1.   Brain imaging showed their blood vessels were more dilated, protecting the brain against abrupt changes in blood flow that can trigger a stroke.

2.   He said her health problems probably did not trigger the stroke but have left her physically and emotionally drained.

3.   That triggered a stroke.

4.   The blockage that triggers ischemic stroke starves an area of the brain of oxygen.

5.   The reduced blood flow can trigger strokes in dopamine-rich areas of the brain.

6.   Another study by Dr. George W. Petty of the Mayo Clinic shows the importance of leaky and deformed heart valves in triggering strokes.

7.   Another study by Dr. George Petty of the Mayo Clinic shows the importance of leaky and deformed heart valves in triggering strokes.

8.   Buildups of fatty deposits in the aorta, the main artery leaving the heart, can trigger strokes if globs break off and drift to the brain.

9.   Routine blows to the neck can rupture the arteries that feed the brain, triggering bleeding strokes.

10.   Then, for no obvious reason, a blood clot lodges in the brain, triggering a stroke.