Long-Term Effect of Selective Nerve Root Block in patients with Lumbar Stenosis

Abstract

Introduction Low back pain with radiculopathy is a common problem encountered both by the young and the elderly. In the young, it may be caused by HNP and/or chemical irritation causing nerve impingement. In the elderly, it is usually caused by a degenerative process causing stenosis. One problem faced by the surgeon is when the patient has an equivocal presentation; wherein surgical outcome becomes unpredictable. The aim of our study was to show the long-term effect of selective nerve root block, using a combination of lidocaine and methylprednisolone, in patients suffering from low back pain with equivocal presentation caused by lumbar spinal stenosis. Materials and Method This has a prospective study design, SNRB was done in patients with equivocal symptoms. A total of 19 patients who satisfied the inclusion criteria were included in the study, informed consent was granted by all the participants. All the patients already underwent at least eight sessions of physical therapy and took oral analgesics with no relief of symptoms. SNRB was done in a sterile environment with the guidance of an image intensifier. A combination of 1 mL methylprednisolone and 1 mL of 2% lidocaine was injected after verification of the needle position in two planes was done. The procedure was completed with the patient awake to elicit sensory changes to confirm proper positioning of the needle. Close follow-up was done at 1 week, 3 weeks, 3 months, 6 months, 1 year, and 3 years post-SNRB. Results After 1 week, 17 patients reported resolution of symptoms. Immediate relief was observed in 15 patients after the injection. At 1 year, all 17 patients still reported no recurrence of pain. Three were lost to follow-up, failing to return for the 3rd year post-SNRB, decreasing the success rate at 3 years to 15 patients out of 19. The remaining two patients required repeat SNRB, with one of the two eventually requiring surgical decompression. Conclusion This study showed that the combination of methylprednisolone and lidocaine was able to provide pain relief in 89% of the participants at 1 year follow-up, and 74% at 3 years. SNRB may be used in treating patients with equivocal presentation, providing faster relief than other conservative management, and evading unnecessary surgery.