Treatment data from the Brazilian fibromyalgia registry (EpiFibro)

Transcranial direct current stimulation is more effective than pregabalin in controlling nociceptive and anxiety-like behaviors in a rat fibromyalgia-like model

OBJECTIVES

Despite the fact that fibromyalgia, a widespread disease of the musculoskeletal system, has no specific treatment, patients have shown improvement after pharmacological intervention. Pregabalin has demonstrated efficacy; however, its adverse effects may reduce treatment adherence. In this context, neuromodulatory techniques such as transcranial direct current stimulation (tDCS) may be employed as a complementary pain-relieving method. Consequently, the purpose of this study was to evaluate the effect of pregabalin and tDCS treatments on the behavioral and biomarker parameters of rats submitted to a fibromyalgia-like model.

METHODS

Forty adult male Wistar rats were divided into two groups: control and reserpine. Five days after the end of the administration of reserpine (1 mg/kg/3 days) to induce a fibromyalgia-like model, rats were randomly assigned to receive either vehicle or pregabalin (30 mg/kg) along with sham or active- tDCS treatments. The evaluated behavioral parameters included mechanical allodynia by von Frey test and anxiety-like behaviors by elevated plus-maze test (time spent in opened and closed arms, number of entries in opened and closed arms, protected head-dipping, unprotected head-dipping [NPHD], grooming, rearing, fecal boluses). The biomarker analysis (brain-derived neurotrophic factor [BDNF] and tumor necrosis factor-α [TNF-α]) was performed in brainstem and cerebral cortex and in serum.

RESULTS

tDCS reversed the reduction in the mechanical nociceptive threshold and the decrease in the serum BDNF levels induced by the model of fibromyalgia; however, there was no effect of pregabalin in the mechanical threshold. There were no effects of pregabalin or tDCS found in TNF-α levels. The pain model induced an increase in grooming time and a decrease in NPHD and rearing; while tDCS reversed the increase in grooming, pregabalin reversed the decrease in NPHD.

CONCLUSIONS

tDCS was more effective than pregabalin in controlling nociception and anxiety-like behavior in a rat model-like fibromyalgia. Considering the translational aspect, our findings suggest that tDCS could be a potential non-pharmacological treatment for fibromyalgia.

Analysis of the Muscular Activity, Peak Torque in the Lower Limbs, and Static Balance after Virtual Rehabilitation in Women with Fibromyalgia: A Randomized Controlled Study

Objective: To analyze the effect of the exergaming on muscular activity at rest and on maximum voluntary isometric contraction by electromyography (EMG) at peak torque, widespread pressure hyperalgesia identified using a tender point count, and static balance in fibromyalgia. Materials and Methods: Thirty-five women were divided into two groups: Wii™ (virtual rehabilitation, n = 16) and control (stretching exercises, n = 19), through simple randomization. The volunteers were evaluated by means of EMG, dynamometry by load cell, baropodometry, and algometry before interventions and reevaluated after the 10th and 20th sessions. The subjects participated fully in three 1-hour treatment sessions per week of 20 sessions. Results: The Wii group showed significant benefits for the peak torque of dorsiflexion movement after 20 sessions and for movement plantarflexion after 10 sessions. The control group showed bilateral improvement in muscular activity in the tibialis anterior muscle after 20 sessions. Both groups showed a significant decrease in tender point count, suggesting improved hyperalgesia after 10 sessions and 20 sessions. No significant improvement was found in static baropodometry in the two evaluated groups. Conclusion: Exergaming have the potential to increase the peak torque for dorsiflexion and plantarflexion movement in women with fibromyalgia. It also produces a decrease in tender point count equal to that with flexibility exercises and does not produce changes in the static balance.

Myorelaxation, respiratory depression and electrocardiographic changes caused by the administration of extract of açai (Euterpe oleracea Mart.) stone in rats

The biological and pharmacological properties of natural polyphenols of the extract of Euterpe oleracea stone (EEOS) are associated with the central nervous system (CNS). To investigate the sedative and myorelaxant activity of EEOS in vivo, this study aimed to present the myorelaxant and sedative effects of EEOS in Wistar rats using spontaneous locomotor activity and motor electrophysiology. A total of 108 animals were used in the following experiments: a) behavioral tests (n = 27); b) electromyographic recordings of skeletal muscle (n = 27); c) respiratory muscle activity recordings (n = 27); d) cardiac muscle activity recordings (n = 27). The behavioral characteristics were measured according to the latency time of onset, the transient loss of posture reflex and maximum muscle relaxation. Electrodes were implanted in the gastrocnemius muscle and in the tenth intercostal space for electromyographic (EMG) signal capture to record muscle contraction, and in the D2 lead for electrocardiogram acquisition. After using the 300 mg/kg dose of EEOS intraperitoneally, a myorelaxant activity exhibited a lower frequency of contractility with an amplitude pattern of low and short duration at gastrocnemius muscle and intercostal muscle, which clearly describes a myorelaxant activity and changes in cardiac activity. The present report is so far the first study to demonstrate the myorelaxant activity of this extract, indicating an alternative route for açai stone valorization and its application in pharmaceutical fields.