title: Transcranial Doppler ultrasonography and transesophageal echocardiography in the investigation of pulmonary arteriovenous malformation in a patient with hereditary hemorrhagic telangiectasia presenting with stroke.
abstract: BACKGROUND
  Hereditary hemorrhagic telangiectasia (HHT) is associated with a high incidence of pulmonary arteriovenous malformations (PAVMs), which can be the underlying cause for cerebral ischemia or brain abscess. The diagnosis of these malformations may be difficult, as clinical or radiological findings may be absent. Transcranial Doppler ultrasound (TCD) with saline contrast and transesophageal echocardiography (TEE) with saline contrast are useful in identifying patients with right-to-left shunts and may help identify PAVMs.
  
  
  METHODS
  A 68-year-old woman with HHT presented with two strokes over a 1-year period. After the first stroke, a transthoracic echocardiogram with saline contrast demonstrated significant right-to-left shunt that was interpreted as a patent foramen ovale. After the second stroke, a TCD contrast study confirmed this right-to-left shunt; however, a TEE contrast study discovered an extracardiac shunt. Pulmonary angiography revealed a left lower lobe PAVM and three telangiectasias involving the right lung. The PAVM was subsequently embolized. Postembolization radiographic imaging showed complete occlusion of the feeding vessel to the PAVM. However, repeated contrast TCD and TEE demonstrated persistent right-to-left shunting.
  
  
  CONCLUSIONS
  In our patient, stroke may have resulted from peripheral venous emboli passing through the PAVM or from endogenous thromboemboli originating within the PAVM. TCD and TEE contrast studies were helpful in judging the efficacy of catheter embolization therapy of PAVM. TCD and TEE with saline contrast may be clinically useful follow-up examinations for recurrence or development of new PAVMs.
authors.affiliation: Saskatchewan Stroke Research Centre, Royal University Hospital, University of Saskatchewan, Saskatoon, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Yeung
authors.forename: K A
authors.initials: KA
authors.lastname: Khan
authors.forename: D H
authors.initials: DH
authors.lastname: Antecol
authors.forename: D R
authors.initials: DR
authors.lastname: Walker
authors.forename: A
authors.initials: A
authors.lastname: Shuaib
mesh_terms: D000368:Aged; D001165:Arteriovenous Malformations / Q000000981:diagnostic imaging* / Q000628:therapy; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D017548:Echocardiography, Transesophageal; D004621:Embolization, Therapeutic; D005260:Female; D005500:Follow-Up Studies; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging; D006801:Humans; D008168:Lung / Q000098:blood supply* / Q000000981:diagnostic imaging; D008171:Lung Diseases / Q000000981:diagnostic imaging; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000000981:diagnostic imaging*; D017585:Ultrasonography, Doppler, Transcranial