high stroke recurrence rate and variable outcomes. Here we review the pathophysiology, clinical presentation, and diagnostic neuroimaging approaches that are helpful in accurate diagnosis and follow-up of children with arterial dissection.

METHODS

MEDLINE searches (2000 to 2018) for articles that contained patients aged less than 18 years with craniocervical arterial dissection was performed, with the goal of analyzing their presenting features, pathophysiological mechanisms, and imaging characteristics and interventions.

RESULTS

Sixteen articles met the study criteria and reported 182 cases of craniocervical arterial dissection, 68% male, average age 8.6 years. Dissection was associated with head and neck trauma in 56% of the cases and frequently involved the posterior (61%) and extracranial locations (64%); the vertebral artery was the most commonly involved artery (60%). The most common clinical presentation was hemiparesis (80/160, 50%), followed by headache (64/164, 39%). Magnetic resonance imaging was the preferred neuroimaging method, followed by cerebral catheter angiography as a gold standard definitive neurovascular imaging modality when the initial vascular imaging revealed nondiagnostic findings.

CONCLUSIONS

The diagnosis of arterial dissection requires a high index of suspicion and consideration for detailed neurovascular imaging, including both the cranial and cervical regions. Neurovascular imaging challenges, especially visualization of arterial abnormalities, highlight the importance of appropriate and timely use of specific neurovascular imaging techniques. Magnetic resonance imaging appears to be the preferred neurovascular imaging modality in children with arterial dissection and may obviate the need for invasive cerebral catheter angiography.

Pediatric Stroke Imaging

BACKGROUND

Pediatric stroke is a distinct clinical entity as compared with that in adults due to its unique and diverse set of etiologies. Furthermore, the role and application of diagnostic imaging has specific constraints and considerations. The intention of this article is to review these concepts in a thorough manner to offer a pediatric stroke imaging framework that providers can employ when taking care of these patients.

METHODS

A comprehensive primary and secondary literature review was performed with specific attention to the common causes of pediatric stroke, appropriate use of neuroimaging, specific imaging findings, and developing techniques which may improve our ability to accurately diagnose these patients.

RESULTS

Findings from this literature review were synthesized and summarized in order to thoroughly review the aforementioned concepts and outline the current consensus-based approach to diagnostic imaging in pediatric stroke. Furthermore, imaging findings drawn from patients seen in our institution are demonstrated to familiarize readers with pediatric stroke neuroimaging.

CONCLUSIONS

The challenges posed by pediatric stroke can be mitigated, in part, by the thoughtful application of diagnostic imaging, with the ultimate hope of improving outcomes for these vulnerable patients.

Treatment for Spontaneous Intracranial Dissecting Aneurysms in Childhood: A Retrospective Study of 26 Cases

OBJECTIVE

This study aimed to assess the clinicoradiological features and treatment outcomes of intracranial dissecting aneurysms (IDAs) in childhood.

METHODS

We conducted a retrospective study of pediatric patients who were treated for spontaneous IDAs in our institute between January 2010 and December 2015. The clinical presentation, aneurysm characteristics, treatment modality, and outcome were studied.

RESULTS

We studied 26 pediatric patients (mean age, 13.4 years; range, 4-18 years) with 31 IDAs who comprised 6.9% of all IDA patients treated during the same period. Seventeen (65.4%) patients were males, and nine (34.6%) were females. The incidence of large (≥10 mm in size) or giant aneurysms (≥25 mm in size) was 65.5%. Twenty-one (80.8%) patients underwent endovascular or surgical treatment and five (19.2%) received conservative treatment. Perioperative complications occurred in three patients, in whom two eventually recovered completely with a Glasgow Outcome Scale (GOS) score of 5 and one partially recovered with a GOS score 4. Overall, 25 (96.2%) patients had a favorable outcome and one (3.8%) had an unfavorable outcome at a mean follow-up of 22.8 months (range, 6-60 months).

