Transcranial direct current stimulation for chronic pain

Transcranial Direct Current Stimulation (tDCS) is a non-invasive method for neuromodulation. By changing the neurons' resting membrane potential, the method can alter the activity in areas of the brain. We therefore wished to review randomised controlled trials (RCTs) that investigate the treatment effect of tDCS on chronic pain. We undertook a search in PubMed with the search terms «transcranial direct current stimulation» and «pain», with «randomized controlled trial» as a filter. Five randomised, controlled trials that used quantitative outcome measures for pain were identified. The studies focused on strongly varying groups of patients suffering from pain. The results from some of the studies showed that stimulation with the aid of tDCS led to a significantly lower level of pain, but seen as a whole, the results were not conclusive. The method should be further investigated in studies that include clearly defined groups of patients suffering from pain, as well as a larger number of participants, before implementation of the method is considered as a treatment option for chronic pain.