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Mechanism underlying painful radiculopathy in patients with lumbar disc herniation
Author(s) -
SamuellyLeichtag Gil,
Eisenberg Elon,
Zohar Yaniv,
Andraous Maisa,
Eran Ayelet,
Sviri Gill E.,
Keynan Ory
Publication year - 2022
Publication title -
european journal of pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.305
H-Index - 109
eISSN - 1532-2149
pISSN - 1090-3801
DOI - 10.1002/ejp.1947
Subject(s) - medicine , mcgill pain questionnaire , sciatica , pain catastrophizing , lumbar , neuropathic pain , low back pain , lumbar disc herniation , physical therapy , visual analogue scale , intensity (physics) , anesthesia , chronic pain , surgery , pathology , physics , alternative medicine , quantum mechanics
Background Painful lumbar radiculopathy is a neuropathic pain condition, commonly attributed to nerve root inflammation/compression by disc herniation. The present exploratory study searched for associations between pain intensity and inflammatory markers, herniated disc size, infection, psychological factors and pain modulation in patients with confirmed painful lumbar radiculopathy scheduled for spine surgery. Methods Prior to surgery, 53 patients underwent the following evaluation: pain intensity measured on a 0–10 numeric rating scale (NRS) and the Short‐Form McGill Pain Questionnaire; sensory testing (modified DFNS protocol); pain processing including temporal summation and conditioned pain modulation (CPM); neurological examination; psychological assessment including Spielberger's Anxiety Inventory, Pain Sensitivity Questionnaire and the Pain Catastrophizing Scale. Pro‐inflammatory cytokine levels (IL‐1b, IL‐6, IL‐8, IL‐17, TNFα, IFNg) and microbial infection (ELISA and rt‐PCR) in blood and disc samples obtained during surgery. MRI scans assessments for disc herniation size/volume (MSU classification/ three‐dimensional volumetric analysis). Results Complete data were available from 40 (75%) patients (15 female) aged 44.8 ± 16.3 years. Pain intensity (NRS) positively correlated with pain catastrophizing and CPM ( r = 0.437, p = 0.006; r = 0.421, p = 0.007; respectively), but not with disc/blood cytokine levels, bacterial infection or MRI measures. CPM ( p = 0.001) and gender ( p = 0.029) were associated with average pain intensity (adjusted R 2 = 0.443). Conclusions This exploratory study suggests that pain catastrophizing, CPM and gender, seem to contribute to pain intensity in patients with painful lumbar radiculopathy. The role of mechanical compression and inflammation in determining the intensity of painful radiculopathy remains obscure. Significance of study Pain catastrophizing, CPM and gender rather than objective measures of inflammation and imaging seem to contribute to pain in patients with painful radiculopathy.