Table 4.
Effect of treatment on brain blood oxygen level–dependent response after painful stimulation in OA knee joint
| Treatment/Brain Region | Cluster Size* | MNI† Coordinates X, Y, Z | Mean‡ Difference | P§ |
|---|---|---|---|---|
| ER-APAP vs no treatment | ||||
| Sensory cortex* | 112 | 24, −44, 62 | −0.3153 | 0.002 |
| Supramarginal gyrus | 134 | 56, −32, 30 | −0.2955 | 0.003 |
| Placebo vs ER-APAP | ||||
| Thalamus | 343 | −6, −4, 12 | −1.1651 | 0.003 |
| Placebo vs no treatment | ||||
| Subgenual prefrontal cortex | 116 | 6, 28, 0 | −0.4541 | <0.001 |
| Frontal cortex | 305 | 38, 26, 26 | −0.3031 | <0.001 |
| Insula | 63 | 40, 26, −10 | −0.5008 | 0.003 |
| Sensory cortex | 176 | 36, −44, 62 | −0.5502 | <0.001 |
ER-APAP = extended-release paracetamol; MNI = Montreal Neurological Institute; OA = osteoarthritis.
Cluster size representing the number of continuous voxels forming an anatomical unit with intensity exceeding a preselected cluster threshold (≥50).
Maximum peak coordinates for the specific cluster as defined by the MNI template.
Mean of difference is calculated as mean of differences of MRI numeric values between first and second named treatment for each subject.
P < 0.01 and a cluster extension threshold of 50 or more continuous voxels were used as criteria to consider a result significant. P values were associated with a paired one-tailed t test.