PRF on bilateral L2 DRG – effective treatment method for lumbar discogenic pain? Fabricio D Assis, MD, FIPP-WIP, Charles A Oliveira, MD, FIPP-WIP, Carlos Tucci, MD, Fabíola P Minson, MD, Jamir Sardá Jr.,PhD
Singular Pain Clinic, Campinas; Albert Einstein Hospital, São Paulo
Introduction
Results
Chronic low back pain is pain that lasts more than 3 months. Its high prevalence takes a substantial social and economic toll on society. Chronic low back pain is commonly caused by discogenic pain, as well as facet arthrosis and sacroiliitis. IASP guidelines state that diagnostic confirmation of discogenic lumbar pain should be supported by positive provocative discography. On examination, patients often present with low back pain, and MRI shows a black disc with or without a high-intensity zone. L2 DRG diagnostic blocks have emerged as an alternative to discography. This study suggests that, because the afferent sympathetic fibers emerging in the L2 DRG are pathways of pain transmission, PRF to this site can effectively treat discogenic pain by blocking themy. We treated 26 patients and audited their pain improvement for over a year. The outcome was significant – over 1 year pain relief, with patients reporting improved quality of life.
Mean patient age: 47 (SD=15.26) Pre-intervention mean pain intensity: 7.4 (SD=2.4) Mean pain duration: 131 months (SD=112) Gender distribution: 65% females. 1-month follow-up (χ=2.1, SD2.0)
Conclusions
Discussion
PRF on the L2 dorsal root ganglion: •Effective, non-specific therapeutic method for discogenic low-back pain •Significant results - 54% pain relief lasting up to 1 yr •22% disability reduction – likely a result of pain improvement
Statistical analysis Significant decrease in pain (p<0.001) for up to 12 months (χ=3.3, SD=2.5). Oswestry Disability Index score prior to intervention, 52.05 (SD=51.0) and at 1 year post-surgical intervention, 35.72 (SD=33) (t=3.10, p=0.01). SF-36 scale scores after 1 year were around 50%, ranging from 41% to 61%.
Study Objectives •To confirm the diagnostic effect of blocking the L2 dorsal root ganglion •To evaluate the efficacy of PRF on L2 dorsal root ganglion for treating chronic discogenic low-back pain. Figure 1. Degenerated disc causing discogenic pain
Materials and methods Between 2007 to 2009, we conducted a cross-sectional retrospective study at the Singular Pain Clinic, in Campinas, Brazil. We: •Selected 26 individuals (7 males and 19 females) who had: - low-back pain for at least 6 mths; Black disc; had had targeted L2 DRG diagnostic block; - experienced at least 50% pain relief on VNS 20 mins post intervention; - complained of pain recurrence
Pain scores before and after PRF (fig. 3a) Figure 3a.
VNS Follow-up Scores Score 0-10
References
Table 1. Description of pain scores (VNS) at different intervals VNS score VNS score VNS score VNS score VNS score VNS score VNS score prior to up to day 3 up to 1 month after 2 months up to 3 months up to 6 months after 1 year procedure Mean 7.40 2.44 2.16 2.22 2.27 2.55 3.35 Std. Dev. 2.16 2.73 2.13 2.28 2.34 2.41 3.34 Skewness -1.408 1.208 .528 .634 .353 .666 .661 Kurtosis 1.955 1.051 -.856 -.846 -1.736 -1.013 -.719 Friedman nonparametric test was used to examine differences between mean scores at several times Chi-square 28.84 asymp. sig. equivalent of p<0.001 df=6
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3. Time
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70% pain reduction at 6-mth VNS evaluation, and after 1 year 54%, verifying efficacy of the procedure. Score 0-10
VNS scores showing decrease in pain intensity after 1year 3b. Pre-intervention ODI score was 52.05 (SD=51.0) and at 1 year post-intervention 35.72 (SD=33) (t=3.10, p=0.01); SF=36 an average 50%, ranging between 41% to 61%.
•Applied bilateral PRF at L2 DRG for 180s - 2p/s; 45V. •Collected data using the Visual Numeric Scale, the Oswestry Disability Index and SF-36 questionnaire - VNS and ODI were scored pre-intervention; at 3d/ 1 m/ 3 m/ 6 m/1 yr; - SF-36 applied 1 yr after intervention •Analyzed the data using: descriptive and inferential statistics; Chi-square test; Friedman non-parametric test using SPSS-1
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Oswestry and SF-36 scores (fig. 3b), disability and quality-of-life evaluations Time Figure 3b.
Table 2. Oswestry Disability Index (ODI) and SF-36 scores ODI ODI Functional Physical Pain General Vitality Social Emotional Time 1 Time 2 ability aspects SF-36 health status SF-36 aspects aspects SF-36 SF-36 SF-36 SF-36 SF-36 Mean 47.13 36.50 41.81 26.13 37.90 46.40 47.72 60.79 43.90 Std. Dev. 17.02 18.76 29.21 40.44 21.61 20.91 22.97 27.35 48.67 t test score for mean dif erence between ODI at T1 and T2 was t=3.10 p=0.01 N= 26
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Reduction in Disability ( %) - Oswestry Index
Mental health SF-36 55.45 23.56
Score (%)
Acknowledgments 47.13%
Time
We thank Silvia Maria B Costa, our head nurse, and Karina R Subi, MD, our resident trainee, for their valuable collaboration on this research project; Optika Medical Supplies for their donation of RF material for our work, and Camille Khan for translations and poster creation.
36.50%
This represents a reduction in disability, from intense to moderate, implying that pain relief positively influenced outcomes.
Fig. 2. After diagnosis, patients received PRF blocks to bilateral L2 DRG, returning to the office 3 days later, then @ 1, 3, 6 months and 1 year for VNS and ODI evaluations.
For further information Please contact charles@singular.med.br. More information on this and related research projects can be obtained at www.singular.med.br and this paper can be downloaded from the website.