Vascular malformations of the brain in hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease)

The role of interventional radiology in treatment of patients with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) also known as Osler-Weber-Rendu disease is a rare autosomal dominant, multi-organ disorder that leads to formation of abnormal vascular connections resulting in devastating and life-threatening complications. Due to its multisystem character, wide range of clinical manifestations and variable expressivity, HHT remains a diagnostic challenge and requires close cooperation of specialists from various medical fields. Interventional radiology plays a key role in the management of this disease, helping maintain the health of HHT patients and minimize the risk of fatal complications. The aim of this article is to review clinical manifestations, diagnostic guidelines and criteria of HHT as well as to present the means of endovascular therapy in the management of HHT patients.

Brain Abscess as a Complication of Hereditary Hemorrhagic Telangiectasia: A Case Report

An 18-year-old male, previously diagnosed with hereditary hemorrhagic telangiectasia (HHT), presented to the outpatient department with a complaint of generalized seizures and fever for the past five days. He had a history of recurrent epistaxis, progressive shortness of breath, and cyanosis. Magnetic resonance imaging (MRI) of the brain revealed an abscess in the temporoparietal region. A computed angiogram of the pulmonary vasculature showed the presence of arteriovenous malformation (AVM). A four-weekly antibiotic regimen was initiated, which resulted in a profound improvement in symptoms. A brain abscess can arise as a complication of vascular malformation in a patient with HHT, providing a nidus for bacteria to migrate toward the brain. Early recognition of HHT is essential in these patients and their affected family members, as screening can help us prevent complications at an earlier stage.

Endovascular Management of Hemorrhagic Stroke

Significant advances in endovascular neurosurgery tools, devices, and techniques are changing the approach to the management of acute hemorrhagic stroke. The endovascular treatment of intracranial aneurysms emerged in the early 1990s with Guglielmi detachable coils, and since then, it gained rapid popularity that surpassed open surgery. Stent-assisted coiling and balloon remodeling techniques have made the treatment of wide-necked aneurysms more durable. With the introduction of flow diverters and flow disrupters, many aneurysms with complex geometrics can now be reliably managed. Arteriovenous malformations and fistulae can also benefit from endovascular therapy by embolization using n-butyl cyanoacrylate (NBCA), Onyx, polyvinyl alcohol (PVA), and coils. In this article, we describe the role of endovascular treatment for the most common causes of intracerebral and subarachnoid hemorrhages, particularly ruptured aneurysms and vascular malformations.

Endovascular treatment of intracranial vascular malformations in children

Paediatric intracranial vascular malformations are rare and different from adult ones in vascular anatomy, pathophysiology, and symptoms. Their impact on the brain and their symptoms will differ in the antenatal period, in neonates, infants, and children. Clinical presentation includes seizures, focal neurological deficit, haemorrhage, congestive heart failure, hydrovenous disorder, and developmental delays. These malformations are thus associated with a poor prognosis if left untreated. Therefore, aggressive management is generally recommended and must be performed by a multidisciplinary team with extensive experience. Endovascular treatment is the first-choice treatment for most paediatric intracranial vascular malformations. Indication and timing for treatment should be decided on the basis of a careful assessment of neurological symptoms, growth and development, cardiac and other systemic manifestations, and imaging of the malformation and the brain tissue. WHAT THIS PAPER ADDS: Paediatric intracranial vascular malformations are rare, but their prognosis is poor if left untreated. Improved clinical, anatomical, and pathophysiological understanding of these complex lesions has improved prognosis.

Endovascular Management of Intracranial Pial Arteriovenous Fistulas: Experience of Largest Series at a Single Center Over Six Years

Introduction:

Intracranial pial fistulas are an extremely uncommon type of vascular pathology consisting of one or multiple arterial connections to a single venous drainage channel without the presence of an intervening nidus. Due to its typical location and high-flow dynamics, its management is difficult and options include endovascular treatment and open surgical treatment. The arterial supply of these lesions is usually derived from pial or cortical vessels, and commonly such lesions are not localized in the dura mater.

Materials and Methods:

Authors report the experience of consecutive ten cases managed at the Instituto Nacional de Neurología y Neurocirugía “Manuel Velasco Suárez” of México extending from 2007 to 2012 with endovascular technique, constituting one of the largest series in the Western literature.

Discussion:

Pial fistulas are associated with a poor natural history, and the selection of individualized therapeutic strategies can provide good outcomes.

Conclusion:

The neuroendovascular intervention is currently considered as safe, low cost, and effective management modality for such lesions.

Surgical Treatment vs Nonsurgical Treatment for Brain Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia: A Retrospective Multicenter Consortium Study

BACKGROUND

Cerebral arteriovenous malformations (AVMs) are common in patients with hereditary hemorrhagic telangiectasia (HHT). However, due to the rarity of HHT and little published evidence of outcomes from management of brain AVMs in this disease, current international HHT guidelines recommend an individualized approach. Specifically, the outcomes for surgical vs nonsurgical management of these lesions have not been reported to date.

OBJECTIVE

To report long-term outcomes of surgical resection of brain AVMs in HHT patients compared to outcomes in nonsurgically treated patients.

METHODS

From the database of the Brain Vascular Malformation Consortium HHT project, 19 patients with 20 resected AVMs (group 1) and 22 patients with 33 AVMs who received nonsurgical treatment (group 2) were studied. The groups were retrospectively reviewed for changes in functional status (modified Rankin Scale score) during the follow-up period.

RESULTS

During the follow-up period, 9% of patients in group 1 suffered from worsening of functional status, whereas this figure was 16% for group 2 (P > .05). Functional outcomes were not statistically different between the 2 groups at the latest follow-up (P > .05).

CONCLUSION

HHT patients treated surgically for brain AVMs appear to have long-term functional outcomes comparable to nonsurgical (including observational) therapy with fewer unfavorable outcomes. It is therefore reasonable to consider surgical resection as a management option in the multidisciplinary team's individualized treatment strategy for HHT patients with brain AVMs.

