Gas Bubble Mechanics in Spinal Cord Decompression Sickness

Spinal-cord decompression sickness (SC-DCS) is a severe neurological condition that arises from the formation and growth of gas bubbles in the spinal nerve tissue as a result of a rapid drop in ambient pressure. This is commonly observed in diving and aerospace operations, yet the details of its pathogenesis are poorly understood. We use a multiphysics approach that combines tissue mechanics and gas diffusion in experiments with computer modeling to understand how gas bubbles damage the spinal cord.

We monitor bubble formation and dissolution in ex-vivo tissues and live rats. The rats were monitored in real-time during decompression and recompression using a novel pressure chamber in an MRI scanner. We observe mechanical tearing of the tissue surrounding the gas bubble, signs of hemorrhage, and dislodging of vascular gas bubbles upon recompression. These findings were quantitatively validated with finite-element modeling of a gas bubble in the spinal cord, taking tissue continuum mechanics and gas diffusion through the tissue into account.

In conclusion, we find that SC-DCS injuries are not just ischemic injuries from bubbles blocking the flow of blood, but also mechanical injuries from a tearing of the tissue, and need to be treated as such.