Chapter 63: Transforaminal Epidural Steroid Injections

Question 1

What is the difference between TFESI and SNRB?

Answer 1

Final needle tip position. If outside intervertebral foramen, it is a SNRB. If inside intervertebral foramen, it is a TFESI. However, the end result is medication delivery to a nerve root both inside and outside of the epidural space.

Question 2

Intrathecal steroid injections were popular in the 1960s until they lost favor for what reason?

Answer 2

Frequency of complications, most notably arachnoiditis.

Question 3

In the 1990s, transforaminal ESIs rose in popularity for what reason?

Answer 3

Diagnostic value - specifically ability to predict disc surgery outcomes.

Question 4

Higher injectate volumes in a SNRB increase the risk of what?

Answer 4

Spread to adjacent nerve roots/structures, reducing the diagnostic/predictive value of the injection.

Question 5

Studies have found that SNRB injectate volumes greater than ___ mL are unlikely to provide diagnostic information specific to one nerve root.

Answer 5

0.5 mL

Question 6

SNRB would be indicated diagnostically/therapeutically in patients complaining of what?

Answer 6

Atypical extremity pain patterns, transitional vertebrae, hx back surgery.

Essentially most helpful for patients with unclear pain generator based on MRI/EMG.