The effect of transcutaneous electrical nerve stimulation on pain, muscle strength, balance, and gait in individuals with dementia: A double blind, pilot randomized controlled trial

Abstract

Introduction: The effect of transcutaneous electrical nerve stimulation (TENS) for functional management in patients with dementia has not been reported yet. Thus, the aim of present study was to investigate the effect of TENS on pain, muscle strength, balance, and gait ability in patients with dementia who have difficulty exercising independently. Methods: Thirty-two subjects with dementia were randomly allocated into either a TENS group (n = 16) or a placebo-TENS group (n = 16). TENS (4 Hz), above motor threshold intensity, was applied to both calf muscles for 20 min, 2 times per day. Placebo-TENS was applied for 30 s and then ramped down to zero for 15 s at the same location. The intervention was performed 5 days per week for 2 weeks. Pain was quantified with pain pressure threshold (PPT). Strength of the calf muscles was assessed using a hand-held dynamometer. To assess balance and gait, functional reach test (FRT), 10-m walk test (10MWT), and timed-up and go test (TUG) were used. Results: There were significant differences in PPT (p = 0.001) after TENS application, and the PPT was significantly increased in TENS group compared with placebo-TENS group (p = 0.0495). TENS group showed significant improvements of plantarflexor strength (p = 0.008). Balance and gait were also significantly affected in TENS group, as assessed by 10MWT (p = 0.018) and TUG (p = 0.007). The placebo-TENS group did not show significant improvements for any outcome measures. Conclusions: These results suggest that TENS application can be used for functional maintenance of patients with dementia. Further research is needed to underpin these preliminary results.