Fibromialgia e disfunção temporomandibular: uma revisão de escopo / Fibromyalgia and temporomandibular disorder: a scoping review

A fibromialgia é uma síndrome complexa com alterações nociplásticas, caracterizadas por hiperalgesia e alodinia, frequentemente acompanhada pela presença de dor orofacial. Estudos têm demonstrado alta prevalência de disfunção temporomandibular (DTM) em pacientes fibromiálgicos, como fator etiológico ou agravante. O objetivo desta revisão de literatura foi identificar os mecanismos modulatórios comuns à fibromialgia e à DTM, e identificar diferentes modalidades de tratamento para os pacientes fibromiálgicos. Foram utilizados 69 artigos dos últimos 5 anos, além de 4 artigos conceituais anteriores a este período. Identificou-se que os principais fármacos utilizados para os sintomas de fibromialgia são pregabalina, amitriptilina, antidepressivos duais, tramadol, baixas doses de naltrexona e canabinoides. A associação de fármacos pode ser útil para aumentar a eficácia do tratamento e reduzir as doses dos mesmos. Por outro lado, novas terapias não farmacológicas, como as técnicas modulatórias não-invasivas, surgem como opções promissoras, promovendo alterações neuroplásticas importantes no tratamento. Conclusão: Há diversas opções terapêuticas farmacológicas e não-farmacológicas disponíveis no tratamento do paciente fibromiálgico para o especialista em DTM. Portanto, a combinação de diferentes abordagens pode auxiliar na obtenção de um protocolo individualizado, adequado às necessidades do paciente.

Fibromyalgia is a complex syndrome with nociplastic changes, characterized by hyperalgesia and allodynia, often accompanied by the presence of orofacial pain. Studies have shown a high prevalence of temporomandibular disorders (TMD) in fibromyalgia patients, as an etiological or aggravating factor. The aim of this review was to identify the modulatory mechanisms common to fibromyalgia and TMD, and to identify different treatment modalities for fibromyalgia patients. 69 articles from the last five years were included, in addition to 4 conceptual articles prior to this date. The main drugs used for fibromyalgia symptoms are pregabalin, amitriptyline, dual antidepressants, tramadol, low-dose naltrexone and cannabinoids. The combination of drugs may be useful in improving treatment efficacy and for reducing the drug's dose. On the other hand, new non-pharmacological therapies, such as non-invasive modulatory techniques, appear as promising options for treatment, promoting important neuroplastic alterations. Conclusion: Several pharmacological and non-pharmacological therapeutic alternatives are available for specialists in TMD. Therefore, combining therapy approaches can help create individualized protocols that are more effective at meeting the demands of fibromyalgia patients.

The profile of dexamethasone combined with transcranial direct current stimulation in rats submitted to an arthritis model / O perfil da dexametasona combinada com estimulação transcraniana por corrente contínua em ratos submetidos a um modelo de artrite

ABSTRACT BACKGROUND AND OBJECTIVES: To pursue safer and more effective treatments for rheumatoid arthritis, the effect of dexamethasone treatment (DEX, 0.25mg/kg) combined with transcranial direct current stimulation (tDCS) in the behavior and neurochemical parameters of arthritic rats was evaluated. METHODS: Thirty-six Wistar rats were divided into four groups: control+DEX (CTRL+DEX), arthritis+DEX (RA+DEX), arthritis+DEX+sham-tDCS (RA+DEX+sham-tDCS) and arthritis+DEX+tDCS (RA+DEX+tDCS). The arthritic model (RA) was induced by complete Freund's adjuvant (CFA) paw administration. Paw edema and mechanical allodynia were assessed by plethysmometer and von Frey apparatus, respectively. Fourteen days after the CFA injection, rats received the treatment for eight days (DEX and/or tDCS). Behavioral parameters were measured with the Open-Field test. ELISA was used to evaluate hippocampal and spinal cord tumor necrosis factor (TNF-α) levels, cerebral cortex and brainstem BDNF levels. RESULTS: In pre-treatment measurements, arthritic rats presented an increase in joint swelling and mechanical allodynia when compared to the control group, confirming chronic pain establishment. A slight antinociceptive effect of dexamethasone combined with tDCS in the pain model was observed. The pain model significantly induced an increase in the grooming behavior and a reduction in the spinal cord and hippocampal TNF-α levels; these effects were reverted in the sham- and active-tDCS-treated rats. However, no effects of DEX or tDCS were observed in the BDNF levels in the cerebral cortex and brainstem. CONCLUSION: Despite the small effect observed, tDCS treatment cannot be discarded as a non-pharmacological adjuvant technique for inflammatory chronic pain treatment.

