title: Cerebral ischemic events associated with 'bubble study' for identification of right to left shunts.
abstract: OBJECTIVE
  Detection of an intracardiac shunt is frequently sought during the evaluation of patients with cryptogenic ischemic stroke and agitated saline intravenous injection, or "bubble study" (BS), is performed in most cases. We present the first attempt to identify the clinical features in patients who had cerebral ischemic events with BS.
  
  
  METHODS
  Using a list serve established by the American Academy of Neurology, a member posted a question regarding the safety of BS in patients with patent foramen ovale. A standardized questionnaire was used to gather data about patients with cerebral ischemic events, details of each case were reviewed, and the findings pooled.
  
  
  RESULTS
  Five patients with ischemic complications of BS (all female, aged 42 to 90 years) were identified from 4 institutions, 3 ischemic strokes and 2 transient ischemic attacks. Events occurred either during or within 5 minutes of BS. Early brain MRIs confirmed acute infarction in 3, including one who had transient symptoms. MRI infarct volumes were small, and deficits were mild in those who developed stroke. Diagnostic evaluation revealed a patent foramen ovale alone in one case, a pulmonary arteriovenous malformation in one case, and a patent foramen ovale and/or pulmonary shunt in 3 cases.
  
  
  CONCLUSIONS
  Ischemic cerebrovascular complications can occur in patients who undergo BS and are associated with the presence of cardiac or pulmonary shunts. The true incidence and degree of disability remains unknown, and further study is indicated to assess the impact of technical differences in BS methodology. Novel methods to promote physician communication such as the use of electronic list serves may reduce barriers to reporting of drug, technique, or device complications and should be explored to identify rare complications that otherwise will likely go unappreciated.
authors.affiliation: Department of Neurology, Boston University Medical Center, Boston University School of Medicine, Boston, MA 02118, USA. joromero@bmc.org
authors.forename: José R
authors.initials: JR
authors.lastname: Romero
authors.forename: James L
authors.initials: JL
authors.lastname: Frey
authors.forename: Lee H
authors.initials: LH
authors.lastname: Schwamm
authors.forename: Bart M
authors.initials: BM
authors.lastname: Demaerschalk
authors.forename: Hari P
authors.initials: HP
authors.lastname: Chaliki
authors.forename: Gunjan
authors.initials: G
authors.lastname: Parikh
authors.forename: Robert F
authors.initials: RF
authors.lastname: Burke
authors.forename: Viken L
authors.initials: VL
authors.lastname: Babikian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001165:Arteriovenous Malformations / Q000000981:diagnostic imaging*; D004452:Echocardiography / Q000009:adverse effects / Q000379:methods; D017548:Echocardiography, Transesophageal / Q000009:adverse effects / Q000379:methods; D005260:Female; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging*; D006306:Health Surveys; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology*; D045423:Microbubbles / Q000009:adverse effects*; D008875:Middle Aged; D020521:Stroke / Q000209:etiology*; D017585:Ultrasonography, Doppler, Transcranial / Q000009:adverse effects / Q000379:methods