When it comes to migraine, the initial choice of therapy could mean the difference between episodic and chronic disease, according to a secondary analysis of the longitudinal migraine study American Migraine Prevalence and Prevention (AMPP), presented at the 2016 American Academy of Neurology annual meeting.
The results showed that poor response to treatment is associated with a 3-fold increase in the risk for disease progression from episodic migraine to chronic migraine, said Richard B. Lipton, MD, Director of the Montefiore Headache Center, Bronx, NY, who presented the study. A better understanding of the remediable risk factors for migraine progression may help to reduce the risk for progression, Dr Lipton said.
“Episodic migraine is sometimes a progressive disease, and we have found that poor treatment optimization is a risk factor for progression,” he said.
“In other words, if people take acute treatments and don't get better, that may be associated with more pain, more allodynia, and headache progression,” Dr Lipton added.
The AMPP epidemiologic study included >8000 patients with episodic migraines who were followed from 2005 to 2009. The 1-year results showed that 83% of patients with episodic migraines in 2005 continued to have them in 2006. However, 2.5% of the patients had episodic migraines that progressed to chronic migraines (defined as a headache on ≥15 days monthly).
Although the risk factors for migraine progression may be related to headache, including attack frequency and allodynia, progression is also related to comorbidities, particularly depression, anxiety, and pain disorders, said Dr Lipton.
“Progression is related to a series of exogenous factors, and given that chronic migraine demonstrably aggregates within families, there may be a genetic foundation for pain progression, as well,” he said.
Treatment-Related Risk Factors
The key is to discover what these risk factors may have in common, said Dr Lipton. It is possible that they all converge to act on a single or a series of common pathways.
Dr Lipton and colleagues theorized that poor response to the treatment of migraine attacks and medication overuse may be associated with the prolonged or intense activation of the trigeminovascular system. Because migraine progression was also associated with treatment-related factors, they referred back to the AMPP data.
“We looked at how well people responded to acute treatment using the validated questionnaire, and we showed that in the group with an optimal response to acute treatment, 1.9% progressed from episodic to chronic migraine over the course of the year. In the group that had the worst response to acute treatment, however, nearly 7% progressed,” said Dr Lipton.
After adjusting for headache frequency, headache-related disability, and symptom severity, the researchers found that poor response to treatment was associated with a 3-fold increase in risk for migraine progression.
“This provides at least some support for our hypothesis that prolonged activation [of the trigeminovascular system] may be associated with increased risk of headache,” said Dr Lipton, who emphasized that many of the risk factors uncovered in the study are also remediable.
The use of opioids and barbiturates, for example, not only is a remediable risk factor for migraine progression but also is an iatrogenic risk factor, he explained.
“In headache medicine, we are perhaps where our stroke colleagues were decades ago: we've identified a series of risk factors that allow us to identify a poor prognosis subgroup, but we've not yet conducted intervention studies to see if we can modify the natural progressive history of migraine,” Dr Lipton concluded.