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Spine and Back Health

What Causes Thecal Sac Compression?



What causes thecal sac compression, and can it affect the cauda equina?

What symptoms would it produce and how is it diagnosed?


Hello, thank you for your question. Unfortunately, your question is much too broad to be able to answer in this forum. The thecal sac is another name for the tube-shaped membrane that runs down the length of the spine, in the central spinal canal. Inside the thecal sac are the spinal cord (which runs about 2/3 of the way down the spine), nerve roots, and spinal fluid. Anything that protrudes into the spinal canal can cause compression of the thecal sac.

The most common things that do this are so-called 'degenerative' conditions of the spine, like spinal stenosis, disc bulging or disc herniations, or bone spurs. Other things are much less likely, like tumors, fractures, infections, etc. Compression of the thecal sac does not cause any symptoms. Compression of the nerves or spinal cord inside the thecal sac can cause pain / numbness / tingling / weakness. It is usually diagnosed by radiology studies, MRI being the most common. I hope this helps clear a few things up for you.

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Response by:

David J Hart, MD David J Hart, MD
Associate Professor of Neurosurgery
School of Medicine
Case Western Reserve University