Author (reference)	Acute Use	Preventive use	Pulses per dose	Seconds of stimulation	Stimulation intervals	Stimulation frequency	Total seconds	Location
Nesbitt et al (52)	Yes	NR	NR	NR	NR	NR	NR	NR
Eren et al (53)	Three pulses acutely	Morning and evening	3	90	NR	2	540/24 h + acute	Left
Tso et al (51)	NR	Yes	2–4	120	NR	2–3 (twice if 4 stimulations)	480–1,080/24 h	Ipsilateral to headache
Trimboli et al (49)	Three consecutive doses	Three times a day	2	90	Consecutive	3	540/24 + acute	Either one side or bilateral
Kamourieh et al (54)	No	Three times a day	2	120	Consecutive	3	720/24 h	Ipsilateral to headache
Moreno-Ajona et al (55)	No	Three times a day	2	120	Consecutive	3	720/24 h	Bilateral

Aa, amplitude adjustment; CCH, chronic cluster headache; CM, chronic migraine; CPH, chronic paroxysmal hemicrania; DC, direct current; HC, hemicrania continua; MC, muscle contraction; NA, not applicable; NR, not reported; PCH, primary cough headache; RTT, refractory to treatment