Illinois Sen. Mark Kirk remains in serious but stable condition after suffering a stroke over the weekend.
His neurosurgeon said Thursday that doctors have removed two small pieces of brain tissue destroyed by the stroke.
Dr. Richard Fessler of Northwestern Memorial Hospital said Wednesday's surgical procedure is common and is meant to create more space around the brain to accommodate expected swelling. Doctors removed a 4-by-8-inch piece of Kirk's skull, also to allow for swelling during an emergency surgery Sunday.
Fessler says the Illinois Republican continues to progress as expected and that there is no change in his neurological or physical prognosis.
The surgeon says the senator was alert, responsive and gave a thumbs up on request during an examination Thursday.