Cerebral ischemia in Rendu-Osler-Weber disease
Neurologic manifestations occur in 8-12% of the patients with Rendu-Osler-Weber disease or hereditary hemorrhagic telangiectasia (HHT), principally infectious and hemorrhagic and, less frequently, ischemic ones. More than a half of these neurologic complications are associated with pulmonary arterio-venous malformations (PAVM). The diagnosis of HHT is based on the presence of telangiectases, hemorrhagic events and a family history with an autosomal dominant pattern. We report a case of a patient diagnosed as having HHT with transient ischemic attacks and a PAVM, which was occluded by the use of embolotherapy. Cerebral ischemia in HHT is related to the existence of a PAVM and results from three mechanisms: 1) secondary poliglobulia and hyperviscosity because of the hypoxemia due to a right-left shunt; 2) communication between the airway and the pulmonary circulation during cough access, which produces gas embolism and hemoptysis; 3) and, finally, paradoxical embolism trough the PAVM, the same mechanism proposed to the infectious neurologic manifestations of the disease. When the diagnosis of HHT is suspected, early search and treatment of PAVM, with embolotherapy or surgery, are necessary in order to avoid respiratory problems (hemoptysis, exertional dyspnea, cianosis, clubbing) and neurologic complications.