Association of anxiety with intracortical inhibition and descending pain modulation in chronic myofascial pain syndrome

Background: This study aimed to answer three questions related to chronic myofascial pain syndrome (MPS): 1) Is the motor cortex excitability, as assessed by transcranial magnetic stimulation parameters (TMS), related to state-trait anxiety? 2) Does anxiety modulate corticospinal excitability changes after evoked pain by Quantitative Sensory Testing (QST)? 3) Does the state-trait anxiety predict the response to pain evoked by QST if simultaneously receiving a heterotopic stimulus [Conditional Pain Modulation (CPM)]? We included females with chronic MPS (n = 47) and healthy controls (n = 11), aged 19 to 65 years. Motor cortex excitability was assessed by TMS, and anxiety was assessed based on the State-Trait Anxiety Inventory. The disability related to pain (DRP) was assessed by the Profile of Chronic Pain scale for the Brazilian population (B:PCP:S), and the psychophysical pain measurements were measured by the QST and CPM. Results: In patients, trait-anxiety was positively correlated to intracortical facilitation (ICF) at baseline and after QST evoked pain (β = 0.05 and β = 0.04, respectively) and negatively correlated to the cortical silent period (CSP) (β = -1.17 and β = -1.23, respectively) (P <0.05 for all comparisons). After QST evoked pain, the DRP was positively correlated to ICF (β = 0.02) (P < 0.05). Pain scores during CPM were positively correlated with trait-anxiety when it was concurrently with high DRP (β = 0.39; P = 0.02). Controls’ cortical excitability remained unchanged after QST. Conclusions: These findings suggest that, in chronic MPS, the imbalance between excitatory and inhibitory descending systems of the corticospinal tract is associated with higher trait-anxiety concurrent with higher DRP

Neurobiological Effects of Transcranial Direct Current Stimulation: A Review

Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique that is affordable and easy to operate compared to other neuromodulation techniques. Anodal stimulation increases cortical excitability, while the cathodal stimulation decreases it. Although tDCS is a promising treatment approach for chronic pain as well as for neuropsychiatric diseases and other neurological disorders, several complex neurobiological mechanisms that are not well understood are involved in its effect. The purpose of this systematic review is to summarize the current knowledge regarding the neurobiological mechanisms involved in the effects of tDCS. The initial search resulted in 171 articles. After applying inclusion and exclusion criteria, we screened 32 full-text articles to extract findings about the neurobiology of tDCS effects including investigation of cortical excitability parameters. Overall, these findings show that tDCS involves a cascade of events at the cellular and molecular levels. Moreover, tDCS is associated with glutamatergic, GABAergic, dopaminergic, serotonergic, and cholinergic activity modulation. Though these studies provide important advancements toward the understanding of mechanisms underlying tDCS effects, further studies are needed to integrate these mechanisms as to optimize clinical development of tDCS

Eficácia da melatonina no tratamento da dor miofascial crônica facial : ensaio clínico randomizado, duplo-cego, controlado com placebo

