Effects of 10-Hz rTMS over the leg motor cortex using a double-cone coil on lower limb motor recovery in subacute stroke: a randomised, double-blind, sham-controlled study

Lower limb dysfunction following stroke poses important challenges to patients' mobility and quality of life. Repetitive transcranial magnetic stimulation (rTMS) using double-cone coils for deep stimulation offers a promising avenue for the improved motor recovery of these patients. However, the efficacy and safety of this approach remain underexplored. A total of 56 subacute stroke patients were randomised to rTMS or sham stimulation (n = 28 per group), over 15 sessions in 3 weeks. The primary outcome was that of Fugl–Meyer assessment of the lower extremity (FMA-LE) at T3, with secondary outcomes, including those of Berg Balance Scale (BBS), modified Barthel index (MBI) and Brunnstrom scale. TecnoBody balance equipment was used to quantify sway length (SL) and sway area (SA). All outcome assessments were performed at baseline (T0), after 1 week (T1), after 2 weeks (T2) and 3 weeks (T3) of intervention. Intention-to-treat and per-protocol analyses were performed. Among the 212 inpatients screened, 56 patients (age, 61.50 ± 5.41 years; 17 women, 46 ischemic) were enrolled in the study. Significant group-by-time interactions occurred, with the rTMS group displaying greater improvements than the sham group in FMA-LE (F = 2.883, P = 0.038) and BBS (F = 3.379, P = 0.020). No significant interactions were observed for MBI (F = 2.245, P = 0.085) or Brunnstrom scale (F = 1.565, P = 0.200). At T3, the rTMS group showed a 1.5 point significantly higher FMA-LE scores (95% confidence interval: 0.567–2.433, P = 0.002) compared with the sham group. TecnoBody balance assessments also showed superior results of the rTMS group for SA (F = 6.902, P < 0.001) and SL (F = 6.837, P < 0.001). Application of 10 Hz rTMS over the leg motor cortex with a double-cone coil holds potential to improve lower-limb motor function in subacute stroke patients. This trial was registered under ClinicalTrials.gov ID No. ChiCTR2100051566, prospectively registered, on September 26, 2021.