Efficacy of percutaneous electrical nerve stimulation for the treatment of chronic low back pain in older adults

OBJECTIVES: To determine the efficacy of a complementary analgesic modality, percutaneous electrical nerve stimulation (PENS), for the treatment of chronic low back pain (CLBP) in community-dwelling older adults. DESIGN: Randomized, controlled clinical trial. SETTING: University of Pittsburgh Pain Evaluation and Treatment Institute. PARTICIPANTS: Thirty-four English speaking, community-dwelling adults aged 65 and older with CLBP of at least moderate intensity experienced every day or almost every day. INTERVENTION: Subjects were randomized to receive twice-weekly PENS and physical therapy (PT) or sham PENS and physical therapy for 6 weeks. MEASUREMENTS: At baseline, immediately after the 6-week intervention period, and 3 months later, the primary outcome measures pain intensity and pain-related disability were assessed. The secondary outcome measures physical performance (timed chair rise, functional reach, gait speed, static and isoinertial lifting), psychosocial factors (mood, sleep, and life control), and cognitive function (measures of attention, concentration, and mental flexibility) were also collected. RESULTS: Subjects randomized to PENS plus PT displayed significant reductions in pain intensity measures from pre- to posttreatment (P <.001), but the sham PENS plus PT group did not (P =.94). These pain reduction effects were maintained at 3-month follow-up. Similarly, significant reductions in pain-related disability were observed at posttreatment (P =.002) for the PENS plus PT group and were maintained at follow-up, but the sham PENS plus PT group did not show reductions in pain-related disability (P =.81). Of the secondary outcome measures, psychosocial function, timed chair rise, and isoinertial lifting endurance also improved significantly at posttreatment for the PENS plus PT group, and their improvement was sustained at 3-month follow-up, but the sham PENS plus PT did not display significant changes on these measures after treatment. CONCLUSION: This preliminary study suggests that PENS may be a promising treatment modality for community-dwelling older adults with CLBP, as demonstrated by reduction in pain intensity and self-reported disability, and improvement in mood, life control, and physical performance. Larger studies with longer duration of follow-up are needed to validate these findings and support the use of PENS in clinical practice.