Migraine prevention is intended to reduce the frequency, suffering and disability associated with migraine attacks. Unfortunately, preventive treatment strategies rarely eliminate migraine, but they can reduce the frequency and severity of attacks.

The ultimate goals of migraine preventive therapy are to:

Reduce frequency, severity, and duration of attacks.

Improve responsiveness to treatment of acute attacks

Reference: american migraine foundation https://americanmigrainefoundation.org/resource-library/understanding-migrainepreventive-treatments/ , consulted on  july 08th,2019