White spots on a brain MRI: What they mean and what to do next

Seeing white spots on a brain MRI can feel scary, especially if the report uses medical terms that aren't familiar. Often, these spots are common age-related findings that are discovered by chance and do not cause symptoms. But the number of spots and your overall health can matter.

When there are many spots, the findings may need closer review. The same may be true when people have risk factors that affect blood vessels, such as high blood pressure or diabetes. In these MRIs, white spots may be linked with a higher risk of thinking changes, trouble walking, mood symptoms, stroke, dementia or other health concerns.

Therefore, it is important to interpret MRI findings together with a person's age, symptoms and medical history.

White spots usually mean areas in the brain's white matter that look brighter than nearby typical white matter on certain MRI images. You may hear them called specks, dots, patches, marks or foci. Common medical terms for these spots are white matter hyperintensities (WMHs), chronic small vessel ischemic changes, white matter changes, and T2 or FLAIR hyperintensities. Rarely, radiologists may refer to them as white matter lesions or leukoaraiosis.

Radiologists also may describe the white matter spots as mild, moderate or severe. These terms describe the amount and extent of the changes seen on MRI and do not necessarily predict how a person feels or functions.

White spots can happen for many reasons. Some of the more common causes and links include:

• Small blood vessel disease. Small changes in the brain's tiny blood vessels are a common reason white spots appear on a brain MRI. These changes are more likely in people with high blood pressure, diabetes, high cholesterol, smoking history or other conditions that affect blood vessels. A healthcare professional may check for these risk factors when white spots are found.
• Aging. White matter hyperintensities are common by midlife and are seen in many older adults. They are often related to age-associated changes in the brain's small blood vessels. Changes related to age do not require urgent treatment. Comparing with prior MRI scans, when available, can help determine whether findings are stable or changing significantly over time.
• Migraine. White spots appear on MRIs in people with migraine. But not everyone with migraine has them, and migraine is not always the cause. The MRI pattern and the person's health history still matter.
• Stroke. A healthcare professional may look at the MRI pattern, symptoms and timing to decide whether a white spot could reflect a past stroke, a recent stroke or another cause. Sudden symptoms such as weakness, numbness, trouble speaking or vision loss need medical attention right away.
• Multiple sclerosis (MS) and other demyelinating conditions. MS is one condition that can cause white matter spots. But white spots on MRI do not automatically mean MS. They can be present in people who do not have MS. MS usually is considered when MRI findings fit a specific pattern and the person has symptoms or other test results that support the diagnosis.
• Infection, inflammation and other conditions. Less common causes of white spots can include inflammation, infection and some genetic conditions. Rarely, Lyme disease that affects the nervous system may be considered if symptoms and possible tick exposure fit. However, MRI spots alone do not diagnose Lyme disease.

Brain MRI reports often use technical words to describe what the radiologist sees. These words do not always point to one diagnosis. A healthcare professional can explain what they mean based on the full MRI report, your symptoms and your health history.

• White matter. White matter is a regular part of the brain. It contains nerve fibers that help connect different gray matter regions of the brain. These nerve fibers include axons and myelin sheaths, which help signals travel between brain regions.
• White matter hyperintensities or white matter changes. These are bright areas in the white matter seen on certain MRI images, often T2 or FLAIR images. These changes may be related to aging, small blood vessel changes, migraine or other causes.
• Lesions. A lesion is an area of changed tissue. The word can sound alarming, but it does not always mean cancer or another serious condition. The cause depends on the MRI pattern and the person's symptoms and health history.
• Mass. A mass means an area that takes up space. Therefore, a mass could be many things, such as an abscess, a hematoma or a tumor. Closer review may be needed to understand what the mass is.
• Tumor. A tumor is an growth of tissue that is not typical. Some tumors are noncancerous, also called benign. Some are cancerous, also called malignant. Even a benign tumor may need monitoring or treatment if it is growing or pressing on nearby nerves, brain tissue or blood vessels.
• Neoplasm. A neoplasm is another word for a growth. This word does not always mean cancer. A healthcare professional can explain whether the MRI pattern suggests a benign growth, a cancerous tumor or a finding that needs more testing.

• Nonspecific. Nonspecific means the finding does not point to one clear cause by itself. It may need to be interpreted with age, symptoms, medical history and prior MRI scans.
• Scattered. Scattered means the spots are spread out rather than grouped in one place. Scattered white spots can be seen with small blood vessel changes, aging or migraine. The size, number and location of the spots can help a healthcare professional understand what they may mean.
• Punctate. Punctate means very small, dotlike spots.
• Focal. Focal means limited to one area.
• Confluent. Confluent means that smaller spots have joined together into larger areas. White matter hyperintensities may be described as punctate, focal or confluent.

