Migraines may be caused by changes in the brainstem and its interactions with the trigeminal nerve – a major pain pathway.
Imbalances in brain chemicals, which help regulate pain in your nervous system, cause the serotonin levels to drop during migraine attacks. This may cause your trigeminal nerve to release substances called neuropeptides, which travel to your brain’s outer covering (meninges). The result is migraine pain.
Other neurotransmitters that plays a role in the pain of migraine, include calcitonin gene-related peptide (CGRP).