title: Association between right-to-left shunts and brain lesions in sport divers.
abstract: BACKGROUND
  Recent studies suggest that healthy sport divers may develop clinically silent brain damage, based on the association between a finding of multiple brain lesions on MRI and the presence of right-to-left shunt, a pathway for venous gas bubbles to enter the arterial system.
  
  
  METHODS
  We performed echocontrast transcranial Doppler sonography in 42 sport divers to determine the presence of a right-to-left shunt. Cranial MRI was carried out using a 1.5 T magnet. A lesion was counted if it was hyperintense on both T2-weighted and T2-weighted fluid attenuated inversion recovery sequences. To test the hypothesis that the occurrence of postdive arterial gas emboli is related to brain lesions on MRI, we measured postdive intravascular bubbles in a subset of 15 divers 30 min after open water scuba dives.
  
  
  RESULTS
  Echocontrast transcranial Doppler sonography revealed a right-to-left shunt in 16 of the divers (38%). Only one hyperintensive lesion of the central white matter was found and that was in a diver with no evidence of a right-to-left shunt. Postdive arterial gas emboli were detected in 3 out of 15 divers; they had a right-to-left shunt, but no pathologic findings on cranial magnetic resonance imaging.
  
  
  CONCLUSIONS
  Our data support the theory that right-to-left shunts can serve as a pathway for venous gas bubbles into the arterial circulation. However, we could not confirm an association between brain lesions and the presence of a right-to-left shunt in sport divers.
authors.affiliation: Department of Neurology, Justus-Liebig-University Giessen, Am Steg 20, 35390 Giessen, Germany. Tibo.Gerriets@neuro.med.uni-giessen.de
authors.forename: Tibo
authors.initials: T
authors.lastname: Gerriets
authors.forename: Kay
authors.initials: K
authors.lastname: Tetzlaff
authors.forename: Alfred
authors.initials: A
authors.lastname: Hutzelmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Liceni
authors.forename: Gerrit
authors.initials: G
authors.lastname: Kopiske
authors.forename: Niklas
authors.initials: N
authors.lastname: Struck
authors.forename: Michael
authors.initials: M
authors.lastname: Reuter
authors.forename: Manfred
authors.initials: M
authors.lastname: Kaps
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000473:pathology*; D001927:Brain Diseases / Q000209:etiology / Q000503:physiopathology*; D002536:Cerebral Arteries / Q000002:abnormalities*; D003287:Contrast Media / Q000008:administration & dosage; D003665:Decompression Sickness / Q000209:etiology / Q000503:physiopathology*; D004242:Diving / Q000009:adverse effects*; D004453:Echoencephalography; D004618:Embolism, Air / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018608:Ultrasonography, Doppler
chemical_list: D003287:Contrast Media