Molecular Changes in the Dorsal Root Ganglion during the Late Phase of Peripheral Nerve Injury-induced Pain in Rodents: A Systematic Review.

The dorsal root ganglion is widely recognized as a potential target to treat chronic pain. A fundamental understanding of quantitative molecular and genomic changes during the late phase of pain is therefore indispensable. The authors performed a systematic literature review on injury-induced pain in rodent dorsal root ganglions at minimally 3 weeks after injury. So far, slightly more than 300 molecules were quantified on the protein or messenger RNA level, of which about 60 were in more than one study. Only nine individual sequencing studies were performed in which the most up- or downregulated genes varied due to heterogeneity in study design. Neuropeptide Y and galanin were found to be consistently upregulated on both the gene and protein levels. The current knowledge regarding molecular changes in the dorsal root ganglion during the late phase of pain is limited. General conclusions are difficult to draw, making it hard to select specific molecules as a focus for treatment.

Cross-cultural adaptation and psychometric validation of the Dutch version of the Core Outcome Measures Index for the back (COMI -back) in patients undergoing surgery for degenerative disease of the lumbar spine.

Introduction: Patient-reported outcome measures (PROMs) are the preferred outcomes measured in patients with lumbar spinal degenerative diseases. As PROMs can be lengthy and therefore pose a burden to patients and researchers, short and standardized PROMs are needed, such as the Core Outcome Measures Index (COMI). Research question: Is the Dutch version of the COMI-back a reliable and responsive PROM to measure outcomes in lumbar degenerative spinal surgery? Methods: After translating and cross-cultural adapting the COMI-back into Dutch, patients who were on the waiting-list for lumbar decompression surgery in a secondary referral center, were enrolled in the validation study. Patients completed a baseline booklet consisting of the COMI-back, likert scales measuring back and leg pain, the Roland-Morris Disability questionnaire, the EuroQoL-5 dimensions and the WHO-Quality-of-Life-BREF questionnaire to test construct validity. Within 2 weeks and before undergoing surgery, patients completed the COMI-back again, to measure test-retest stability. Three months after surgery, a global treatment outcome (GTO) question and the COMI-back were completed to test responsiveness. Results: The COMI-back was successfully translated and adapted into Dutch. One-hundred-thirty-five patients completed the baseline booklet, 93 the test-retest questionnaire and 102 the responsiveness questionnaire. The COMI-summary score and four of five COMI-domains, showed good to very good correlation to the reference questionnaires (ρ â€‹> â€‹0.41). The COMI-back showed a good test-retest stability with an intraclass correlation coefficient of 0.81 for the summary score. Furthermore, the standard error of agreement was 0.65 and the minimal detectable change was 1.8 points. The ROC-curve showed an area under the curve of 0.89 (95% CI 0.82 to 0.95). Conclusion: The Dutch version of the COMI-back has satisfactory psychometric properties and is a reliable and responsive patient-reported outcome measure in patients undergoing surgery for lumbar degenerative disease.