F‐Wave Suppression Induced by Suprathreshold High‐Frequency Repetitive Trascranial Magnetic Stimulation in Poststroke Patients with Increased Spasticity. Issue 3 (24th October 2012) - Wupuer, Sidikejiang
Abstract Objective High‐intensity and high‐frequency repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex was carried out in poststroke patients with increased spasticity, and the changes in F‐wave parameters in comparison with M‐wave parameters induced by rTMS were examined. Methods Ten‐hertz rTMS pulses were delivered to the primary motor cortex of the lesion side at 110% intensity of the resting motor threshold, and F‐waves were obtained from the first dorsal interosseous muscle. F‐waves were recorded before (pre‐stim) and immediately after the end of rTMS (post‐stim) in poststroke patients. Results F‐wave persistence and F/M Amp.Ratio increased significantly in patients with lesions in upper motor tract as compared with healthy subjects (Wilcoxon rank sum test, p = 0.00023 and p = 0.0073, respectively). After the rTMS application, both F‐wave persistence and F/M Amp.Ratio decreased significantly (paired t‐test, p = 0.0095 and p = 0.037, respectively). However, the F‐wave amplitude did not show a statistically significant variance in poststroke patients. Conclusions High‐frequency suprathreshold rTMS may suppress the F‐waves by enhancing the inhibitory effect on spinal excitability through the corticospinal tract, and F‐wave persistence and F/M Amp.Ratio can be used to determine the effect of rTMS on patients with increased spasticity.