A total of 40 female patients were enrolled into this study, after having given their informed consent, and all were suffering from migraine without aura, diagnosed according to the criteria established by the International Classification of Headache Disorders (ICHD-II) . The patients were examined at the Women’s Headache Center, Department of Gynaecology and Obstetrics of Turin University. Inclusion criteria were: at least two migraine attacks per month for a 1-year period before enrollment; no more than 15 days of pain per month. The study had the maximum duration of 3 months. None of the patients were on prophylactic therapy, but were allowed to continue taking their usual symptomatic treatment. The patients’ medical history had to include the presence of nausea as accompanying symptomatology of their migraine, documented by a diary noting at least 1 month of attacks with nausea, prior to the inclusion in the study. Subjects taking antiemetics to control their nausea, whether as a single product or present as a compound in a combination product for the control of migraine, were excluded from the study. The patients enrolled were asked to fill in a dedicated diary recording the details of the length and intensity of the migraine attacks along with the accompanying symptomatology, paying particular attention to the presence of nausea. A device known as the Sea-Band® was given to the patients to control their nausea. The Sea-Bands® are elastic wristbands with a 1 cm protruding round plastic button; these devices apply continual pressure to the PC6 acupuncture point with the aim of decreasing, or completely eliminating nausea (Fig. 1). The PC6 point, also called Neiguan, is located on the anterior surface of the forearm, 3 fingers widths up from the first wrist crease and between the tendons of the flexor carpi radialis and palmaris longus. The Sea-Bands® were applied bilaterally on both wrists on the Neiguan point, starting from the onset of the migraine attack and left in place for no less than 4 h, or for the whole attack period.
The patients were asked to document a total of six migraine attacks: three without the use of the Sea-Band® wristbands (phase C, control) and three with the application of the Sea-Bands® (phase SB). The sequence of the treatment given for the attacks (with, or without Sea-Bands®) was chosen at random according to a scheme provided by the computer and was applied to each single patient.
The section of the diary provided that covered the symptom of nausea was detailed to include information as to the time of symptom onset and symptom resolution, the intensity of nausea at the onset (T0), at 30 (T1), 60 (T2), 120 (T3) and 240 (T4) minutes evaluated on a scale from 0 to 10, where 0 indicated no nausea and 10 the maximum sensation of nausea.
Diary analysis was carried out by an impartial operator who did not know in which attacks the Sea-Bands® were used or not. In this preliminary study, the analysis of diaries is focused only on nausea symptomatology.
The average values of nausea in phases C and SB were calculated at different times throughout the study and a statistical evaluation of the differences between the values obtained in T0, T1, T2, T3 and T4 in the two groups studied was performed using a non-parametric Friedman test for repeated measures.
Moreover, a non-parametric Wilcoxon test for paired data was always performed for each level of the variable ‘‘time’’ to evaluate the difference between phase C and phase SB. This test also took into consideration the average intensity of the three attacks in each of the two phases. All values given in the following text are reported as arithmetic means (±SEM). A Chi square test was applied for proportions. All analyses were performed using the Statistical Package for the Social Sciences (SPSS) software program.