• T2 and FLAIR images. T2 and FLAIR are two MRI sequences used for examining brain tissue. FLAIR is especially helpful for seeing white matter changes because it makes the fluid-filled spaces in the brain look darker, which can make nearby bright spots easier to see.
• Enhancement. Enhancement means an area looks brighter after contrast is given through a vein. Contrast can help provide more information about a finding, such as whether there is inflammation, a tumor or other conditions.
• Mass effect. Mass effect means something is pressing on nearby brain tissue. This may happen with a tumor, a swelling or another condition.
• Incidental finding. Incidental means by chance. White matter hyperintensities are sometimes found this way. Benign tumors, cysts or blood vessel-related findings also may be found this way.

Location can matter, but it is only one part of the picture. A healthcare professional also looks at the size, number and shape of the spots, whether they are new or changing, whether contrast was used, and whether the spots match your symptoms.

These locations may give healthcare professionals more information about what the spots could mean:

• Frontal lobe. White spots in the front part of the brain can have many causes. In people with migraine, white spots often are found in the frontal lobes involving the white matter below the brain's outer layer.
• Back of the brain. This area usually means the occipital lobes, which help with vision. White spots in this area may need closer review if you have vision changes or other new symptoms.
• Deep white matter. White spots deep in the brain may be related to aging or small blood vessel changes, especially if you have high blood pressure, diabetes or other blood vessel risk factors.
• Near the ventricles. The ventricles are fluid-filled spaces in the brain. Spots near the ventricles can be seen with small blood vessel changes. They also can be seen with multiple sclerosis, although the pattern is typically different than that seen with small blood vessel changes. A small amount of linear brightness in this location can be typical.
• Near the cortex. The cortex is the brain's outer layer. Spots in this area are often referred to as juxtacortical when they contact the cortex. They are more often seen in people with MS. These are different from spots in a subcortical location, which are often seen with migraine and small blood vessel changes.
• Brain stem or cerebellum. Spots in these areas may need closer review, especially if you have symptoms. These areas also may be looked at when checking for multiple sclerosis. However, spots in a certain area of the brainstem called the pons are often seen with small blood vessel changes.

When people ask about white spots on a brain MRI, they often mean white matter hyperintensities, which are not the same as tumors. White spots usually refer to areas of signal change in the brain's white matter. A tumor or benign neoplasm usually appears as a mass or growth, not as scattered white matter spots.

A tumor usually has other features, such as a masslike shape, swelling, pressure on nearby brain tissue, growth over time or changes after contrast is given. If your MRI report mentions a mass, tumor or neoplasm, ask your healthcare professional what type of finding is suspected and whether you need monitoring, treatment or a second opinion.

The next step depends on the MRI findings and why you had the MRI. Some white spots may be expected with age, migraine history or small blood vessel changes. Other spots may need closer review.

You may need more evaluation if:

• The spots are new or significantly increasing in number or size.
• The spots are extensive or in a pattern that raises concern.
• The spots are linked with symptoms.
• The MRI shows swelling, a mass or changes after your care team gives you contrast.
• The pattern suggests stroke, inflammation or demyelination.
• The MRI report mentions a mass, tumor or neoplasm.

A healthcare professional may review symptoms, ask about past strokelike symptoms, check blood pressure and diabetes, compare the MRI with older scans, or recommend follow-up imaging. You may get a referral to a specialist, such as a neurologist or endocrinologist, if the pattern or symptoms suggest a specific condition.

Prior MRI scans can be helpful. If the same spots or findings have been present for years and have not changed, that stability may be reassuring.

Consider asking your healthcare professional these questions:

• Are the spots scattered or in a pattern that suggests a specific cause?
• Are the spots in the white matter or somewhere else?
• Do any areas enhance with contrast?
• Is there swelling, compression or a mass?
• Could the findings be related to migraine, small blood vessel disease, aging or a prior injury?
• Do the findings suggest stroke?
• Should this MRI be compared with an older scan?
• Do I need follow-up imaging?
• Should I have blood pressure, diabetes, cholesterol or other vascular risk factors checked?
• Do I need to see a neurologist, a neurosurgeon or another specialist?

You should discuss white spots with a healthcare professional, especially if the MRI was done because of new symptoms. Some symptoms may or may not be related to white spots on MRI, but they can signal conditions that need urgent evaluation.

Seek medical care right away for symptoms such as:

• Sudden weakness or numbness.
• Trouble speaking.
• Sudden vision loss or double vision.
• New seizure.
• New or severe headache — or a major change in headache pattern.
• New confusion.
• New trouble with balance or walking.