title: Cohort study of multiple brain lesions in sport divers: role of a patent foramen ovale.
abstract: OBJECTIVE
  To investigate the role of a patient foramen ovale in the pathogenesis of multiple brain lesions acquired by sport divers in the absence of reported decompression symptoms.
  
  
  METHODS
  Prospective double blind cohort study.
  
  
  METHODS
  Diving clubs around Heidelberg and departments of neuroradiology and neurology.
  
  
  METHODS
  87 sport divers with a minimum of 160 scuba dives (dives with self contained underwater breathing apparatus).
  
  
  METHODS
  Presence of multiple brain lesions visualised by cranial magnetic resonance imaging and presence and size of patent foramen ovale as documented by echocontrast transcranial Doppler ultrasonography.
  
  
  RESULTS
  25 subjects were found to have a right-to-left shunt, 13 with a patent foramen ovale of high haemodynamic relevance. A total of 41 brain lesions were detected in 11 divers. There were seven brain lesions in seven divers without a right-to-left shunt and 34 lesions in four divers with a right-to-left shunt. Multiple brain lesions occurred exclusively in three divers with a large patent foramen ovale (P = 0.004).
  
  
  CONCLUSIONS
  Multiple brain lesions in sport divers were associated with presence of a large patent foramen ovale. This association suggests paradoxical gas embolism as the pathological mechanism. A patent foramen ovale of high haemodynamic relevance seems to be an important risk factor for developing multiple brain lesions in sport divers.
authors.affiliation: Department of Neuroradiology, University of Heidelberg, Klinikum Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Knauth
authors.forename: S
authors.initials: S
authors.lastname: Ries
authors.forename: S
authors.initials: S
authors.lastname: Pohimann
authors.forename: T
authors.initials: T
authors.lastname: Kerby
authors.forename: M
authors.initials: M
authors.lastname: Forsting
authors.forename: M
authors.initials: M
authors.lastname: Daffertshofer
authors.forename: M
authors.initials: M
authors.lastname: Hennerici
authors.forename: K
authors.initials: K
authors.lastname: Sartor
mesh_terms: D001930:Brain Injuries / Q000175:diagnosis / Q000209:etiology*; D015331:Cohort Studies; D004242:Diving / Q000293:injuries*; D004311:Double-Blind Method; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000150:complications; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D018608:Ultrasonography, Doppler