West Palm Beach, Florida — Migraine, a common comorbidity in multiple sclerosis (MS) is not part of the MS prodrome, new research suggested.
Investigators found that patients with MS were more likely than controls to develop migraine shortly before disease diagnosis, suggesting the headache type is not a forerunner of MS.
"The risk [of migraine] was concentrated in the year of their first [MS] symptom, or the year prior, instead of many years before," lead investigator Vinicius A. Schoeps, MD, MPH, postdoctoral fellow at the University of California San Francisco, told Medscape Medical News.
The findings were presented here at the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2024.
MS a Migraine Trigger?
Worldwide up to 43% of patients with MS report migraine. Recent data point to a 3- to 5-year clinically symptomatic prodromal phase of MS and suggest migraine may be one of its potential constituents. However, the relationship between the two disorders remains unclear.
The investigators wanted to determine whether migraine is part of the MS prodrome because if this is the case, it could provide a potential opportunity for early intervention to delay or prevent the disease.
The team analyzed incidence cases of MS and matched controls in the Kaiser Permanente Southern California health system from 2011 to 2014. Participants took part in structured in-person interviews that included questions about migraine.
The 591 MS cases had an average age of onset at 36 years, with a similar index date for controls. Among the cases, 71% were women, 42% were White, 32% Hispanic, and 21% Black. Almost 40% of cases had obesity. These demographic data were similar in the control group.
In those with MS, 13% had a history of mononucleosis compared with 6% of controls. Epstein-Barr virus, which causes conditions such as mononucleosis, was considered a likely cause of MS.
Migraine was diagnosed before MS onset in 27% of cases and before the index date in 21% of controls (adjusted odds ratio [aOR], 1.36; P = .03). Migraine onset occurred later in cases vs controls (mean, 21 years vs 17 years; P = .008).
Migraine was also more likely to occur at the same time or 1 year prior to MS symptoms or the index date in cases vs controls (4.3% vs 1.3%; aOR, 3.54; P = .002).
"These findings suggest that migraine can be triggered by MS rather than part of the constellation of nonspecific symptoms that constitute the 3- to 5-year-long MS prodrome," the investigators reported.
"The inflammatory setting of the first relapse might be actually triggering the migraine," Shoeps said. He added that patients with MS developed migraines later in life.
"There could be a different pathological process in people who have traditional migraine at the most common age where people get their diagnosis of migraine — and have them throughout their lifetime — vs having a migraine at older age and a diagnosis of MS close to that period of time," he said. However, he noted, the study design does not allow for this type of analysis.
Commenting on the findings for Medscape Medical News, Anibal Chertcoff, MD, PhD, an assistant professor in the Multiple Sclerosis Research Centre at the University of Manitoba, Winnipeg, Manitoba, Canada, noted the study's large population and well-balanced case and control groups are strengths of the study.
However, Chertcoff, who was not involved in the research, cautioned that the study is cross-sectional noting that he is "not convinced this is the best type of study design to provide insights into cause-and-effect relationships."
Chertcoff added the findings are limited by their reliance on data from a single health system.
Disclosures were not provided. A grant from the National Institute of Neurologic Disorders and Stroke to an author helped support the study. Chertcoff received funding from MS Canada and the Michael Smith Foundation for Health Research and support from Novartis to attend a scientific meeting.