Low Back Pain With Persistent Radiculopathy; the Clinical Role of Genetic Variants in the Genes SOX5, CCDC26/GSDMC and DCC.

In a recently published genome-wide association study (GWAS) chronic back pain was associated with three loci; and . This GWAS was based on a heterogeneous sample of back pain disorders, and it is unknown whether these loci are of clinical relevance for low back pain (LBP) with persistent radiculopathy. Thus, we examine if LBP with radiculopathy 12 months after an acute episode of LBP with radiculopathy is associated with the selected single nucleotide polymorphisms (SNPs); rs34616559, rs7833174 and rs4384683.

The association between selected genetic variants and individual differences in experimental pain.

Objectives: The underlying mechanisms for individual differences in experimental pain are not fully understood, but genetic susceptibility is hypothesized to explain some of these differences. In the present study we focus on three genetic variants important for modulating experimental pain related to serotonin (SLC6A4 5-HTTLPR/rs25531 A>G), catecholamine (COMT rs4680 Val158Met) and opioid (OPRM1 rs1799971 A118G) signaling. We aimed to investigate associations between each of the selected genetic variants and individual differences in experimental pain.

Psychophysical or spinal reflex measures when assessing conditioned pain modulation?

Background: Assessing conditioning pain modulation (CPM) with spinal reflex measures may produce more objective and stable CPM effects than using psychophysical measures. The aim of the study was to compare the CPM effect and test-retest reliability between a psychophysical protocol with thermal test-stimulus and a spinal reflex protocol with electrical test-stimulus.

Methods: Twenty-five healthy volunteers participated in two identical experiments separated by minimum 1 week.

A tonic heat test stimulus yields a larger and more reliable conditioned pain modulation effect compared to a phasic heat test stimulus.

Introduction: The interest in conditioned pain modulation (CPM) as a clinical tool for measuring endogenously induced analgesia is increasing. There is, however, large variation in the CPM methodology, hindering comparison of results across studies. Research comparing different CPM protocols is needed in order to obtain a standardized test paradigm.