Tissue and neuronal lesions result in sensitization of the nociceptors and facilitation of the central and peripheral nervous conduction.

CONTEXT AND OBJECTIVE: The role of immune response and proinflammatory cytokines in the pathogenesis of chronic pain has been of growing interest. In order to evaluate whether there is any association between disc herniation and elevated cytokine levels, we measured cytokine levels in patients with chronic low back pain and in healthy subjects. DESIGN AND SETTING:Analytical cross-sectional study at the Pain Clinic of Universidade Federal da Bahia (UFBA). METHODS:Cytokine levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique on 23 patients with low back pain (G1) and on 10 healthy subjects (G2). RESULTS:The levels of tumor necrosis factor-alpha [TNF-alpha] (G1 = 5.6 ± 2.3 pg/ml; G2 = 1.6 ± 0.5 pg/ml; P = 0.01) and interleukin-6[IL-6] (G1 = 4.1 ± 3.0 pg/ml; G2 = 0.9 ± 0.4 pg/ml; P = 0.01) were higher in G1. There were no statistically significant differences in relation to interleukin-1 [IL-1] (G1 = 0.5 ± 0.3 pg/ml; G2 = 0.5 ± 0.1 pg/ml; P = 1) or soluble tumor necrosis factor receptor [sTNF-R] (G1 = 572 pg/ml ± 36; G2 = 581 ± 50 pg/ml; P = 0.87). CONCLUSION:The patients with chronic low back pain due to disc herniation presented higher levels of TNF-alpha and IL-6, but not of IL-1 or sTNF-R. RESUMO CONTEXTO E OBJETIVO:A função da resposta imunológica e das citocinas pró-inflamatórias na patogênese da dor crônica tem tido interesse crescente. Para avaliar se há correlação entre hérnia de disco e aumento de citocinas, foi medida a concentração de citocinas em pacientes com lombalgia crônica e em indivíduos sadios. TIPO DE ESTUDO E LOCAL: Estudo transversal analítico realizado na Clínica de Dor da Universidade Federal da Bahia (UFBA).MÉTODO: As concentrações de citocinas foram medidas pela técnica de ELISA (enzyme linked immunosorbent assay) em 23 pacientes com lombalgia (G1) e 10 sadios (G2). RESULTADOS:As concentrações de fator-alfa de necrose tumoral [TNF-alpha] (G1 = 5.6 ± 2.3 pg/ml; G2 = 1.6 ± 0.5 pg/ml; P = 0,01) e interleucina-6 [IL-6] (G1 = 4.1 ± 3.0 pg/ml; G2 = 0.9 ± 0.4 pg/ml; P = 0,01) foram maiores no G1. Não houve diferença estatisticamente significante para interleucina-1 [IL-1] (G1 = 0.5 ± 0.3 pg/ml; G2 = 0.5 ± 0.1 pg/ml; P = 1) e receptor solúvel do factor de necrose tumoral [sTNF-R] (G1 = 572 pg/ml ± 36; G2 = 581 ± 50 pg/ml; P = 0,87).CONCLUSÃO: Os pacientes com lombalgia crônica por hérnia de disco apresentam concentrações maiores de TNF-alpha e IL-6, mas não de IL-1 ou sTNF-R.

JUSTIFICATIVA E OBJETIVOS:

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Postoperative persistent chronic pain is a complex and still unclear etiology entity, which interferes heavily in the life of the subject. Neuropathic pain resulting from surgical trauma is still the most common expression of this entity. Techniques to prevent nerve injury are recommended and should be used whenever possible. Despite efforts to understand and select risk patients, the management and prevention of this syndrome remain challenging and inappropriate.

-Objective: To evaluate the frequency of anxiety and depression disorders in patients with chronic pain. Method: Patients receiving care at the pain clinic of the Federal University of Bahia between February 2003 and November 2006. The MINI PLUS -Mini International Neuropsychiatric Interview was used to evaluate the patients and establish psychiatric diagnoses. Results: 400 patients were evaluated mean age was 45.6±11.37 years; 82.8% were female, 17.3% male; 48.5% were married; 55.1% were Catholics; and 40.5% had only high school education. Of these 29.9% reported intense pain and 70.8% reported suffering pain daily. The most frequent medical diagnosis was herniated disc (24.5%), and 48.5% of patients had been undergoing treatment at the pain clinic for less than 3 months. Comorbidities found were depressive episodes (42%), dysthymia (54%), social phobia (36.5%), agoraphobia (8.5%) and panic disorder (7.3%). Conclusion: Psychiatric comorbidities are prevalent in patients suffering chronic pain. Pain has been one of the major concerns of human beings since the beginning of humanity; however, the interpretation of pain varies from one culture to another 1 . Chronic pain is defined in the literature as pain that persists beyond the time required to cure the lesion; pain that is continuous and recurrent. It is generally characterized as vague, ill-defined and aggravated by environmental or psychopathological stress factors 2 .Chronic pain plays a significant role in incapacitating the individual, making it impossible for him/her to perform the physical or mental activities previously carried out normally. As a result, changes develop in the individual's quality of life in general and disorders and symptoms of anxiety and depression become evident 3 . Studies have shown that patients with chronic diseases and women have a much higher risk of developing psychiatric comorbidities compared to the general population 4 .Therefore, the objective of this study was to evaluate the frequency of disorders of anxiety and depression in patients with chronic pain.

In patients with herniated intervertebral disks and carpal tunnel syndrome, plasma levels of TNF-+/- and IL-6 were higher than in healthy volunteers, while differences in the concentrations of sTNF-R and IL-1(2) were not observed. Plasma levels of TNF-+/-, but not of IL-6, sTNF-R, and IL-1(2), decreased after treatment with tramadol (100 mg every 12 hours).

Chronic pain causes functional incapacity and compromises an individual's affective, social, and economic life. OBJECTIVE: To study the cognitive behavioral therapy (CBT) effectiveness in a group of patients with chronic pain. METHODS: A randomized clinical trial with two parallel groups comprising 93 patients with chronic pain was carried out. Forty-eight patients were submitted to CBT and 45 continued the standard treatment. The visual analogue, hospital anxiety and depression, and quality of life SF-36 scales were applied. Patients were evaluated before and after ten weeks of treatment. RESULTS: When the Control Group and CBT were compared, the latter presented reduction of depressive symptoms (p=0.031) and improvement in the domains 'physical limitations' (p=0.012), 'general state of health' (p=0.045), and 'limitations by emotional aspects' (p=0.025). CONCLUSIONS: The CBT was effective and it has caused an improvement in more domains of quality of life when compared to the Control Group, after ten weeks of treatment.