Symptoms of migraine that may mimic sinus disease include sinus pressure or pain, nasal congestion, runny nose, watery eyes and itchy nose. How can this be?
The answer is in the biology of the neurologic system. Scientists agree through rigorous research that migraine is a trigeminovascular disorder. Activation of the trigeminovascular system causes vasodilation of the (meningeal) blood vessels lining the brain, inflammation, and neurochemical production.
These three branches of the trigeminal nerve are known as the ophthalmic branch, the maxillary branch and the mandibular branch respectively. Activation of this trigeminal system results in parasympathetic nervous system involvement causing nasal congestion and watery, itchy eyes. (For more scientific information on sinus and migraine click here.)
So why is this relevant?
According the largest study of migraine patients ever conducted called the American Migraine Prevalence and Prevention Study, only about half of the patients that fit the International Headache Society criteria for migraine had actually been diagnosed. Of those that were undiagnosed, 42% believed they actually had “sinus” headache.
According to the American Migraine Foundation, at least 36,000,000 Americans have migraine. This would indicate that almost 8 million migraine sufferers believe they have sinus headache, and thus, are not getting appropriate treatment for migraine.
In a small pilot study conducted in 2001 with 47 patients that had self-diagnosed “sinus” headache, 98% of the participants fit the International Classification of Headache Disorders for migraine-type headache.
In a much larger study in 2004, almost 3000 patients were screened for sinus headache in 452 primary care clinics in North America. The patients had either self-diagnosed or physician-diagnosed sinus headache. Ninety-seven percent of the patients reported moderate to severe head pain plus some autonomic symptoms (sinus pressure or pain, nasal congestion, rhinorrhea, watery eyes, and itchy nose). Of the 2991 patients in the study, 88% of the patients were found to have migraine or probable migraine headaches according to the International Headache Society Criteria for diagnosing migraine.
In another study conducted in 2002 by Barbanti, et al, researchers looked at the percentage of migraine patients with autonomic features. Autonomic features included eye watering, eye redness, eyelid drooping, eyelid swelling, nasal congestion and nasal running. One hundred and seventy-seven consecutive migraine patients were interviewed, revealing that 45% of these patients had at least one autonomic feature with their migraine headaches.
Weather is known to be a significant trigger for migraine headaches, and coupled with the autonomic features that can accompany migraine, it is easy to see why there is so much confusion about sinus and migraine. Also, according to a paper published in the Journal of Neurology, Neurosurgery and Psychiatry on the comorbidities of chronic migraine in 2010, the two top comorbities are allergy (60%) and sinusitis (45%).
Without a correct diagnosis based on sound criteria, patients cannot get optimal treatment and therapy.
Read Sinus Headache or Migraine (PDF) or "Allergy, Rhinitis and Migraine Headache" about the link between allergy, sinus and migraine.