Transcranial direct-current stimulation (tDCS) is gaining interest as a potentially useful nonpharmacologic approach to the treatment of chronic pain, now with new research from a clinical randomized trial showing significant improvements in pain associated with knee osteoarthritis in older adults. The study, presented at the American Pain Society (APS) 2017 Annual Scientific Meeting, involved 40 adults aged 50 to 70 years (mean age, 59 years), including 21 women, with pain from knee osteoarthritis. They were randomly assigned to receive five daily sessions of tDCS or a sham treatment for 20 minutes in each session. The treatment involved placement of the anode electrode over the primary motor cortex of the brain hemisphere that was contralateral to the affected knee, and the cathode electrode was placed over the supraorbital regions ipsilateral to the affected knee. The results, after the five daily sessions, showed a greater reduction in knee pain on a clinical pain severity scale of 0 to 100 in the tDCS group (18.50 ± 3.60) compared with the sham group (6.45 ± 2.26), for a mean difference between the groups of 12.05 (P = .007; Cohen’s d = 0.90). Adam J. Woods, MD, assistant director of the Center for Cognitive Aging and Memory at the University of Florida’s McKnight Brain Institute, Gainesville, a coauthor on the study, underscored that the results were encouraging.
“The overall effect size was large and exciting,” he said in presenting the findings at the meeting.