Targeting inflammation as a treatment modality for neuropathic pain in spinal cord injury: a randomized clinical trial

Abstract

BackgroundThe purpose of the present study was to examine the effectiveness of an anti-inflammatory intervention as a treatment for neuropathic pain following spinal cord injury (SCI).MethodsThis randomized, parallel-group, controlled clinical trial (NCT02099890) examined 20 participants with varying levels and severities of SCI, randomized (3:2) to either a 12-week anti-inflammatory diet, or control group. Outcome measures consisted of self-determined indices of pain as assessed using the neuropathic pain questionnaire (NPQ) and markers of inflammation as assessed by various pro- and anti-inflammatory cytokines, as well as the eicosanoids PGE2 and LTB4.ResultsA significant group × time interaction was found for sensory pain scores (p < 0.01). A Mann-Whitney test revealed that the change scores (3-month baseline) were significantly different between groups for IFN-y (U = 13.0, p = 0.01), IL-1β (U = 14.0, p = 0.01), and IL-2 (U = 12.0, p = 0.01). A Friedman test revealed the treatment group had a significant reduction in IFN-y (x2 = 8.67, p = 0.01), IL-1β (x2 = 17.78, p < 0.01), IL-6 (x2 = 6.17, p < 0.05), while the control group showed no significant change in any inflammatory mediator. A stepwise backward elimination multiple regression analysis showed that the change in sensory neuropathic pain was a function of the change in the proinflammatory cytokines IL-2 and IFN-y, as well as the eicosanoid PGE2 (R = 0.689, R2 = 0.474).ConclusionsOverall, the results of the study demonstrate the efficacy of targeting inflammation as a means of treating neuropathic pain in SCI, with a potential mechanism relating to the reduction in proinflammatory cytokines and PGE2.Trial registrationClinicalTrials.gov, NCT02099890Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-016-0625-4) contains supplementary material, which is available to authorized users.

A systematic review and meta‐analysis of nutrition interventions for chronic noncancer pain

“…After the removal of duplicates, a total of 7080 studies was identified in the search. Following full‐text screening, 71 studies were identified for inclusion, with 23 eligible for meta‐analysis. The abstracts for the majority of the papers were not sufficiently detailed to determine whether the full text should be retrieved.…”

“…Approximately 30% ( n = 21) of the studies were conducted in the USA , with five undertaken in Australia , four conducted in each of Germany , Japan and Spain , and three conducted in each of Denmark , Finland , Sweden , Iran and the Netherlands . Of the included studies, 47 were randomised controlled trials (RCT) , eight were nonrandomised trials , nine were pre–post studies , six were randomised cross‐over trials and one a longitudinal study .…”

“…Assessment of study quality rated 31 studies as of positive quality , 36 as neutral and four studies were classified as being of negative study quality . Of the 33 studies classified as neutral, information regarding the randomisation process ( n = 29) or the intervention description ( n = 13) was lacking.…”

Targeting cytokines for treatment of neuropathic pain

“…A number of pro-inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-17, have been found to be elevated in animal models of neuropathic pain. The same cytokines have also been found to be increased in the cerebrospinal fluid (CSF) and blood of patients with chronic neuropathic pain conditions [13–16]. Therefore, pharmacologically lowering the levels of inflammatory cytokines may reduce pain, which has been demonstrated for various cytokines in both animal models and clinical studies (Table 1).…”

Maintenance of diet participation in individuals with spinal cord injury: effect on mood and neuropathic pain

“…To this end, our lab performed a randomized controlled trial to explore the efficacy of utilizing an anti-inflammatory diet for the purpose of treating symptoms of neuropathic pain and depression. We found that the implementation of a 3-month anti-inflammatory diet was effective at reducing serum concentrations of proinflammatory mediators, and this reduction translated into significant improvements in both neuropathic pain [10] and depression [11]. Further, participants demonstrated excellent adherence to the diet with an average compliance score of 89%.…”