The use of repetitive transcranial magnetic stimulation (rTMS) for the treatment of spasticity

Spasticity is a common disorder in patients with injury of the brain and spinal cord, especially in patients affected by multiple sclerosis (MS). In MS, spasticity is a major cause of long-term disability, it significantly impacts daily activities and quality of life and is only partially influenced by traditional spasmolytic drugs. Transcranial magnetic stimulation (TMS) is a noninvasive tool that can be used to modulate cortical excitability of the leg motor area, inducing remote effects on the excitability of the spinal circuits. The H reflex is a reliable electrophysiologic measure of the stretch reflex, and has been used in previous studies to test the effects of rTMS of the motor cortex on spinal circuitry. Based on these premises, originating from physiological studies in normal subjects, some studies have demonstrated that rTMS of the leg motor cortex can be beneficial in the management of spasticity by enhancing corticospinal tract excitability and reducing H reflex amplitude.