A Fluid Structure Interaction Simulation of the Cerebrospinal Fluid, Spinal Cord, and Spinal Stenosis Present in Syringomyelia

Abstract

Syringomyelia (SM) is a neurological disease in which a fluid-filled cystic cavity, or syrinx, forms in the spinal cord (SC) resulting in progressive loss of sensory, motor functions, and/or pain in the patient. It has been hypothesized that abnormal cerebrospinal fluid (CSF) pressure distribution and absorption in the subarachnoid space (SAS), resulting from a CSF flow blockage (stenosis), could be a key etiological factor for syrinx pathogenesis. In particular, the magnitude of the abrupt SAS pressure waves produced during coughing has been correlated with headache and pain in the patient. To better understand the influence of coughing on the spinal SAS, four axisymmetric fluid-structure interaction (FSI) in silico models representative of various conditions associated with SM were constructed. Each of the models was subjected to a cough-like CSF pressure pulse. The CSF flow stenosis was shown to attenuate and decelerate the CSF wave propagation in the SAS. The spinal SAS distensibility was also shown to have significant influence on the wave propagation. The in silico pressure results were found to be in agreement with a set of similar in vitro experiments [1].