What does my MRI results scattered foci throughout white brain matter mean?

[JaneDR2012]

I had what every doctor is saying is called a TIA.  My MRI results concluded with scattered foci in white brain matter, cortical & stem.  I was sitting & waiting for an appointment & when I was called I sprung out of my chair but felt no sensation of movement on the entire left side of my body for 3-6 seconds before being able to raise my right arm to prevent myself from slamming into the wall directly in front of me.  I did not mention this to anyone except my spouse upon return to home.  At my spouses insistance I contacted my primary care physician who directed me to the emergency room right away.  The emergency room physicians could not see evidence of a stroke so they gave me tests, x-rays & ordered an MRI.  My MRI says that I have extensive scattered foci throughout the brain with severe blockages in some areas.  Please explain all this!