Cerebrovascular arterial dissection in children and young adults

Quantitative Analysis Using High-Resolution 3T MRI in Acute Intracranial Artery Dissection

BACKGROUND AND PURPOSE

Quantitative measurements, as well as qualitative characterizations, of the vessel walls of the small intracranial arteries became clinically available and reliable beyond the resolution limit of 1.5 T high-resolution magnetic resonance imaging (HR-MRI) with the development of 3 T HR-MRI. We present the quantitative dissection findings of spontaneous and unruptured acute intracranial artery dissection (SID) using 3 T HR-MRI and investigate the differences between each cerebral artery.

METHODS

Twenty-eight lesions (anterior cerebral artery = 6; middle cerebral artery = 4; vertebral artery = 18) from 26 patients (17 male and 9 female patients; mean age = 47 years; age range = 32-74 years) with presumptive diagnoses of SID were included. The diagnosis was determined based on the clinical features, findings on luminal angiography (such as digital subtraction angiography, computed tomography, or magnetic resonance angiography), and HR-MRI. HR-MRI was performed within one month from onset. The neuroimaging indices (maximal outer diameter and area, remodeling index and modified remodeling index, and wall thickness and wall area index) of aneurysmal dilatation and the signal intensities of the intramural hematomas were rated using HR-MRI. The results were compared between each cerebral artery.

RESULTS

The maximal outer diameter and area, remodeling index and modified remodeling index, and wall thickness index and length were significantly different between anterior and posterior circulation (P < .05). The mean relative signal intensities of the intramural hematoma showed consistent values, regardless of the cerebral arteries, without significant difference.

CONCLUSIONS

Neuroimaging indices of aneurysmal dilatation may be adjunctive indicators in the evaluation of SID.

Management of pediatric craniocervical arterial dissections

PURPOSE

Craniocervical arterial dissections (CCADs) represent a preventable cause of acute ischemic stroke (AIS). Our objective was to describe clinical presentation, imaging features, treatment strategies, and report clinical and imaging outcomes of CCADs at a large pediatric tertiary referral center.

METHODS

Electronic medical records were queried using variations of the word dissection for patients under 25 years of age with neuroimaging over a 13-year period. Medical and imaging records were reviewed to identify carotid, vertebral, or intracranial dissections. Demographics, presenting symptoms, presence of AIS, mechanism of injury, dissection location, dissection treatment, and complications stemming from treatment were collected. Clinical outcome was classified according to modified Rankin Scale (mRS) score. Imaging follow-up was obtained until the dissection healed or stabilized.

RESULTS

A total 6,289 patients met initial search criteria. Of the 42 (0.7%) patients with CCADs, 23 (54.8%) had internal carotid artery (ICA) dissections, and 17 (40.5%) had vertebrobasilar (VB) dissections. More females had ICA dissections (p = 0.002), and more males had VB dissections (p = 0.01). CCADs associated with traumatic presentation occurred in 34 patients (81.0%), while 8 (19.0%) were spontaneous. Good outcomes (mRS 0-3) were noted for 36 patients, and 5 had poor outcomes (mRS 4-6). In the 17 patients with vessel occlusion, 50.0% had partial or complete recanalization at a mean follow-up of 23.9 months.

CONCLUSIONS

CCAD is commonly related to trauma and presents with AIS. The majority of patients experience good clinical outcome. Recanalization of initial vessel occlusion occurs in half of cases at 2 years.

Posttraumatic carotid artery dissection in children: not to be missed!

BACKGROUND

Post-traumatic carotid artery dissection (PTCAD) may result in acute arterial ischemic stroke (AIS). Pediatric PTCAD is rarely diagnosed prior to onset of neurological symptoms. We report on neuroimaging findings in a series of children with PTCAD.

METHODS

Five children with head or neck trauma were included in this study. Clinical histories were reviewed for mechanism of trauma, symptoms, complications, therapy, and outcome. Computed tomography (CT), magnetic resonance imaging (MRI), and CT/MR angiography (CTA, MRA) studies were retrospectively evaluated for signs and complications of PTCAD and presence and extent of skull base fractures.

