Correlation between severity of lumbar spinal stenosis and lumbar epidural steroid injection

Lumbar spinal stenosis (LSS) is a narrowing of the spinal canal that causes mechanical compression of the spinal nerve roots. The compression of these nerve roots can cause leg pain, as well as neurogenic claudication. Lumbar epidural steroid injections have commonly been used in patients with LSS. The aim of our study was to determine the relationship between the severity of LSS using a grading system (grade 1 = mild stenosis with separation of all cauda equina; grade 2 = moderate stenosis with some cauda equina aggregated; grade 3 = severe stenosis with none of the cauda equina separated) and the subject's response to computed tomography-guided lumbar epidural steroid injection (CTG-LESI) and to evaluate the short-term effectiveness.

Forty-seven consecutive patients with degenerative LSS were enrolled in this prospective study. All subjects underwent lumbar spine magnetic resonance imaging. Two radiologists independently graded lumbar central canal stenosis based on T2-weighted axial images. All CTG-LESI were performed in the procedure room. Outcome measures were obtained using the 5-point patient's satisfaction scale at 2 and 8 weeks post-treatment. To evaluate the outcome, we divided the patients into two groups according to their response to the treatment.

Improvement (including reports of slightly improved, much improved, and no pain) was observed in 37 patients (78.7%) at 2 weeks and 36 patients (77.6%) at 8 weeks after the procedure. There was no statistically significant correlation between pain relief and age.

The grade of LSS appears to have no effect on the degree of pain relief associated with CTG-LESI. However, CTG-LESI seems to provide effective short-term pain relief due to LSS.