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.