Dr. Richard Fessler at Northwestern Memorial Hospital said the swelling in Kirk's brain has subsided enough to replace part of his skull that had been removed to relieve pressure.
"This is an important milestone in his recovery and a step toward the next phase, rehabilitation. He remains in good condition," said Fessler.
The 52-year-old senator checked himself into Lake Forest Hospital in late January after having headaches and dizziness. He was transferred to Northwestern Memorial Hospital the next day. Tests showed he had an ischemic stroke on the right side of his brain.