Iron imbalance in brain may cause migraine

By Will Boggs, MD

NEW YORK, Sep 28 (Reuters Health) - Abnormalities in the way the brain's pain control center handles iron may lead to the development of migraine attacks and headaches, according to a study by Kansas researchers.

During migraine, a portion of the brain known as the periaqueductal gray matter (PAG) may fail to "switch on" to prevent pain, Dr. K. Michael Welch of the University of Kansas Medical Center in Kansas City told Reuters Health.

"In migraine, a trigger such as stress activates the PAG but it does not switch on because it is dysfunctional," he explained, "or else switches on an abnormal part."

The result? "Pain instead of no pain," according to Welch.

His team studied levels of iron in the PAG of patients with either migraine headaches or recurrent, non-migraine headaches and compared them to levels in people without headache or migraine.

Changes in iron levels can reflect changes in the way the cells of the PAG work, the authors pointed out.

According to the report, published in a recent issue of the journal Headache, iron levels in the PAG were significantly increased in patients with migraine and those with headache compared to the headache-free group.

In fact, the researchers pointed out, the longer patients had experienced headaches, the higher the iron levels in the PAG were, though iron levels at the beginning of their illness were still clearly higher than normal.

Increased iron levels may be both a cause of migraine attacks and a result of repeated headaches, the investigators noted.

"Thus, we believe that the increased (iron levels) in our migraine groups reflect impaired iron (balance), possibly associated with (nerve) dysfunction or damage," the authors concluded.

"Perhaps the PAG abnormality is essential to the cause of the headache in migraine," Welch said. "The gradual deposition of iron increases dysfunction, and headaches coalesce from episodic to continuous."

How, then, might one minimize the damage from increased iron stores? Welch advised, "Treat episodes quickly and prevent (attacks) whenever possible."