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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Capillary telangiectasia is a vascular abnormality primarily of the brainstem. The clinical relevance is unclear as is the association with clearly pathologic findings such as cavernous haemangioma. We report on four cases with capillary telangiectasia proven by follow-up and describe the imaging characteristics. T2 abnormality was only observed in half of the patients as was the presence of a discernable collecting vein. Whereas two cases were incidental findings in neurologically normal persons and one had symptoms clearly attributable to lacunar stroke, one patient may have had symptoms due to the vascular abnormality in the pons.
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PMID:Presumed capillary telangiectasia of the pons: MRI and follow-up. 1087 9

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.
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PMID: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. 1139 79

Pulmonary arteriovenous malformations are congenital vascular malformations in the lungs, which act as shunts so that the blood is not oxygenated or filtered. These patients are typically hypoxaemic with exercise intolerance and are at high risk of paradoxical emboli to the brain. About 25% of patients with the Rendu-Osler-Weber syndrome (hereditary haemorrhagic telangiectasia) have these pulmonary malformations. A modern treatment strategy is embolisation with balloon or coils of the afferent arteries to the arteriovenous malformations. It is a minimally invasive procedure with a very high technical success and few complications. Embolisation prevents cerebral stroke and abscess and pulmonary haemorrhage and further raises the functional level. Screening for pulmonary arteriovenous malformations in patients at risk is recommended.
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PMID:[Pulmonary arteriovenous malformations. Current therapeutic principles]. 1152 79

Coronary artery-left ventricular (LV) fistulas are extremely rare and can cause myocardial ischemia from coronary steal. We describe an elderly woman who presented with unstable angina from multiple and extensive coronary artery-LV fistulas. She also had clinical features suggestive of hereditary hemorrhagic telangiectasia (HHT). Association of coronary artery-LV fistulas with HHT has not been reported and can pose a management dilemma in view of the risks of extensive cardiopulmonary surgery and potential complications of myocardial ischemia, stroke, and brain abscess.
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PMID:Multiple coronary artery-left ventricular fistulas associated with hereditary hemorrhagic telangiectasia. 1159 93

Pulmonary arteriovenous malformations (PAVM) are rare pulmonary vascular anomalies. Although most patients are asymptomatic, PAVMs can cause dyspnoea from right-to-left shunt. Because of paradoxical emboli, various central nervous system complications have been described including stroke and brain abscess. There is a strong association between PAVM and hereditary haemorrhagic telangiectasia. Chest radiography and contrast enhanced computed tomography are essential initial diagnostic tools but pulmonary angiography is the gold standard. Contrast echocardiography is useful for diagnosis and monitoring after treatment. Most patients should be treated. Therapeutic options include angiographic embolisation with metal coil or balloon occlusion and surgical excision.
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PMID:Pulmonary arteriovenous malformation. 1193 21

We report on a 57-year-old woman with three episodes of ischemic strokes and hereditary hemorrhagic telangiectasia (HHT). Tests for inherited and acquired thrombophilia showed elevated anticardiolipin immunoglobulin (Ig)M antibodies (on three separate occasions), anti-prothrombin IgG antibodies, and the heterozygous form of factor V Leiden. This is the first case of HHT, a primary antiphospholipid syndrome, combined with factor V Leiden. No detectable arteriovenous malformation was found and ischemic episodes, documented by computer tomography, were related to the presence of antiphospholipid antibodies and possibly the carriership of factor V Leiden mutation. Since aspirin provoked severe nasal hemorrhages, treatment with ticlopidine was initiated after the third stroke. Over an 18-month follow-up, ischemic episodes were absent and we regarded oral anticoagulation as unjustifiable.
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PMID:Hereditary hemorrhagic telangiectasia, factor V Leiden and antiphospholipid syndrome: a case report. 1199 68

The zebrafish mutant violet beauregarde (vbg) can be identified at two days post-fertilization by an abnormal circulation pattern in which most blood cells flow through a limited number of dilated cranial vessels and fail to perfuse the trunk and tail. This phenotype cannot be explained by caudal vessel abnormalities or by a defect in cranial vessel patterning, but instead stems from an increase in endothelial cell number in specific cranial vessels. We show that vbg encodes activin receptor-like kinase 1 (Acvrl1; also known as Alk1), a TGFbeta type I receptor that is expressed predominantly in the endothelium of the vessels that become dilated in vbg mutants. Thus, vbg provides a model for the human autosomal dominant disorder, hereditary hemorrhagic telangiectasia type 2, in which disruption of ACVRL1 causes vessel malformations that may result in hemorrhage or stroke. Movies available on-line
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PMID:Disruption of acvrl1 increases endothelial cell number in zebrafish cranial vessels. 1205 Jan 47

