Trans Spinal Stimulation (TSS)

The aim of this technologie is neuromodulation and thus it’s next to Trans Spinal Stimulation, TSS it’s also called neurostimulation. In easy words it helps the person with a Spinal Cord Injury (SCI) which want to do a voluntary desired movement, help activating the necessary fibers of the spinal cord - It kind of amplifies the signals and puts it over the necessary threshold to make neuromodulation possible, so the person can strengthen or multiply the remaining fibers of the spinal cord and thus help to get better recovery.

Terminology

Afferent fibers → conducts signals from the periphery to the central nervous system (CNS)

Dura → in neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord.

Cerebrospinal fluid (CSF) →  is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.

Interneurons → an interneuron is a nerve cell of the central nervous system (CNS) that interconnects two other nerve cells, in the narrower sense a sensory (afferent) and a motor (efferent) neuron.

Dorsal roots  → the dorsal root of spinal nerve (or posterior root of spinal nerve, or sensory root) is one of two "roots" which emerge from the spinal cord. It emerges directly from the spinal cord, and travels to the dorsal root ganglion.

Neuromodulation → it works in this case by modulating the spinal cord circuitries. To do this, electrodes are externally placed on a patient’s back, and electrical stimulation is delivered via the electrodes by a portable pulse generator (PPG). This system is used to facilitate motor function recovery.

Application

A/ Trans-spinal direct current stimulation (tsDCS) at the cervical (dotted red) or thoracic (solid red) spinal level with the reference electrode commonly placed on the shoulder. B/ Typical tsDCS signal with several seconds of ramp up and ramp down current. The treatment intensity and duration are adjusted by the DC Amplitude and DC Timeframe. [1] [2]

A/ Multisite trans-spinal pulsed current stimulation at the cervical (dotted red) and thoracolumbar (solid red) levels with reference electrodes commonly placed above the iliac crests. B/ Typical tsPCS signal delivered at a frequency of 5–30 Hz with a 0.1–1 ms pulse width modulated at 10 kHz biphasic stimulation. 10kHz is the carrier frequency that reduces the impedance of the skin and thus allows more current to get in and can help minimize pain. [1] [2]