Although the results of our study suggest that EMDR may be a safe and promising treatment option in chronic pain conditions, the small number of high-quality studies leads to insufficient evidence for definite treatment recommendations.

Psychological trauma is associated with an increased risk for chronification of nonspecific chronic back pain (nsCLBP) independent of posttraumatic stress disorder (PTSD). However, the mechanisms underlying the role of psychological trauma in nsCLBP are less clear than in PTSD. Therefore, this study considered whether psychological trauma exposure (TE) is accompanied by specific alterations in pain perception. The study included 56 participants with nsCLBP and TE (nsCLBP-TE), 93 participants with nsCLBP without TE (nsCLBP-W-TE), and 31 pain-free controls. All participants underwent a thorough clinical evaluation. The standardized quantitative sensory testing protocol of the "German Research Network on Neuropathic Pain" was used to obtain comprehensive profiles on somatosensory functions in painful (back) and non-painful areas (hand). The protocol consisted of thermal and mechanical detection as well as pain thresholds, vibration thresholds, and pain sensitivity to sharp and blunt mechanical stimuli. Psychological trauma was validated by structured clinical interview. Trauma-associated symptom severity, anxiety, and depressive symptomatology were assessed by self-report questionnaires. Differences in somatosensory function were seen only for pressure pain thresholds. Compared with controls, nsCLBP-TE revealed hyperalgesia generalized in space with lower thresholds in painful and non-painful areas, whereas nsCLBP-W-TE demonstrated localized alterations with decreased thresholds only in the pain-affected area of the back (P ≤ 0.006). Our findings suggest an augmented central pain processing in nsCLBP-TE (alterations in painful and non-painful areas), whereas nsCLBP-W-TE show only local changes (alterations only in the painful area) suggesting regional sensitization processes. This finding might explain why TE without PTSD is associated with an increased prevalence of chronic pain.

Even after long duration CLP presents with a local hypersensitivity for PPT, suggesting a somatotopically specific sensitization of nociceptive processing. However, CWP patients show widespread ongoing pain and hyperalgesia for different stimuli that is generalized in space, suggesting the involvement of descending control systems, as also suggested for FMS patients. Because mechanisms in nonspecific chronic back pain with CLP and CWP differ, these patients should be distinguished in future research and allocated to different treatments.

ObjectiveEye movement desensitization and reprocessing (EMDR)—an evidence-based approach to eliminate emotional distress from traumatic experiences—was recently suggested for the treatment of chronic pain. The aim of this study was to estimate preliminary efficacy of a pain-focused EMDR intervention for the treatment of non-specific chronic back pain (CBP).DesignRandomized controlled pilot study.Methods40 non-specific CBP (nsCBP) patients reporting previous experiences of psychological trauma were consecutively recruited from outpatient tertiary care pain centers. After baseline assessment, patients were randomized to intervention or control group (1:1). The intervention group received 10 sessions standardized pain-focused EMDR in addition to treatment-as-usual (TAU). The control group received TAU alone. The primary outcome was preliminary efficacy, measured by pain intensity, disability, and treatment satisfaction from the patients’ perspective. Clinical relevance of changes was determined according to the established recommendations. Assessments were conducted at the baseline, posttreatment, and at a 6-month follow-up. Intention-to-treat analysis with last observation carried forward method was used. Registered with (NCT01850875).ResultsEstimated effect sizes (between-group, pooled SD) for pain intensity and disability were d = 0.79 (CI95%: 0.13, 1.42) and d = 0.39 (CI95%: −0.24, 1.01) posttreatment, and d = 0.50 (CI95%: 0.14, 1.12) and d = 0.14 (CI95%: −0.48, 0.76) at 6-month follow-up. Evaluation on individual patient basis showed that about 50% of the patients in the intervention group improved clinically relevant and also rated their situation as clinically satisfactory improved, compared to 0 patients in the control group.ConclusionThere is preliminary evidence that pain-focused EMDR might be useful for nsCBP patients with previous experiences of psychological trauma, with benefits for pain intensity maintained over 6 months.