The Effect of Percutaneous Injection of Lumbar Nerve Roots in Diagnosis and Treatment of Sciatica

Baek, Woon Il; Lee, Jang Chul; Lee, Chang Lyung; Son, Eun Ik; Kim, Dong Won; Yim, Man Bin; Kim, In Hong

Abstract

Clinical evaluation and imaging studies such as magnetic resonance imaging, computed tomography, and/or myelography can localize the pathologic process in most patients with lumbar radiculopathy. However, these studies occasionally fail to demonstrate exactly the cause and site for ongoing radicular symptom. So we evaluated 54 patients for the efficacy of selective nerve root blocks to identify a symptomatic nerve. The lumbar nerve root injections were performed at L3 root in 1 patients, at L4 root in 4 patients, at L5 root in 46 patients, and at S1 root in 3 patients. Among them, forty two patients were done before operation(HNP 32, stenosis 5, spondylolisthesis 5), 9 patients were done after operation due to poor results (root injury 2, infection 2, adhesion 1, incorrect diagnosis 4), and 3 patients had improved radiculopathies following nerve root injection(HNP 2, stenosis 1). The results of the nerve root injections and of the operations were not affected by age and sex. There was a good correlation between the response of the nerve root injection and the result of the operation(p<0.05). The concentration of bupivacaine 0.5% has no additional effect comparing to 0.25%(70%/73.5%) solution in spite of its adverse effect causing transient motor weakness. Additional use of depomedrol(50mg) proved to be no more beneficial. Three patients had Improved symptoms for a long period after nerve root injection which consequently made operation unnecessary. Five patients with previous history of operations had moderate pain relief. In summary, lumbar nerve root injection can be used as a functional diagnostic tool to predict operative result and as a treatment modality following failure of a previous surgery.