A STROKE can happen seemingly without warning. As blood clots block circulation to large portions of the brain, tissue begins to die and you can lose your senses, motor skills and memories.
Fortunately, our brains don’t give up without a fight. An emergency back-up system kicks in, opening dormant bridges between blocked arteries and healthy ones that normally supply different areas of the brain. This enables blood to flow around the blockage, resupplying starved brain tissue with oxygen and glucose (see Diagram).
Doctors have known about this “collateral” system for decades, but precisely how it works, and why some…
