Influence of occupational diving upon the nervous system: an epidemiological study.

Neurological signs and symptoms were recorded from 156 air and saturation divers and 100 controls. Fifty one (33%) of the divers had had symptoms from the central nervous system during decompression. Also, 22 (14%) had been unconscious while diving. In total 79 (51%) had had decompression sickness (DCS). Twelve (8%) of the divers and no controls had had specific neurological symptoms (vision disturbances, vertigo, reduced skin sensitivity) in non-diving situations, and six (4%) of the divers (no controls) had had episodes of cerebral dysfunction (seizures, transient cerebral ischaemia, transient amnesia). The divers had significantly more general symptoms from the nervous system and more abnormal neurological findings than the controls. The most prominent symptoms were difficulties in concentration and problems with long and short term memory. The most prominent abnormal findings in the divers were compatible with dysfunction in the distal spinal cord or nerve roots, and polyneuropathy. The general neurological symptoms and findings were independently significantly correlated with diving exposure, prevalence of DCS, and age.