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. 2023 Feb;51(2):3000605231153326.
doi: 10.1177/03000605231153326.

Effectiveness of caudal block in patients with spinal stenosis accompanied by redundant nerve root syndrome

Sieun Yoon  1 , Hyeongchun Kim  2   3 , Chi-Bum In  1   3
Affiliations

Effectiveness of caudal block in patients with spinal stenosis accompanied by redundant nerve root syndrome

Sieun Yoon et al. J Int Med Res. 2023 Feb.

Abstract

Objective: Redundant nerve root syndrome (RNRS) is characterized by tortuous, elongated, and enlarged nerve roots in patients with lumbar spinal stenosis. This study was performed to evaluate the effects of caudal block in patients with RNRS and assess factors associated with RNRS.

Methods: Patients with lumbar spinal stenosis who underwent caudal block were retrospectively analyzed. A comparative analysis of pain reduction was conducted between patients with RNRS (Group R) and those without RNRS (Group C). Generalized estimating equation analysis was used to identify factors related to the treatment response. RNRS-associated factors were analyzed using logistic regression analysis.

Results: In total, 54 patients were enrolled (Group R, n = 22; Group C, n = 32). Group R had older patients than Group C. The caudal block showed less pain reduction in Group R than in Group C, but the difference was not statistically significant. Generalized estimating equation analysis showed that RNRS was the factor significantly associated with the treatment response. The dural sac anteroposterior diameter and left ligamentum flavum thickness were associated with RNRS in the logistic regression analysis.

Conclusions: Caudal block tended to be less effective in patients with than without RNRS, but the difference was not statistically significant.

Keywords: Redundant nerve root syndrome; caudal block; dural sac diameter; generalized estimating equation analysis; ligamentum flavum thickness; pain reduction; spinal stenosis.

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Conflict of interest statement

The authors declare that there is no conflict of interest.

Figures

Figure 1.
Figure 1.
Redundant nerve root syndrome on T2-weighted magnetic resonance imaging.
Figure 2.
Figure 2.
Spinal cord CSA: area distributed by the dural sac on axial magnetic resonance imaging. Distance from C to S: distance from conus medullaris to the most stenotic level in the lumbar spine. CSA, cross-sectional area.
Figure 3.
Figure 3.
Morphology of RNRS on magnetic resonance imaging. (a) RNRS type: type I = tortuous, type II = thickened. (b) RNRS shape: shape I = serpentine, shape II = loop and (c) Location of RNRS (above/below/above and below): above or below based on the most stenotic lesion. RNRS, redundant nerve root syndrome.
Figure 4.
Figure 4.
Study flow diagram. MRI, magnetic resonance imaging; hx, history; NRS, numeric rating scale.
Figure 5.
Figure 5.
Percentage of pain reduction <1 month after caudal block based on preprocedural pain score in patients with (Group R) and without (Group C) redundant nerve root syndrome. The graph shows the mean and standard deviation. Group R showed less pain relief, but there was no statistically significant difference between the two groups. NRS, numeric rating scale.
Figure 6.
Figure 6.
Treatment response after caudal block in patients with (Group R) and without (Group C) redundant nerve root syndrome.
Figure 7.
Figure 7.
Comparison of radiological parameters of the spine in the two groups. AP, anteroposterior; SI, superoinferior; L, left; R, right. *Significant difference between the two groups.
See this image and copyright information in PMC

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