The sociodemographic characteristics and the patterns of basal activity of the cephaleas were determined for all the patients. The 19 patients who fulfilled the inclusion criteria were allocated to treatment according to a computer generated randomization procedure with 4 consecutive balanced blocks of two patients (one active, one placebo). They were randomized, in a simple way, in two groups of exposition: the real and the placebo one. Patients were evaluated by the researchers at the third and sixth months of treatment. Along this time, the patients registered in their diaries the frequency and clinical characteristics of the episodes of cephaleas during both treatments.