#DOWNSIDE TO DORSAL COLUMN STIMULATION GENERATOR#

To achieve closed-loop control, the Evoked Compound Action Potential (ECAP), representing the summation of all action potentials elicited by a given stimulus pulse, is measured. Recently, the development of closed-loop SCS, which maintains a constant level of dorsal column fibre activation by automatically adjusting the stimulus amplitude, has been shown to be superior to open-loop stimulation paradigms (paradigms with constant stimulus amplitude Mekhail et al., 2019).

The dorsal columns present an ideal target for the stimulation of primary sensory afferent fibres as they compose one of the major pathways conveying non-nociceptive sensory information. This principle is the basis for the development of a range of neuromodulation therapies targeting these fibres in different locations along their pathway, from the periphery (e.g., transcutaneous electrical nerve stimulation ( Vance et al., 2014)), to dorsal root ganglion stimulation ( Pope et al., 2013 Krames, 2015), and dorsal column stimulation (i.e., SCS). Although the exact mechanisms of action are not completely understood, it is established that stimulation of primary afferent (PA) mechanosensory fibres produces pain relief in patients with chronic neuropathic pain ( Sdrulla et al., 2018). Spinal cord stimulation (SCS) is a widely-used therapy for chronic pain management with a proven track record of efficacy and a favourable safety profile compared to pharmacological therapies ( Kapural et al., 2015 North et al., 2016 Deer et al., 2018 Thomson et al., 2018 Mekhail et al., 2019 Russo et al., 2020). Identification of PSDC fibre activation in humans emphasises the need for further investigation into the role they play in pain relief and the sensory response sensation (paraesthesia) experienced by patients undergoing SCS. A clear difference in conduction velocities between the primary afferents and the PSDC fibres were observed. Synaptic activation occurred in 9 of the 14 patients analysed and depended on the vertebral level of stimulation.

Our investigation in humans with chronic neuropathic pain undergoing SCS therapy, found that post-synaptic dorsal column (PSDC) fibres can be activated synaptically by the primary afferents recruited by stimulation, and axonically by the stimulation pulses directly. While the efficacy of SCS has been demonstrated, the precise mechanism of action and nature of the fibres activated by stimulation remain largely unexplored. Spinal cord stimulation (SCS) treatment for chronic pain relies on the activation of primary sensory fibres ascending to the brain in the dorsal columns. Thomas’ NHS Foundation Trust, London, United Kingdom

1Saluda Medical, Macquarie Park, NSW, Australia.

device malfunction, lead/electrode break or migrationīiological, e.g.Gerrit Eduard Gmel 1 * † Rosana Santos Escapa 1 Teddy Edmond Benkohen 1 Dave Mugan 1 John Louis Parker 1 Stefano Palmisani 2 Paddle: placed surgically via laminectomy or laminotomyĭevice-related, e.g. Two types of electrodes can be implanted 2:Ĭylindrical: placed via percutaneous technique under fluoroscopy

#DOWNSIDE TO DORSAL COLUMN STIMULATION GENERATOR#

ProcedureĪn internal pulse generator is implanted in the subcutaneous tissues of the flank, paraspinal, abdominal or upper gluteal regions with leads extending into the spinal canal with epidural electrodes placed adjacent to the dorsal columns. Patients may feel a tingling sensation in the area of electrodes placement when the stimulator is on. Although it varies between individuals, generally it reduces pain sensation by ~60% 1. The underlying pathophysiology is not entirely understood, however, increase in levels of GABA and serotonin stimulated by an electrical pulse in the area of dorsal horns is one of the potential mechanisms 1.

It uses low voltage electrical current delivered by electrodes on the surface of the cord to prevent pain signal from reaching the brain. failed back syndrome, brachial plexopathy, complex regional pain syndrome). Spinal cord stimulators, also known as dorsal column stimulators, are surgically placed devices to aid with symptom relief in individuals with chronic neurological pain (e.g.

Downside to dorsal column stimulation