Fig. 5.
Power analysis results. The probability of obtaining a statistically significant (P < 0.05) difference between placebo and gabapentin (Y-axis) at a given sample size (X-axis) for both objective and subjective outcome measures are shown. The objective outcome measures are the % blood oxygen level dependent response to secondary punctate mechanical hyperalgesia obtained from the left posterior insula (LtPIN; green), left secondary somatosensory cortex (LtSII; blue), and right nucleus cuneiformis (rNCF; red). The subjective outcome measures are the punctate hyperalgesia intensity (INT; black closed circles) and unprovoked ongoing pain (OGP).