CONCLUSION

Pediatric IDAs are rare. In this series, endovascular management was a relatively safe and effective method of treatment for pediatric IDAs. However, continued follow-up is required because of the possibility of aneurysm recurrence and de novo aneurysm formation after treatment.

The insidious appearance of the dissecting aneurysm: Imaging findings and related pathophysiology. A report of two cases

Intracranial dissecting aneurysms have been frequently reported to present with fairly challenging and time-variable imaging findings that can be mostly explained by the pathological mechanisms that underline the dissection. We present two cases of spontaneous dissecting aneurysm of the supraclinoid ICA, both clinically presenting with SAH, but characterized by different progression of clinical symptoms and imaging. However, in both cases an outpouch and a mild fusiform dilation of the supraclinoid ICA was present in the initial CTA performed after the occurrence of symptoms. These findings were well depicted by the MPR reformats performed retrospectively. We postulate that this finding may represent the point of initial transmural dissection and we recommend that careful analysis of the CTA MRP reformatted images should be performed in order to detect this finding promptly.

Vascular disease

The child presenting with possible sentinel transient ischemic event or stroke requires prompt diagnosis so that strategies to limit injury and prevent recurrent stroke can be instituted. Cerebral arteriopathy is a potent risk factor for arterial ischemic stroke in childhood. Though acute imaging study in the setting of possible stroke is often a head computed tomography, when possible magnetic resonance imaging (MRI) is recommended as the first-line study as confirmation and imaging evaluation of ischemic stroke will typically require MRI. The MRI scanning approach should include diffusion-weighted imaging (DWI) early in the sequence order, since normal DWI excludes acute infarct with rare exception. In most cases, arterial imaging with time-of-flight (TOF) magnetic resonance angiography (MRA) is warranted. Dedicated MRA may not be possible in the acute setting, but should be pursued as promptly as possible, particularly in the child with findings and history suggestive of arteriopathy, given the high risk of recurrent stroke in these children. MRA can overestimate the degree of arterial compromise due to complex/turbulent flow, and be insensitive to subtle vessel irregularity due to resolution and complex flow. In cases with high imaging suspicion for dissection despite normal MRA findings, catheter angiogram is indicated. A thoughtful, stepwise approach to arterial neuroimaging is critical to optimize diagnosis, treatment, and primary and secondary prevention of childhood stroke.

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

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

Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection

Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.

Evolution of a chronic dissecting aneurysm on magnetic resonance imaging in a pediatric patient

Clinical and imaging manifestations of the so-called partially thrombosed aneurysm (PTA) are different from those of the classic intracranial saccular aneurysm. Given some of their peculiar imaging features, it had been hypothesized that some PTAs occur due to repeated intramural hemorrhages. The authors present a case of PTA that evolved from an acute dissecting aneurysm as shown by serial imaging. A previously healthy 5-year-old boy had a sudden onset of left hemiparesis. Initial MRI sequences showed a perforating vessel infarction in the right basal ganglia area secondary to an acute distal middle cerebral artery (MCA) dissection as demonstrated on conventional angiography. Conservative management with close observation of this dissection was chosen, and serial MRI studies revealed layering of blood of various ages within the wall of an aneurysmal outpouching of the MCA, thereby leading to the imaging appearance of a PTA. The findings in this case indicate that some PTAs may be caused by repeated or chronic dissections, with blood entering the wall through an endothelial defect. Understanding the pathological mechanism underlying the formation of these aneurysms will help inform appropriate treatment strategies.

