Incidence of Neuropathic Pain in Patients with Thoracic Disc Pathologies Presenting with Chronic Upper Back Pain and Correlation of Herniation Grade with Pain Severity

AIM: To determine the incidence of neuropathic pain (NP) in patients with thoracic disc herniation (TDH) and to determine whether there is any correlation between pain severity and herniation grade. MATERIAL and METHODS: A total of 110 patients diagnosed with TDH with chronic non-specific thoracic spine pain were included in our cross-sectional observational study. Data including magnetic resonance imaging findings, bulging, protrusion, extrusion and sequestration were retrospectively analysed. We determined the incidence of NP in patients by administering the self report form Douleur Neuropathique 4 (DN4) questionnaire. Pain severity was assessed using Numeric Rating Scale scores. RESULTS: In our study, 79.1% of TDHs were located below the T7-8 level. The patients were divided into two subgroups on the basis of the results of the DN4 questionnaire: NP subgroup, 43 (39.1%), and non-NP subgroup, 67 (60.9%). Although there was no statistically significant association between presence of NP and herniation grade bulging, protrusion or sequestration (p>0.05), the rate of herniation in the extrusion grade was statistically significantly higher in patients with NP than in those without NP (p=0.004). The pain severity of the patients with herniation grade extrusion was statistically higher than that of patients with other non-extrusion grades (p=0.035). CONCLUSION: TDH should be considered in patients with neuropathic chronic back, chest and abdominal pain. If the patient's pain characteristics indicate NP, a diagnosis of TDH becomes more likely, considering that nearly 4 out of 10 patients with TDH have NP.