Effects of repetitive peripheral magnetic stimulation on post-stroke upper extremity spasticity using ultrasound elastography: A randomized controlled trial

Objectives: This study aims to investigate the efficacy of repetitive peripheral magnetic stimulation (rPMS) on post-stroke upper extremity spasticity and the fibroelastic properties of spastic muscles using shear-wave elastography (SWE). Patients and methods: Between March 2022 and April 2024, a total of 48 stroke patients with elbow and/or wrist flexor spasticity were enrolled in this double-blind randomized controlled study. Of these, 46 patients completed the study and were randomized into the rPMS group (6 males, 16 females; mean age: 63.27 years; range, 30 to 87 years) and the sham group (14 males, 10 females; mean age: 60.75 years; range, 33 to 86 years). All patients received a conventional rehabilitation program and 10 sessions of rPMS over two weeks. The Modified Ashworth Scale (MAS), Modified Tardieu Scale (MTS, spasticity grade and spasticity angle), SWE, and Fugl-Meyer assessment of the upper extremity (FMA-UE) were used to assess spasticity and motor function prior to treatment, after treatment, and at a four-week follow-up. Results: Between-group analyses showed no significant differences in mean wrist flexor MAS score changes at any time point. The mean elbow flexor MAS scores demonstrated a significantly greater reduction in the rPMS group (-0.60±0.73) compared with the sham group (–0.05±0.46) post-treatment (p=0.036).There were no significant between-group differences in wrist flexor spasticity grade changes at any time point (p>0.05). The mean wrist flexor spasticity angle demonstrated a significantly greater reduction in the rPMS group (–9.05±11.1) compared to the sham group (–0.05±6.92) at the follow-up (p=0.030). For elbow flexors, the changes in mean spasticity grade or angle were similar between the groups at any time point (p>0.05). Comparison of the mean shear wave velocity changes in the biceps, brachialis, and pronator muscles revealed no significant differences between groups (p>0.05). The increase in FMA-UE scores was significantly greater in the rPMS group than in the sham group both after treatment (2.68±3.32 vs. 0.58±0.92, p=0.006) and at follow-up (3.45±5.09 vs. 1.04±2.15, p=0.015). No serious side effects were reported. Conclusion: Repetitive peripheral magnetic stimulation is a noninvasive and well-tolerated physical therapy modality. As an adjunct to conventional rehabilitation, it may selectively reduce post-stroke upper extremity spasticity and improve motor function.