Overview
This study aims to determine whether peripheral magnetic stimulation (PMS) during balance training in patients with diabetic polyneuropathy reduces fall risk, as measured by balance tests, and lessens disease severity compared to balance training with sham stimulation.
This proof-of-concept study will utilize the Magnetic and Balance Training Activator (MAGBATA), a platform mounted with a magnetic stimulation coil that delivers electromagnetic pulses directly to the plantar surfaces of the feet while patients stand. A racetrack coil (RT-120), connected to the MagPro X100 magnetic stimulator with MagOption (MagVenture, Farum, Denmark), will be used. Parameters for the repetitive peripheral magnetic stimulation (rPMS) protocol will be configured to facilitate sensory input, enhance brain plasticity, and promote axonal regeneration.
Description
This single-center randomized controlled trial will use a two-group parallel design and include 40 patients with diabetic polyneuropathy who meet the eligibility criteria. Participants will be randomly assigned to either the active intervention group or the control group.
The active intervention group will receive a warm-up exercise consisting of 25 repetitions of ankle dorsiflexion with concurrent 10 Hz rPMS applied to the tibialis anterior of each leg. Following the warm-up, participants will stand on the MAGBATA platform and perform 20 cycles of one-leg stance exercises under the supervision of a physiotherapist. Each cycle lasts 20 seconds and consists of 3 seconds of 20 Hz rPMS applied to the plantar surface of the foot while the participant stands on one leg, followed by 12 seconds of rest during which the participant stands on both legs. The same sequence will then be repeated for the other leg. Stimulation intensity will be determined prior to the warm-up. The coil will be placed over the tibialis anterior to determine the minimal contraction threshold (MCT), defined as the lowest intensity that produces a visible contraction. The stimulation intensity will be set at 110% of the MCT for the warm-up exercise and 120% for the treatment during balance exercises.
The control group will receive the same procedure, but with sham stimulation during both the warm-up and one-leg stance phases.
The intervention will consist of 8 sessions, conducted twice per week with at least one day of rest between sessions. Outcome assessments include one-leg stance test (OLST) with eyes open, timed up and go test (TUGT), and short physical performance battery (SPPB); these assessments will be conducted at baseline and after the 4-week intervention. Additionally, a rehabilitation physician, blinded to group allocation, will perform electrophysiologic studies at baseline and week 8 to assess disease severity. These studies will include bilateral measurements of sural nerve amplitude and conduction velocity, tibial compound motor action potential (CMAP) amplitude and conduction velocity, and tibial F-wave latency.
Eligibility
Inclusion Criteria:
- Diabetes mellitus type 2 with any symptoms of distal polyneuropathy, including numbness, paresthesia, dysesthesia, or lower leg weakness.
- Abnormal 10g monofilament test.
- Abnormal one-leg stance test (OLST) with eyes open.
Exclusion Criteria:
- Chronic foot ulceration.
- Severe leg or foot pain not controllable with medications or other interventions.
- Significant foot deformity, including severe pes cavus, severe claw toe, or toe amputation.
- Body mass index (BMI) over 35 kg/m².
- Visual acuity less than 20/100 after correction with glasses or contact lenses.
- Postural instability or coordination disorders resulting from musculoskeletal, vestibular, or central nervous system conditions.
- Symptoms such as confusion, drowsiness, dizziness, or a high risk of falls due to any disease or recent medication changes within a two-week period.
- Presence of cardiac pacemaker, knee prosthesis, or metal implants in the lower legs.
- Inability to walk or stand for at least 5 minutes.
- Inability to understand, comprehend, or follow instructions required to conduct the study, or to provide informed consent.