Cenário clínico: A síndrome dolorosa miofascial (SDM), causa comum de dor musculoesquelética, pode ser incapacitante e desafiadora terapeuticamente, devido à ineficácia dos tratamentos convencionais para dor. Intervenções terapêuticas alternativas precisam ser pesquisadas para alcançar vias do processo de doença não contempladas com a terapêutica clássica. Dentre estas, o uso da melatonina, com efeitos cronobiótico, ansiolítico e analgésico, tem se apresentado como uma opção terapêutica atrativa no tratamento da SDM, que cursa com alterações de sono, dor, sintomas depressivos e de ansiedade. Objetivos: Avaliar a eficácia da melatonina exógena na redução da dor, no limiar de dor à pressão (LDP) e na qualidade de sono de pacientes com SDM facial. Métodos e Resultados: Um estudo randomizado, controlado foi realizado em 45 mulheres com dor miofascial, com idades entre 18 e 40 anos, segundo critérios Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD). A eficácia da melatonina oral foi avaliada na redução da dor e melhora tanto do limiar de dor a pressão (LDP) como da qualidade do sono. Os participantes foram randomizados para receber 5 mg / dia de melatonina, 5 mg / dia ciclobenzaprina, ou placebo durante um período de quatro semanas. O efeito absoluto das intervenções, apresentado como ES (tamanho do efeito) sobre a dor: placebo versus melatonina foi de 2,08 (1,17-2,97) e de ciclobenzaprina vs placebo foi de -1,25 (0,45-2,06)]. O número de pacientes necessários para tratar (NNT) para evitar a dor moderada a intensa foi 3 (95% CI, 2-4) e 18 (95% IC, 9 a a) nos grupos de melatonina e de ciclobenzaprina, respectivamente, em relação ao placebo. O ES no LDP melatonina vs placebo e ciclobenzaprina vs placebo foi de 2,72 (1,69-3,75) e 1,01 (0,23-1,79), respectivamente. O ES na escala visual analógica de Qualidade de Sono (VASQS) utilizada para avaliar a forma como as pacientes se sentiram ao acordar, durante o período de tratamento, foi nos grupos melatonina versus placebo de 2,47 (1,49-3,45) e 1,01 (0,23-1,79), respectivamente. Conclusão: Melatonina foi mais eficaz do que placebo para melhorar a dor miofascial crônica facial e ambos os tratamentos foram mais eficazes do que placebo para melhorar o LDP e a qualidade de sono.Background: The Myofascial Pain Syndrome (SDM), a common cause of musculoskeletal pain, can course with disability and can be a therapeutical challenge, due to the ineffectiveness of conventional treatments for pain. Alternative therapeutic interventions must be researched to achieve the process of the disease process that in not dealt with the classical therapy. Among these, the use of melatonin, which takes effect chronobiotic, anxiolytic and analgesic, has been presented as an attractive therapeutic option in the treatment of SDM, which leads to sleep disturbances, pain, anxiety and depressive symptoms. Objectives: Evaluate the efficacy of exogenous melatonin in reducing pain, pain pressure threshold (PPT) and the sleep quality of patients with chronic myofascial face pain. Methods and Results: A randomized, controlled trial was conducted with 45 females, aged 18 to 40 years who presented myofascial pain according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD) guidelines. The efficacy of oral melatonin was evaluated in reducing pain and improving both the pain pressure threshold (PPT) and sleep quality. Participants were randomized to receive 5 mg/day melatonin, 5 mg/day cyclobenzaprine, or a placebo during a four-week period. The absolute effect of interventions, presented as ES (effect size) on pain for melatonin vs. placebo was 2.08 (1.17 to 2.97) and for cyclobenzaprine vs. placebo -1.25 (0.45 to 2.06)], respectively. The Number of Patients Needed to be Treated (NNT) to prevent moderate to intense pain was 3 (95% CI, 2 to 4) and 18 (95% CI, 9 to ) in the melatonin and cyclobenzaprine groups, respectively compared to the placebo. The ES on the PPT for melatonin vs. placebo and cyclobenzaprine vs. placebo was 2.72 (1.69 to 3.75) and 1.01 (0.23 to 1.79), respectively. The ES on the Visual Analog Sleep Quality Scale (VASQS) scores used to assess how they felt when they woke up during the treatment period for the melatonin vs. placebo were 2.47 (1.49 to 3.45) and 1.01 (0.23 to 1.79), respectively. Conclusion: Melatonin was more effective than placebo for improving chronic myofascial face pain and both treatments were more effective than placebo for improving sleep quality and the PPT

Eficácia da melatonina no tratamento da dor miofascial crônica facial : ensaio clínico randomizado, duplo-cego, controlado com placebo