Rendu-Osler-Weber disease, or hereditary hemorrhagic telangiectasia (HHT), is an autosomal dominant disorder with incomplete penetrance, characterized by vascular anomalies which may virtually develop in many organs. The prevalence varies and may range from 1/3,500 to 1/5,000 in specific regions. Two chromosal sites have been at least identified: in HHT1, mutations at chromosome 9 alter the protein endoglin and in HHT2, mutations at chromosome 12 alter the protein activine or ALK-1. Clinical manifestations include recurrent epistaxis, mucocutaneous telangiectases that bleed easily, and larger arteriovenous malformations in parenchymatous organs. Epistaxis is the first symptom, occurring in the vast majority of affected persons. The lung is the most common site for arteriovenous malformations. Brain abscess, transient ischemic attack and ischemic stroke occur exclusively in patients with pulmonary arteriovenous malformations and right-to-left shunt, which facilitates the passage of emboli into the cerebral circulation. Transcatheter embolotherapy with detachable balloons or stainless-steel coils has been used in order to occlude such malformations and to prevent such complications. At present a genetic diagnosis is possible in only a few families. The clinical diagnosis is based on 4 criteria: family history, epistaxis, mucocutaneous telangiectases and arteriovenous malformations. The diagnosis will be definite if 3 criteria are present, suspected if 2 criteria are present, unlikely if fewer than 2 criteria are present. In conclusion, the authors examine clinical features of 28 HHT patients observed in the HHT University Centre of Bari from September 2000 to May 2001.
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PMID:Hereditary hemorrhagic teleangiectasia (Rendu-Osler-Weber disease). 1210 2

Pulmonary arteriovenous malformation (PAVM) predisposes affected patients to a significantly increased risk of stroke. Most commonly, PAVM is seen in patients with hereditary haemorrhagic telangiectasia (HHT), an inherited disorder that can be difficult to diagnose in young people because of variable age-related penetrance. As such, stroke in the young adult may be the presenting feature of underlying PAVM in a previously undiagnosed patient. The importance of considering this diagnosis in the evaluation of young adults with cryptogenic stroke is underscored by the availability of both sensitive screening and effective treatment for PAVM, from which this at-risk population can greatly benefit.
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PMID:Pulmonary arteriovenous malformation: a rare, treatable cause of stroke in young adults. 1462 88

Vascular interventions are important and helpful for treatment of various pathologies of the head and neck. Interventional neuroradiology of the head and neck includes image-guided biopsies, vessel occlusion, and local chemotherapy. Knowledge of anatomy, functional relationships between intra- and extracranial vessels, and pathology are the basis for therapeutic success. The interventional neuroradiologist is responsible for appropriate selection of patients based on clinical information, indications, and risk assessment. Neuroradiologic imaging, especially CT and MR imaging, and appropriate analysis of angiographic findings help ensure indication for treatment and plan an intervention. Technical equipment, including an angiographic unit, catheters, needles, embolizing materials, and so forth, are important. Knowledge of hemodynamics is relevant to avoid complications and to find the optimal technique for solving the clinical problem. Indications for image-guided biopsies are preverterbal fluid-collections, spinal and paraspinal inflammations and abscesses, deep cervical malignancies, vertebral body, and skull base tumors. Special care should be taken to preserve critical structures in this region, including spinal nerve roots, cervical plexus, main peripheral nerves, and vessels. Indications for vessel occlusion are emergency situations to stop bleeding in vascular lesions (traumatic, malformation, or tumors) by reduction of pressure, preoperative reduction of blood flow to minimize the surgical risk, palliative occlusion of feeding vessels to produce tumor necrosis, or potential curative (or presurgical) occlusion of vascular malformations. Pressure reduction to support normal coagulation, such as epistaxis, in hereditary hemorrhagic telangiectasia can be achieved by proximal vessel occlusion with large particles or platinum coils. Prevention of intraoperative bleeding requires occlusion of the microvascular bed with small particles. Examples of these interventions are: a hemangioma of the hard palate, a juvenile angiofibroma, a hemangiopericytoma, a malignant meningioma, a malignant fibrous histiocytoma, and a glomus tumor. Effective treatment of vascular malformations, such as AV fistulas or angiomas, needs exact occlusion of the fistula or the angiomatous nidus, which is demonstrated in the case of an AV angioma of the base of the tongue. Chemotherapy with local intra-arterial cisplatin combined with intravenous administration of sodium thiosulfate as antidote is indicated as an adjuvant modality in a multimodal regimen of oropharyngeal squamous cell carcinoma or as palliative treatment of recurrent and otherwise untreatable malignant tumors of the head and neck. Examples are a carcinoma of the alveolar ridge, a squamous cell carcinoma of the floor of the mouth, and a nasopharyngeal lymphoepithelioma. Palliative treatment of a bleeding oropharyngeal cancer is another example of interventional treatment. Selective treatment, either occluding or pharmacologic, may be preoperative, palliative, or curative. The objective is reduction of surgical risk, improvement of quality of life, or curative therapy of a lesion. Thus, the interventional treatment should not be associated with morbidity or mortality. Major complications, such as cerebral stroke, blindness, or cranial nerve palsies, can result from application of inappropriate techniques or poor evaluation of angiographic findings and should be avoided in the majority of cases. Sometimes collateral lesions are unavoidable. These include inflammation, necrosis, and nerve damage. Based on neuroradiologic experience, most of those risks are predictable. The benefits, risks, and expected damages of neuroradiologic interventions must be balanced during the informed consent procedure with the patient. Avoiding complications, handling unavoidable problems, and dealing with complications is a skill founded on knowledge and experience. Continuing education is a firm basis to push the limits of interventions and expand benefits without increasing risk for the patient. Nevertheless, state-of-the-art external carotid intervention should, in skilled hands, have a permanent morbidity far below 1% and no mortality.
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PMID:Interventional neuroradiology of the head and neck. 1463 95


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