The team — from University Hospital Mannheim and Heidelberg University, both in Germany — is presenting the new findings this week at the annual meeting of the Radiological Society of North America, held in Chicago, IL.
"It would be helpful," notes Dr. Melissa Meyer, a radiology resident, "to have a diagnostic tool supporting or even diagnosing migraine and differentiating migraine from all other types of headaches."
Migraine diagnosis is challenging
Migraine is a common type of severe head pain that is often described as "an intense pulsing or throbbing pain" in one part of the head.
To qualify as migraine, however, other factors must also be considered. As well as pain, these factors include the number of attacks (a minimum of five lasting up to 72 hours) and other symptoms such as nausea and vomiting, or enhanced sensitivity to light and sound.
Migraine affects more than 10 percent of people worldwide and is thought to be around three times more common in women than in men.
The prevalence of migraine is high in the United States, where it affects around 1 in 7 people. Along with other types of headache, migraine is a leading cause of outpatient and emergency room visits.
Some migraine attacks can occur with vision changes known as "aura." Around one third of people who get migraine can predict the headache because the aura — which appears as light flashes or zig-zag patterns across the field of vision, or even loss of vision — arrives first.
Migraine is challenging to diagnose because the symptoms vary widely, with the result that many cases are not diagnosed and treated. Some patients with tension headaches can also be misdiagnosed with migraine and consequently receive the wrong treatment.
Sodium MRI to study living brain tissue
Scientists are making increasing use of sodium MRI as as a way to measure biomedical properties of living tissue in a noninvasive manner.
For their study, Dr. Meyer and the team decided to use sodium MRI to study migraine because there is evidence that sodium has an important chemical role in the brain.
The researchers enlisted 12 women — aged 34, on average — who were being clinically examined for migraine. The women gave information about the frequency, duration, and intensity of their migraine attacks and auras.
They also recruited another 12 age-matched women who were in good health and who did not get migraines to act as controls.
Then, the researchers examined the brain tissue of all the participants using sodium MRI and compared measures of sodium concentration of the migraine group with those of the control group.
Cerebrospinal fluid sodium tied to migraine
There were no statistically significant differences between the two groups in the sodium levels of the gray and white matter, cerebellum, and brain stem.
However, levels of sodium in the cerebrospinal fluid were significantly higher in the migraine group than in the control group.
Cerebrospinal fluid, which envelopes both the brain and spinal cord, not only cushions the brain but also stabilizes its chemical environment.
Dr. Meyer hopes that these findings will help with the "challenging diagnosis of a migraine." She and the team will continue to investigate the link between sodium and migraine.
"As this was an exploratory study, we plan to examine more patients, preferably during or shortly after a migraine attack, for further validation."
Dr. Melissa Meyer