How can doctors tell an Alzheimer's patient suffered a stroke, and estimate the time?

A family member with Alzheimer's experienced increased muscle weakness over a few days, but rather sudden permanent inability to walk at all. Doctors said he had experienced a stroke 5 days before and also 5 or 6 yrs ago. I want to know how a CAT scan indicating a stroke in an Alzheimer's patient would differ from just plain Alzheimer's brain. Is it different densities or something? Also, how do they know how long ago the stroke was? The 5yr thing especially seems strange since he was still working then...

My father has Alzheimers and also suffered a few mild strokes. I will tell you what his doctor told us.
They can tell when a person has a stoke because a stroke damages the brain tissue. The areas of the brain affected by the stroke will show up on their equipment differently than the rest of the brain. With my dad they showed up as brighter white spots with dark areas near them (thats the now dead part of the brain)

Just like when you break a bone a stroke will leave scar tissue. (the damaged areas of the brain) The doctors can tell you basically when you broke a bone even if it happened as a child. Same thing with a stroke and the damage it caused. They can look at the tissues and see how much rewiring around the areas has happened, they know how fast the parts of the brain heal or rewire, so they can pinpoint when a stroke happened. The closer to the occurance time the better the "when it happened" diagnosis. Thats why the difference between 5 days and 5 or 6 years. People can have small strokes that effect them at the time, but they can recover from those. However those strokes should be seen as warning signs and be followed up by a doctors exam and monitoring.

no difference. the doctor can tell the approximate age of injury to the brain by the scan. ask the doctor these questions next time!

Hi Bad, My dad has this terrible disease. He also had a stroke about 6 years ago and some what they call mini strokes at least 4 of those. When they scan the Alzheimer patient for the disease where they have had regular strokes and mini strokes they show on the scan in different color. I have seen this on my dad's brain. They pointed out where the mini strokes were and the one he had 6 years ago. Different color tells them different things about the different strokes. It all makes sense if you can see the scan while they are doing it. It's really weird the way these medical people can pin point things wrong with us.
A Friend.
poppy1