Clinical presentation and treatment paradigms of brain arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is characterized by recurrent spontaneous epistaxis, mucocutaneous telangiectases, and multisystem arteriovenous malformations (AVMs). Brain AVMs typically present at birth and are identified in approximately 10-20% of patients with HHT. A retrospective review was undertaken of all HHT patients with known single or multiple brain AVMs treated at our institution. Thirty-nine patients with brain AVM(s) were diagnosed with HHT. Most patients presented with at least one Curaçao criterion. A total of 78 brain AVMs were identified in 39 patients. Two-thirds of patients had solitary brain AVMs, whereas 33% of patients harbored at least two lesions (range: 2-16). Brain AVMs of the supratentorial cerebral hemispheres comprised 83% of all lesions, whereas infratentorial lesions accounted for only 17%. Of the 55 brain AVMs assigned Spetzler-Martin grading, the majority of patients were Grade 1 (73%), and 23% and 4% were Grades 2 and 3, respectively. Patients were treated with surgery alone (51%), embolization alone (6%), embolization followed by surgery (9%), stereotactic radiosurgery (11%), stereotactic radiosurgery followed by surgery (3%), or observation (20%). Of patients who underwent genetic analysis, 62% possessed mutations in ENG (HHT type 1), whereas 38% had mutations in ACVRL1 (HHT type 2). This robust patient cohort of brain AVMs in 39 patients with HHT advances the collective understanding of this disease's varied presentation, diagnostic workup, genetic underpinnings, and available treatment options.

Spontaneous resolution of ruptured intracranial pial arteriovenous fistula following spinal surgery

Pial arteriovenous fistulae (AVFs) are rare vascular abnormalities that are distinct from arteriovenous malformations and dural AVFs. These vascular lesions have been linked with trauma, ischemic syndromes, venous thrombotic diseases, and intracranial surgical procedures. In this report we describe a case of an intracranial ruptured pial AVF immediately following uneventful spinal surgery in an elderly patient with subsequent spontaneous resolution. He was a previous heavy smoker with a 60-pack-year history and alcohol abuse. His examination was positive for morbid obesity and mild weakness of the anterior tibialis and gastrocnemius muscles bilaterally. He underwent uneventful spinal surgery, suffering a generalized seizure shortly after extubation. Imaging studies demonstrated acute subarachnoid hemorrhage and cerebral angiography identified a pial AVF. He was stabilized medically and follow-up angiography demonstrated spontaneous resolution of the pial AVF. This case highlights a rare vascular malformation with rupture following uneventful spinal surgery.

Pediatric intracranial dural arteriovenous fistulas: age-related differences in clinical features, angioarchitecture, and treatment outcomes

OBJECTIVE Intracranial dural arteriovenous fistulas (DAVFs) are rare in children. This study sought to better characterize DAVF presentation, angioarchitecture, and treatment outcomes. METHODS Children with intracranial DAVFs between 1986 and 2013 were retrospectively identified from the neurointerventional database at the authors' institution. Demographics, clinical presentation, lesion angioarchitecture, treatment approaches, angiographic outcomes, and clinical outcomes were assessed. RESULTS DAVFs constituted 5.7% (22/423) of pediatric intracranial arteriovenous shunting lesions. Twelve boys and 10 girls presented between 1 day and 18 years of age; boys presented at a median of 1.3 years and girls presented at a median of 4.9 years. Four of 8 patients ≤ 1 year of age presented with congestive heart failure compared with 0/14 patients > 1 year of age (p = 0.01). Five of 8 patients ≤ 1 year old presented with respiratory distress compared with 0/14 patients > 1 year old (p = 0.0021). Ten of 14 patients > 1 year old presented with focal neurological deficits compared with 0/8 patients ≤ 1 year old (p = 0.0017). At initial angiography, 16 patients harbored a single intracranial DAVF and 6 patients had 2-6 DAVFs. Eight patients (38%) experienced DAVF obliteration by the end of treatment. Good clinical outcome (modified Rankin Scale score 0-2) was documented in 77% of patients > 1 year old at presentation compared with 57% of patients ≤ 1 year old at presentation. Six patients (27%) died. CONCLUSIONS Young children with DAVFs presented predominantly with cardiopulmonary symptoms, while older children presented with focal neurological deficits. Compared with other pediatric vascular shunts, DAVFs had lower rates of angiographic obliteration and poorer clinical outcomes.

Onyx Embolization of Intracranial Pial Arteriovenous Fistula

Intracranial pial arteriovenous fistulas (AVFs) are rare cerebrovascular lesions consisting of one or more arterial connections to a single venous channel without an intervening nidus. Because of the location and high flow dynamics of these lesions, neurosurgeons may have a difficulty deciding between endovascular treatment and open surgical treatment. We report on a patient who underwent endovascular treatment with liquid embolic agent. A 50-year-old man with a decreased mental state and a tonic seizure event was brought to our hospital. Computed tomography (CT) of the brain showed a subcortical hematoma in the right temporoparietal lobe. On three-dimensional cerebral artery CT, there was no evidence of definite cerebrovascular abnormality. Cerebral angiography showed a pial AVF supplied by the right middle cerebral artery with early drainage into the right superior cerebral vein. The patient was treated with Onyx embolization for definitive closure of the fistula. The patient was transferred to the department of rehabilitation medicine two weeks later with grade 4 left hemiparesis. The application of advanced equipment, such as the latest angiography and endovascular tools, will facilitate the correct diagnosis and delicate treatment of pial AVF.

Posterior Fossa Arteriovenous Pial Fistula: Diagnostic and Endovascular Therapeutic Features

Intracranial arteriovenous fistulas (AVFs) are rare vascular cerebral lesions composed of one or more corticalpial arterial feeders directly connected with a single draining vein. They differ from the other AV malformations in that they lack a nidus and are located outside the dural leaflets. Because of high flow and pressure AVFs have a high risk of hemorrhage and if untreated cause death in up to 63% of cases. Treatment can be endovascular or microneurosurgical. We describe an infant with hydrocephalus and raised intracranial pressure and MRI findings of a single dilated venous vessel with a proximal varix in the perimedullary spaces confirmed by CT angiography and DSA that found a single artery-single vein fistula we successfully occluded with GDC coils.

The Role of Macrophage in the Pathogenesis of Brain Arteriovenous Malformation

Brain arteriovenous malformation (BAVM) is an important risk factor for intracranial hemorrhage, especially in children and young adults. Inflammation has been implicated in BAVM lesion progression. Among various inflammatory components, macrophage is one of the major inflammatory cells present in human ruptured and unruptured BAVM and in the BAVM lesions of animal models. The role of macrophage in BAVM pathogenesis is not fully understood. In this review, we summarize recent studies on macrophages and introduce a non-invasive imaging protocol as a potential tool for detecting macrophage in BAVM and predicting the risk of BAVM rupture.

Rare manifestations in a case of Osler-Weber-Rendu disease

Osler-Weber-Rendu disease (OWRD) is a rare vascular dysplasia that presents most commonly with epistaxis. The most dreaded complication, however, is an intracranial haemorrhage. We present a patient with two rare manifestations of OWRD, subdural haematoma and portal venous hypertension, both seldom reported in the literature. The patient made a full recovery and continues to do well at this time.

