Gerard Francisco, Chief Medical Officer of Memorial Hermann Hospital's Texas Institute for Rehabilitation and Research (TIRR), talks with patient Luis Gonzalez as he stops to pose for photos during a news conference and guided tour of the facility where US Representative Gabrielle Giffords (D-AZ) will receive treatment in Houston January 22, 2011. [Photo/Agencies]

HOUSTON – Representative Gabrielle Giffords has begun what will likely be a months-long recovery at a Houston rehabilitation center two weeks after being shot in the head by an Arizona gunman, medical staff said on Saturday.

The day after Giffords flew in a private plane to Houston's massive Texas Medical Center from Tucson, she is in the early stages of therapy in the intensive care unit of Memorial Hermann hospital.

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"She's doing very well," said Gerard Francisco, chief medical officer at the Institute for Rehabilitation and Research at Memorial Hermann, who is overseeing Giffords' months-long rehabilitation journey.

"We initiated therapy yesterday and had therapy today as well," Francisco told reporters on a tour of the rehab center. "She is responding very well."

Giffords, 40, suffered a gunshot wound to the head at close range on January 8 when a gunman opened fire at an event where she was meeting with constituents. Doctors have described her progress so far as akin to a miracle.

Jared Lee Loughner, a 22-year-old college dropout, is charged with the shooting. Six bystanders including a federal judge and a 9-year-old girl were killed in the incident, and 13 others were wounded, Giffords among them.

Giffords remains in the intensive care unit because of a drain in place to remove a buildup of fluid in her skull, which puts her at higher risk for infection.

Rehab under way 

Even in the intensive care ward, Giffords could undergo some rehab activities, including moving in bed, sitting and standing, and other strengthening exercises, Francisco said.

Giffords will get more intensive rehabilitation at the Institute for Rehabilitation and Research, renowned for its treatment of brain and spinal cord injuries. Once she is out of the intensive care unit, doctors said, she faces at least four to six months of intensive therapy.

Rehabilitation center staff gave journalists a tour of their facilities -- including a large gymnasium-like room full of exercise mats, weight machines and treadmills where brain-injury patients relearn the rudimentary movement skills.

"The biggest challenge is discipline - you have to repeat things so many times," said Lex Frieden, a rehabilitation expert at the hospital.

Giffords will likely have to relearn basic skills like tying her shoes, and "the repetition is boring and requires a lot of discipline," Frieden told reporters.

The rehabilitation center is decked out with specialized equipment, including a weight-assisted treadmill that suspends patients in a harness and allows them to relearn walking skills without bearing their full weight.