Effects of Repetitive Peripheral Magnetic Stimulation Versus Sham Stimulation on Upper Limb Spasticity After Stroke: A Double-Blind Randomized Controlled Trial

Background: Upper limb spasticity after stroke occurs due to neural hyperexcitability and secondary alterations in muscle properties. Repetitive peripheral magnetic stimulation (rPMS) is a non-invasive technique used to reduce spasticity. This study aimed to compare the effects of rPMS versus sham stimulation on upper limb spasticity and muscle stiffness using shear wave elastography (SWE). Methods: This prospective, double-blind randomized controlled trial included 32 stroke patients with upper limb spasticity (Modified Ashworth Scale (MAS) ≥ 2 in the elbow flexors), who received rPMS or sham stimulation in addition to conventional rehabilitation (n = 16 per group). Spasticity was assessed using MAS, and muscle stiffness using SWE. Results: The rPMS group showed a transient short-term reduction in upper limb spasticity compared with the control group at the end of treatment (p = 0.045); however, this effect was not sustained at the 2-week follow-up. No significant between-group differences were observed in muscle stiffness, upper limb motor function, or activities of daily living. Conclusions: This study provides preliminary evidence that rPMS may produce a transient, short-term reduction in upper limb spasticity after stroke. However, this effect was not sustained at follow-up or accompanied by significant improvements in muscle stiffness or functional outcomes.