Slosh Simulation in a Computer Model of Canine Syringomyelia

Area of Science:

• Neurology
• Biomechanical Engineering
• Computational Biology

Background:

• The pathogenesis of syringomyelia, characterized by fluid-filled cavities within the spinal cord, remains incompletely understood.
• A proposed mechanism involves epidural venous distention during increased intrathoracic pressure, leading to a fluid "slosh" within the syrinx.
• This fluid dynamics could drive syrinx dissection into spinal cord parenchyma and craniocaudal cavity propagation.

Purpose of the Study:

• To investigate the validity of the
• slosh" hypothesis for syringomyelia pathogenesis.
• To model the effects of epidural cerebrospinal fluid (CSF) pulse on syrinx formation and propagation in a canine model.

Main Methods:

• Modification of a previously developed canine syringomyelia computer model to incorporate an epidural pressure pulse.
• Running simulations on spinal cord models with no cavities, small syrinxes at various locations, and progressively expanding caudal syrinxes.

Main Results:

• Simulations revealed stress peaks at the locations of small syrinxes, most pronounced where they initially form.
• During caudal syrinx expansion, peak stress was typically at the caudal end.
• However, stress moderated when the syrinx reached the lumbar region.

Conclusions:

• The findings provide support for the "slosh" hypothesis, indicating that small cervical syrinxes may propagate caudally.
• Reduced focal stress in large syrinxes may explain their rapid expansion followed by a stable shape over time.