Johnson was responding to the voice of his wife, Barbara, and following directions after the surgery, the senator's office said in a statement. "He was reaching for and holding her hand."
Johnson was stricken as Democrats prepared to take a 51-to-49 majority in the new Senate when it convenes next month. Democrats seized control of both chambers of Congress from Republicans in November midterm elections.
If Johnson were to leave office, a replacement would be named by South Dakota's Republican governor, Mike Rounds. A Republican appointee would create a 50-50 tie and effectively allow the GOP to retain Senate control because of Vice President Dick Cheney's tie-breaking vote.
Johnson was rushed to the George Washington University Hospital at midday Wednesday after becoming disoriented and stammering during a conference call with reporters.
Eisold said doctors stopped the bleeding in Johnson's brain and drained the blood that had accumulated there. "It is premature to determine whether further surgery will be required or to assess any long-term prognosis," Eisold said.
Yesterday afternoon Johnson underwent an additional procedure to prevent blood clots. The procedure is standard after surgery, said Julianne Fisher, Johnson's spokeswoman. There were no other developments , she said . "No news is good news," she said.
Johnson's condition, arteriovenous malformation, causes arteries and veins to grow abnormally large, become tangled, and sometimes burst. The condition is often present from birth.
Noah Pinegar, a Johnson spokesman, said the senator's diagnosis was a surprise. "No one was aware of it, including Tim," he said.
Senator Harry Reid, Democrat of Nevada, who will become majority leader when the new Senate convenes Jan. 4, said: "We're all praying for a full recovery. We're confident that will be the case."
