Table 1.
Description of the included studies.
| Author (Year) | Study Design | Diagnosis | Groups Characterization (Intervention: n, Age, % Females) | Intervention | Control | BDNF: Sample/Analysis Kit | BDNF Results | Pain Outcome | Pain Results |
|---|---|---|---|---|---|---|---|---|---|
| Dall’Agnol et al., 2014 [24] | RCT | CMPS | rTMS: n = 11, 45.83 (9.63), 100% Sham: n = 12, 44.83 (14.09), 100% |
rTMS. Left motor cortex (M1). Trains: 16 series of 10 sec.pulse/high-frequency of 10 Hz biphasic magnetic stimulator 26 s rest. 1600 pulses per session. 10 sessions. |
Sham Identical experience but without the impulses |
Serum/ELISA | Not expose intra-group changes rTMS Increased BDNF vs. Sham |
VAS | Higher pain score was correlated negatively with serum BDNF level [r-squared = 0.89, Beta= −0.15, SE = 0.008, (CI) 95% −0.17 to −0.13]. |
| Botelho et al., 2018 [25] | RCT | CMPS | EIMS n = 12 48.36 (10.97) 100% Sham n = 12 46.00 (13.55) 100% |
EIMS Paraspinal region related to the nerve roots (the splenius capitis and semispinalis capitis). 20-min at at 2 Hz. 10 sessions |
Sham The same device but the output jack plug was broken |
Serum/ELISA | Intra-group: EIMS increased BDNF EIMS Increased BDNF vs. Sham |
VAS | Increase in serum BDNF induced by the EIMS was correlated negatively with pain at the end of follow-up (Beta: 0.67 t = 2.24 p = 0,02 (CI) 95% = 0.07 to 1.26) |
| Dos Santos et al., 2018 [26] | RCT | FM | tDCS n = 20, 49.15 (8.43) 100% Sham n = 20 50.05 (11.19) 100% |
tDCS with a cognitive training task. Anode over the left DLPFC, cathode at right supraorbital region. 2 mA for 20 min. The cognitive training: online app of a Dual N-Back task. 8 consecutive days. |
Sham The stimulator was turned off after a ramp-up of 30 s of stimulation |
Serum/ELISA | Does not expose the results | VAS | Does not expose the results |
| Da Graca-Tarragó et al., 2019 [27] | RCT | Knee OA | a-EIMS/A-TDCS n = 15 66 (9.08) 100% A-tDCS/s-EIMS n = 15 64.4 (9.82) 100% S-TDCS/a-EIMS n = 15 64.40 (6.02) 100% s-tDCS/S-EIMS n = 15 63.87 (7.07) 100% |
a-tDCS Anodal in the contralateral primary motor cortex (M1), cathode in the contralateral supraorbital region. 2 mA, rumps 30 s, 0.057 mA/cm2, electrodes 35 cm 2.5 s, 30 min. a-EIMS Needles (40 mm × 0.25 mm + constant current 2 Hz, intensity adjusted to tolerability, location 12 L1-S2, vast medial, rectur femoris, vast lateral, anterior tibialis and pes anserine bursae, 5 s, 30 min. |
Sham transcranial direct current stimulation (s-tDCS) The stimulator was turned off after a ramp-up of 30 s of stimulation Sham intramuscular electrical stimulation (s-EIMS) electrodes were placed on the sites where the needles were placed. No electrical stimulation passed to the patient |
Serum/ELISA | Not expose intra-group changes No difference between groups neither at baseline nor at the treatment end |
VAS, PPT | Serum BDNF levels at baseline were correlated negatively with the PPT at the end of the treatment All groups showed decreased pain scores over time The aTDCS/aEIMS produced higher reduction compared with all three groups |
| Medeiros et al., 2016 [28] | RCT | CMPS | a-rTMS/a-DIMST n = 11 49.18 (11.63) 100% a-rTMS/s-DIMST n = 12 45.83 (9.63) 100% s-rTMS/a-DIMST n = 12 47.25 (11.00) 100% s-rTMS/s-DIMST n = 11 46.73 (13.09) 100% |
a-TMS Coil over the left primary motor cortex. 600 pulses at 10 Hz frequency 80% resting motor threshold (rMT) intensity. 10 sessions for 20 min each one. a-DIMST Needles (40 mm × 0.25 mm). Nerve roots C2-C3, C3-C4, and C4-C5. Distance from the spinous process line: 1.5 cm). 10 sessions for 20 min using a frequency of 2 Hz. |
Sham repetitive transcranial magnetic stimulation (s-TMS) A sham coil was used Sham deep intramuscular stimulation therapy (s-DIMST) Used an electroacupuncture device where the electrical connection between the stimulator and the patient was broken at the output jack plug of the stimulator |
Serum/ELISA | No changes in BDNF levels | VAS | All groups presented lower level of Pain VAS than sham-rTMS sham-DIMST. |
| RCT: randomized controlled trial; rTMS: Repetitive transcranial magnetic stimulation; EIMS: Intramuscular electrical stimulation; DIMST: deep intramuscular stimulation therapy; tDCS: transcranidirect current stimulation; ELISA: enzyme-linked immunosorbent assay; BDNF: Brain derived neurotrophic factor; VAS: Visual Analogic Scale; KOOS: Knee injury and Osteoarthritis Outcome Score; PPT: Pressure pain threshold; FM: Fibromyalgia; CMPS: Chronic Myofascial Pain Syndrome: OA: Osteoarthritis; DLPFC: Dorso lateral prefrontal cortex. | |||||||||
| Autor (year) | Study design | Diagnosis | Groups characterization (Intervention: n, age, % females) | Intervention | Control | BDNF: sample/analysis kit | BDNF Results | Pain outcome | Pain results |
| Liu et al., 2019 [22] | RCT | Knee OA |
Exercise: (a) Tai Chi n = 35 58.61 (7.62) (b) Baduanjin n = 35 59.66 (7.36) (c) Stationary cycling n = 35 61.26 (7.53) Control n = 35 56.88 (6.51) |
Exercise; Tai Chi, Baduanjin and Stationary cycling. 1 h 5/w for 12 w |
Control: Basic health education 1 h, 1/w for 12 w | Serum/ELISA | Not expose intra-group changes No difference between groups |
KOOS pain | Taichi, Baduanjin and cycling decreased pain (increased KOOS pain score) vs. control |
| Jablochkoba et al., 2019 [21] | RCT | FM |
Resistance exercisen = 41 100% Relaxation therapy n = 34 100% |
Resistance exercise Supervised: 10-min warm-up + 50 min. started with 40% MVC, developed up to 70–80%. 2/w for 15 w |
Relaxation therapy: 25-min supervised mental exercises. 2/week. | Plasma/(ECLIA) | Intra-group: No changes in BDNF levels in FM (either in the exercise or in the relaxion group) No differences between groups (exercise vs. relaxion group) |
VAS | No significant multivariate relationships were found between the changes in BDNF and pain in FM |
| RCT: randomized controlled trial; ECLIA: electrochemiluminescence assay panel; BDNF: Brain derived neurotrophic factor; VAS: Visual Analogic Scale; KOOS: Knee injury and Osteoarthritis Outcome Score; FM: Fibromyalgia; OA: Osteoarthritis. | |||||||||