Effectiveness of intraoperative indocyanine green videoangiography in direct surgical treatment of pediatric intracranial pial arteriovenous fistula

Intracranial pial arteriovenous fistulas (AVFs) are rare cerebrovascular lesions. The authors report a rare case of pediatric pial AVF treated by direct disconnection with the aid of indocyanine green (ICG) videoangiography. A 3-year-old girl presented with developmental problems. Magnetic resonance imaging revealed brain atrophy and an anomalous left temporal vascular mass. Angiography showed a high-flow pial AVF in the early arterial phase fed by the M1 portion of the left middle cerebral artery and draining into the superficial sylvian vein and the vein of Trolard with a large varix. Given that her fistula was located in a superficial region that was easily accessible by craniotomy, the authors successfully disconnected her pial AVF by direct surgery aided by ICG videoangiography, which clearly confirmed the shunting point. In this report, the authors discuss the existing literature and compare the relative merits of endovascular versus surgical options for the treatment of pial AVF.

Cerebral arteriovenous malformations: evaluation and management

There has been increased detection of incidental AVMs as result of the frequent use of advanced imaging techniques. The natural history of AVM is poorly understood and its management is controversial. This review provides an overview of the epidemiology, pathophysiology, natural history, clinical presentation, diagnosis, and management of AVMs. The authors discussed the imaging techniques available for detecting AVMs with regard to the advantages and disadvantages of each imaging modality. Furthermore, this review paper discusses the factors that must be considered for the most appropriate management strategy (based on the current evidence in the literature) and the risks and benefits of each management option.

Endovascular management of arteriovenous malformations of the brain

Arteriovenous malformations (AVMs) of the brain are rare, complex, vascular lesions that can result in significant morbidity and mortality. Modern treatment of brain AVMs is a multimodality endeavor, requiring a multidisciplinary team with expertise in cerebrovascular neurosurgery, endovascular intervention, and radiation therapy in order to provide all therapeutic options and determine the most appropriate treatment regimen depending on patient characteristics and AVM morphology. Current therapeutic options include microsurgical resection, radiosurgery (focused radiation), and endovascular embolization. Endovascular embolization is primarily used as a preoperative adjuvant before microsurgery or radiosurgery. Palliative embolization has been used successfully to reduce the risk of hemorrhage, alleviate clinical symptoms, and preserve or improve neurological function in inoperable or nonradiosurgical AVMs. Less frequently, embolization is used as 'primary therapy' particularly for smaller, surgically difficult lesions. Current embolic agents used to treat brain AVMs include both solid and liquid agents. Liquid agents including N-butyl cyanoacrylate and Onyx are the most commonly used agents. As newer embolic agents become available and as microcatheter technology improves, the role of endovascular treatment for brain AVMs will likely expand.

Pial arteriovenous fistula with giant varices: report of two cases with good surgical outcome

Pial arteriovenous fistulas (pAVF) are rare vascular lesions consisting of one or more arterial connections to a single venous channel without any intervening nidus of vessels or capillaries. Case 1: A 65-year-old woman with a complaint of headache and left hand paresthesia was referred to us. Magnetic resonance imaging showed a large saccular lesion with signal void in the posterior part of the right sylvian fissure and catheter angiography showed a giant venous aneurysm fed by one branch of the middle cerebral artery (MCA) and draining into the vein of Trolard. Case 2: A 12-year-old boy was transferred to our hospital with a history of sudden loss of consciousness and hemiplegia. Brain computed tomography revealed a massive hemorrhagic mass in the right hemisphere and cerebral angiography showed a pAVF with a large aneurysmal varix, which was fed by multiple branches of the right MCA and draining into the superior sagittal sinus. Both patients underwent craniotomy and after ligation of vascular connections, aneurysmal varices were removed completely. Surgical resection can be a safe method for treatment of pAVFs, particularly in those with large varices.

Cerebral vascular malformations in hereditary hemorrhagic telangiectasia

Object

Hereditary hemorrhagic telangiectasia (HHT) is a hereditary disorder characterized by mucocutaneous telangiectasias, frequent nosebleeds, and visceral arteriovenous malformations (AVMs). Few reports have outlined the prevalence of the various cerebral vascular malformations found in patients with HHT. The authors set out to define the prevalence of cerebral vascular malformations in a population of HHT patients who underwent imaging with 3-T imaging (MRI/MR angiography [MRA]) of the brain.

Methods

A retrospective review of prospectively collected data was carried out using a database of 372 HHT patients who were seen and examined at the Georgia Regents University HHT Center and screened with 3-T MRI/MRA. Data were tabulated for numbers and types of vascular malformations in this population.

Results

Arteriovenous malformations were identified in 7.7%, developmental venous anomalies in 4.3%, and cerebral aneurysms in 2.4% of HHT patients. The HHT AVMs tended to be supratentorial, small, and cortical in this series, findings consistent with other recent studies in the literature. An arteriovenous fistula, cavernous malformation, and capillary telangiectasia were identified in 0.5%, 1%, and 1.9% of HHT patients, respectively.

Conclusions

Few studies have investigated the prevalence of the various vascular malformations found in HHT patients screened with 3-T MRI/MRA of the brain. Hereditary hemorrhagic telangiectasia AVMs are more likely to be multiple and have a tendency toward small size and cortical location. As such, they are often treated using a single-modality therapy.

Brain arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia: clinical presentation and anatomical distribution

BACKGROUND

Hereditary hemorrhagic telangiectasia is an autosomal dominant genetic disease with a wide array of vascular malformations involving multiple organs. Brain arteriovenous malformations can lead to intracranial hemorrhage and are often diagnosed only after patients become symptomatic. Early diagnosis and interventional treatment may prevent neurologic sequelae or death. Because of the rarity of defined cases, the spectrum of presentations in children with brain arteriovenous malformations and hereditary hemorrhagic telangiectasia has not been explored in detail. Here, we report our experience in children with hereditary hemorrhagic telangiectasia and brain arteriovenous malformations regarding both disease manifestations at presentation and the spectrum of brain arteriovenous malformation manifestations.

METHODS

A retrospective review of demographics, clinical manifestations, and brain magnetic resonance imaging/computed tomography scan findings in 115 patients with confirmed hereditary hemorrhagic telangiectasia (HHT) was conducted using the Hospital for Sick Children's HHT Clinic database for the years 1997-2012.

