This study involved 177 volunteers who had migraines for over 18 years on average.  Many of  participants also suffered from neck pain.  The average response of the group that received chiropractic care showed a statistically significant improvement in migraine frequency, duration, and disability.  The study also showed that those who received chiropractic care were able to reduce their medication use, with a significant number able to discontinue their medication. Journal of Manipulative and Physiological Therapeutics, (JMPT),  Feb. 2000.