High Level of Childhood Trauma Predicts a Poor Response to Spinal Cord Stimulation in Chronic Neuropathic Pain.

BACKGROUND: Spinal cord stimulation (SCS) relieves pain by delivering doses of electric current to the dorsal column of the spinal cord and has been found to be most effective in the treatment of neuropathic pain. Psychological distress is a significant risk factor for the development of chronic pain and has been found to affect the outcome of SCS. Childhood trauma is a risk factor for chronic pain, but has not previously been studied in SCS patients.

OBJECTIVES: The objective of this prospective registry-based study was to investigate the prevalence of 5 domains of childhood trauma (emotional neglect, emotional abuse, physical neglect, physical abuse, and sexual abuse) and their relationship with the outcome of spinal cord stimulation on patients suffering from treatment-resistant chronic pain.

METHODS: SCS patients treated at Kuopio University Hospital between 1/1/2015 and 12/31/2016 were sent a survey in the mail, the Trauma and Distress Scale, assessing childhood trauma (n = 43). Neuropathic pain, disability, anxiety, and depression were measured in the patients pre-surgery and at 6 and 12 months post-surgery. The patients who provided their name on the questionnaire (n = 22) and had suffered from 3 or more domains of trauma were grouped as the high-trauma group (n = 13) and the rest as the low-trauma group (n = 9).

RESULTS: The questionnaire was completed by 40 patients (93%). At least 1 domain of trauma was experienced by 35 (88%) patients, and at least 2 by 24 (60%). The low-trauma group displayed a statistically significant decrease in the mean PainDETECT score from 21.5 before SCS to 16.5 at 12 months post-surgery (Wilk's lambda = 0.297, F(2,9) = 10.6, P = 0.004), contrary to the high- trauma group (Wilk's lambda = 0.904, F(2,6) = 0.3, P = 0.739).

LIMITATIONS: Only 22 of the 40 patients provided their name on the questionnaire, which decreased the sample size on follow-up.

CONCLUSION: This was the first study to investigate childhood trauma in SCS patients. Patients who had experienced high amounts of childhood trauma did not experience any relief from neuropathic pain 12 months' post-SCS, contrary to the low-trauma group. Childhood trauma might be a factor worth screening in the preoperative evaluation and aftercare of SCS candidates.

KEY WORDS: Spinal cord stimulation, the Trauma and Distress Scale, chronic pain, childhood trauma, childhood abuse, childhood neglect, chronic back pain, back pain, psychological distress, neuropathic pain.