Understanding what epilepsy and migraines are is the first step to understanding the connection between the two conditions. Epilepsy is a brain disorder that causes recurring, unprovoked seizures (via the Epilepsy Foundation). A seizure is defined by the Mayo Clinic as a sudden electrical disturbance in the brain, causing an individual to lose control of their behavior, feelings, and movements. Having two or more seizures within 24 hours leads to an epilepsy diagnosis.
A migraine is a recurrent headache that can cause throbbing or pulsating pain on one side of the head, accompanied by nausea, vomiting, sensitivity to light, and vision changes (via the Cleveland Clinic). Cortical spreading depression (CSD) occurs in both epilepsy and migraine patients. According to a 2018 article published in Neurological Research, CSD is a wave of increased electrocortical activity and vasodilation, followed by sustained decreased activity and prolonged vasoconstriction. The Association of Migraine Disorders explains that epilepsy and migraines share other similarities. Both have a genetic component, and people with epilepsy are twice as likely to experience migraines. Numbness in the face or arm can be a symptom of both medical conditions, and each is frequently misdiagnosed and undertreated.