Vestibular symptoms and otoneurological findings in retired offshore divers

Inner ear barotraumas and decompression sickness (DCS) may cause acute vestibular symptoms in divers. The result may be irreversible damage to the vestibular end organs or their central connections. We examined a group of offshore divers in order to find out how many divers experience vestibular symptoms later in life and how this was related to occupational history and objective findings.

A questionnaire was sent to 230 offshore divers (mean age 52 yr) and 166 age-matched non-diving controls. Most of the divers had retired from diving. A subgroup (n=96) of the divers was referred for examination, including a clinical otoneurological examination, electronystagmography, bithermal caloric tests, and platform posturography. In addition, 42 of the controls were examined.

The prevalence of dizziness (28%), spinning vertigo (14%), and unsteady gait (25%) was significantly higher in divers than controls (p < 0.0005). These symptoms were strongly associated with a previous history of DCS, particularly type I, which was reported by 61% of the divers. Symptoms were less strongly associated with the number of dives. In referred divers with dizziness, the prevalence of abnormal postural sway, nystagmus, canal paresis, or pathological smooth pursuit was 32%, 9%, 7%, and 11%, respectively.

Reasons for the high prevalence of vestibular symptoms among the divers are discussed. The high exposure to DCS is probably an important factor.