Word: oxygenation
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Like 500,000 other Americans each year, Lee was suffering a stroke. Something had cut off the flow of oxygen and nutrient-rich blood to a portion of her brain. Sometimes the culprit is a leaky artery. But in Phillips' case, as in 80% of strokes, the problem, revealed by a CAT scan, was a clot that was plugging up one of the blood vessels in her head. Unless the clot was dislodged, part of her brain would die, leaving her at least partly paralyzed...
Half a million Americans suffer strokes each year. Four times out of five, the cause is a wayward clot that blocks an artery and robs the brain of oxygen-rich blood. Nerve cells start to die, depriving key parts of the body of the cerebral instructions they need to function. TPA can change all that by dissolving the clot and restoring blood flow before any damage is done to the brain. "It's the first bright sign that we've had that something we're doing actually works," says Dr. Cathy Helgason, a professor of neurology at the University...
...Still, untold trillions of charged particles manage to leak through. Some are trapped to form the Van Allen radiation belts that surround the earth. Others spiral down the magnetic field lines that project from the North and South poles. Energy unleashed by this disturbance excites atoms of nitrogen and oxygen, which in turn emit pulses of colored light. The result: an aurora...
...real losses in being paralyzed," he says, "is the absence of spontaneity. You can't do things like go for a cup of coffee on a whim. Whenever I leave the house, it's a huge operation. I have the nurses. The van has to be equipped with an oxygen tank, emergency meds and an Ambu bag, which is like a balloon used to pump air into someone manually. We had an episode when I was coming back from New York one time in the winter, and the vent failed just as we were coming up the driveway...
...causes electrical impulses traveling through nerve cells in the area to go haywire, and the overload causes many neurons to kill themselves. The dying nerve cells leak calcium, which attracts enzymes to the area that chew on the tissues. The by-products are free radicals, unstable compounds that scavenge oxygen from healthy cells, often destroying them. As these cells die, they trigger a secondary wave of destruction that sweeps from the injured area and radiates outward. Blood flow to the central nervous system is slowed, immune cells flood the area and, in a frenzied attempt to clear away the debris...