A Double-Blind, Randomized, Controlled Trial of Epidural Conus Medullaris Stimulation to Alleviate Pain and Augment Rehabilitation in Patients with Subacute Thoracic Spinal Cord Injury (SCI)

ABSTRACT Spinal Cord Injury (SCI) represents a significant unmet need, posing a tremendous health and economic challenge for patients and society. Pain is a common complaint among people affected by SCI, and its persistence negatively impacts their quality of life (QOL). Approximately 65–85% of patients with SCI suffer from pain, and one-third of these characterize the pain as severe. While some treatments reduce the severity of pain in some individuals, no treatments that are currently available consistently relieve pain in the SCI chronic pain population. Persistent pain is one of the consequences of SCI that has consistently been shown to significantly decrease perceived quality of life (QOL). Pain interferes with sleep, cognitive, emotional, and physical health and functioning. Pain relief has been identified as one of the highest areas of unmet needs in a recent study of 1,000 individuals with SCI. Epidural Electrical Stimulation (EES), also known as Spinal Cord Stimulation in (SCS), is a common FDA-approved therapy for chronic neuropathic pain of trunk and limb. Recent studies have demonstrated the ability of EES to augment motor recovery in SCI rehabilitation. EES of spinal elements distal to a lesion has demonstrated previously untapped rehabilitative potential in patients with ‘complete’ SCIs. We propose a double-blind, prospective, randomized clinical trial where patients with subacute, traumatic, complete thoracic SCIs with American Spinal Injury Association (ASIA) Impairment Scale A are randomized to receive either “EES on” (treatment) or “EES off” (control) of the target regions for pain control (lead overlying the spinal cord anatomy corresponding with their pain distribution) and neurorestoration (lead overlying the conus medullaris) as an adjunct to physical therapy (PT). The objective of this study is to examine the feasibility of EES on improving pain and rehabilitation outcomes in patients with SCI. We hypothesize that patients who receive EES will outperform their counterparts in the control group in pain and exploratory endpoints including motor, sensory, bladder and QOL outcomes. We also hypothesize that when the control group crosses over to late stimulation, they will show improvement on a lesser scale than the early intervention group, but that these patients will also show significant improvement compared to their own control period. We propose the following Aims: Aim 1 will compare the impact of EES on pain and QOL in patients with SCI between control and placebo groups, using the SCI version of the Multidimensional Pain Inventory (MPI-SCI); Aim 2 will compare motor recovery as assessed by EMG and dynamometry between intervention and control groups at up to 9-months, followed by a second comparison of unblinded early versus late stimulation for another 9-month period; Aim 3 will compare the impact of EES on sensory, bladder and quality- of-life in patients with SCI between intervention and control groups, outcomes. Impact: If successful, this HEAL project would help determine whether this well-established clinical intervention can help patients with SCI neuropathic pain and have more widespread clinical applicability.