RESULTS

Eleven patients (four girls and seven boys) were diagnosed with hereditary hemorrhagic telangiectasia and brain arteriovenous malformations during this period. Five patients initially presented with epistaxis, four presented with intracranial hemorrhage, and two were asymptomatic with a positive family history of confirmed hereditary hemorrhagic telangiectasia. Although all children had an index case with hereditary hemorrhagic telangiectasia in the family, in three patients, hereditary hemorrhagic telangiectasia was not diagnosed before the child's presentation with intracranial hemorrhage. Multiple brain arteriovenous malformations were found in five patients, with one patient having bithalamic arteriovenous malformations.

CONCLUSIONS

This study highlights the importance of both family history and early clinical signs to prompt further diagnostic testing to avoid intracranial hemorrhage from brain arteriovenous malformations in children with hereditary hemorrhagic telangiectasia.

Intracranial pial arteriovenous fistula caused by dural tenting: case report

We describe a rare case where a patient developed intracranial pial arteriovenous (AV) fistula due to dural tenting. The patient was a 63-year-old woman who had undergone neck clipping for an unruptured middle cerebral artery (MCA) aneurysm. The surgery was performed without any problems and her postoperative course was uneventful. Two weeks after cerebral angiography operation revealed a pial AV fistula fed by the right MCA and drained into the vein of Trolard through the Sylvian vein which had not existed before surgery. Being diagnosed as de novo pial AV fistula, surgical repair was performed. The AV fistula was located just beneath the dural tenting. The fistulous point was confirmed with fluorescein video angiography and obliterated using a clip. Although rare, we should pay attention to the AV fistula due to dural tenting as the complications of cranial surgery.

An institutional series and literature review of pial arteriovenous fistulas in the pediatric population: clinical article

OBJECT

Pial arteriovenous fistulas (PAVFs) are a rare form of cerebrovascular disease that tend to be overrepresented in the pediatric population. There have been limited studies of the clinical features and outcomes in this group of patients. Here, the authors attempt to better delineate this clinical entity with institutional cases and a review of the literature.

METHODS

A retrospective review of cases at our institution was performed to identify all pediatric patients treated for a PAVF between 2000 and 2012.

RESULTS

Five patients treated for a PAVF were identified. Patients had a mean age of 1.9 years at diagnosis, and the most common presenting symptoms were seizure and macrocephaly. Patients were treated primarily with embolization, and 3 patients required both N-butyl cyanoacrylate (NBCA) glue and coiling. Four of the patients had complete obliteration of the PAVF and had a pediatric overall performance category score of either 1 (n = 3) or 2 (n = 1) at follow-up. There was 1 death due to heart failure. Analysis of the literature review suggested that a younger age or presence of intracerebral hemorrhage (ICH) or congestive heart failure (CHF) at presentation likely predicts a worse prognosis. Older patients presented more often with ICH, whereas younger patients presented significantly more often in CHF. The majority of pediatric patients reported on in the literature were treated with endovascular embolization, most commonly with NBCA glue alone. Most patients (65.4%) in the literature had an excellent outcome without neurological deficit.

CONCLUSIONS

Pial AVFs represent a serious yet rare form of cerebrovascular disease. Pediatric patients with ICH or CHF at presentation or those who are very young are likely to have a worse prognosis. Endovascular management of these patients has greatly changed the natural history of this disease, but the complication and mortality rates suggest the need for continued insights and advances in treatment.

Giant calcified thrombosed varices secondary to a pial arteriovenous fistula associated with hereditary hemorrhagic telangiectasia

A 28-year-old woman presented with an unusual case of giant thrombosed varix with calcified walls that had mass effects secondary to a pial single-channel arteriovenous fistula (AVF) associated with hereditary hemorrhagic telangiectasia (HHT). She consulted our hospital for chronic headache. She had been diagnosed with HHT based on genetic testing when her 3-year-old son presented with subarachnoid hemorrhage due to spinal AVF. Imaging studies revealed pial single-channel AVF with multiple varices. The varices in the right frontal lobe were over 6 cm in diameter and had laminar thromboses and calcified walls. Because of the mass effect, direct surgical flow disconnection was performed followed by removal of the varices using an internal decompression technique. Postoperatively, the patient was discharged with no neurological symptoms and no longer suffered chronic headache. Intracerebral varices are occasionally associated with high-flow AVF, and usually treated by interrupting the feeding arteries leaving the varices intact. This extremely rare case of intracerebral giant thrombosed varices with calcified wall and mass effect indicates that surgical removal of varices should be considered.

Endovascular treatment of cerebral dural and pial arteriovenous fistulas

Dural arteriovenous fistulas (DAVFs) are arteriovenous shunts from a dural arterial supply to a dural venous channel, typically supplied by pachymeningeal arteries and located near a major venous sinus. Pial arteriovenous fistulas (PAVFs) are composed of one or more arterial feeders draining into a single vein in the absence of an intervening nidus. Fistulas manifesting features of high risk for rupture should be treated aggressively, the spectrum of treatment varies from endovascular, surgical resection, and stereotactic radiosurgery. This article describes the natural history, clinical presentation, and treatment of dural and pial fistulas, with emphasis on endovascular treatment.

The diagnosis and management of brain arteriovenous malformations

Although uncommon in the general population, cerebral arteriovenous malformations (AVMs) can pose a significant health risk if a rupture occurs. Advances in noninvasive imaging have led to an increase in the identification of unruptured AVMs, presenting new challenges in management, given their poorly understood natural history. Over the past decade, there have been significant developments in the management and treatment of intracranial AVMs. This article discusses the pathophysiology, natural history, clinical presentations, and current treatment options, including multimodal approaches, for these vascular malformations.

Pediatric intracranial nongalenic pial arteriovenous fistulas: clinical features, angioarchitecture, and outcomes

BACKGROUND AND PURPOSE

NGAVFs are rare vascular malformations usually presenting in infancy or childhood. We sought to identify clinical and angiographic predictors of clinical outcome for these lesions.

MATERIALS AND METHODS

Retrospective review of a neurointerventional data base identified 386 pediatric patients with intracranial AVFs and AVMs, from which a cohort of 25 patients with NGAVF were selected for medical record and imaging analysis.

