Somatosensory nociceptive characteristics differentiate subgroups in people with chronic low back pain

Abstract

The objectives of this study were to explore the existence of subgroups in a cohort with chronic low back pain (n = 294) based on the results of multimodal sensory testing and profile subgroups on demographic, psychological, lifestyle, and general health factors. Bedside (2-point discrimination, brush, vibration and pinprick perception, temporal summation on repeated monofilament stimulation) and laboratory (mechanical detection threshold, pressure, heat and cold pain thresholds, conditioned pain modulation) sensory testing were examined at wrist and lumbar sites. Data were entered into principal component analysis, and 5 component scores were entered into latent class analysis. Three clusters, with different sensory characteristics, were derived. Cluster 1 (31.9%) was characterised by average to high temperature and pressure pain sensitivity. Cluster 2 (52.0%) was characterised by average to high pressure pain sensitivity. Cluster 3 (16.0%) was characterised by low temperature and pressure pain sensitivity. Temporal summation occurred significantly more frequently in cluster 1. Subgroups were profiled on pain intensity, disability, depression, anxiety, stress, life events, fear avoidance, catastrophizing, perception of the low back region, comorbidities, body mass index, multiple pain sites, sleep, and activity levels. Clusters 1 and 2 had a significantly greater proportion of female participants and higher depression and sleep disturbance scores than cluster 3. The proportion of participants undertaking <300 minutes per week of moderate activity was significantly greater in cluster 1 than in clusters 2 and 3. Low back pain, therefore, does not appear to be homogeneous. Pain mechanisms relating to presentations of each subgroup were postulated. Future research may investigate prognoses and interventions tailored towards these subgroups.

Somatosensory Test Responses and Physical and Psychological Functioning of Children and Adolescents with Chronic Non-neuropathic Pain

“…The mechanisms may involve central plasticity and inhibition of central pathways by nociceptive input from deep tissues[60,61]. There is little in the pediatric literature about such hyposensitive phenomena in active chronic pain contexts.Within the adult literature, a mix of hypersensitive and hyposensitive responses is not uncommon[57,62,63], especially cutaneous hyposensitivity to touch and vibration, with pressure pain hypersensitivity, as in this study. Such observations, not as yet adequately understood, lead to Copyright © 2016 Wolters Kluwer Health, Inc.…”

Comparison of 2 Lumbar Manual Therapies on Temporal Summation of Pain in Healthy Volunteers

“…We theorized that SMT would have the greatest effect on a facilitatory cluster because SMT is an effective treatment for only some patients with low back pain 46,47 and there are subgroups of patients with low back pain that have enhanced TSP. 44 In turn, we hypothesized that the attenuation of TSP by SMT would be greatest in the facilitatory cluster.…”

Assessment of Pain Sensitivity in Patients With Chronic Low Back Pain and Association With HTR2A Gene Polymorphism

“…However, a limited number of studies emphasized on the perception of pain and pain threshold of patients with chronic low back pain (CLBP). 4,5 The association between high pain sensitivity in chronic pain conditions including low back pain was investigated, and it was reported that the pressure pain threshold (PPT) decreased due to long lasting pain. 4,6 One of the proposed mechanisms of pain sensitivity was sensitization of the central nervous system.…”

“…4,5 The association between high pain sensitivity in chronic pain conditions including low back pain was investigated, and it was reported that the pressure pain threshold (PPT) decreased due to long lasting pain. 4,6 One of the proposed mechanisms of pain sensitivity was sensitization of the central nervous system. 5 The serotoninergic system, and the 5-hydroxytryptamine (5-HT) as the key neurotransmitter, has an antinociceptive role in the dorsal horn of the descending tract of the spinal cord.…”