The key in trying to forecast her recovery lies in whether Rep. Gifford is left-handed or right-handed, he added. Almost all right-handed people are left-brain dominant and the left brain controls cognitive function and some speech. Left-handed people can be dominant on either side.
"If she's left-handed, odds are that the statistics are more in her favor that there'll be fewer cognitive and, perhaps, speech concerns," Cohen said.
Although there's been some speculation that Giffords may be left-handed, this hasn't been reported definitively.
Much also depends on the speed at which the bullet entered the brain. Speed sends off shock waves that can damage surrounding areas. There may also be bleeding or bone fragments, which exacerbate an injury, Cohen explained.
"It's a series of hurdles for the victim," he explained. "Whatever part of the brain that that bullet went through, even if it was a small cylinder of trajectory, that [area] is now permanently injured [but] the repercussions are unknown. There's some permanent and some recoverable damage depending on how injured that part of the brain gets."
"It's a traumatic brain injury [but] she's young and she's otherwise healthy," Cohen said. "She'll be able to recover some and, depending on the injury, her recovery can take up to a year."
The U.S. National Institutes of Health has more on traumatic brain injury.
SOURCES: Anders Cohen, M.D., chief, neurosurgery and spine surgery, The Brooklyn Hospital Center, New York City; David Langer, M.D., director, cerebrovascular research, Cushing Institutes of Neuroscience, North Shore/Long Island Jewish Medical Center, Great Neck, N.Y.; Associated Press; Washington Post
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