Giffords, D-Ariz., was shot in the head at close range while talking with constituents at a supermarket in Tucson in January. Dr. Gerard Francisco told Politico Giffords' recovery to date has exceeded his expectations, but he declined to speculate about when she might be able to resume her duties in Congress, saying that "wouldn't be fair to her."
"I think in about a year or so, we will have a better idea of what her functional abilities are going to be eventually," said Francisco, who was on Capitol Hill Thursday for a briefing of the Bipartisan Disabilities Caucus.
Francisco told Politico Giffords was "very fortunate she did not experience a lot of the complications that many other people have" after she was shot.
"And she was able to get an intense rehabilitation program," he said. "I really think we were able to guide the recovery of the brain because of the intensity we were able to bring to her."
Giffords Chief of Staff Pia Carusone told The Arizona Republic this month the congresswoman was not close to ready to return to work.
Arizona has a May 2012 deadline for candidates to file for re-election.
Notable deaths of 2014 [PHOTOS]
Clemson student dies in cruise ship fall