Question
Hello

My MRI scan results describe a "small central disc protrusion seen at L5-S1 causing thecal indentation". I don't understand what this really means and would like this to be explained.

I experience very slight pain in my lower left side of my back and a numbness in my left thigh when I sit continuously for while with no movement

I have been advised to avoid strenuous activity for at least two months and need to use a L S corset belt while riding my motorbike.

I need to understand the long term effect this would have on the activities that I can perform

Thanks

Answer
Dear Jefferson,

This is actually pretty clear cut and easy to understand when you define the terms and have an illustration to visualize...let me explain.

The disc is a small fibrous and gelatinous "shock absorber" which is located between vertebra in the spine. Injury or degeneration can changes the orientation of the disc and create a breakdown of the fibers or a bulge.  When the disk bulges it can likened to squeezing an ice cream sandwich where the ice cream starts to bulge out from the center.  In your spine, the last disc in the spine has bulged out directly backward, but not to the sides.

Thecal indentation:  the outer covering of the spinal cord is called the thecal sac and contains the cerebral spinal fluid (CSF) which covers and nourishes the spinal cord.  There are three layers to the thecal sac, called the dura matter, arachnoid matter and pia matter.  The dura is the otter most layer and is highly innervated with pain fibers.  So in your case the disc is pressing on the thecal sac, but not the spinal cord itself.

You are fortunate at this time to only have a small bulge, and your MRI does not indicate any tearing of the outside annular portion of the disc.  Therefore, your pain/numbness may actually just subside over the next few weeks.  However, realize that once the disc is injured it does not heal well and you will be left with residual injury (symptomatic or not).  So I agree that you need to watch your motions and avoid strenuous activity so that the disc is not injured worse.  The disc has to heal with scar tissue and this will take a few weeks.  Wearing the corset while on your motor bike is important to provide support to the disc while in the seated position (which is the worst position for the disc) but the compression/vibration you get from the bike can make the disc worse as well...the corset will help to disperse those forces while riding.

However, you want the scar tissue to form as normally as possible and this can only happen with controlled stress and motion.  Chiropractic adjustments would be a good option to help restore proper motion in the area while reducing stress on the disc...we see these cases weekly in our office...there fore I would suggest that you seek out the care of a chiropractic physician if you have access to one locally.

If not there are also some devices you can purchase which will help to rehab the disc and create increased spinal motion to reduce disc stress.  One i utilize in my office that can be purchased by the public is called the POSTURE PUMP.  You can find them online for about $200, and they are easy to use at home.

For illustrations on the spinal anatomy and disc please check out my website.  On the left of the home screen there will be a tab called Chiropractic Information...in that tab click on spinal anatomy or disc herniation for more comprehensive information.  There is also a glossary section where you can explore terms.

Hope this helps Jefferson!

Respectfully,
Dr. Shawn Leatherman
www.suncoasthealthcare.net