Suggest Treatment For Persistent Migraines

My partner has been suffering for migraines for many years now. We have tried all the possible medication from a chemis. Have also been to our GP and he has tried everything including the melts and even epilepsy medication. He had a MRI scan but it came back clear. They are mostly on the right side of the time. His migraines are very frequent ( 4-5 times a week) for up to 3days a time for the longest. My mother was a sufferer and she was given an injection? many years ago, i have also read online that an injection can be used. Is this still available?