What's differences in these diagnostics?

[SteveE]

Based on myleogram, surgeon says I have lateral recess stenosis on the right side at L45 and has recommended microsurgery to decompress the nerve root. I want to confirm diagnosis by having a SNR. What is the difference, if any, between a SNR and a right sided at L45 transforaminal epidural injection?

[paindoc]

The difference between a SNRB and a transforaminal at the same level is subtle but important. A SNRB is designed to be diagnostic whereas the TF is meant to be therapeutic. Based on your radiographic findings and hopefully physical exam findings, your physician is trying to confirm what he has found. By blocking only the nerve root as it passes out of its corresponding foramen, location of pain can be determined if you recweive relief...that is a SNRB. A TF is used when the pysician knows where the pain is coming from and it trying to reduce it by advancing the tip of his needle further into the foramen and allowing medication to pass into the anterior epidural space as well as along the nerve root sleeve. Therapeutically, this accomplishes three things. First, it gets the medication in the anterior part of the epidural space where the problem is (unlike a simple posterior epidural whose medication may or may not get to the intended target). Second, depending on the type of medication used and the volume used, it is often effective in lysing adhesive pathology potentially tethering the nervr root as any inflammatory process can produce adhesion...not just scarring after surgery. Third, pain relief from the the first two points and the fact that the medication still spreads down the nerve root sleeve. The techniques are similar for your physician but just different enough to make the difference between therapeutic and diagnostic pain relief. Hope this helps.