RESUMO
INTRODUCTION: Refractory migraine is a particularly disabling form of chronic migraine, unresponsive to multiple prophylactic strategies. Ketogenic diet (KD) is useful to treat migraine but poorly tested for refractory migraine. OBJECTIVE: We started exploring the efficacy and safety of KD, as compared to a non-ketogenic dietary regimen similar in reduction of carbohydrate intake (low-carb diet, LCD), in refractory migraine. Secondary objective was to explore whether ketones have a role in the prophylaxis induced by KD on migraine. RESULTS: In a first trial, 22 patients with refractory migraine were included and completed the study. Thirteen (mean age 36.8 ± 12.9 years, 11 females, 2 males) were assigned to the KD arm and eight (mean age 50.9 ± 10.8 years; all females), not eligible for KD, to LCD. Patients treated with KD showed a significant reduction in the frequency of migraine attacks, intensity of headache, and amount of drug intake. No significant benefit was seen in the LCD group. A relationship between ketone production and effect on headache was observed among patients with a good response to KD. In a second study, additional 31 refractory migraineurs were treated with these two dietary regimens, 26 with the same KD scheme and 5 with a LCD. Results were comparable with those of the first study. CONCLUSIONS: KD might be a useful option in refractory migraine. Ketones seem to have a role in migraine modulation and their regular measurement might be useful to monitor KD in migraineurs. Larger, randomized, and controlled trials are needed to confirm these data.