RESULTS

PTCAD was located at the level of the skull base in all children and was associated with a skull base fracture in two. The diagnosis was made in five children by combined MRI/MRA and in two by CTA. Air in the carotid canal suggested skull base injury with PTCAD in two children. PTCAD was complicated by AIS in three children.

CONCLUSION

PTCAD may result from neck and head trauma. To avoid secondary AIS, radiologists should be familiar with neuroimaging findings in children, especially as acute PTCAD may initially be clinically silent. Consequently, pediatric neuroradiologists should actively exclude PTCAD in children with head and neck trauma.

Stent placement for the treatment of a symptomatic intracranial arterial dissection in an adolescent

Intracranial arterial dissection is an important cause of stroke in young patients. Treatment options include observation, antiplatelet or anticoagulation regimens, and endovascular stent placement. The authors describe the case of a 14-year-old boy who presented with a symptomatic, posttraumatic dissection extending from the intracranial internal carotid artery to the middle cerebral artery. Images obtained approximately 48 hours after this incident revealed a subacute right frontal lobe infarct, and a CT stroke study (CT angiography and CT perfusion) confirmed the vascular injury and associated decreased perfusion, prompting revascularization with a self-expanding stent. The patient did well clinically after stent placement and showed no evidence of restenosis on follow-up angiography 3 and 6 months later. This report is, to the authors' knowledge, the first description of the use of a stent for a symptomatic intracranial dissection in an adolescent.

Late complications of vertebral artery dissection in children: pseudoaneurysm, thrombosis, and recurrent stroke

Craniocervical arterial dissection is an important cause of childhood arterial ischemic stroke, accounting for 7.5% to 20% of cases. Significant neurologic morbidity and mortality may result and recurrence risk may be higher than in adults. However, the natural history and long-term outcome of pediatric dissection are poorly studied. We report 3 cases of extracranial vertebral artery dissection with complications including pseudoaneurysm formation, recurrent stroke, and late spontaneous thrombosis of the dissected artery. These cases illustrate the dynamic processes involved in vascular injury and healing of vertebral artery dissection in children over years, with potential implications for long-term management and prevention of recurrence.

Vertebral artery dissection in a patient with Wildervanck syndrome

Vertebral artery dissection as a cause of stroke is rarely reported in children. The association between vertebral artery dissection and Klippel-Feil syndrome is also very rare. We report on a case of vertebral artery dissection with posterior circulation involvement in a child with Klippel-Feil syndrome after a hard physical-training lesson. She was also diagnosed with Wildervanck syndrome, with additional clinical findings. Vertebral artery dissection should be considered in patients with Klippel-Feil syndrome who present with acute-onset neurologic signs. Movements such as hyperextension with rotation of the neck should be avoided in these cases.

Paediatric dissecting posterior cerebral aneurysms: report of two cases and review of the literature

INTRODUCTION

Intracranial aneurysms in the paediatric population are uncommon, accounting for 2% to 6% of all aneurysms, and spontaneous arterial dissection is rarely reported as the cause of aneurysms in children, especially in the posterior cerebral artery.

METHODS

Two cases of paediatric spontaneous posterior cerebral artery dissecting aneurysms are reported, one in a 33-month-old male child presenting with aneurysmal rupture and subarachnoid haemorrhage and the other in a 9-year-old boy with an unruptured aneurysm.

RESULTS

The first child was successfully treated by endovascular parent vessel occlusion without neurological deficit and in the second a spontaneous thrombosis of the aneurysm and its parent artery occurred associated with hydrocephalus and a favourable outcome.

CONCLUSION

Dissecting aneurysms are dynamic lesions with variable and unpredictable evolution and close follow-up and/or early treatment is warranted. Spontaneous arterial dissection is a rare, probably still under-recognized, cause of intracranial aneurysms that may be responsible for a significant number of aneurysms and spontaneous aneurysmal thromboses in children.