Cenário clínico: A síndrome dolorosa miofascial (SDM), causa comum de dor musculoesquelética, pode ser incapacitante e desafiadora terapeuticamente, devido à ineficácia dos tratamentos convencionais para dor. Intervenções terapêuticas alternativas precisam ser pesquisadas para alcançar vias do processo de doença não contempladas com a terapêutica clássica. Dentre estas, o uso da melatonina, com efeitos cronobiótico, ansiolítico e analgésico, tem se apresentado como uma opção terapêutica atrativa no tratamento da SDM, que cursa com alterações de sono, dor, sintomas depressivos e de ansiedade. Objetivos: Avaliar a eficácia da melatonina exógena na redução da dor, no limiar de dor à pressão (LDP) e na qualidade de sono de pacientes com SDM facial. Métodos e Resultados: Um estudo randomizado, controlado foi realizado em 45 mulheres com dor miofascial, com idades entre 18 e 40 anos, segundo critérios Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD). A eficácia da melatonina oral foi avaliada na redução da dor e melhora tanto do limiar de dor a pressão (LDP) como da qualidade do sono. Os participantes foram randomizados para receber 5 mg / dia de melatonina, 5 mg / dia ciclobenzaprina, ou placebo durante um período de quatro semanas. O efeito absoluto das intervenções, apresentado como ES (tamanho do efeito) sobre a dor: placebo versus melatonina foi de 2,08 (1,17-2,97) e de ciclobenzaprina vs placebo foi de -1,25 (0,45-2,06)]. O número de pacientes necessários para tratar (NNT) para evitar a dor moderada a intensa foi 3 (95% CI, 2-4) e 18 (95% IC, 9 a a) nos grupos de melatonina e de ciclobenzaprina, respectivamente, em relação ao placebo. O ES no LDP melatonina vs placebo e ciclobenzaprina vs placebo foi de 2,72 (1,69-3,75) e 1,01 (0,23-1,79), respectivamente. O ES na escala visual analógica de Qualidade de Sono (VASQS) utilizada para avaliar a forma como as pacientes se sentiram ao acordar, durante o período de tratamento, foi nos grupos melatonina versus placebo de 2,47 (1,49-3,45) e 1,01 (0,23-1,79), respectivamente. Conclusão: Melatonina foi mais eficaz do que placebo para melhorar a dor miofascial crônica facial e ambos os tratamentos foram mais eficazes do que placebo para melhorar o LDP e a qualidade de sono.Background: The Myofascial Pain Syndrome (SDM), a common cause of musculoskeletal pain, can course with disability and can be a therapeutical challenge, due to the ineffectiveness of conventional treatments for pain. Alternative therapeutic interventions must be researched to achieve the process of the disease process that in not dealt with the classical therapy. Among these, the use of melatonin, which takes effect chronobiotic, anxiolytic and analgesic, has been presented as an attractive therapeutic option in the treatment of SDM, which leads to sleep disturbances, pain, anxiety and depressive symptoms. Objectives: Evaluate the efficacy of exogenous melatonin in reducing pain, pain pressure threshold (PPT) and the sleep quality of patients with chronic myofascial face pain. Methods and Results: A randomized, controlled trial was conducted with 45 females, aged 18 to 40 years who presented myofascial pain according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD) guidelines. The efficacy of oral melatonin was evaluated in reducing pain and improving both the pain pressure threshold (PPT) and sleep quality. Participants were randomized to receive 5 mg/day melatonin, 5 mg/day cyclobenzaprine, or a placebo during a four-week period. The absolute effect of interventions, presented as ES (effect size) on pain for melatonin vs. placebo was 2.08 (1.17 to 2.97) and for cyclobenzaprine vs. placebo -1.25 (0.45 to 2.06)], respectively. The Number of Patients Needed to be Treated (NNT) to prevent moderate to intense pain was 3 (95% CI, 2 to 4) and 18 (95% CI, 9 to ) in the melatonin and cyclobenzaprine groups, respectively compared to the placebo. The ES on the PPT for melatonin vs. placebo and cyclobenzaprine vs. placebo was 2.72 (1.69 to 3.75) and 1.01 (0.23 to 1.79), respectively. The ES on the Visual Analog Sleep Quality Scale (VASQS) scores used to assess how they felt when they woke up during the treatment period for the melatonin vs. placebo were 2.47 (1.49 to 3.45) and 1.01 (0.23 to 1.79), respectively. Conclusion: Melatonin was more effective than placebo for improving chronic myofascial face pain and both treatments were more effective than placebo for improving sleep quality and the PPT

Región : diario de la mañana: Año X Número 2762 - 1932 Junio 03

Numeración errónea en el original