Tai Chi for the Prophylaxis of Episodic Migraine: the Efficacy Examination and Mechanism Exploration

Inclusion Criteria: * Chinese woman, aged 18-65 years. * Have a clinical diagnosis of episodic migraine (migraine with less than 15 attacks per month) with or without aura according to the International Classification of Headache Disorders, 3rd edition (ICHD-3). * First migraine attack before the age of 45 years. * Between two and six migraine attacks in one month. * At least one of the following migraine characteristics is met: nausea, vomiting, photophobia, or phonophobia. * Duration of migraine attacks is 2-72 h without acute medication or at least 1 h with acute medication. * Able to undertake designated level of Tai Chi exercise. * Live in Hong Kong. Exclusion Criteria: * Severe migraine attacks with disabilities that cannot perform moderate intensity physical activity. * Secondary headache and other neurological disease. * More than 5 days of non-migrainous headache per month. * Experience with Tai Chi or other body-mind exercises (yoga, biofeedback, medication, etc.) after diagnosis of migraine. * Undergoing other alternative therapeutic treatments during recruitment period, or received other alternative therapeutic treatments in the past 12 weeks. * Pregnancy, lactation period, or currently using contraceptives. * Use of pharmacological prophylactic treatment for migraine in the past 12 weeks. * Drug abuse, take antipsychotic or antidepressant drugs, or take analgesics for other chronic pain more than 3 days a month in the past 12 weeks. * Epilepsy, or have a psychiatric disease.