CHICAGO — Sen. Mark Kirk of Illinois could lose full use of his left arm and experience facial paralysis after a weekend stroke that required emergency surgery, but his physician said Monday the prospects for a complete mental recovery are strong.
Dr. Richard Fessler said it likely would be "very difficult" for the first-term Republican senator to regain movement in his left arm, and that his left leg and face also may be affected. Kirk was in intensive care at Northwestern Memorial Hospital, where he appeared to recognize those around him and was responding to verbal commands, Fessler said.
Though Fessler could not say when Kirk would be able to return to work, he described the senator as "young, very healthy and in good shape."
"Sen. Kirk's job is cerebral, and I believe the functions required to do his job are going to be fine," said Fessler, a neurosurgeon who removed a 4-by-8-inch piece of Kirk's skull Sunday night to relieve swelling on his brain.
Kirk, 52, had reported feeling dizzy and checked himself into Lake Forest Hospital over the weekend before being transferred to Northwestern. Tests showed he had a tear in the carotid artery on the right side of his neck. Carotid arteries carry blood to the brain and carotid tears are a common cause of strokes in people in their 50s or younger.
Fessler said Kirk would undergo rehabilitation, but added that the "the prospects for his full physical recovery, particularly on the left side of his body, are not great."
Dr. Joseph Broderick, a University of Cincinnati stroke expert, said that when removing part of the skull is required, "that is a pretty significant stroke" that likely has caused substantial damage.
The damage typically occurs when clots formed from a carotid artery tear lodge in the brain, depriving brain cells of oxygen. Brain cells then die and may fill with fluid, causing swelling. The process can take days or even weeks, he said.
"Those people almost always will have some type of deficit long-term. Some may get back to being functional, but some are left with very severe deficits," Broderick said.
Kirk's family said in a statement that he had "always shown great courage and resilience and we are confident that the fighter in him will prevail."
"We are very grateful for the excellent treatment and care provided by the doctors and their medical teams ... We are equally grateful for the love and support of our family and friends," the family said.
Illinois Sen. Dick Durbin, a Democrat, said Monday he was shocked to learn of Kirk's stroke because Kirk appeared to be a picture of health. A Kirk aide said the senator is a regular swimmer and has to pass medical checks every six months in the reserves.
West Virginia Sen. Joe Manchin, with whom Kirk planned to sit during Tuesday night's State of the Union Address, issued a statement calling Kirk a "dear friend and truly a great American."
He said he's confident Kirk "will make a speedy recovery and I will do everything I can to support him and his family until he is able to join us back here in Washington."
People can return successfully to high-profile jobs after serious brain injuries. Sen. Tim Johnson, D-S.D., suffered a brain hemorrhage in December 2006 and returned to the Senate the following fall. His speech was a bit slurred, and sometimes he used a scooter to get around. He later won re-election and chairs the Banking Committee.
Tradition holds that Kirk will continue to hold his seat in the Senate while recovering from the stroke. Democrats currently have a 51-47 advantage in the chamber, including the two independents who caucus with the party.
Kirk, a Naval reserve commander, won Barack Obama's vacated Senate seat for the Republican Party in 2010 after a hard-fought election during which the moderate from Chicago's northern suburbs had to make the transition to a statewide candidate who had to appeal to more conservative voters.
Kirk won the seat by campaigning as the level-headed voice of experience facing a young Democrat, citing his five previous terms in Congress.
Upon reaching the Senate, Kirk landed a seat on the powerful Appropriations Committee and late last year joined forces with Democratic Sen. Bob Menendez of New Jersey in imposing crippling sanctions on Iran.
The two senators sponsored an amendment to the annual defense bill that targets foreign financial institutions that do business with the Central Bank in Tehran. In a rare unanimous vote, the Senate backed the measure 100-0. Obama signed the wide-ranging defense bill with the sanctions on New Year's eve.
• Associated Press writers Tammy Webber and Lindsey Tanner in Chicago, Christopher Wills in Springfield and Andrew Taylor and Donna Cassata in Washington contributed to this report.