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Combined neuromodulatory interventions in acute experimental pain: assessment of melatonin and non-invasive brain stimulation.

da Silva NR, Laste G, Deitos A, Stefani LC, Cambraia-Canto G, Torres IL, Brunoni AR, Fregni F, Caumo W - Front Behav Neurosci (2015)

Bottom Line: The mean change from the baseline on amplitude of motor evocate potential (MEP) was significantly higher in the melatonin+a-tDCS (-19.96% ± 5.2) compared with melatonin+s-tDCS group (-1.36% ± 5.35) and with placebo+s-tDCS group (3.61% ± 10.48), respectively (p < 0.05 for both comparisons).While melatonin alone or combined with a-tDCS did not significantly affect CPM task result, and serum BDNF level.The melatonin effectively reduced pain; however, its association with a-tDCS did not present an additional modulatory effect on acute induced pain.

View Article: PubMed Central - PubMed

Affiliation: Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS) Porto Alegre, Brazil.

ABSTRACT
Transcranial direct current stimulation (tDCS) and melatonin can effectively treat pain. Given their potentially complementary mechanisms of action, their combination could have a synergistic effect. Thus, we tested the hypothesis that compared to the control condition and melatonin alone, tDCS combined with melatonin would have a greater effect on pain modulatory effect, as assessed by quantitative sensory testing (QST) and by the pain level during the Conditioned Pain Modulation (CPM)-task. Furthermore, the combined treatment would have a greater cortical excitability effect as indicated by the transcranial magnetic stimulation (TMS) and on the serum BDNF level. Healthy males (n = 20), (aged 18-40 years), in a blinded, placebo-controlled, crossover, clinical trial, were randomized into three groups: sublingual melatonin (0.25 mg/kg) + a-tDCS, melatonin (0.25 mg/kg) + sham-(s)-tDCS, or sublingual placebo+sham-(s)-tDCS. Anodal stimulation (2 mA, 20 min) was applied over the primary motor cortex. There was a significant difference in the heat pain threshold (°C) for melatonin+a-tDCS vs. placebo+s-tDCS (mean difference: 4.86, 95% confidence interval [CI]: 0.9 to 8.63) and melatonin+s-tDCS vs. placebo+s-tDCS (mean: 5.16, 95% CI: 0.84 to 8.36). There was no difference between melatonin+s-tDCS and melatonin+a-tDCS (mean difference: 0.29, 95% CI: -3.72 to 4.23). The mean change from the baseline on amplitude of motor evocate potential (MEP) was significantly higher in the melatonin+a-tDCS (-19.96% ± 5.2) compared with melatonin+s-tDCS group (-1.36% ± 5.35) and with placebo+s-tDCS group (3.61% ± 10.48), respectively (p < 0.05 for both comparisons). While melatonin alone or combined with a-tDCS did not significantly affect CPM task result, and serum BDNF level. The melatonin effectively reduced pain; however, its association with a-tDCS did not present an additional modulatory effect on acute induced pain.

No MeSH data available.


Related in: MedlinePlus

Motor-evoked potential (MEP) changes from baseline presented as percentages (post intervention minus pre-intervention). A letter b indicates a significant difference between the melatonin+a-tDCS group and the melatonin+s-tDCS and placebo+s-tDCS groups (p < 0.05). All comparisons were performed using a mixed analysis of variance model, followed by the Bonferroni correction for multiple post hoc comparisons. tDCS = transcranial direct current stimulation.
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Figure 3: Motor-evoked potential (MEP) changes from baseline presented as percentages (post intervention minus pre-intervention). A letter b indicates a significant difference between the melatonin+a-tDCS group and the melatonin+s-tDCS and placebo+s-tDCS groups (p < 0.05). All comparisons were performed using a mixed analysis of variance model, followed by the Bonferroni correction for multiple post hoc comparisons. tDCS = transcranial direct current stimulation.

Mentions: Similar analyses showed significant main effects of the intervention group for MEPs (F(2,46) = 11.55; p = 0.03). There was significant difference in MEP amplitude between the treatment group melatonin+a-tDCS and the melatonin+s-tDCS group (−19.96% ± 5.2 vs. −1.36% ± 5.35; mean difference: −18.60%, 95% CI: −42.44 to −7.12; p = 0.03) and melatonin+a-tDCS and the placebo+s-tDCS group (−19.96% ± 5.2 vs. 3.61% ± 10.48; mean difference: −23.57%, 95% CI: −39.68 to −1.2; p = 0.01). However, there was no significant difference in MEP amplitude between the melatonin+s-tDCS and the placebo+s-tDCS group (−1.36% ± 5.35 vs. 4.31% ± 10.56; mean difference: −5.67%, 95% CI: −39.68 to −1.2; p = 0.48). The differences between the groups in the percentage of variation before and after treatment are shown in Figure 3.


