Low Back Pain Visual Analog Research Articles

Effectiveness of Percutaneous Neuromodulation Therapy for Patients with Chronic and Severe Low Back Pain

Abstract: Percutaneous neuromodulation therapy (PNT) is a minimally invasive approach to the treatment of low back pain (LBP), involving electrical stimulation applied to percutaneous electrodes placed within the lumbar paraspinal tissues during 30‐minute treatment sessions. This study reports the effects of PNT on a population of patients with chronic and severe levels of LBP. This study was performed in an outpatient clinical research setting. Thirty‐nine patients were enrolled who had stable levels of LBP lasting at least 6 months, with enrollment LBP visual analog scale (VAS) scores of at least 5 on a scale of 10. The patients were treated with PNT 2 times per week for 4 weeks. Baseline VAS scores of LBP, physical activity, sleep, and the Oswestry Questionnaire were recorded. The final assessment was made 48 hours after the last treatment. After 4 sessions, the patients completed a “responder screen” questionnaire whereby, to continue treatment, they had to indicate both a perceived benefit and improvement in LBP and/or activity levels. Thirty‐one patients completed the study protocol. Of the 18 patients (58% of 31) who passed the responder screen, 14 (78% of 18, 45% of 31) had ≥30% improvement in LBP and/or activity levels. Mean LBP scores decreased by 37% to 4.5 ± 2.2 from 7.1 ± 1.0 (P=0.0001); activity scores improved by 39% to 4.0 ± 2.1 from 6.7 ± 1.5 (P=0.0005); sleep scores improved by 40% from 6.2 ± 2.6 to 4.0 ± 2.6 (P=0.0003). Oswestry scores improved from 44 ± 12 to 33 ± 15 (P=0.002). In conclusion, for patients with chronic and severe stable levels of low back pain, PNT appears promising for pain level reduction and improvement in function.

Do cerebral potentials to magnetic stimulation of paraspinal muscles reflect changes in palpable muscle spasm, low back pain, and activity scores?

Objective: Previous studies have shown that cortical-evoked potentials on magnetic stimulation of muscles are influenced by muscle contraction, vibration, and muscle spasm. This study was carried out to determine whether these potentials correlate with palpatory muscle spasm, patient symptoms, and disability in patients with low back pain. Methods: A prospective observational study was performed on 13 subjects with a history of low back pain visiting an orthopedic hospital-based clinic. Patients were screened for serious pathologic conditions by an orthopedic surgeon. The patients were then evaluated for the presence of muscle spasm by one of the investigators who was blinded to the results of the evoked potential studies. Patients were asked to complete a low back pain visual analogue scale (VAS) and a Roland-Morris Activity Scale (RMAS). Cortical-evoked potentials were recorded with a magnetic stimulator placed over the lumbar paraspinal muscles with the patient in the prone position. The palpatory examination, VAS, RMAS, and the cortical potentials were repeated after 2 weeks of therapy commonly used to reduce muscle spasm. Results: The patients demonstrated a significant decrease in low back pain VAS and RMAS scores after treatment compared with before treatment. There was a reduction in the amount of palpatory muscle spasm in 11 of 13 cases. The cortical potentials before treatment were attenuated compared with previously reported controls and showed a significant increase before and after treatment in the amplitude of these potentials with multivariate analysis of variance. There was significant correlation between the changes in cortical potentials after treatment and the changes noted in paraspinal muscle spasm and VAS and RMAS scores. Conclusions: This study confirms the previous report that the amplitude of cerebral-evoked potentials on magnetic stimulation of paraspinal muscles is depressed in the presence of palpable muscle spasm. The close correlation among these potentials, paraspinal muscle spasm, and clinical symptoms suggests that the measurement of muscle activity may be more important in the assessment of low back pain than is commonly accepted. (J Manipulative Physiol Ther 2000;23:458-64)