Figure 4From: Electroacupuncture analgesia is associated with increased serum brain-derived neurotrophic factor in chronic tension-type headache: a randomized, sham controlled, crossover trialMean pain according to intervention period and sequence phase. Bars indicate the SEM. Bars with the same letter are not significantly different from each other. Both interventions significantly reduced pain when compared to baseline. Electroacupuncture (EA) was superior to Sham in reducing pain.Back to article page