The efficacy of lumbar sympathetic nerve block for neurogenic intermittent claudication in lumbar spinal stenosis

Background: The symptoms of LSS include radicular symptoms (RS) and IMC. IMC is thought to be caused by circulatory disturbances in the cauda equina nerves and does not often resolve naturally. There are reports of increased cauda equina nerve blood flow in canine spinal stenosis models as a result of lumbar sympathetic resection. Thus, we believed that improvement of IMC in LSS may be achieved by performing a LSNB to produce a medium-term effect. Materials and Methods: Patients with LSS suffering from IMC in both legs were enrolled in this study. Those with IMC symptoms alone were classified as cauda equina-type (CE group), while those who also suffered from RS were classified as mixed-type (M group). LSNB was performed on both sides using a neurolysis in both groups. Evaluation was using the Zurich claudication questionnaire (ZCQ). Results: Twenty-six subjects were completed the six-month observation period. In contrast to the CE group who, throughout the observation period, experienced significant improvements in Symptom Severity (SS) and Physical Function (PF) scores compared with those before treatment, no such significant differences were observed in the M group throughout the observation period. In addition, a significant decrease in the SS scores of the CE group one-month after treatment and in the PF and Patient Satisfaction (PS) scores both one-month and two-months after treatment was observed in comparison with the M group. Conclusion: Our results show that LSNB for LSS is more effective in improving neurogenic intermittent claudication than radicular symptoms, and this suggests that LSNB could become an effective treatment for cauda equina-type lumbar spinal stenosis that is resistant to other conservative treatment