Addition of transcranial direct current stimulation to quadriceps strengthening exercise in knee osteoarthritis: A pilot randomised controlled trial

Abstract

A randomised, assessor- and participant-blind, sham-controlled trial was conducted to assess the safety and feasibility of adding transcranial direct current stimulation (tDCS) to quadriceps strengthening exercise in knee osteoarthritis (OA), and provide data to inform a fully powered trial. Participants were randomised to receive active tDCS+exercise (AT+EX) or sham tDCS+exercise (ST+EX) twice weekly for 8 weeks whilst completing home exercises twice per week. Feasibility, safety, patient-perceived response, pain, function, pressure pain thresholds (PPTs) and conditioned pain modulation (CPM) were assessed before and after treatment. Fifty-seven people were screened for eligibility. Thirty (52%) entered randomisation and 25 (84%) completed the trial. One episode of headache in the AT+EX group was reported. Pain reduced in both groups following treatment (AT+EX: p<0.001, partial η2 = 0.55; ST+EX: p = 0.026, partial η2 = 0.18) but no between-group differences were observed (p = 0.18, partial η2 = 0.08). Function improved in the AT+EX (p = 0.01, partial η2 = 0.22), but not the ST+EX (p = 0.16, partial η2 = 0.08) group, between-group differences did not reach significance (p = 0.28, partial η2 = 0.052). AT+EX produced greater improvements in PPTs than ST+EX (p<0.05) (superolateral knee: partial η2 = 0.17; superior knee: partial η2 = 0.3; superomedial knee: partial η2 = 0.26). CPM only improved in the AT+EX group but no between-group difference was observed (p = 0.054, partial η2 = 0.158). This study provides the first feasibility and safety data for the addition of tDCS to quadriceps strengthening exercise in knee OA. Our data suggest AT+EX may improve pain, function and pain mechanisms beyond that of ST+EX, and provides support for progression to a fully powered randomised controlled trial.

The Immediate Effects of Transcranial Direct Current Stimulation on Quadriceps Muscle Function in Individuals With a History of Anterior Cruciate Ligament Reconstruction: A Preliminary Investigation

“…Future research should investigate whether utilizing tDCS in acute stages of rehabilitation would be protective to the documented deficits in corticospinal excitability of ACLR patients. Previous tDCS studies in other populations have used multiple treatment sessions of active tDCS where they saw beneficial effects resulting from the treatment, 24,25 and we believe that future research should investigate the effect of multiple tDCS sessions in the ACLR population. It is vital for researchers to understand the dose response of tDCS in ACLR patients to investigate how many tDCS sessions result in beneficial gains in neuromuscular function.…”

“…We also expected to see an improvement in subjective scores after the tDCS condition based on the improvement in pain and symptom scores in patients with osteoarthritis and total knee arthroplasty. 24,25 When observing the change scores and effect sizes for KOOS Pn (d = 0.41; CI, −0.48 to 1.30; tDCS = 2.8% increase, sham = 0.6% increase) and KOOS Sx (d = 0.52; CI, −0.37 to 1.41; tDCS = 4.7% increase, sham = 3.1% increase), there was a statistically significant increase from the premeasurement and postmeasurement regardless of the condition. The slight improvement of these scores may be a result of the 20 minutes of treadmill walking.…”

“…23 Although tDCS has historically been used in the rehabilitation field to treat neurologically impaired patients (eg, stroke, Parkinson disease, etc), it has recently shown promise in improving muscle strength and decreasing pain and opioid use in individuals with musculoskeletal conditions such as osteoarthritis and total knee arthroplasty. 24,25 Theoretically, excitability of the areas directly below the electrodes can be manipulated, which may potentially increase neural activity to the peripheral muscle being used. As mentioned above, patients with ACLR exhibit deficits in excitability of the motor cortex, therefore, the patients with ACLR may benefit from an increase in corticospinal activation during exercise via tDCS, as well as potential reductions in pain, allowing for greater levels of peripheral muscle activation to be used and thus optimizing the benefits from the exercises being performed.…”

“…As mentioned above, patients with ACLR exhibit deficits in excitability of the motor cortex, therefore, the patients with ACLR may benefit from an increase in corticospinal activation during exercise via tDCS, as well as potential reductions in pain, allowing for greater levels of peripheral muscle activation to be used and thus optimizing the benefits from the exercises being performed. 25,26 Therefore, the purpose of this study was to determine if a single treatment of tDCS would improve quadriceps muscle activity and reduce self-reported levels of pain and dysfunction during exercise in participants with a history of ACLR. We hypothesized that tDCS would improve quadriceps muscle activity and reduce pain in participants with a history of ACLR.…”

Osteoarthritis year in review 2018: rehabilitation and outcomes

“…Thus, while evidence supports combined interventions for thumb OA, we are unable to make specific recommendations regarding combined interventions for knee OA, or for other affected joints. With respect to adjunct interventions, we found evidence to support the use of tape for knee OA 21,55,57 , assistive devices for hand OA 59 , thumb splints for thumb OA 60 , manual therapy for knee OA 23,45,47,53 and neck OA 65 , acupuncture for knee OA 44 , and electrophysical agents for knee OA 19,22,48 (Tables III and IV), while conflicting evidence was found for transcranial direct current stimulation (tDCS) 30,37 (Table IV). Taken together with established clinical guidelines, our findings reinforce that these interventions should be adjuncts to accompany core recommended interventions for OA, rather than be used as standalone or key treatments 2,3,9e16 .…”