Efficacy of Repetitive Transcranial Magnetic Stimulation in Preventing Poststroke Spasticity: A Sham-Controlled Trial

BACKGROUND: Poststroke spasticity significantly impairs recovery, yet preventive strategies remain limited. This study evaluated the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in reducing the development and severity of spasticity in patients with early subacute stroke, offering a possible early intervention. METHODS: In this double-blind, randomized, sham-controlled trial, 70 patients with early subacute stroke (7–30 days) were randomized to receive 3 sessions of low-frequency (1 Hz, 1000 pulses at 90% resting motor threshold) rTMS over contralesional primary motor cortex (n=35) or sham stimulation (n=35), alongside standard care. The primary outcome was upper-limb spasticity assessed using the modified Modified Ashworth Scale. Secondary outcomes included handgrip strength, muscle power assessed by the Medical Research Council scale, pain assessed by the Visual Analogue Scale, modified Rankin Scale, and Stroke Impact Scale 3.0. RESULTS: rTMS therapy significantly lowered spasticity scores at 1 and 3 months across all assessed upper-limb joints ( P =0.001), improved handgrip strength ( P =0.01), and prevented pain ( P =0.001). Stroke Impact Scale scores at 1 month showed greater gains in activities of daily living, mobility, hand function, social participation, and recovery in the rTMS group ( P =0.001). Functional independence (modified Rankin Scale) was significantly better in the rTMS group ( P =0.006) at 3 months. On binary logistic regression, sham stimulation was associated with greater odds of developing spasticity at 1 month (shoulder odds ratio [OR], 8.29 [95% CI, 1.95–35.27], P =0.04; elbow OR, 7.62 [95% CI, 1.69–34.35], P =0.08; wrist OR, 5.18 [95% CI, 1.60–16.78], P =0.06). At 3 months, sham stimulation remained predictive, with higher odds of spasticity at the shoulder (OR, 15.3 [95% CI, 8.26–28.43]), elbow (OR, 13.43 [95% CI, 3.94–45.78]), wrist (OR, 19.9 [95% CI, 4.9–80.96]), and fingers (OR, 26.25 [95% CI, 5.19–132.87], all P =0.001). Minor adverse events like headache and light-headedness were observed in 5 patients. CONCLUSIONS: Low-frequency rTMS over contralesional primary motor cortex significantly prevented spasticity, improved motor recovery, reduced pain, improved functional outcomes and quality of life in early subacute stroke, supporting its role as a promising adjunctive therapy in early stroke rehabilitation. REGISTRATION: URL: https://ctri.nic.in/ ; Unique identifier: CTRI/2024/01/061225.