Using cranial electrotherapy stimulation to treat pain associated with spinal cord injury
Tan, Gabriel, Rintala, Diana H., Thornby, John, Yang, June, Wade, Walter, and Vasilev, Christine. Using cranial electrotherapy stimulation to treat pain associated with spinal cord injury. Journal of Rehabilitation Research and Development. 2006; 43(4):461-474. Presented at the South Central VA Health Care Network’s Pain Management Initiative 2nd Annual Pain Management Symposium: Campaign Against Pain. Jackson, Mississippi, April 7, 2006. Download Article
Prior treatments for chronic pain in persons with spinal cord injury (SCI) have not been effective. This is a double-blind, sham controlled design with random assignment examining the effects of daily one hour active (N = 18) or sham (N = 20) CES treatments for 21 consecutive days on pain intensity and interference activities in 38 male veterans who had received care at a Department of Veterans Affairs spinal cord injury (SCI) Center. Treatments were self administered at home. The active CES group reported significantly decreased daily pain intensity (p = 0.03) compared with the sham CES group. The active CES group also showed significantly decreased pain interference (p = 0.004).
40 veterans who were 6 months to 60 years post SCI with chronic musculoskeletal or neuropathic pain were recruited in from the Michael E. DeBakey VA Medical Center in Houston, Texas. Exclusion criteria were documented history of noncompliance, evidence of substance abuse, and history of severe cognitive and or mental disorder that might interfere with the treatment regimen. Attrition was limited to 2 participants.
A physiatrist specializing in SCI conducted a brief examination to determine whether the participants’ pain was neuropathic or musculoskeletal. Participants used daily 0 – 10 pain rating scales to record pain immediately before and after each daily one hour treatment session. Pre-and post-intervention pain interference was assessed with the Pain Interference subscale of the BPI. A two-sample t-test was used to determine whether the average change score for the active CES group significantly differed from that of the sham CES group. Paired t-tests were used to determine whether pain ratings significantly changed from pre- to post session.
After the double-blind phase, the sham group were offered the opportunity to participate in an open label phase with an active CES device for another 21 consecutive days. 17 of the sham CES treated subjects (85%) agreed to the open label phase. The active and sham CES groups did not differ significantly with regard to their average precession pain ratings (mean equals 6.46 active CES versus 6.08 sham CES). The average change in daily pain intensity from pre- to post session was significantly larger for the active CES group (mean = -0.73) than the sham CES group (mean = -0.08, P = 0.03). The treatment effect size was medium to large (Cohen d = 0.76). Participants who received sham CES did not show significantly reduced pain (P = 0.34), whereas participants who received active CES did show significantly reduced pain (P = 0.02). The 17 sham CES participants who subsequently participated in the open label phase reported significant post session pain reduction (P = 0.003). None of the changes in the BPI pain intensity subscale items was statistically significant for any of the 3 groups. However, in paired t-tests for the active CES group, seven of the 10 individual pain interference subscale items significantly changed and reflected small to moderate effect sizes: General activity (Cohen d = 0.67), self-care (Cohen d = 0.58), sleep (Cohen d = 0.53), social activities (Cohen d = 0.51), normal work (Cohen d = 0.45), enjoyment of life (Cohen d = 0.42), and recreational activities (Cohen d = 0.38). A paired t-test within the active CES group revealed that the composite pain interference score decreased significantly (mean change = 14.6, P = 0.004, Cohen d = 0 .50). Neither the individual BPI pain interference subscale items or the composite pain interference score changed significantly in the sham group (mean change = -4.7, P = 0.24). However after crossover into the open label phase, pain interference with sleep decreased significantly (Cohen d = 0.40). Changes were greater in the 3 participants in the active group who had nontraumatic SCI. These results suggest that CES can effectively treat chronic pain in persons with SCI and may lower the burden of long-term pharmacologic management.