The Workshop on Long-Term Health Hazards of Diving with Regard to the Central Nervous System

Research in the 1950s called attention to the possible existence of a chronic progressive encephalomyelopathy that occurred as a result of repeated decompressions from raised environmental pressures. This neurologic disorder could occur in the absence of decompression sickness, but was more common in individuals with a history of prior decompression sickness. In this presentation the general problem of chronic progressive encephalomyelopathy is addressed on three levels 1 cases of central nervous system degeneration occurring in individuals exposed to repeated decompressions without any history of preceding decompression sickness or air embolism 2 individuals incurring central nervous system damaging decompression sickness or air embolism during the course of a decompression from raised environmental pressure, and subsequently, developing chronic progressive central nervous system degeneration despite refraining from further diving 3 individuals afflicted by decompression sickness or air embolism who developed chronic progressive central nervous system degeneration in the setting of continued diving. Although ischemia appears to play a major role in neuraxis damage in decompression sickness and the analogous process of stroke in humans does not generally show chronic progression, it does not seem possible to confirm or deny the occurrence of this chronic progressive encephalomyclopathy at present.