RESULTS

NGAVFs constituted 7.3% of pediatric intracranial vascular lesions with a nondural arteriovenous shunt. Seven of 8 patients who presented in the first month of life had CHF and harbored large, complex fistulas with multiple sites of arteriovenous shunting. Single-hole fistulas predominated later in childhood and more frequently presented with seizures, hemorrhage, or focal neurologic deficits. More treatment procedures were performed in subjects presenting at ≤ 2 years of age compared with older children (median = 3 versus 2, P = .041), and in those harboring a multi-hole fistula versus those with a single-hole fistula (median = 3 versus 2, P = .003). Eighteen patients (72%) had complete posttreatment elimination of NGAVF shunting. Compared with patients presenting at >2 years of age, patients presenting in the first 2 years of life were more likely to have a multi-hole fistula (100% versus 25%, P = .0001) and to have a poor clinical outcome (54% versus 0%, P = .0052), defined as a pediatric mRS of ≥ 3.

CONCLUSIONS

The morbidity of NGAVF appears higher than previously reported despite a somewhat higher rate of angiographic cure. Poor clinical outcome occurred primarily in patients with multi-hole NGAVFs presenting at ≤ 2 years of age.

Embolization and radiosurgery for arteriovenous malformations

The treatment of arteriovenous malformations (AVMs) requires a multidisciplinary management including microsurgery, endovascular embolization, and stereotactic radiosurgery (SRS). This article reviews the recent advancements in the multimodality treatment of patients with AVMs using endovascular neurosurgery and SRS. We describe the natural history of AVMs and the role of endovascular and radiosurgical treatment as well as their interplay in the management of these complex vascular lesions. Also, we present some representative cases treated at our institution.

Brain arteriovenous malformation multiplicity predicts the diagnosis of hereditary hemorrhagic telangiectasia: quantitative assessment

BACKGROUND AND PURPOSE

The purpose of this study was to quantitatively estimate the relationship between multiplicity of brain arteriovenous malformations (bAVMs) and the diagnosis of hereditary hemorrhagic telangiectasia (HHT).

METHODS

We combined databases from 2 large North American bAVM referral centers, including demographics, clinical presentation, and angiographic characteristics, and compared patients with HHT with non-HHT patients. Logistic regression analysis was performed to quantify the association between bAVM multiplicity and odds of HHT diagnosis. Sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratios were calculated to determine accuracy of bAVM multiplicity for screening HHT.

RESULTS

Prevalence of HHT was 2.8% in the combined group. bAVM multiplicity was present in 39% of patients with HHT and was highly associated with diagnosis of HHT in univariate (OR, 83; 95% CI, 40-173; P<0.0001) and multivariable (OR, 86; 95% CI, 38-195; P<0.001) models adjusting for age at presentation (P=0.013), symptomatic presentation (P=0.029), and cohort site (P=0.021). bAVM multiplicity alone was associated with high specificity (99.2%; 95% CI, 98.7%-99.6%) and negative predictive value (98.3%; 95% CI, 97.6%-98.8%) and low sensitivity (39.3%; 95% CI, 26.5%-53.2%) and positive predictive value (59.5%; 95% CI, 42.1%-75.2%). Positive and negative likelihood ratio was 51 and 0.61, respectively, for diagnosis of HHT. HHT bAVMs were also more often smaller in size (<3 cm), noneloquent in location, and associated with superficial venous drainage compared with non-HHT bAVMs.

CONCLUSIONS

Multiplicity of bAVMs is highly predictive of the diagnosis of HHT. The presence of multiple bAVMs should alert the clinician to the high probability of HHT and lead to comprehensive investigation for this diagnosis.

Coil-based endovascular treatment of single-hole cerebral arteriovenous fistulae: experiences in 11 patients

BACKGROUND

An SHF is rare pial arteriovenous shunt with no nidal component, of which the feeder drains directly into a single venous channel. Casting with NBCA was described previously, but its control demands operator to accumulate a considerable learning curve. We are to present our experiences of coil-based endovascular treatment of SHF.

METHODS

Eleven patients harbored 12 SHFs (5 men, 6 women; mean age, 28.4 years; age range, 4-73 years), and they presented with hemorrhage, seizure, collapse, orbital mass, and as an incidental lesion. The location was frontal for 3, temporal for 5, parietal in 2, and occipital in 2 patients. The angioarchitectures, the methods of endovascular treatment, and outcomes were analyzed.

RESULTS

Fifteen feeders arose from 4 anterior, 8 middle, and 3 posterior cerebral arteries. The coil framework was constructed at the fistula before the penetration of a low concentrated NBCA. Nine fistulae were occluded completely, and 3 fistulae were occluded to near-completion with micro-AVM. There was no recanalization of SHF, either growth of a micro-AVM during follow-up period (mean, 48.3 months; range, 6-120 months). One patient with postprocedure hemorrhage developed hemiplegia, but 1 patient with seizure and the other 9 asymptomatic patients were uneventful.

CONCLUSIONS

The coil-based endovascular treatment can achieve safe and stable occlusion of SHF, and the preventions against venous thrombosis and perfusion breakthrough should be essential.

Endovascular treatment of brain arteriovenous fistulas

BACKGROUND AND PURPOSE

Brain arteriovenous fistulas (BAVFs) are dangerous lesions with significant risks for hemorrhage and re-hemorrhage; thus, the management of BAVFs is an important subject. Flow disconnection can be accomplished by surgical or endovascular techniques. We reviewed the experience in our endovascular treatment of patients with BAVFs.

MATERIALS AND METHODS

From March 2006 to March 2008, a total of 9 consecutive patients with nontraumatic BAVFs were treated at Beijing Tiantan Hospital. Dural arteriovenous fistulas and Galen aneurysmal malformations were excluded from this study. We retrospectively reviewed the medical records, cerebral angiograms, and endovascular reports for each patient. Radiographic outcome was assessed by posttreatment angiography. Clinical outcome was assessed for every patient.

RESULTS

There were 9 patients with a total of 11 BAVFs. The mean age at presentation was 17.8 years. The clinical presentations were intracranial hemorrhage in 4 patients, headaches in 2 patients, and seizure in 1 patient, with 2 patients diagnosed incidentally. All lesions were supratentorial, and a venous varix was found on angiographic examination. Seven patients were treated with coils, 1 with Onyx-34, and 1 with a combination of coils and glue. All 9 lesions were completely obliterated as demonstrated on follow-up angiographic examination. With a mean follow-up of 5.7 months (range, 3-12 months), all patients were neurologically excellent with no symptoms (modified Rankin Scale, 0).

CONCLUSIONS

BAVFs are more frequent in younger patients and frequently lead to intracranial hemorrhage. Staged endovascular coil embolization of BAVFs may be a good appropriate treatment technique.