RESUMO JUSTIFICATIVA E OBJETIVOS: Para investigar métodos mais seguros e eficazes para o manejo da artrite reumatoide, avaliou-se o efeito do tratamento com dexametasona (DEX, 0,25mg/kg) combinado com estimulação transcraniana por corrente contínua (ETCC) sobre parâmetros comportamentais e bioquímicos de ratos submetidos a um modelo de artrite reumatoide. MÉTODOS: Trinta e seis ratos Wistar foram alocados em 4 grupos: controle+DEX (CTRL+DEX), artrite+DEX (AR+DEX), artrite+DEX+sham-ETCC (AR+DEX+sham-ETCC) e artrite+DEX+ETCC (AR+DEX+ETCC). O modelo de artrite foi induzido pela administração de complete Freund's adjuvant (CFA) na pata. Edema na pata e a alodínia mecânica foram avaliadas por pletismômetro e teste de von Frey, respectivamente. 14 dias após injeção de CFA, ratos foram tratados por 8 dias (DEX e/ou ETCC). Atividade locomotora foi avaliada pelo teste do campo aberto. TNF-alfa (hipocampo e medula espinal) e BDNF (córtex e tronco) foram mensurados por ELISA. RESULTADOS: Nas medições pré-tratamento, ratos com artrite exibiram aumento de o inchaço articular e alodínia mecânica comparados ao grupo controle, confirmando o estabelecimento de modelo de dor crônica. Também se observou discreto efeito antinociceptivo da dexametasona combinada com ETCC no modelo de artrite. O modelo de dor induziu um aumento no comportamento de grooming e reduziu os níveis de TNF-alfa no hipocampo; estes efeitos foram revertidos nos grupos sham- e ETCC ativo. Entretanto, não foram observados efeitos da DEX ou ETCC nos níveis de BDNF no córtex cerebral ou no tronco encefálico. CONCLUSÃO: Apesar dos discretos efeitos observados, não se pode descartar a ETCC como uma abordagem terapêutica não farmacológica para o manejo da dor crônica inflamatória na artrite reumatoide.

Neuroinflammatory effects of tDCS in ovariectomized rats with chronic inflammation

Introduction: Postmenopausal women are more susceptible to chronic conditions, such as osteoporosis, arthritis, and other inflammatory diseases. We investigated the effects of transcranial direct current stimulation (tDCS) on biomarker levels in ovariectomized rats subjected to an inflammatory model. Methods: Twenty adult female Wistar rats underwent ovariectomy and complete Freund's adjuvant (CFA)-induced inflammation. We divided them into 2 groups: OAS (sham tDCS) and OAT (active tDCS). Fifteen days later, the rats underwent bimodal tDCS treatment (20 min, 0.5 mA, 8 days). After 24 h of the last tDCS session, we killed the rats and collected tissue samples (hypothalamus, cerebral cortex, and brainstem) for biomarker analysis by ELISA. We removed the paws for histological analysis. Results: Active tDCS increased hypothalamic and cortical TNF-α and NGF levels, hypothalamic and brainstem IL-1ß levels, and hypothalamic IL-10 levels. Histology of paws showed an inflammatory profile. We observed a small tDCS effect, not statistically significant. Discussion: Bimodal tDCS had an effect on the central inflammatory axis, with a small effect on the peripheral site as evaluated by histology in the current study. (AU)

