Stellate Ganglion Block Reduces the Radicular Pain and Salivary Alpha-Amylase Activity in Patients with Cervical Spondylosis

Background The effects of stellate ganglion block (SGB) on radicular pain associated with cervical spondylosis remain to be clarified. So we measured salivary alpha-amylase which reflects sympathetic nerve activity under psychological stress after SGB block or trigger points injection (TPI). Study Design A randomized, prospective, controlled trial Setting After institutional approval and informed consent, 40 patients who was suffered from neck-shoulder pain associated with cervical radiculopathy were randomly divided into two groups according to nerve block treatment. Group A (n=20, male 10 patients, female 10 patients, 50±8yr, mean±SD) received SGB and group B (n=20, male 10 patients, female 10 patients, 52±6yr) received TPI. SGB or TPI was produced by 6 ml of 1% mepivacaine a total of 5 times (twice per week). Visual analogue scale (VAS) and the concentration of salivary alpha-amylase were measured before (T0) each nerve block and 3 days (T1), 6 days (T2), 9 days (T3), 12 days (T4) and 15days (T5) after each nerve block. The consumption of non-steroidal anti-inflammatory drug (NSAID) was measured at T0 and T5 in each group. Results In group A, VAS was median 74 (range 60, 78) at T0 and showed a significant decrease at T3 [53 (48, 65), p<0.05], T4 [50 (42, 66), p<0.05] and T5 [48 (26,57), p<0.05]. The concentration of salivary alpha-amylase was median 116 (range 96, 144) KU/ml at T0 and showed a significant decrease at T3 [86 (79, 105), p<0.05], T4 [79 (68, 88)] and T5 [70 (55, 84), p<0.05]. In group B, VAS and the concentration of salivary alpha-amylase showed no change throughout the time course. VAS in group A was significant lower than that in group B at T3, T4 and T5. The concentration of salivary alpha-amylase was significant lower than that in group B at T4 and T5. The consumption of NSAID in group A was significantly lower than that in group B at T5. Limitations Subjects are out patients. Patients include radicular pain due to different pathogenesis, e.g., cervical herniated intervertebral disc, disc bulging, and neuro-foramen narrowing. Conclusion The results indicate that SGB shows the reduction of VAS scale and the concentration of salivary alpha-amylase in patients with cervical spondylosis. These results show that salivary alpha-amylase activity could reflect the physical stress with radicular pain.