Often, when an MRI is done for another reason, white spots are also seen on the scan. These are what are called in medicine ‘incidental findings’, because we were not looking for them.
What causes them?
There are two major causes of white spots:
- Stroke-like changes – these are changes related to the same risk factors that cause stroke, namely high blood pressure, high cholesterol, diabetes and smoking. These need to be watched and treated as appropriate
- Inflammation – a variety of auto-immune diseases, from Sjogren’s syndrome to lupus and Multiple Sclerosis, can cause these changes. They do tend to look different, in shape and location, from the Stroke-like changes. These need to be investigated differently, from blood and eye tests to others, such as a lumbar puncture.
What do they mean?
Depending on the amount of brain affected, they are usually not causing any problems (what is called ‘asymtomatic). However, if they accumulate more and more, they can affect thinking and memory and also, are a marker of an increased risk for stroke (if they are of the 1. Stroke like changes) and worse type of stroke.
They also affect other changes, such as speed of movement, as described in a 2015 study.