The symposium is co-organised by The Ann Conroy Trust, in association with Aesculap Academia.
The Ann Conroy Trust is Registered Charity No: 1165808.
We provide Support, Education and Research for patients living with Chiari Malformation, Syringomyelia and associated conditions.
F31 Syringomyelia pathology: insights from animal models and ultrastructural studies.
Lam M, Hemley S, Najafi E, Berliner J, Bilston L, Stoodley M.
Syringomyelia includes a range of conditions characterized by the presence of fluid-filled cavities in the spinal cord. The mechanisms of syrinx formation remain poorly understood and treatment options are limited. Perivascular spaces have been hypothesized to play a role by providing rapid access for cerebrospinal fluid in the subarachnoid space into the spinal cord tissue but their anatomical details have not been well described.
We used transmission electron microscopy to study the ultrastructure of perivascular spaces and the surrounding spinal cord tissue, in healthy Sprague Dawley rats and in a model of post-traumatic syringomyelia. The model was created using a motorized spinal cord impactor, followed by a subarachnoid injection of kaolin to produce arachnoiditis. In healthy animals, CSF tracers (horseradish peroxidase, ovalbumin-AF647; 45kD, and nano-gold, 5 nm) were used to investigate the continuity of fluid pathways between subarachnoid space and central canal.
Animals with post-traumatic syringomyelia appeared to have an intact blood-brain barrier. However, spinal cord perivascular spaces were strikingly enlarged. Perivascular spaces were continuous with the extracellular spaces of the surrounding tissue and with the vascular wall basement membranes. Other abnormalities included an abundance of immune-type cells in the subarachnoid space, broadening of extracellular spaces and loss of tissue integrity. Five minutes after injection at cisterna magna, CSF tracers were distributed throughout the tissue and fluid compartments. Surprisingly, tracers were also seen in the lumen of blood vessels, suggesting trans-vascular clearance.
These findings have potential implications for CNS fluid volume regulation, as well as clinically for the detection of CNS-derived biomarkers in blood, the regulation of immune response and for delivery of therapeutic agents