White matter changes seen by chance on a brain MRI

What the report means

ESO describes cerebral small vessel disease as brain changes seen on CT or MRI that are thought to come from disease of the small blood vessels deep in the brain. When they are found on a scan done for something else, in a person with no stroke or other brain diagnosis, ESO calls them covert, and the AHA/ASA calls them silent. (ESO 2021)(AHA/ASA 2017)

Words a brain scan report may use (simplified)
Report wording	What it describes
White matter hyperintensities (WMH), white matter lesions, leukoaraiosis	Bright spots in the white matter on certain MRI pictures, thought to be of vascular origin (ESO 2021)(Debette 2010)
Lacunes, silent brain infarcts	Small areas of past damage (infarcts) seen on the scan without any known stroke (ESO 2021)(AHA/ASA 2017)
Microbleeds	Tiny spots of past bleeding; part of the AHA/ASA statement, but not covered by the ESO guideline (AHA/ASA 2017)(ESO 2021)

The AHA/ASA calls silent cerebrovascular disease the most common incidental finding on brain scans. (AHA/ASA 2017)

How common it is with age

A 2010 review found white matter hyperintensities in 11% to 21% of adults around age 64 and in 94% of people at age 82. (Debette 2010)
ESO says the number of people with these changes, and the amount per person, go up with age. They usually grow over time, though they can also get smaller. (ESO 2021)
The AHA/ASA found strong evidence that silent cerebrovascular disease is a common problem of aging. (AHA/ASA 2017)

What the finding is linked to

The 2010 review pooled long-term studies and found white matter hyperintensities linked to about 3.3 times the risk of stroke, 1.9 times the risk of dementia and 2.0 times the risk of death during follow-up. These are group averages from studies, not a forecast for one person. (Debette 2010) The AHA/ASA says silent brain infarcts and white matter hyperintensities are linked to future stroke apart from other risk factors, and that no trials have been done in people with these silent changes alone. (AHA/ASA 2017) ESO adds that the changes are more likely in people who are older or have high blood pressure or diabetes. (ESO 2021)

What guidance says comes next

Look at risk factors. The 2010 review says finding white matter hyperintensities should prompt detailed screening for risk factors for stroke and dementia, even though the benefit of doing so is not formally proved. (Debette 2010)
Blood pressure. All ESO group members suggest blood pressure should be monitored. (ESO 2021) USPSTF recommends blood pressure screening for all adults 18 or older, with readings outside the clinic to confirm high blood pressure. (USPSTF 2021) See blood pressure screening and what blood pressure readings mean.
Blood sugar. ESO says that for people with prediabetes or diabetes, blood sugar should be monitored to the usual standards of care. (ESO 2021) See diabetes screening.
Cholesterol. MedlinePlus lists high cholesterol among factors linked to stroke, next to high blood pressure, diabetes and age. (MedlinePlus) See cholesterol test by age.
Repeat scans. ESO did not count growth of the changes on later scans as an outcome for clinical decisions, and none of the sources sets a routine repeat MRI for this finding alone. (ESO 2021)

If memory or thinking worries come up, see memory screening (Mini-Cog and MoCA).

Who it applies to

Adults told a brain MRI or CT done for another reason shows white matter changes or small vessel disease, and who have had no stroke, TIA or dementia diagnosis. ESO wrote its guideline for this group. (ESO 2021) After a stroke, see screenings after a stroke instead.

NHS, symptoms of a stroke: (NHS)

Remember FAST: face weakness, arm weakness, speech problems, time to call 999. Other signs include weakness or numbness down 1 side of the body, blurred vision or loss of sight, confusion, feeling dizzy or falling over, and a severe headache.

Call 999 now if:

you think you're having, or have had a stroke
you've had signs of a stroke within the last 24 hours even if they've now stopped

MedlinePlus: if you think that you or someone else is having a stroke, call 911 right away. (MedlinePlus)

NICE says people who have had a suspected TIA (mini-stroke) should be referred at once to be seen by a specialist within 24 hours of the symptoms starting. (NICE NG128)

Routine age-based screening

White matter changes on a scan do not replace the routine screenings for your age. See screenings by age and gender. Other brain findings have their own pages: a pituitary spot found by chance, and brain aneurysm screening when it runs in the family.

Where they differ:

What counts. The AHA/ASA statement covers silent brain infarcts, white matter hyperintensities and microbleeds. (AHA/ASA 2017) ESO covers only white matter hyperintensities and lacunes. (ESO 2021)
Age norms. The 2010 review reports how common the changes are at each age. (Debette 2010) ESO prefers not to use age norms, because risk rises at any age and no safe threshold is known. (ESO 2021)
Emergency number and wording. The NHS uses FAST and 999 and says to call even if signs stopped within the last 24 hours. (NHS) MedlinePlus says to call 911 right away. (MedlinePlus)

Your doctor decides what your result means for you.

Questions people ask

What are white matter changes on a brain MRI?

They are bright spots (hyperintensities) in the deep parts of the brain on certain MRI pictures. ESO says they are thought to come from disease of the small blood vessels in the brain, called small vessel disease, and are often found on scans done for other reasons in people with no stroke or memory problems. (ESO 2021)

Are white matter changes normal with age?

They become very common with age. A 2010 review found them in 11% to 21% of adults around age 64 and in 94% at age 82. ESO says the number and size of these spots go up with age, but its group prefers not to call any amount normal for an age, because no safe threshold is known. (Debette 2010) (ESO 2021)

Do white matter changes mean I will have a stroke or dementia?

Not on their own. Studies link them to a higher chance of stroke, dementia and death over time, but they describe groups, not one person. The AHA/ASA says no trials have been done in people with these silent changes alone. (Debette 2010) (AHA/ASA 2017)

What checks usually follow?

The 2010 review says the finding should prompt a look at stroke and dementia risk factors. ESO says blood pressure should be monitored and, for people with prediabetes or diabetes, blood sugar too. Your doctor decides which checks you need. (Debette 2010) (ESO 2021)

Which symptoms need an emergency call?

Call 999 (UK) or 911 (US) for sudden face drooping, arm weakness or speech problems, or other sudden stroke signs such as loss of sight, severe headache or loss of balance, even if they stop. (NHS) (MedlinePlus)