In the first 48 to 72 hours, the acute phase right after surgery, her brain has likely swollen from the accident so doctors are no doubt engaged in life-saving measures to keep the swelling down, which means administering steroid medications and removing part of the skull, Cohen said.
"The brain is tucked inside the skull, which is protection. Now it [the skull] becomes your enemy because it can't swell. It becomes a pressure cooker," he said.
The piece of the skull will be put back in place once the swelling subsides, but Giffords also faces the possibility of infection because a non-sterile object -- the bullet -- entered her body. She is likely receiving antibiotics for this, Cohen said.
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 add injury, Cohen explained.
"It's a series of hurdles for the victim," he said. "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," he added.
"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 of 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.
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