Cafeteria diet increases liquid intake and serum creatinine levels in rats

Introduction: Important changes in human dietary pattern occurred in recent decades. Increased intake of processed foods leads to obesity, which is related with the development of chronic diseases such as type 2 diabetes mellitus, hypertension, as well as cardiovascular and chronic kidney diseases. The prevalence of hypertension has also dramatically increased in recent years, and high sodium intake contributes to this scenario. In healthy individuals, kidneys are the primary end-organs that regulate sodium homeostasis. This study aims to evaluate renal function parameters and systolic blood pressure measurements in an animal model of obesity. Methods: Sixty-day-old male Wistar rats (n=30) were divided into two groups: standard (SD) and cafeteria diet (CD). Cafeteria diet was altered daily and was composed by crackers, wafers, sausages, chips, condensed milk, and soda. All animals had free access to water and chow and the experiment was carried out for 6 weeks. Weight gain, sodium and liquid intake control, systolic blood pressure measurements, and renal function parameters were evaluated. Results: Animals exposed to cafeteria diet had an increase of 18% in weight compared to the control group. Sodium intake was increased by cafeteria diet and time (F(1,28)=773.666, P=0.001 and F(5,28)=2.859, P=0.02, respectively) and by the interaction of both factors (F(6,28)=2.859, P=0.02). On liquid intake occurred only effect of cafeteria diet and time (F(1,28)=147.04, P=0.001 and F(5,28)=3.996, P=0.003, respectively). Cafeteria diet exposure also induced an increase on creatinine serum levels (P=0.002), however this effect was not observed on creatinine urine levels (P>0.05) nor on systolic pressure measurements (Students' t test, P>0.05). Conclusions: Obesity induced by cafeteria diet exposure increases liquid intake and alters creatinine serum levels, an important renal function marker. Considering the high consumption of hypercaloric food currently in the world, further studies are required to elucidate the modifications on renal function triggered by this diet over time (AU)

One-time Exposure to General Anesthetics Alters Nociceptive Response and Nucleotide Hydrolysis in Infant Rats.

Aims: The objective was to evaluate the single exposure of general anesthetics with or without a surgical procedure at postnatal day 14 (P14) on nociceptive behavioral responses. Furthermore, we evaluated ectonucleotidase activities at P14 and P30. Place of Study: All experiments were performed at the Animal Experimentation Unit of Hospital de Clínicas de Porto Alegre. The Institutional Committee approved the experimental protocol f (GPPG-HCPA protocol No: 08149). Methodology: Fourteen-day-old male Wistar rats were divided into two experimental designs (ED): the 1st ED – control (C), isoflurane (ISO), isoflurane/surgery (ISO-SUR) and the 2nd ED – control (C), fentanyl/S(+)-ketamine (FK) and fentanyl/S(+)- ketamine/surgery (FK-SUR). Nociceptive responses were evaluated using the formalin and tail-flick tests, and the ectonucleotidase activities were evaluated by spinal cord synaptosome. All assessments were performed at P14 and P30. Results: The FK and FK-SUR groups displayed an increased latency at P30. For the ectonucleotidase activity analysis, the following results were observed: (a) in the 1st ED, the ISO group displayed a reduction in ATPase and ADPase, and both ISO and ISOSUR displayed a reduction in AMPase activity at P14; (b) in the 2nd ED, the FK group displayed an increase in AMPase activity at P14 and increased ATPase activity at P30, and both FK and FK-SUR exhibited an increase in AMPase activity at P30. Conclusion: Our results indicate that single administration of general anesthetics at P14 is able to promote changes in the nociceptive response in the intermediate-term, and in the ectonucleotidase activities in the short- and medium-terms.