Saturday, February 19, 2011

Scientists still trying to learn how the brain repairs itself

NEW YORK — — Compared to a sleek new laptop, that three-pound mass of fatty tissue called the brain may not look like much. But when it's injured, it adapts and rewires its circuits in new ways.

That's the kind of flexibility that doctors and rehabilitation specialists hope to encourage in Gabrielle Giffords, the Arizona congresswoman who was shot in the head Jan. 8 in Tucson.

Details about her recovery have been thin. But members of her staff say she recently began speaking for the first time since the attack. Brain injury patients who regain speech typically begin to do that about four to six weeks after the injury, experts say.

Still, recovery for the 40-year-old Giffords will be a long journey, as it is for anyone with a significant brain injury. Patients can make remarkable progress. But experts caution that they shouldn't expect to be exactly the same.

It's too early to say whether Giffords might be able to return to her job in Congress. Most people with such injuries have some impairment for the rest of their lives.

Scientists are still unraveling just how the brain works to recover from traumatic injury and how to help it repair as much as possible.

They're dealing with an organ about the consistency of cold porridge. It contains maybe 100 billion densely packed nerve cells, each of which is connected to 1,000 or so other nerve cells, called neurons. Those connections form circuits that are the foundation of the brain's activity.

Brain injuries can disrupt that in several ways. A car accident can smash a head, stretching and tearing brain tissue across a wide area. A bullet causes more localized damage, but the impact can also damage neuron connections farther away.

Either way, brain injury produces an "utter quagmire" of disruptions in brain functioning that doctors have only blunt tools to fix, said Dr. Jonathan Fellus, director of the brain injury program at the Kessler Institute for Rehabilitation in West Orange, N.J.

What all this disruption means to the patient depends on what brain circuits have been affected. People might have trouble reasoning, finding words, remembering things, organizing priorities, recognizing faces, understanding what's said to them, or doing multiple things at once.

So how can the brain get better?

In some cases, brain cells that were impaired but not killed by the initial injury get back on track. Also, the brain's wiring is not fixed. In response to an injury, neurons can alter their patterns of connections.

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