Dissecting giant vertebro-basilar aneurysms

OBJECT

Vertebro-basilar dissecting aneurysms (VDAs) are very rare in children. Strokes or subarachnoid hemorrhage are characteristic clinical manifestations, but often only non-specific symptoms are found. Radiological diagnosis may be difficult to obtain and therapy hard to perform. We report on a child who presented with an intracranial mass effect due to a giant VDA.

METHODS

The patient was a 8-year-old girl with right hemiparesis, ataxia, dysphagia and dysphonia and worsening of her neurological deficits. Neuroimaging discovered a giant dissecting aneurysm arising from the left vertebral artery and involving the vertebro-basilar junction. Endovascular treatment by coil embolization was performed. The post-operative course initially showed a remarkable improvement in her clinical condition. Afterwards, she developed cerebral hemorrhage and died.

CONCLUSION

VDAs may have an unusual presentation and their therapy still remains a challenge. Endovascular embolization is a valid option but, as it is surgery, it may cause the death of the patient.

Blunt carotid artery injury

Blunt carotid artery injury is an uncommon injury with a potentially devastating outcome. Although treatment is often unhelpful for an established neurologic deficit, there is frequently a delay between the episode of trauma and the onset of neurology. This delay provides a window of opportunity where early detection and intervention may significantly improve outcome and prevent lifelong morbidity in a generally young trauma patient population. This paper will review the literature regarding incidence, outcome, treatment options and optimal methods of diagnosis for this lesion. The following synopsis of a case seen at Royal Perth Hospital Emergency Department illustrates several of the classical features of blunt carotid injury, including delayed presentation and pattern of associated injuries. The patient, a 19-year-old female, presented following a single vehicle motor crash. On arrival she had a Glasgow Coma Scale (GCS) of 14 with no focal neurologic deficit. Multiple injuries were identified, including a large scalp laceration, a compound fracture of the mandible, pneumothorax, sternal fracture, subcapsular haematoma of the liver, and a knee laceration. Initial computed tomography (CT) scan of the head was normal. Twenty hours after the motor vehicle accident the patient's conscious state deteriorated to GCS 9. Repeat CT head demonstrated changes consistent with a left middle cerebral artery infarct. Cerebral angiography revealed traumatic dissection of the left internal carotid artery with complete occlusion of the lumen just distal to its origin. After 13 days in the intensive care unit and 2.5 months in the rehabilitation unit, she was discharged with a persistent severe receptive and expressive aphasia, as well as a dense right hemiparesis. She is now living at home with community supports.

Dissecting hematoma of intracranial internal carotid artery in an 8-year-old girl

BACKGROUND

An 8-year-old girl had a minor fall without head trauma and she collapsed the following day while playing. She was awake but mute with focal neurologic signs when admitted to hospital. Radiologic imaging studies showed a progressive left cerebral infarct with left hemisphere vascular narrowing and beading. She died on the third hospital day.

METHODS

Autopsy including exploration of neck vessels and neuropathological examination was performed. Postmortem studies included immunostaining for immunoglobulins and fixed complement.

RESULTS

Subtotal subintimal dissections of both proximal supraclinoid internal carotid arteries were found microscopically. On the left, the subintimal dissection extended into the major branches of the left internal carotid artery as dissecting hematomas with a major compromise of the arterial lumina. Specific IgM deposition at the dissection sites was found. A literature review shows that subintimal dissection of the intracranial internal carotid artery or its branches occurs rarely, it is often fatal, and it is present in patients with a mean age of 17.5 years in cases studied pathologically. Trauma and physical exertion are the most common associated factors.

CONCLUSIONS

Among the causes of ischemic stroke in young individuals, dissecting hematomas of the intracranial portions of the internal carotid artery system rank low. Few reported cases have identifiable pre-existing pathology. The pathogenesis of dissecting hematomas in this region is reviewed and expanded with speculation regarding relevant developmental, anatomical, flow stress and possibly humoral factors that are involved in the disruption of the arterial elastica and subsequent development and extension of a subintimal hematoma resulting in luminal closure and often death.