Fig. 3.

a Mean VAS during the crossover period. VAS visual analog scale. Mean VAS during crossover period. There was no statistically significant difference between period 1 and 2 (no period effect), enabling the periods to be combined for analysis of the treatment effect. There was no statistical difference in the pain suppression effect of 1000 Hz and 30 Hz. b Percentage pain suppression in open-label follow-up at 12 months. MCID minimal clinically important difference, VAS visual analog scale. Percentage pain suppression in open-label follow-up at 12 months: 85% of the patients had greater than 34% pain suppression (MCID), 80% of the patients had greater than 50% pain suppression, and 45% patients had greater than 80% pain suppression