SUMMARY

Two cases of pulmonary arteriovenous fistulas with hemiparesis and other neurologic findings, possibly from paradoxical embolization, are described. Many theories have been put forward to explain the pathophysiology of the frequently present neurologic manifestations. We regard paradoxical embolization through the fistula as the most important factor in the pathogenesis of the neurologic deficit. Due to the potential hazard of paradoxical cerebral embolization and possible subsequent brain abscess formation, surgical resection of all pulmonary arteriovenous fistulas wherever feasible is recommended. Additional Indexing Words: Pulmonary arteriovenous fistula Brain abscess Cerebral embolism OVER 350 cases of pulmonary arteriove-nous fistula have been recognized ' since the initial autopsy diagnosis of this condition by Churton in 18972 and the first clinical diagnosis by Smith and Horton in 1939.3 Clinical manifestations of pulmonary arterio-venous fistulas include cyanosis, clubbing, extracardiac murmur, pulmonary hemorrhage, secondary polycythemia, and pulmonary mass.4-6 Hereditary hemorrhagic telangiectasis is frequently present.7 8 Of particular interest is the approximately 33 % incidence of neurologic abnormalities.9-1 Headache, dizziness, tinnitus, convulsions, and hemiplegia are occasionally present. Although neurologic symptoms are often transient, permanent damage has occurred.5 ' 10, 12 The neurologic manifestations have been attrib