Determinação dos limiares de percepção sensorial e de resposta motora nas diferentes fases do ciclo menstrual

Abstract

objective: to identify the variation of sensory perception and motor response in the different phases of the menstrual cycle. method: thirty women aged 18 to 40 years old (23.7 ± 3.60), with body mass index between 18.5 and 25kg/m 2 (21.15 ± 2.32) and menstrual cycle of 21-35 days, participated in this study. a pulse generator was used, with pulsed electric current frequency of 50hz and variable phases of 20 (l20), 50 (l50), 100 (l100), 300 (l300), 500 (l500), 1000 (l1000) and 3000µs (l3000). the threshold of sensory perception (tSp) was identified as the first sensation of increased current intensity and the threshold of motor response (tmR) as the minimum muscle contraction detected. Five collections were done, at each of the following phases: phase 1-menstrual (p1), phase 2-follicular (p2), phase 3-ovulatory (p3), phase 4-luteal (p4) and phase 5-premenstrual (p5). the data analysis consisted of the Friedman test followed by the Rank test, carried out in the BioStat 4.0 ® software, with a significance level of 5%. Results: the tSp was lower in p5 than in the other menstrual phases, for the l20, l300, l500, l1000 and l3000 currents. For the tmR, there was difference in the l20, l50, l500 and l1000 currents between p5 and all other phases; in the l100 current, between p1 and p5; and in the l300 and l3000 currents for p1, p2 and p3 versus p5. Conclusions: the thresholds of sensory perception and motor response varied systematically through the phases of the menstrual cycle, thus influencing motor-sensory behavior.

Diferenças de gênero no limiar sensitivo para estimulação elétrica nervosa em adultos jovens

“…The changes found in the electric sensory thresholds between young men and women corroborate findings in literature, which describe that the speed of sensorimotor functions can change with oscillations in circulating hormone levels, especially levels of E 2 and P 2 through the estrous cycle. 2,11 Lund et al 10 investigated differences in the electric sensory threshold and pain threshold before, during and after the use of TENS, and observed an increase of ST in men and women after the use of TENS (high frequency), although there was a greater variation in the women's group. In the studies of Avila et al 15 , using another kind of neuromuscular electrical stimulation, the tolerated electrical current amplitude, that is, TT, was also higher for men than for women.…”

“…Initially, the electrical current amplitude was gradually increased for determination of the perception threshold (ST) in each joint, then raised to the maximum limit tolerated (TT) by the individuals before pain. 1,2,4 The values of LS and TT for electrical current (mǖ)of each knee were acquired and recorded, and soon afterwards superficial thermotherapy was applied with rerecording of the sensitive thresholds.…”

“…[1][2][3][4][5] Particularly in rehabilitation medicine, as the main analgesic and non-pharmacological therapeutic methods, such as electrotherapy, thermotherapy (including cryotherapy) and phototherapy, depend directly on the sensorimotor pathways and on their adaptability. [1][2][3][4][5][6][7] To this effect, the evaluation of the sensory perception threshold (ST), that is, the lower quantity of energy capable of evoking a perception, and of the tolerance threshold (TT), the higher quantity of energy tolerated before pain, are essential measurements for studies of the superficial, thermal tactile and painful sensory pathways. 1,2 Recent investigations have evidenced that the NSS can undergo direct and indirect influences of various endogenous and exogenous physical and chemical factors for the regulation of sensory perception and of pain thresholds.…”

“…[1][2][3][4][5][6][7] To this effect, the evaluation of the sensory perception threshold (ST), that is, the lower quantity of energy capable of evoking a perception, and of the tolerance threshold (TT), the higher quantity of energy tolerated before pain, are essential measurements for studies of the superficial, thermal tactile and painful sensory pathways. 1,2 Recent investigations have evidenced that the NSS can undergo direct and indirect influences of various endogenous and exogenous physical and chemical factors for the regulation of sensory perception and of pain thresholds. [1][2][3][4] The discovery that the circulating levels of sex hormones (SH), especially estrogen E2 and progesterone P2, besides the reproductive 8 and cardioprotective 9 roles, can exercise modulatory effects on the neuronal functions and alter the superficial cutaneous sensitivity 1,2 , gave rise to intriguing questions about the parameters of conformation/therapeutic modulation in analgesia in both genders, particularly in associations with thermal resources.…”

“…1,2 Recent investigations have evidenced that the NSS can undergo direct and indirect influences of various endogenous and exogenous physical and chemical factors for the regulation of sensory perception and of pain thresholds. [1][2][3][4] The discovery that the circulating levels of sex hormones (SH), especially estrogen E2 and progesterone P2, besides the reproductive 8 and cardioprotective 9 roles, can exercise modulatory effects on the neuronal functions and alter the superficial cutaneous sensitivity 1,2 , gave rise to intriguing questions about the parameters of conformation/therapeutic modulation in analgesia in both genders, particularly in associations with thermal resources. [5][6][7][8][9][10][11] Considering that transcutaneous electrical nerve stimulation (TENS) appears as one of the most reliable and effective non-pharmacological resources for analgesia [3][4][5][6][7][10][11][12][13][14][15] , it became worth investigating the variations of the NSS between genders, and whether previous changes in skin temperature induced by heating/cooling would interfere in the adjustment/peripheral control of the NSS.…”