A case of multiple pial arteriovenous fistulas associated with dural arteriovenous fistula

Pial arteriovenous fistulas (AVFs) are known as rare cerebrovascular lesions. They are composed of ≥ 1 arterial feeding vessels and a single draining vein that usually has high perfusion pressure and generally occur in infants. Cases involving adults are very rare and the developmental mechanisms and natural history of these lesions remain unknown. The authors present a case of multiple pial AVFs in an adult in whom the lesions developed after radiosurgical treatment of dural AVFs. Direct disconnection of pial arterial supplies was performed, and the abnormal shunts were successfully eliminated. The authors report the clinical course of this case and discuss the characteristics of and treatment strategy for multiple pial AVFs, reviewing the published literature.

Intracranial pial arteriovenous fistula

A 33-year-old woman presented with a rare intracranial pial arteriovenous fistula manifesting as monoparesis and hypesthesia of the right lower extremity. Computed tomography demonstrated an approximately 10-mm diameter subcortical hematoma in the left postcentral gyrus. Two months after suffering the ictus, angiography demonstrated a pial arteriovenous fistula in the late arterial phase fed by the left paracentral artery and drained into the left precentral vein. No nidus or dural arteriovenous fistula was detected. Left parietal craniotomy was performed and the pial arteriovenous fistula was extirpated by electrocoagulation. Intraoperative angiography demonstrated disappearance of the fistula. She experienced no postoperative neurological deterioration, but hypesthesia of the right leg persisted. Obliteration of the pial arteriovenous fistula was reconfirmed by postoperative angiography. She suffered no rebleeding episodes during the 36-month follow-up period. Pial arteriovenous fistula causing mild symptoms should be treated by flow disconnection because the direct arteriovenous shunt and attendant high blood flow usually results in huge venous varices. To determine whether direct surgery or endovascular treatment is appropriate, the position and shape of the lesion must be known.

Treatment of multiple arteriovenous malformations in pediatric patients with hereditary hemorrhagic telangiectasia and spontaneous hemorrhage. Report of two cases

Due to inheritance of an autosomal dominant genetic mutation, patients with hereditary hemorrhagic telangiectasia (HTT) have an increased risk of harboring a cerebral arteriovenous malformation (AVM). They are also significantly more likely to have multiple AVMs. The natural history of AVMs in patients with HHT as well as their rate of hemorrhage is not clearly defined. Furthermore, spontaneous regression of such lesions has been reported. Treatment of cerebral AVMs in patients with HHT presents a particular challenge, especially with detection of incidental lesions following screening of asymptomatic patients. The management of HHT in two pediatric patients in whom hemorrhaging from a cerebral AVM occurred but who also had other lesions is presented here. Both patients were treated with stereotactic radiosurgery.

Spontaneous regression of a cerebral arteriovenous malformation in a child with hereditary hemorrhagic telangiectasia. Case report

Patients with hereditary hemorrhagic telangiectasia (HHT) are at risk for the development of cerebral arteriovenous malformations (AVMs). The authors report a case of a spontaneously regressing cerebral AVM in a patient with HHT. The lesion was diagnosed on the basis of findings on screening magnetic resonance imaging and regressed completely before any treatment was undertaken. The spontaneous regression of cerebral AVMs is a rare and poorly understood phenomenon. Only one other instance of spontaneous regression of a cerebral AVM in a patient with HHT has been reported in the literature. The authors compare angiographic and clinical features in previously reported cases of spontaneous regression of cerebral AVMs with those in the present case to determine the characteristics common to this phenomenon.

Unusual giant cerebral venous varix associated with brain abscess: variant of hereditary hemorrhagic telangiectasia--case report

A 35-year-old man suffered secondary generalized tonic-clonic convulsions due to a large brain abscess. Neuroimaging incidentally revealed another tumor-like lesion. Cerebral angiography confirmed that the lesion was an unusual giant venous varix associated with a high-flow pial arteriovenous fistula (AVF) and showed one more small arteriovenous malformation (AVM). Pulmonary AVF, which can cause brain abscess, was also detected. Surgical ligation of the AVF and removal of the small AVM via individual craniotomies resulted in successful extirpation of the cerebrovascular malformations. Although the typical mucocutaneous symptoms were absent in this patient, the combination of arteriovenous anomalies was highly suggestive of hereditary hemorrhagic telangiectasia.

Vascular Endothelial Growth Factor Plasma Levels Are Significantly Elevated in Patients with Cerebral Arteriovenous Malformations

BACKGROUND

Since growth and de novo generation of cerebrovascular malformations were demonstrated, a strictly congenital model cannot be further supported as unique factor in the pathogenesis of cerebral arteriovenous malformations (AVMs). Vascular endothelial growth factor (VEGF) has previously been demonstrated to be highly expressed in AVMs by immunohistochemical methods. However, systemic VEGF levels have not been analysed previously. This study aimed to investigate VEGF plasma concentrations as a possible plasma marker for neovascularization in patients with cerebral AVMs compared to healthy controls.

METHODS

The study included 17 patients with cerebral AVMs and 40 healthy controls. VEGF plasma concentrations were measured by a specific enzyme immuno-assay.

RESULTS

VEGF plasma concentrations were significantly higher in patients with cerebral AVMs (mean 140.9 pg/ml, SD 148.5 pg/ml and median 63.0 pg/ml) compared to a healthy control group (mean 44.7 pg/ml, SD 36.4 pg/ml and median 35.0 pg/ml), p = 0.0003.

CONCLUSIONS

Our findings suggest that VEGF plasma concentrations might play a role in the pathogenesis of cerebral AVMs. Further studies are necessary and would contribute to an improved understanding of the pathogenesis of cerebral AVMs.

Surgical treatment of pial cerebellar arteriovenous fistulas with aneurysm of the main feeding artery

BACKGROUND

Intracranial pial arteriovenous fistulas (pAVFs) are rare vascular lesions only recently considered distinct from arteriovenous malformations. Conservative management was associated with a high mortality rate. The abnormality of the lesion arises from its high-flow nature. The authors present a case of a cerebellar pAVF associated with aneurysms of the main feeding artery that was surgically treated.

CASE DESCRIPTION

A 54-year-old woman was referred to us after an attack of severe headache and vomiting. Computerized tomography scan visualized a hematoma of the fourth ventricle. Digital subtraction angiography (DSA) revealed a cerebellar pAVF mainly fed by the right posteroinferior cerebellar artery (PICA) and with drainage into one of the superior cerebellar veins. The PICA presented a saccular aneurysm on its fourth segment and a fusiform dilatation on its third segment. The patient underwent surgical operation via a midline suboccipital craniotomy. The fusiform dilatation was wrapped and the saccular aneurysm was clipped. The most fistulous connections were closed. The draining vein at the level of torcular herophili was closed by application of a clip. Control DSA demonstrated exclusion of both the aneurysms and the fistula from the circulation. At 1-year follow-up, the patient was neurologically intact.

