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IL Sen. Kirk suffers stroke, undergoes surgery

Chip Somodevilla / Getty Images file

WASHINGTON, DC - OCTOBER 18: U.S. Sen. Mark Kirk (R-IL) speaks during a news conference about the 25th anniversary of the Electronic Communications Privacy Act (ECPA) October 18, 2011 in Washington, DC.

Updated 1:29 p.m.

Illinois Sen. Mark Kirk underwent successful surgery on Monday after having suffered a stroke on Saturday night, his office announced Monday.

Kirk underwent surgery to remove a 4 inch by 8 inch piece of his skull to relieve swelling in the brain, Dr. Richard Fessler of Northwestern Memorial Hospital told reporters late Monday morning in Chicago.

The 52-year-old senator suffered his stroke on the right side of his brain, an area that threatens Kirk's physical function on the left side of his body. Fessler said that Kirk's future use of his left arm will be "very difficult," and that the stroke could mean difficulty in his left leg, and in the left side of his face.

Kirk checked himself into the hospital on Saturday. according to a statement released by his office this morning. He had been experiencing dizziness and headaches, and subsequent tests revealed that he had suffered a stroke.

"Early this morning the Senator underwent surgery to relieve swelling around his brain stemming from the stroke. The surgery was successful," Kirk's office said. "Due to his young age, good health and the nature of the stroke, doctors are very confident in the Senator's recovery over the weeks ahead."

Kirk's doctor suggested that there was little he could have done to have prevented the stroke. He will remain in the intensive care unit for the indefinite future, though Fessler said he was optimistic that Kirk had retained mental function, given the fact that he is responding "briskly" to commands.

Kirk, a Republican, was elected to the Senate in 2010, filling the seat once held by President Obama. He had served five previous terms in the House of Representatives, and is a U.S. Navy reservist.

Fessler said it was "way too soon to try and predict" when Kirk might be able to return to work.