BOSTON—At Island Neurological Associates in Plainview, New York, researchers uncovered a prevalence of chronic migraine among their population of patients with multiple sclerosis (MS) that was higher than would be expected in the general population. They reported their results at the 59th Annual Scientific Meeting of the American Headache Society. “Since migraine as a whole is generally accepted to occur in about 12% of the population, it appears that our MS patient prevalence of 21% significantly exceeds this [prevalence],” said Ira Turner, MD, a headache subspecialist at the Long Island facility. Similarly, “chronic migraine is thought to occur in 1% to 2% of the general population, but [it occurs] in 7% of our MS population,” Dr. Turner said.
Ira Turner, MD
Observing that MS and migraine are both chronic neurologic conditions in which inflammatory processes play an important role, Dr. Turner and colleagues sought evidence for increased migraine prevalence in the MS population. “Anecdotally, it has been our experience that there is a comorbidity of headache disorders in our MS patient population,” Dr. Turner said.
The investigators conducted a retrospective review of the electronic medical record (EMR) system at their community-based Comprehensive MS Center and Center for Headache Care and Research. They reviewed the EMR for all patients with a diagnosis of any form of MS. The EMR was then queried to determine which of the patients with MS had any headache diagnosis listed as a comorbidity. Those headache diagnoses were then reviewed and separated into those that met ICHD-3 beta criteria for chronic migraine, episodic migraine with aura, episodic migraine without aura, episodic cluster headache, chronic cluster headache, tension-type headache, or a nonspecific diagnosis of headache.
The researchers found 610 active patients with a diagnosis of MS. Of these, 139 (23%) also had a headache diagnosis listed in the EMR as a comorbidity. Migraine without aura was coded in 62 patients (10%), migraine with aura in 26 (4%), and chronic migraine in 45 (7%). Combining these diagnoses yielded a prevalence of comorbid migraine of 21% in the MS population studied. Episodic cluster headache was diagnosed in one patient, tension-type headache in two patients, and nonspecific headache in four patients. The prevalence of these three diagnoses was less than 1% each.
“While there is a potential bias caused by our practice having both an MS center and a headache center, this increased prevalence seems to be of great interest and would appear to warrant further investigation,” Dr. Turner said.
—Glenn S. Williams