High frequency and chronic migraine increase the sensitivity to pain in fibromyalgia (FM) patients, according to the study “Impact of migraine on fibromyalgia symptoms,” published in The Journal of Headache and Pain.
Fibromyalgia is a chronic and widespread pain condition that often co-exists with other diseases, such as headaches. Although fibromyalgia pathophysiology is still incompletely known, the syndrome displays generalized hypersensitivity to pain, a symptom that is also observed in patients suffering from high frequency and chronic headaches. Moreover, clinical observations in FM patients with concurrent migraine presents heightened fibromyalgia symptoms immediately after a headache attack, suggesting that migraines may trigger FM pain.
On this basis, study authors verified whether the hypersensitivity to pain in patients with both diseases were different from patients with only fibromyalgia or migraine. They also tested whether hypersensitivity was dependent on migraine frequency and if migraine attacks acted as triggering factors for FM symptoms.
A total of 203 women were included in the study and divided into five groups: 40 fibromyalgia patients; 41 high frequency episodic migraine (8-14 days a month) patients; 40 chronic migraine patients (more than 14 days a month); 42 who had fibromyalgia plus high frequency episodic migraine; and 40 who had fibromyalgia plus chronic migraine.
In a second phase of the study, 86 women with both fibromyalgia and frequent episodic migraine were divided into two distinct groups in which 47 received treatment for migraine and 39 were in the non-treatment group.
For all patients, pain thresholds to electrical stimulation were measured in multiple body sites, and muscle pressure pain thresholds were assessed in the same locations and in the 18 tender points. Patients also kept a three-month diary to record the number of monthly migraine attacks and the number of monthly FM peak pain episodes.
The team, led by Maria A. Giamberardino of the Fibromyalgia and Headache Center, Department of Medicine and Science at the University of Chiety, Italy, found that the lowest electrical and pressure thresholds were found in patients with fibromyalgia plus migraine, followed by FM plus high frequency episodic migraine; fibromyalgia; chronic migraine; and high frequency episodic migraine patients.
Additionally, FM monthly peak pain episodes were progressively higher in fibromyalgia, FM plus high frequency episodic migraine, and FM plus migraine groups, with 86-87 percent of the peaks occurring within 12 hours after a migraine attack in patients with both conditions. Consistently, the reduction of the number of migraine attacks with treatment significantly reduced the number of fibromyalgia pain peaks and increased both the electrical pain and pressure pain thresholds, revealing a decreased generalized pain hypersensitivity in these patients.
These results suggest that the co-existence of migraine and FM enhances the generalized hypersensitivity toward painful stimuli when compared to one condition only.
“Prevention of headache chronification in migraine patients would thus appear crucial also for preventing the development of fibromyalgia in predisposed individuals or its worsening in co-morbid patients,” the authors concluded in their study.