Abstract
INTRODUCTION: Post-traumatic syringomyelia typically occurs in the spinal cord adjacent to a region of arachnoiditis. This research tests the hypothesis that pressure pulses in the subarachnoid space (SAS) are higher adjacent to the arachnoiditis than in its absence. A fluid-structure interaction (FSI) analysis has been performed to study this behaviour under both normal physiological conditions and in the presence of arachnoiditis.
METHOD: A 2-dimensional axisymmetric cylindrical FSI model has been developed to represent the spinal cord and the SAS. CSF flow into the SAS is defined from MRI flow studies. Arachnoiditis is modelled as narrowing of the SAS. This model was based on a patient suffering from post-traumatic syringomyelia. Only the cervical region where arachnoiditis occurs has been modelled, that is from C1 to T1.
RESULTS: Pressures in the SAS adjacent to arachnoiditis are almost three times higher (7.2 Pa vs. 21.67 Pa) than without arachnoiditis, with peak pressure occurring at the time of peak fluid inflow from the foramen magnum.
DISCUSSION: The model supports the hypothesis that pressure pulses in the SAS are higher in the presence of the arachnoiditis than in normal unobstructed SAS. This elevated pressure may be implicated in syrinx formation.
These abstracts were prepared by Dr Robert J. Moore. Correspondence should be addressed to him at Spine Society of Australia, Institute of Medical and Veterinary Science, The Adelaide Centre for Spinal Research, Frome Road, Adelaide, South Australia 5000.
