GOP Sen. Mark Kirk Has Surgery After Suffering Stroke -- May Lose Use of Left Arm

Sen. Mark Kirk (R-IL) suffered a stroke over the weekend and had to have surgery to relieve swelling in the brain, the Chicago Tribune reports.

"On Saturday, Senator Kirk checked himself into Lake Forest Hospital, where doctors discovered a carotid artery dissection in the right side of his neck," his office said in a statement.

"He was transferred to Northwestern Memorial Hospital in Chicago, where further tests revealed that he had suffered an ischemic stroke," it added. "Early this morning, the senator underwent surgery to relieve swelling around his brain stemming from the stroke. The surgery was successful."

In an update delivered by doctors Monday afternoon, doctors said Kirk may lose control of his left arm:

Richard Fessler, a neurosurgeon at Northwestern Memorial Hospital, told reporters at a news conference Monday afternoon that the physical effects of Kirk’s stroke could be long-lasting.

“I think his prospects for a full mental recovery are pretty good,” Fessler said of Kirk. “I think the prospects for his full physical recovery, particularly on the left side of his body, are not great. . . . I think the use of his left arm is going to be very difficult. I’m hopeful for the use of his left leg.”

Kirk may be best known for becoming the senator who filled Barack Obama's vacant Senate seat. He defeated Democrat Alexi Giannoulias after then-Governor Rod Blagojevich was caught trying to sell the seat.

This is a breaking story. Updates will be added.