Assessment of Motor Cortical Excitability by Concurrent Transcranial Ultrasonic Neuromodulation (TUS) and Transcranial Magnetic Stimulation (TMS)

Low-intensity transcranial focused ultrasound is an emerging non-invasive neuromodulation technique that uses acoustic energy to modulate neuronal excitability with high spatial precision. The mechanisms underlying TUS neuromodulation in humans and particularly how these relate to excitation and inhibition remain poorly understood.We combine concurrent and concentric transcranial ultrasound stimulation (TUS) with transcranial magnetic stimulation (TMS) in order to probe the effect of ultrasound on corticospinal excitability using the motor evoked potential (MEP).