Recurrent inner ear decompression sickness associated with a patent foramen ovale.

Isolated inner ear injuries occurring during shallow scuba dives are an uncommon manifestation of decompression sickness in recreational divers. We describe a patient who presented with the typical symptoms of inner ear involvement after 2 independent dives within the decompression limits. The diver reported symptoms of unilateral (right-sided) hearing loss, tinnitus, and vertigo after dives to 35 and 50 m. After treatment with hyperbaric oxygen, his symptoms completely resolved. To confirm the hypothesis of inner ear decompression sickness (IEDCS), we examined the patient for a right-to-left shunt by cranial Doppler ultrasound and found a patent foramen ovale. The existence of a patent foramen ovale is suspected to be a risk factor for developing neurological symptoms of decompression sickness. There was no evidence of any other risk factors, so we suggest that the relevant right-to-left shunt in our patient may have been the predisposing factor that caused the inner ear symptoms during his scuba dive.