People with multiple sclerosis (MS) are about two times more likely to have migraines than healthy people while migraines affect around 24% of people with the neurodegenerative condition, a recent meta-analysis suggests. The mechanisms behind the higher risk in MS, “continue to elude us, and further investigation is warranted to unravel this complex relationship,” wrote the researchers in “The association between multiple sclerosis and migraine: a meta-analysis," a review study published in Multiple Sclerosis and Related Disorders. MS is a neurological condition where a misguided immune attack causes damage to healthy parts of the brain and spinal cord, interfering with the normal function of nerve cells and leading to a range of symptoms. A common symptom of MS is migraine, which may occur due to direct MS-related damage to certain brain structures or as a result of changes in metabolic activity. A feature of migraine is severe pain or a pulsing sensation, usually on one side of the head. It's often accompanied by nausea, vomiting, and extreme sensitivity to light and sound. A migraine can be preceded by an aura, which normally includes changes in vision such as flashes of light or blind spots, or tingling in the hands or face. Most migraines occur without an aura, however. Determining the prevalence of migraine in MS. Few studies have examined the prevalence of migraine in MS and the estimates of its frequency seem to change depending on the race and ethnicity of study participants. The possible risk factors that may contribute to migraines in MS also remain elusive, leading researchers in Iran to retrospectively analyze published studies that evaluated the presence of migraines in adults with MS. The analysis included 35 studies published between 1969-2023, involving 27,678 people with MS. Most patients were women, consistent with the disease being less common in men. Their mean age range was between 30-55.7 and most had minimal to moderate disability levels, as determined by Expanded Disability Status Scale (EDSS) scores that ranged between 2-3 points in most studies. Based on data from 20 studies, the overall prevalence of migraine in MS patients was 24%. This prevalence wasn't affected by age, MS duration, disability level, type of study, and location of study population. About 18% of patients had migraine without aura, while only about 7% had migraine with aura, data from 10 studies showed. Data from 279,603 healthy controls were also obtained from 13 studies, which let researchers analyze the likelihood of migraines developing in MS patients compared with healthy people. People with MS were shown to be 1.96 times more likely to have migraines than healthy people. But MS patients were 20% less likely to have migraines with an aura. Migraines without an aura were 2.25 times more likely to occur in the MS group. Statistical analyses revealed some factors that increased the likelihood of migraines in MS. These included being 45 or older, having MS for less than 10 years, and being in Europe. Cohort studies, which follow patients for long periods of time to study how different factors affect their outcomes, and studies published before 2010 also tended to report a higher likelihood of migraine. "These significant results highlight the potential influence of age, study type, MS duration, geographic location, and publication year on the odds of migraine in pwMS [people with MS] compared to healthy population," the researchers wrote. "Our results show that the estimated pooled prevalence of migraine in pwMS is 24%. Also, our analysis revealed that the risk of migraine in pwMS was 1.96 times higher than that of healthy controls." More research and interventions were needed to address the burden of migraine among MS patients, they said.