ABSTRACT
BACKGROUND: Fibromyalgia (FM) is conceptualized as a central sensitization (CS) condition, that presents high serum brain-derived neurotrophic factor (BDNF) and neuroglia activation. Although the S100B protein regulates neuroglia functions, it has been traditionally used as a proxy of central nervous system damage. However, neither BDNF nor S100B association with the clinical picture of FM has been elucidated. To explore their association with the pressure-pain threshold (PPT) in FM, we performed a cross-sectional study, including 56 females with confirmed FM aged 18-65 years. Linear regression models were used to adjust for potential confounding factors between serum BDNF, S100B and PPT. RESULTS: Serum BDNF and S100B were correlated (Spearman's Rho = 0.29). Serum BDNF (log) and S100B (log) were correlated with the PPT (log) (Partial η2 = 0.129, P = 0.012 for the BDNF (log), and Partial η2 = 0.105, P = 0.025 for the S100B (log)). Serum BDNF (log) was inversely associated with PPT (log) (ß = -1.01, SE = 0.41), age (ß = -0.02, SE = 0.15) and obsessive compulsive disorder (ß = -0.36, SE = 0.15), while serum S100B (log) was inversely associated with PPT (log) (ß = -1.38, SE = 0.50), only. CONCLUSIONS: Both neuroglia key mediators in the CS process were inversely correlated with the PPT. Serum assessment of BDNF and S100B deserve further study to determine its potential as a proxy for the CS spectrum in FM.
Subject(s)
Brain-Derived Neurotrophic Factor/blood , Fibromyalgia/blood , Fibromyalgia/physiopathology , Pain Threshold/physiology , Pressure/adverse effects , S100 Calcium Binding Protein beta Subunit/blood , Cross-Sectional Studies , Female , Humans , Linear Models , Male , Retrospective StudiesABSTRACT
Quantitative sensory testing (QST) is defined as the determination of thresholds for sensory perception under controlled stimulus. Our aim was to validate a new QST device for Brazilian sample. In 20 healthy adults, thermoalgesic thresholds were assessed using a QST prototype (Heat Pain Stimulator-1.1.10; Brazil). A 30 × 30 mm² thermode with a 1°C/s stimulus change rate were applied. Thresholds of three consecutive stimuli were averaged in two different sessions separated by at least two weeks. Additionally long thermal heat pain stimulus was performed. To evaluate the consistency of our method we also analyzed 11 patients with small fiber neuropathy. Results showed good reproducibility of thermal perception thresholds in normal individuals and plausible abnormal thresholds in patients. We conclude that our QST device is reliable when analyzing the nociceptive pathway in controls and patients.
Teste de quantificação sensitiva (TQS) significa determinação de limiares de percepção sensitiva frente a um estímulo de intensidade controlada. Nosso objetivo foi validar um novo equipamento de TQS adaptado à população brasileira. Em 20 adultos saudáveis, limiares termoalgésicos foram avaliados, utilizando um aparelho protótipo do TQS (Heat Pain Stimulator-1.1.10; Brazil). Foi utilizado um termodo de 30 × 30 mm², com estímulo térmico de 1°C/s. A média dos limiares de três estímulos consecutivos foi obtida em duas sessões diferentes, separadas por pelo menos 2 semanas. Adicionalmente, foram aplicados estímulos térmicos dolorosos de longa duração. Para avaliar a consistência do nosso método, foram também analisados 11 pacientes com neuropatia de fibras finas. Os resultados mostraram boa reprodutibilidade dos limiares de percepção nos indivíduos saudáveis, assim como limiares anormais nos pacientes. Em conclusão, nosso aparelho de TQS apresentou boa confiabilidade ao analisar a via nociceptiva de controles e pacientes.
Subject(s)
Adult , Female , Humans , Male , Neuralgia/diagnosis , Pain Measurement/instrumentation , Pain Threshold/physiology , Peripheral Nervous System Diseases/diagnosis , Sensory Thresholds/physiology , Thermosensing/physiology , Case-Control Studies , Neuralgia/physiopathology , Peripheral Nervous System Diseases/physiopathology , Reference Values , Reproducibility of ResultsABSTRACT
Quantitative sensory testing (QST) is defined as the determination of thresholds for sensory perception under controlled stimulus. Our aim was to validate a new QST device for Brazilian sample. In 20 healthy adults, thermoalgesic thresholds were assessed using a QST prototype (Heat Pain Stimulator-1.1.10; Brazil). A 30 × 30 mm(2) thermode with a 1°C/s stimulus change rate were applied. Thresholds of three consecutive stimuli were averaged in two different sessions separated by at least two weeks. Additionally long thermal heat pain stimulus was performed. To evaluate the consistency of our method we also analyzed 11 patients with small fiber neuropathy. Results showed good reproducibility of thermal perception thresholds in normal individuals and plausible abnormal thresholds in patients. We conclude that our QST device is reliable when analyzing the nociceptive pathway in controls and patients.