CONCLUSIONS

The association of a cerebellar pAVF and an aneurysm is rare. Surgical treatment of multiple-channel arteriovenous fistulas by closure of venous varix should guarantee the exclusion from the circulation and avoid recruitment of new arterial connections and recurrence. Attention must be paid to normal venous channels draining into the varix.

Neuroradiologie de la maladie de rendu osler

Hereditary Hemorrhagic telangiectasia is an autosomal dominant vascular disorder with high penetrance and variable expressivity. Most cases are caused by mutations in the endoglin gene on chromosome 9 (HHT type 1) or the activin receptor-like kinase 1 gene on chromosome 12 (HHT type 2). HHT is characterized by mucocutaneous telangiectases and visceral arteriovenous malformations (AVMs). Neurological complications occur in 8 to 10% of the patients. Brain ischemia or abscess are often associated with pulmonary arteriovenous fistula. Cerebral or spinal arteriovenous malformations are frequent but have a lower risk of haemorrhage than sporadic AVMs and routine screening should not be practiced in adult patients. Routine screening should be discussed for children with a familial history of cerebral haemorrhage and/or HHT type 1.

Rendu-Osler-Weber disease with a giant intracerebral varix secondary to a high-flow pial AVF: case report

BACKGROUND

Intracranial varices are rare and most are associated with vein of Galen arteriovenous malformations (AVM) or fistulas (AVF).

DESCRIPTION

A 43-year-old left-handed man presented with right hemihypesthesia and spastic gait. Neuroradiological examination revealed a spinal AVF and a giant intracerebral varix associated with a high-flow pial AVF. He had recurrent episodes of nasal bleeding, which were also confirmed in his mother's medical history, and telangiectases in the tip of his tongue and fingers. He was diagnosed with Rendu-Osler-Weber disease. After resection of the spinal AVF that produced his symptoms, we surgically exposed and obliterated the giant varix and AVF under intra- and postoperative hypotension and mild barbiturate therapy. The arteriovenous shunt was completely obliterated without hyperperfusion of the surrounding brain.

CONCLUSION

This is an extremely rare case of Rendu-Osler-Weber disease with a giant intracerebral varix secondary to a high-flow pial AVF that did not involve the vein of Galen.

Cerebral vascular abnormalities in a murine model of hereditary hemorrhagic telangiectasia

BACKGROUND AND PURPOSE

Hereditary hemorrhagic telangiectasia type 1 (HHT1) is an autosomal dominant vascular dysplasia caused by mutations in the endoglin gene and characterized by dilated vessels and arteriovenous malformations (AVMs). To understand the etiology of this disorder, we evaluated the cerebral vasculature of endoglin heterozygous (Eng+/-) mice, which represent the only animal model of HHT1.

METHODS

The cerebral vasculature of Eng+/- and Eng+/+ mice from C57BL/6 (B6) and 129/Ola (129) strains with a differential susceptibility to HHT1 was studied with corrosion casting. Casts were observed by scanning electron microscopy to detect malformations and evaluate arterial diameters and orientation of endothelial nuclei. Measurements were taken to assess relative constriction at arteriolar branching points and downstream relative dilatation.

RESULTS

Three of 10 Eng+/- mice demonstrated abnormal vascular findings including AVMs, while none of 15 Eng+/+ mice did. The incidence of relative constriction at arteriolar branching points was significantly less in both Eng+/- groups than in their Eng+/+ counterparts. The occurrence of relative dilatation was significantly greater in B6-Eng+/- than in B6-Eng+/+ mice. Endothelial nuclei were significantly rounder and deviated more from the direction of blood flow in Eng+/- than in Eng+/+ mice.

CONCLUSIONS

Eng+/- mice showed significant structural alterations in cerebral blood vessels, indicating that the level of endoglin on endothelium is critical for maintenance of normal vasculature. Since endoglin haploinsufficiency is associated with HHT1, such changes in arteriolar structures might occur in HHT1 patients and predispose them to AVMs and their sequelae.

The prevalence and manifestations of hereditary hemorrhagic telangiectasia in the Afro-Caribbean population of the Netherlands Antilles: a family screening

Hereditary hemorrhagic telangiectasia (HHT) has been reported rarely in people of African descent. The prevalence in the Afro-Caribbean population of the Netherlands Antilles is suspected to be high. A family screening in this population was done to arrive at a point prevalence and to identify patients with pulmonary involvement. By clinical history and physical examination, 219 persons over age twelve with a first-degree relative with HHT were screened. The diagnosis was based on the new diagnostic criteria [Shovlin et al., 2000]. Chest-roentgenogram and pulse-oximetry or measurement of arterial oxygen pressure were used to detect pulmonary involvement. HHT was diagnosed in 112 individuals (51%), with at least a point prevalence of 1 in 1,331 inhabitants of Curaçao and Bonaire older than twelve years. The diagnosis was uncertain in 27; this was partly due to the new stringent criteria. Epistaxis was present in 98% and telangiectases in 99%. Facial telangiectases were relatively rare due to pigmented skin. Pulmonary involvement was found in 28% with serious-mainly neurological-complications in 48%. The point-prevalence of HHT in the Afro-Caribbean population of the Netherlands Antilles is the highest known in the world. Pulmonary involvement in this population is not rare and causes serious complications.

Usefulness of Multidetector 3D-CT Angiography in the Evaluation of Infantile Perimedullary Spinal Arteriovenous Fistula

SUMMARY

We report an infantile huge perimedullary spinal arteriovenous fistula (SAVF) associated with Hereditary-Hemorrhagic-Telangiectasia (HHT), which was treated by glue embolization in one session. Three-dimensional Multidetector Computed Tomography Angiography (3D-MCTA) was useful in pre- and post-endovascular intervention.

Surgical and endovascular flow disconnection of intracranial pial single-channel arteriovenous fistulae

INTRODUCTION

Intracranial pial single-channel arteriovenous (AV) fistulae are rare vascular lesions of the brain. They differ from AV malformations in that they lack a true "nidus" and are composed of one or more direct arterial connections to a single venous channel. They often are associated with a venous varix because of their high-flow nature. The pathological aspects of pial AV fistulae arise from their high-flow dynamics; therefore, we think that disconnection of the AV shunt is enough to obliterate the lesion, and that lesion resection is unnecessary. Flow disconnection can be accomplished via surgical or endovascular means. Certain lesions have angiogeometric configurations, however, that are unfavorable for endovascular treatment. We reviewed the experience in our combined neurosurgical and neuroendovascular unit in the treatment of patients with pial single-channel AV fistulae.