A vertebral artery dissection with basilar artery occlusion in a child

This paper presents the case report of an 11-year-old boy with an acute dissection with thrombosis of the left vertebral artery and thrombosis of the basilar artery. The patient was treated with acute systemic thrombolysis, followed by intra-arterial thrombolysis, without any clinical improvement, showing left hemiplegia, bilateral clonus, hyperreflexia, and impaired consciousness. MRI indicated persistent thrombosis of the arteria basilaris with edema and ischemia of the right brainstem. Heparinization for 72 hours, followed by a two-week LMWH treatment and subsequent oral warfarin therapy, resulted in a lasting improvement of the symptoms. Vertebral artery dissection after minor trauma is rare in children. While acute basilar artery occlusion as a complication is even more infrequent, it is potentially fatal, which means that prompt diagnosis and treatment are imperative. The lack of class I recommendation guidelines for children regarding treatment of vertebral artery dissection and basilar artery occlusion means that initial and follow-up management both require a multidisciplinary approach to coordinate emergency, critical care, interventional radiology, and child neurology services.

Radiological changes in infantile dissecting anterior communicating artery aneurysm treated endovascularly. A case report and five-year follow-up

Intracranial aneurysms are extremely rare in infants, and to our knowledge only seven infants treated for ruptured spontaneous dissecting aneurysms have been reported. Good outcomes have been achieved with endovascular treatment of infantile aneurysm. We the endovascular treatment of a one-month-old girl for ruptured dissecting aneurysm located in the anterior communicating artery, and the unique radiological changes that were observed during the perioperative and follow-up periods. These changes suggest that blood coagulation and fibrinolytic response play a part in the repair and healing processes of dissecting aneurysms. Careful neuroradiological surveys are needed for pediatric dissecting aneurysms treated endovascularly.

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.

Ruptured dissecting vertebrobasilar aneurysm in childhood: what is the therapeutic strategy?

BACKGROUND/AIMS

Pediatric aneurysms are rare, accounting for 0.5-4.6% of all intracranial aneurysms. Dissecting vertebrobasilar aneurysms (DVBA) are more frequently observed among children than adults. Cases acutely presenting with subarachnoid hemorrhage need a prompt treatment because of the higher mortality related to untreated cases. Options for an active DVBA management depend on the features of the malformation and include endovascular and surgical approaches.

METHODS

We refer to an 8-year-old healthy female, who presented with a sudden severe headache and vomit, followed by a half-hour loss of consciousness. A CT scan revealed subarachnoid hemorrhage, and brain MR angiography showed a lesion with mass effect on bulbar structures, suggestive of an aneurysm of the vertebrobasilar junction. The intracranial angiography confirmed this diagnosis and showed a relevant revascularization coming from the anterior cerebral circulation.

RESULTS

Endovascular treatment was considered as a suitable option and occlusion of both vertebral arteries, saving the left posterior inferior cerebellar artery, was performed. No neurological deficits appeared after embolization, and the patient was clinically stable at 18 months of follow-up.

CONCLUSION

In the 'stent era', parent vessel deconstruction throughout endovascular balloon or coil occlusion could be considered in patients with a sound collateral circulation and when cerebellar hemisphere and encephalic trunk feeding is not compromised.

The many faces of intracranial arterial dissections

Intracranial arterial dissecting diseases are rare and challenging diseases with a high associated morbidity and mortality. Their common pathomechanic origin is related to blood entering the vessel wall via an endothelial and intimal tear. Depending on the fate of the thus established intramural hematoma, different symptoms may ensue including mass effect, subarachnoid hemorrhage or ischemia. If the mural hematoma ruptures all vascular layers of the intradural artery, a subarachnoid hemorrhagic will occur. If the intramural hematoma reopens distally into the parent vessel on the other hand, ischemic embolic events may happen following intramural clot formation. If the mural hematoma does neither open itself into the parent vessel nor into the subarachnoid space, the vessel wall may dilate leading to occlusion of perforator branches and local ischemia. Organization of the mural hematoma may result in a chronic dissecting process which may eventually lead to formation of a "giant partially thrombosed" aneurysm with thrombus of varying ages within the vessel wall, ingrowth of vasa vasorum and recurrent dissections with subsequent growth of the aneurysm from the periphery. Treatment strategies of these diseases should take the underlying pathomechanism into consideration and include, depending on the presentation medical treatment, parent vessel occlusion, flow reversal or diversion, surgical options or a combined treatment protocol.