Prevalence of patent foramen ovale (PFO) and MRI-lesions in mild neurological decompression sickness (type B-DCS/AGE).
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.
Koch
A E
AE
German Naval Medical Institute, Kiel-Kronshagen, Germany.
Kirsch
H
H
Reuter
M
M
Warninghoff
V
V
Rieckert
H
H
Deuschl
G
G
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