title: Prevalence of patent foramen ovale (PFO) and MRI-lesions in mild neurological decompression sickness (type B-DCS/AGE).
abstract: BACKGROUND
  Neurological decompression sickness (DCS/AGE) may cover two variants with either severer and probably central nervous (Type A) or milder and sometimes doubtful neurological symptoms (Type B). The pathophysiology of the Type B-DCS/AGE might be different from the Type A-variant. In Type A-DCS/AGE a higher PFO-prevalence (patent foramen ovale) points towards an embolic origin of the Type A-symptomatology. This is not necessarily expected for the Type B-DCS/AGE if the pathophysiology here is micro-embolic or even non-embolic.
  
  
  METHODS
  18 patients with Type B-DCS/AGE were tested against matched controls for presence and size of a PFO with echocardiography and transcranial ultrasound with echo-contrast. Prevalence and number of Type A-brain lesions were visualized by cranial MRI as possible sequelae from gas-embolic events.
  
  
  RESULTS
  PFO-prevalence in both groups, the patients with Type B-DCS/AGE (5/18) as well as the controls (7/18) was similar to published PFO-prevalences in normals without any difference between patients and controls (p = 0.725). Also the number of MRI-lesions (ACFs) was the same for Type B-DCS/AGE cases (15 ACFs in 5 patients) and controls (37 ACFs in 8 divers).
  
  
  CONCLUSIONS
  Indirect findings suggesting embolic brain injuries are found with similar frequency in patients with Type B-DCS/AGE and normal controls, which is in contrast to data about Type A-DCS/AGE. This is compatible with different pathophysiological mechanisms involved in the Type A- and Type B-DCS/AGE.
authors.affiliation: German Naval Medical Institute, Kiel-Kronshagen, Germany.
authors.forename: A E
authors.initials: AE
authors.lastname: Koch
authors.forename: H
authors.initials: H
authors.lastname: Kirsch
authors.forename: M
authors.initials: M
authors.lastname: Reuter
authors.forename: V
authors.initials: V
authors.lastname: Warninghoff
authors.forename: H
authors.initials: H
authors.lastname: Rieckert
authors.forename: G
authors.initials: G
authors.lastname: Deuschl
mesh_terms: D000328:Adult; D001927:Brain Diseases / Q000175:diagnosis / Q000503:physiopathology*; D016022:Case-Control Studies; D003665:Decompression Sickness / Q000503:physiopathology*; D004452:Echocardiography; D004618:Embolism, Air / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D054092:Foramen Ovale, Patent / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D015995:Prevalence; D018709:Statistics, Nonparametric