Symptoms of Spinal Stenosis Do Not Improve After Epidural Steroid Injection

This study was carried out to evaluate the therapeutic effect of epidural steroid injection on pseudoclaudication in patients with lumbar degenerative spinal canal stenosis.Fifty-three patients who complained of pseudoclaudication of less than 20 m in walking distance were randomly divided into three groups. Group 1 (n = 16) underwent epidural injection with 8 ml of saline. Group 2 (n = 18) underwent epidural block with 8 ml of 1% mepivacaine. Group 3 (n = 19) underwent epidural block with a combination of 8 ml of 1% mepivacaine and 40 mg of methylprednisolone. The criteria of evaluation were as follows: excellent effect,100 m in walking distance; good effect, 20-100 m in walking distance; poor effect,20 m in walking distance.In group 1, the numbers of patients who showed a good effect were two (12.5%) after 1 week, one (6.5%) after 1 month, and one (6.5%) after 3 months. In group 2, the numbers of patients who showed a good or excellent result were 10 (55.5%) after 1 week, three (16.7%) after 1 month, and one (5.6%) after 3 months. In group 3, the numbers of patients who showed a good or excellent result were 12 (63.2%) after 1 week, three (15.8%) after 1 month, and one (5.3%) after 3 months. There was no significant difference in the effectiveness of treatment between group 2 and group 3 throughout the time course.The results suggest that epidural steroid injection has no beneficial effect on the pseudoclaudication associated with spinal canal stenosis as compared with epidural block with a local anesthetic alone.