Migraine, epilepsy, post-traumatic syndromes, and spreading depression

Migraine was previously considered to be a blood vessel disorder. However, current evidence suggests that the circulatory changes associated with migraine may result from a disorder of cerebral function. Because migraine and epilepsy share in common certain clinical features, these two disorders may result from a similar underlying disturbance of the brain. Tiredness, yawning, feelings of coldness, changes of mood, craving for food, and fluid retention usually occur a day before the onset of a migraine attack. Similarly, symptoms following a migraine attack may include limited ability to tolerate food, tiredness, yawning, mood changes, and diuresis or increased elimination of water. The aura itself may involve various senses and develop over a 30-minute period. The evidence suggests that migraine is a central dysautonomia, or disease of the autonomic nervous system, associated with blood vessel changes and triggered by a metabolic event. The links between migraine and epilepsy, and the common factors between migraine, epilepsy, and symptoms occurring after a head injury are discussed. A possible underlying mechanism for the development of migraine may involve the effect of potassium ions on cortical function leading to a spreading depression. Persons with abnormalities in potassium metabolism have a high incidence of migraine. A mechanism of spreading depression could account for some of the symptoms of migraine, including pain, and is consistent with a relation between migraine, epilepsy, and syndromes following head injury. (Consumer Summary produced by Reliance Medical Information, Inc.)