METHODS

From 1991 to 1999, the combined neurovascular unit at the Massachusetts General Hospital treated nine consecutive patients with nontraumatic intracranial pial single-channel AV fistulae. Carotid-cavernous fistulae and vein of Galen malformations were excluded from this analysis. The combined neurovascular team planned the treatment strategy for each patient on the basis of the anatomic location and the angiogeometry of each lesion. We retrospectively reviewed the medical records, office charts, operative reports, endovascular reports, and x-rays for each patient. Radiographic outcome was assessed by use of posttreatment angiography. Clinical outcome was assessed by an independent nurse practitioner.

RESULTS

A treatment strategy of flow disconnection was used in all nine patients and was accomplished surgically in six patients, endovascularly in two patients, and by combined techniques in one patient. All nine lesions were completely obliterated as demonstrated radiographically, including obliteration of the venous varices associated with three of the lesions. With a mean long-term clinical follow-up of 3.2 years (range, 0.3-8.4 yr), four patients were neurologically excellent with no deficits, two patients had pretreatment neurological deficits that did not worsen after treatment, one patient had transient dysphonia and dysphagia postoperatively that resolved, one patient had mild weakness after treatment, and one patient had moderate homonymous hemianopia after treatment.

CONCLUSION

Single-channel pial AV fistulae can be treated by a strategy of flow disconnection. Resection of the lesion is not necessary. Flow disconnection can be accomplished either surgically or endovascularly; however, certain angiogeometric configurations are more favorable for surgical treatment. An experienced combined neurosurgical and neuroendovascular team can carefully determine the most appropriate treatment modality on the basis of patient-specific and angiospecific factors.

Potential role of modifier genes influencing transforming growth factor-beta1 levels in the development of vascular defects in endoglin heterozygous mice with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder because of mutations in the genes coding for endoglin (HHT1) or ALK-1 (HHT2). The disease is associated with haploinsufficiency and a murine model was obtained by engineering mice that express a single Endoglin allele. Of a total of 171 mice that were observed for 1 year, 50 developed clinical signs of HHT. Disease prevalence was high in 129/Ola strain (72%), intermediate in the intercrosses (36%), and low in C57BL/6 backcrosses (7%). Most mice first presented with an ear telangiectasia and/or recurrent external hemorrhage. One-third of mice with HHT showed severe vascular abnormalities such as dilated vessels, hemorrhages, liver and lung congestion, and/or brain and heart ischemia. Disease sequelae included stroke, hydrocephalus, fatal hemorrhage, and congestive heart failure. Thus the murine model reproduces the multiorgan manifestations of the human disease. Levels of circulating latent transforming growth factor (TGF)-beta1 were significantly lower in the 129/Ola than in the C57BL/6 strain. Intercrosses and 129/Ola mice expressing reduced endoglin also showed lower plasma TGF-beta1 levels than control. These data suggest that modifier genes involved in the regulation of TGF-beta1 expression act in combination with a single functional copy of endoglin in the development of HHT.

Endovascular embolisation of a cerebral arteriovenous fistula with hereditary haemorrhagic telangiectasia. Case report and review of the literature

SUMMARY

We report a case of cerebral arteriovenous fistula (AVF) associated with hereditary haemorrhagic telangiectasia (HHT). Although the patient had no symptoms from the cerebral AVF, the AVF was successfully embolised using a twostaged double provocative test. We reviewed the literature of HHT and have concluded that there are two types of cerebral arteriovenous communication in patients with HHT and endovascular embolisation is the most reasonable therapy for the fistula type from the standpoint of its angioarchitecture.

Brain abscess in patients with hereditary hemorrhagic telangiectasia: case report and literature review

Hereditary hemorrhagic telangiectasia (HHT), or Osler-Weber-Rendu disease, affects multiple organ systems. Brain abscess is a potential complication, and this disease carries a high mortality. In the setting of HHT the abscess most likely results from paradoxical septic emboli or bacterial seeding of an ischemic portion of the brain after paradoxical sterile emboli. Brain abscess is the diagnosis that must be ruled out in patients with HHT presenting with new onset neurologic symptoms. The clinician can be misled by seemingly benign and nonspecific symptoms, signs, and laboratory test results. Appropriate diagnostic imaging with computed tomography or magnetic resonance imaging of the head is mandatory. We present a case of brain abscess in a patient with HHT presenting to the Emergency Department. The review of the literature deals with the pathophysiology and manifestations of HHT with particular focus on the pathologic and clinical features, and management of cerebral abscess in this setting. Differences between patients with brain abscess with or without HHT are highlighted.

Cerebrovascular manifestations in 321 cases of hereditary hemorrhagic telangiectasia

BACKGROUND AND PURPOSE

Patients with hereditary hemorrhagic telangiectasia (HHT) are at risk for developing cerebral vascular malformations and pulmonary arteriovenous fistulae. We assessed the risk of neurological dysfunction from these malformations and fistulae.

METHODS

Three hundred twenty-one consecutive patients with HHT seen at a single institution over a 20-year period were studied. Any evidence of prior neurological symptoms or presence of an intracranial vascular malformation was recorded. All cases of possible cerebral arteriovenous malformation were confirmed by conventional arteriography.

RESULTS

Twelve patients (3.7%) had a history of cerebral vascular malformations. Ten patients had arteriovenous malformations, 1 had a dural arteriovenous fistula, and 1 had a cavernous malformation. Seven patients (2.1%) presented with intracranial hemorrhage, 2 presented with seizures alone, and 3 were discovered incidentally. The average age at the time of symptomatic intracranial hemorrhage was 25.4 years. All patients with a history of intracranial hemorrhage were classified as Rankin grade I or II at a mean follow-up interval of 6.0 years. A history of cerebral infarction or transient ischemic attack was found in 29.6% of patients with HHT and a pulmonary arteriovenous fistula.

CONCLUSIONS

The risk of intracranial hemorrhage is low among people with HHT. Furthermore, a majority of these patients have a good functional outcome after hemorrhage. The data do not suggest a compelling indication for routine screening of patients with HHT for asymptomatic cerebral vascular malformations. By comparison, pulmonary arteriovenous fistulae are a much more frequent cause of neurological symptoms in this population.