Although migraine headaches affect nearly 23 million Americans, no diagnostic test for the problem exists. In fact, physiological proof of the headaches has never been found. But Johns Hopkins neurologist Marco Pappagallo thinks he has discovered the source of migraine pain--the meninges, the protective outer coverings of the brain.
Pappagallo had noticed that people with meningitis and people with migraines complained of nearly identical symptoms--throbbing headache, nausea, and sensitivity to light and sound. But while meningitis pain encompasses the entire head and neck, migraine pain is focused on specific areas, such as behind the eyes or one side of the head. Pappagallo took brain scans of patients as they experienced migraines and also asked them to draw pictures showing where they felt pain. The drawings matched the inflamed areas of the meninges that showed up in the brain scans.
Pappagallo attributed the inflammation of the meninges to the release of neuropeptides by an overly sensitive cranial nerve. But the reason for the nerve irritation is still unknown. Further research is necessary before Pappagallo's technique can be used as a diagnostic test. Nonetheless, his office is already deluged with inquiries from migraine sufferers. "They call my office and say, ÔI want a picture to show to my employers--otherwise they don't believe me.'"
