Feasibility, Acceptability, and Efficacy of Home-Based Transcranial Direct Current Stimulation on Pain in Older Adults with Alzheimer's Disease and Related Dementias: A Randomized Sham-Controlled Pilot Clinical Trial

Although transcranial direct current stimulation (tDCS) is emerging as a convenient pain relief modality for several chronic pain conditions, its feasibility, acceptability, and preliminary efficacy on pain in patients with Alzheimer's disease and related dementias (ADRD) have not been investigated. The purpose of this pilot study was to assess the feasibility, acceptability, and preliminary efficacy of 5, 20-min home-based tDCS sessions on chronic pain in older adults with ADRD. We randomly assigned 40 participants to active (n = 20) or sham (n = 20) tDCS. Clinical pain intensity was assessed using a numeric rating scale (NRS) with patients and a proxy measure (MOBID-2) with caregivers. We observed significant reductions of pain intensity for patients in the active tDCS group as reflected by both pain measures (NRS: Cohen's d = 0.69, p-value = 0.02); MOBID-2: Cohen's d = 1.12, p-value = 0.001). Moreover, we found home-based tDCS was feasible and acceptable intervention approach for pain in ADRD. These findings suggest the need for large-scale randomized controlled studies with larger samples and extended versions of tDCS to relieve chronic pain on the long-term for individuals with ADRD.