Some small studies have suggested that people with migraine may have some detectable brain differences compared to people who don’t have this neurological condition.

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Migraine is often used as shorthand for a severe headache, but the term “migraine” actually refers to a neurological condition that affects about 39 million people in the United States.

Research and imaging studies have suggested that certain structures and functions of the “migraine brain” might differ slightly from those of the “typical” brain. More definitive research may eventually provide insight into the nature of migraine headaches, as well as other common migraine symptoms like migraine aura and sensitivity to light.

While it’s too early to draw any conclusions from the existing research, it’s possible that migraine may be associated with minor injuries to brain tissue. This possibility only underscores the importance of developing new migraine treatment and prevention options.

Studies using advanced neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), are helping researchers understand more about how migraine develops and how the condition affects brain structure and function over time.

Some small studies have noted varied differences in the brains of people with episodic and chronic migraine headaches.

Chronic migraine is defined as having headaches at least 15 days per month, while episodic migraine involves migraine headaches 14 or fewer days per month.

But research suggests that this dividing line may not adequately address the complex nature of migraine, which may exist on a spectrum between episodic and chronic episodes.

Several research studies that used advanced neuroimaging techniques have detected differences between the brains of people with migraine compared to people without migraine. But the studies were all very small, and the results varied.

Pons

The pons is part of the brainstem, the region that connects the base of the brain to the spinal cord. The pons is responsible for several unconscious brain functions, including sleep and breathing.

In a 2019 study involving 64 people, researchers found that participants with migraine tended to have weaker function connectivity between the posterior pons and the left superior parietal lobe, the left temporal gyrus, and the left middle frontal gyrus. The reason for this difference was unclear, but the researchers did suggest that a deficit in pain processing could play a role in migraine.

Perivascular spaces

Perivascular spaces are fluid-filled passageways in the brain that play a role in fluid regulation and drainage. There are a lot of unanswered questions about the relevance of these spaces in neurologic, inflammatory, and vascular conditions. But researchers believe that the normal function of perivascular spaces is important to brain health.

A very small 2022 study on migraine noted a handful of cases where MRI images revealed a slight enlargement of the perivascular spaces in a region of the brain called the centrum semiovale. Many other conditions and factors, such as age, play a role in the shape, size, and number of perivascular spaces, so there is not nearly enough evidence to suggest a connection to migraine. But connections could be explored in larger-scale studies at some point in the future.

Hypothalamus

The hypothalamus is a part of the brain that manages hormones and other body systems, including sleep, hunger, sex drive, blood pressure, and temperature.

A 2020 study suggested that the hypothalamus-brainstem network might also play an important role in the migraine brain. The study found heightened activation of the hypothalamus during the headache phase of episodic migraine, suggesting that migraine headaches could originate in the hypothalamus.

Other parts of the hypothalamus appear to play a role in migraine chronification, which is the transition from episodic migraine to chronic migraine.

Pain network

The brain’s pain network, also known as the pain matrix, includes several brain regions, including the thalamus, anterior cingulate cortex, basal ganglia, and prefrontal cortices.

A 2021 study suggested that people with migraine may have less connectivity and greater segregation among the regions of the pain network compared with people who don’t have migraine.

Cortical thickness

The brain’s cortex is the outer layer of the cerebrum, the largest region of the brain. The somatosensory cortex region of the brain, located in the parietal lobe, is responsible for processing pain and many other sensations.

Some small studies have found increased thickness in people who have migraine compared with those who don’t. This development may also explain why people with migraine also experience other symptoms, such as jaw or neck pain.

Some emerging evidence suggests that migraine might be associated with structural or functional brain changes.

Structural changes may include those related to the anatomy of the brain and the connectivity between brain cells in the many regions of the brain. Functional changes are those associated with thinking skills, processing information, memory, and motor control.

A 2021 study suggested that two key structural changes associated with migraine are white matter abnormalities (such as reduced blood flow to the nerve fibers that make up white matter) and changes to the volume of white and gray matter.

While using fMRI to reveal structural and functional brain changes during migraine episodes has helped researchers learn much more about the condition’s process, there are some challenges in using this advanced neuroimaging tool.

For instance, certain changes in the pain and visual processing areas can occur during a migraine headache but not when someone with migraine is asymptomatic.

There are also some limitations in fMRI’s ability to detect detailed changes in neurons involved in certain mental functions.

Recent research, including a 2021 study in the American Journal of Pathology, has suggested that migraine headaches are significant risk factors for white matter brain lesions. White matter refers to the vast network of nerve fibers connecting neurons in various brain regions. These lesions, or tissue injuries, could potentially lead to physical or cognitive problems.

The brain’s functional networks — those parts of the brain that work together in regulating or carrying out functions ranging from sensory processing to memory formation — may provide clues about the likelihood of episodic migraine progressing into chronic migraine or vice versa.

A 2020 study suggested that using neuroimaging to create models of whole-brain functional connectivity may be helpful in predicting the frequency of migraine headaches.

A migraine headache with aura means that in addition to severe pain, a person may see flashes of light, experience a tingling sensation in the limbs, or have other symptoms.

It’s not entirely understood how or why aura sometimes accompanies a migraine headache, but one theory suggests that dysfunction among neurons in the cerebral cortex may cause a range of abnormal sensory responses.

The brain of someone who has migraine may differ in some important ways from the brain of an individual without the neurological condition, but more research is needed.

These differences may include reductions in white matter or thicker regions of the cortex, as well as functional differences that result in people with migraine having memory and concentration problems that may not affect people without migraine.

There’s still much researchers are learning about migraine, but the hope is that the more that can be learned about how the condition develops and progresses, the more likely it is that better treatments will emerge.