Axial Low Back Pain: One Painful Area – Many Perceptions and Mechanisms

Abstract

Axial low back pain can be considered as a syndrome with both nociceptive and neuropathic pain components (mixed-pain). Especially neuropathic pain comprises a therapeutic challenge in practical experience and may explain why pharmacotherapy in back pain is often disappointing for both the patient and the therapist. This survey uses epidemiological and clinical data on the symptomatology of 1083 patients with axial low back pain from a cross sectional survey (painDETECT). Objectives were (1) to estimate whether neuropathic pain contributes to axial low back pain and if so to what extent. (2) To detect subgroups of patients with typical sensory symptom profiles and to analyse their demographic data and co-morbidities. (3) To compare patients with and without prior intervertebral disc surgery (IVD). Neuropathic pain components could be detected in 12% of the entire cohort. Cluster analyses of these patients revealed five distinct subgroups of patients showing a characteristic sensory profile, i.e. a typical constellation and combination of symptoms. All subgroups occurred in relevant numbers and some showed distinct neuropathic characteristics while others showed nociceptive features. Post-IVD-surgery patients showed a tendency to score more “neuropathic” than patients without surgery (not statistically significant). Axial low back pain has a high prevalence of co-morbidities with implication on therapeutic aspects. From these data it can be concluded that sensory profiles based on descriptor severity may serve as a better predictor for therapy assessment than pain intensity or sole diagnosis alone. Standardized phenotyping of pain symptoms with easy tools may help to develop an individualized therapy leading to a higher success rate in pharmacotherapy of axial low back pain.

Tanshinone IIA represses inflammatory response and reduces radiculopathic pain by inhibiting IRAK-1 and NF-κB/p38/JNK signaling

“…Our results strongly demonstrated the potential of TSA for the treatment of IVD degeneration-related back pain. Both nociceptive and neuropathic pathophysiological mechanisms are involved in the development of back pain [35,36], and IVD degeneration is the major underlying cause. IVD degeneration is induced by phenotypic changes in the NP cells, which cause tissue degradation [4] and neoinnervation of the disc, contributing to the transmission of pain in vivo [37,38].…”

“…In humans, back pain is caused by complex interactions of biological, psychological and social factors, and therefore it is considered as a syndrome with both nociceptive and neuropathic components involved in [35]. Nociceptive nerves are a major transmitter of discogenic back pain, therefore alteration of nerve growth into the disc by TSAmediated inhibition of neurotrophins can modulate the development of acute and chronic nociceptive pain [47].…”

The appropriate management of persisting pain after spine surgery: a European panel study with recommendations based on the RAND/UCLA method

“…As was also noticed during the panel discussions, some of these may need further refinement. This is particularly true for the concept of neuropathic (versus nociceptive or mechanical) pain for which there is currently much debate on its precise nature [14,[42][43][44][45] and role in the diagnostic evaluation and treatment choice for patients with PPSS [12-14, 46, 47]. Further research may also consider the inclusion of additional somatic variables, potentially relevant to treatment choice, such as sagittal balance [15,16].…”

Classification and Treatment of Chronic Neck Pain

“…Given that patients with mixed pain syndromes may have extended periods in which either neuropathic or nonneuropathic components predominate (ie, someone with degenerated disks and nerve root involvement may experience only occasional radicular symptoms), it is likely that their instrument-derived pain scores would fall into the intermediate range between the 2 discrete categories. In a large-scale study that sought to identify neuropathic pain in individuals with purely axial low-back pain, Förster et al 46 found a 12% incidence based on the painDETECT questionnaire. So whereas it is logical to conclude that pain scores intermediate between likely and unlikely neuropathic pain suggest a "mixed" condition, this contention remains speculative.…”