Combined neuromodulatory interventions in acute experimental pain: assessment of melatonin and non-invasive brain stimulation.

da Silva NR, Laste G, Deitos A, Stefani LC, Cambraia-Canto G, Torres IL, Brunoni AR, Fregni F, Caumo W - Front Behav Neurosci (2015)

Motor-evoked potential (MEP) changes from baseline presented as percentages (post intervention minus pre-intervention). A letter b indicates a significant difference between the melatonin+a-tDCS group and the melatonin+s-tDCS and placebo+s-tDCS groups (p < 0.05). All comparisons were performed using a mixed analysis of variance model, followed by the Bonferroni correction for multiple post hoc comparisons. tDCS = transcranial direct current stimulation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4379934&req=5

Figure 3: Motor-evoked potential (MEP) changes from baseline presented as percentages (post intervention minus pre-intervention). A letter b indicates a significant difference between the melatonin+a-tDCS group and the melatonin+s-tDCS and placebo+s-tDCS groups (p < 0.05). All comparisons were performed using a mixed analysis of variance model, followed by the Bonferroni correction for multiple post hoc comparisons. tDCS = transcranial direct current stimulation.
Mentions: Similar analyses showed significant main effects of the intervention group for MEPs (F(2,46) = 11.55; p = 0.03). There was significant difference in MEP amplitude between the treatment group melatonin+a-tDCS and the melatonin+s-tDCS group (−19.96% ± 5.2 vs. −1.36% ± 5.35; mean difference: −18.60%, 95% CI: −42.44 to −7.12; p = 0.03) and melatonin+a-tDCS and the placebo+s-tDCS group (−19.96% ± 5.2 vs. 3.61% ± 10.48; mean difference: −23.57%, 95% CI: −39.68 to −1.2; p = 0.01). However, there was no significant difference in MEP amplitude between the melatonin+s-tDCS and the placebo+s-tDCS group (−1.36% ± 5.35 vs. 4.31% ± 10.56; mean difference: −5.67%, 95% CI: −39.68 to −1.2; p = 0.48). The differences between the groups in the percentage of variation before and after treatment are shown in Figure 3.

Bottom Line: The mean change from the baseline on amplitude of motor evocate potential (MEP) was significantly higher in the melatonin+a-tDCS (-19.96% ± 5.2) compared with melatonin+s-tDCS group (-1.36% ± 5.35) and with placebo+s-tDCS group (3.61% ± 10.48), respectively (p < 0.05 for both comparisons).While melatonin alone or combined with a-tDCS did not significantly affect CPM task result, and serum BDNF level.The melatonin effectively reduced pain; however, its association with a-tDCS did not present an additional modulatory effect on acute induced pain.

View Article: PubMed Central - PubMed

Affiliation: Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS) Porto Alegre, Brazil.

ABSTRACT
Transcranial direct current stimulation (tDCS) and melatonin can effectively treat pain. Given their potentially complementary mechanisms of action, their combination could have a synergistic effect. Thus, we tested the hypothesis that compared to the control condition and melatonin alone, tDCS combined with melatonin would have a greater effect on pain modulatory effect, as assessed by quantitative sensory testing (QST) and by the pain level during the Conditioned Pain Modulation (CPM)-task. Furthermore, the combined treatment would have a greater cortical excitability effect as indicated by the transcranial magnetic stimulation (TMS) and on the serum BDNF level. Healthy males (n = 20), (aged 18-40 years), in a blinded, placebo-controlled, crossover, clinical trial, were randomized into three groups: sublingual melatonin (0.25 mg/kg) + a-tDCS, melatonin (0.25 mg/kg) + sham-(s)-tDCS, or sublingual placebo+sham-(s)-tDCS. Anodal stimulation (2 mA, 20 min) was applied over the primary motor cortex. There was a significant difference in the heat pain threshold (°C) for melatonin+a-tDCS vs. placebo+s-tDCS (mean difference: 4.86, 95% confidence interval [CI]: 0.9 to 8.63) and melatonin+s-tDCS vs. placebo+s-tDCS (mean: 5.16, 95% CI: 0.84 to 8.36). There was no difference between melatonin+s-tDCS and melatonin+a-tDCS (mean difference: 0.29, 95% CI: -3.72 to 4.23). The mean change from the baseline on amplitude of motor evocate potential (MEP) was significantly higher in the melatonin+a-tDCS (-19.96% ± 5.2) compared with melatonin+s-tDCS group (-1.36% ± 5.35) and with placebo+s-tDCS group (3.61% ± 10.48), respectively (p < 0.05 for both comparisons). While melatonin alone or combined with a-tDCS did not significantly affect CPM task result, and serum BDNF level. The melatonin effectively reduced pain; however, its association with a-tDCS did not present an additional modulatory effect on acute induced pain.

No MeSH data available.


Related in: MedlinePlus