Table 4.
Relationship between intracortical inhibition and descendent pain modulatory system with the brain-derived neurotrophic factor (BDNF) according to the spectrum of structural pathology and absence of tissue injuries (n = 100).
| Dependent variable | Type III sum of squares | df | Mean square error | F | P | Partial eta squared |
|---|---|---|---|---|---|---|
| Change of NPS (0–10) during CPM-task | 73.097 | 3 | 24.36 | 4.60 | 0.005 | 0.30 |
| Short intracortical inhibition (log) | 3.88 | 3 | 1.29 | 3.75 | 0.014 | 0.11 |
| B | SEM | t | P | Partial eta squared | ||
| Change of NPS (0–10) during CPM-task | ||||||
| Intercepted | 0.10 | 0.69 | 0.16 | 0.880 | 0.00 | |
| Absence of structural pathology (n = 73) | 4.46 | 0.76 | 5.90 | 0.001 | 0.28 | |
| Presence of structural pathology (n = 27) | 0a | – | – | – | – | |
| BDNF (adjusted index) | −0.09 | 0.03 | −3.02 | 0.003 | 0.09 | |
| Interaction | ||||||
| Absence of structural pathology vs. BDNF (index adjusted; n = 65) | −0.07 | 0.03 | −2.31 | 0.020 | 0.06 | |
| Presence of structural pathology vs. BDNF (index adjusted; n = 27) | −0.29 | 0.07 | −4.33 | 0.001 | 0.18 | |
| Short intracortical inhibition (log) | ||||||
| Intercepted | −0.80 | 0.18 | −4.55 | 0.001 | 0.19 | |
| Absence of structural pathology (n = 73) | −0.45 | 0.19 | −2.34 | 0.020 | 0.06 | |
| Presence of structural pathology (n = 27) | 0a | – | – | – | – | |
| BDNF (index adjusted) | 0.00 | 0.008 | 0.05 | 0.95 | 0.00 | |
| Interaction | ||||||
| Absence of structural pathology vs. BDNF (index adjusted; n = 65) | −0.001 | 0.003 | −0.29 | 0.78 | 0.001 | |
| Presence of structural pathology vs.BDNF (index adjusted; n = 27)§ | 0.01 | 0.006 | 1.77 | 0.08 | 0.04 | |
§Take in account that the severity of pain, age, depression symptoms, and use of psychotropic medication as dummy variable.