'Grueling' Rehab Awaits Gabrielle Giffords, Experts Say

She survived a gunshot wound to the head, can stand with a little help and even gave her husband a neck massage from her hospital bed. But now, Rep. Gabrielle Giffords is facing what may prove to be her biggest challenge yet: rehab.

"It will be grueling. It's hard work, and it's definitely a lot harder than the first stage, at least for her," Dr. Christina Kwasnica, director of the Neuro Rehabilitation Program at St. Joseph's Hospital and Medical Center in Phoenix, told AOL News by phone.

As the 40-year-old congresswoman heads to Houston today to begin a monthslong recovery at a rehabilitation center, doctors say her progress has been impressive. But they warn that people who've suffered severe brain trauma like Giffords often have to relearn even the simplest tasks, from tying their shoes to forming complete sentences.

"One of the hardest parts is realizing how long the road is," Kwasnica said. "People who are successful like the congresswoman often think that if they just work hard they'll recover quickly, but it doesn't work that way. It just depends on how quickly the brain is healing."

Giffords' new doctors at TIRR Memorial Hermann Hospital in Houston avoided predicting when she might be fully recovered. Mark Kelly, Giffords' astronaut husband, has said his wife may be walking on her own within two months, but her new doctor, Dr. John Holcomb, said it was too soon to tell.

"Captain Kelly is an astronaut and a space shuttle commander. You never want to say no to what he says. He's got great hope, they've got great support for family," Holcomb told ABC's "Good Morning America." "And you know the individual outcomes of individual patients are always a little unclear. But she has done remarkably well with great care in Tucson and we expect that to continue."

In Houston, Giffords will first get a medical checkup to make sure she tolerated the travel well from Tucson and is strong enough to begin rehabilitation. Then, the hard work will begin for the congresswoman. Doctors have said her recovery will include at least two to three hours a day of intensive rehab for speech, and for occupational therapy with exercise equipment to help her fine-tune her motor skills and language. Giffords' doctors won't say how long she'll remain at the Houston center, but neurological experts have said the process could take three months.

Because the bullet went through the left side of her brain, doctors say Giffords' vision and language could be especially affected. "Some with brain injury like this lose the ability to speak, lose the ability to understand. Their personality changes, they have problems with memory, it changes how they relate to people," Gerard Francisco, the chief doctor at the Houston center, told reporters, according to The Washington Post.

While Giffords' progress has been described as miraculous, doctors say brain injuries are incredibly complex, and they caution that there's a possibility she may never recover completely. They say that even in rehab, medical risks remain. Too much stimulation too quickly, for example, can cause seizures in survivors of traumatic brain injury.

"The nerve cells in the brain have been damaged and stressed, so if they're pressed too soon, it can trigger a seizure. Just getting up too quickly or doing a crossword puzzle when the brain isn't ready can cause one," said Dr. Mark Herceg, head of Rehabilitation Psychology and Neuropsychology at Burke Rehabilitation Center in White Plains, N.Y.

Herceg said Giffords is also at an increased risk for dramatic weight loss and even depression. "Her brain chemistry has been altered," he told AOL News. "Sometimes the brain's ability to be hungry or recognize that the body needs food is a concern."

And surgeons will also have to replace the portion of the skull they removed to allow for brain swelling just after the shooting, a procedure neurosurgeons say is simple but will put still more strain on the congresswoman's healing body.