US Sen Johnson critical after brain surgery

WASHINGTON, Dec 14 (Reuters) US Democratic Sen Tim Johnson was in critical condition after undergoing brain surgery, the US Capitol physician said today, an illness that could deprive Democrats of their precarious hold on the incoming Senate.

The party narrowly wrested control from President George W Bush's Republicans in the US Congress in last month's elections, gaining just a 51-49 majority in the Senate when it convenes on January 4.

However, if Johnson, 59, were to leave office, Republicans could gain control of the Senate.

Adm John Eisold, attending physician of the United States Capitol, said Johnson had undergone brain surgery and was in critical condition. He said it was not known whether further surgery was required.

''Senator Tim Johnson was found to have had an intracerebral bleed caused by a congenital arteriovenous malformation,'' Eisold said in a statement.

''He underwent successful surgery to evacuate the blood and stabilize the malformation. The senator is recovering without complication in the critical care unit. ... It is premature to determine whether further surgery will be required or to assess any long-term prognosis.'' Johnson, who had prostate surgery in 2004, was taken to George Washington University Hospital on Wednesday with stroke-like symptoms.

If the senator had to be replaced, South Dakota law says Republican Gov Michael Rounds would name someone to finish the final two years of his six-year term. An election for a successor would be held in November 2008.

If Rounds named a Republican, that would put the Senate at 50-50, with Vice President Dick Cheney breaking any tie and putting Republicans in charge.

Bush's party could therefore continue to set the agenda in the Senate, undermining the hopes of Democrats for more influence over Bush's policies.

Johnson's wife, Barbara, said his family was ''encouraged and optimistic.'' A congenital arteriovenous malformation means the senator was born with a tangle of blood vessels, in this case in his brain.

When they burst and bleed, they often kill patients before they can get to the hospital, but quick surgery can correct the defect.

However, brain damage can result from the bleeding, just as it can from a stroke.

REUTERS AB KN2120