Revisiting intradural spinal cord stimulation: an introduction to a novel intradural spinal cord stimulation device

Abstract

Abstract Background: Spinal cord stimulation has been in use for decades and is growing as a therapeutic treatment option. A significant problem arising from the epidural location of the lead is electrical shunting through the cerebrospinal fluid, providing sub-optimal delivery of the electrical current specifically to the Aβ fibers of the dorsal column. Objective: Our goal is to design a safe and effective intradural spinal cord stimulator (SCS) that places the stimulating electrodes directly against the pia similar to what is currently employed with the auditory brainstem implant. Methods: We have reviewed the literature on the early original intradural SCSs and designed, built, and tested an improved device that seeks to overcome the limitations the existing epidural stimulators. Results: In particular, we have shown that the present design of our device allows for motion of the spinal cord without the device being displaced itself, exerts a surface pressure on the spinal cord surface that is below what would cause ischemia or vessel injury, activates somato-sensory evoked potentials at a lower threshold than epidural stimulation, and (iv) does not cause deleterious neurological deficits in a chronic ovine model of intradural stimulator implantation. Conclusion: While further studies to prove long-term safety and durability of the device are underway, we believe that revisiting an intradural approach to spinal cord stimulation may continue to improve our ability to treat certain chronic pain states and possibly the spasticity associated with spinal cord injuries.