Botulinum toxin type A for preventing episodic migraine

Botulinum toxin type A is being developed to prevent episodic migraine. Migraine is a debilitating headache disorder. Symptoms may include nausea (feeling sick), vomiting (being sick), and increased sensitivity to light, sound or smells. Migraine may be with or without aura (symptoms visual disturbances, problems with speech, numbness or pins and needles). The headaches of episodic migraine (with or without aura) occur on fewer than 15 days per month. Episodic migraine may develop into long-term (chronic) migraine (headache on 15 or more days a month). It is not known what causes migraine. Some conditions such as depression and anxiety, and triggers such as stress and tiredness, can cause migraines in some people. There is no cure for migraine, and management of episodic migraine is focused on preventive treatment to reduce headache frequency, duration, and severity.