Fig. 4From: Which is the best transcranial direct current stimulation protocol for migraine prevention? A systematic review and critical appraisal of randomized controlled trialsAdherence of available randomized controlled trials on transcranial direct current stimulation to the guideline recommendations for clinical trials of neuromodulation devices for the treatment of migraine in adults [14]. A green circle indicates that the criterion was met; a red circle, that it was not met; an amber circle, that it was not specifiedBack to article page