Transcranial Ultrasound (TUS) Therapy can be used to transmit ultrasonic energy into the motor cortex region of the brain to promote recovery and rehabilitation following the brain injury that occurs after a stroke. Unlike deep brain stimulation (DBS) which involves the placement of electrodes in a specific region of the brain or direct cortical stimulation (DCS), which requires the positioning of electrodes in the subdural or epidural space, TUS can be performed non-invasively without having to surgically implant electrodes inside the cranium.
It is broadly accepted that TUS has the ability to induce a physical response on body tissues. This has been demonstrated through the transmission of ultrasound into the motor cortex region of the brain to generate evoked action potentials through out various parts of the body. The underlying mechanism of action is theorized to be the result of individual pressure waves imparting a physical force on the axonal membranes to induce reversible changes in the ion transport mechanisms, which in turn alters the depolarization-repolarization cycle associated with nerve transmission. By varying the pulse sequences, it has been demonstrated that TUS can be applied therapeutically to up-regulate or down-regulate neuronal activity in the motor cortex as a method to enhance the body’s natural neuroplastic repair mechanisms following stroke when used in combination with traditional repetitive therapy.
When compared to other non-invasive brain stimulation technologies such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), TUS has the advantage of penetrating deeper regions of the brain. Whereas tDCS and TMS can only penetrate 1-2 centimeters beyond the surface of the skull, TUS is capable of penetrating the deepest neuronal structures of the brain, that have been exposed to injury following a stroke. In addition, TUS is the only non-invasive brain stimulation technology to receive regulatory approval outside the U.S. for post-stroke recovery