U.S. Sen. John Fetterman arrives for President Joe Biden's State of the Union address to a joint session of Congress at the Capitol on Tuesday in Washington. He remains hospitalized after feeling lightheaded Wednesday. Associated Press

Carolyn Kaster

PHILADELPHIA — U.S. Sen. John Fetterman remained hospitalized Thursday, Feb. 9, evening and was being monitored for signs of a seizure after checking himself into a Washington hospital Wednesday night because he was feeling lightheaded.

His office said Thursday evening that doctors at George Washington University hospital had ruled out a second stroke, following the one he had in May, after reviewing the results of an MRI and other tests.

"He is being monitored with an EEG for signs of seizure — so far there are no signs of seizure, but he is still being monitored," Fetterman spokesperson Joe Calvello said in a statement. "We will continue to provide information as it comes in, and we will have more updates as we get them."

The update came after an initial statement late Wednesday night disclosed that Fetterman had gone to the hospital after feeling unwell during a Democratic retreat.

"Towards the end of the Senate Democratic retreat today, Senator John Fetterman began feeling lightheaded. He left and called his staff, who picked him up and drove him to The George Washington University Hospital. Initial tests did not show evidence of a new stroke, but doctors are running more tests and John is remaining overnight for observation," Calvello said in the initial statement.

It's been less than a year since Fetterman suffered a stroke that he said almost killed him. Despite being off the campaign trail for nearly three months, Fetterman handily defeated his Republican opponent, celebrity doctor Mehmet Oz, in November. He has been in the Senate for barely more than a month, after helping Democrats expand their narrow majority.

Calvello said Wednesday night that Fetterman was "in good spirits and talking with his staff and family."

Any extended absence for Fetterman, 53, would leave Democrats with a tenuous majority, especially after Sen. Kirsten Sinema, I-Ariz., left the party. Even with her vote on most issues, Democrats have a 51-49 edge. Given the Republican majority in the House, no major legislation is expected, but any absence could affect Senate Democrats' ability to approve President Joe Biden's nominations.

Fellow Democratic senator, Bob Casey, is also expected to miss at least some time from the Senate in the near future because of pending surgery for prostate cancer.

On Thursday the Senate confirmed a federal appellate judge nominated by Biden, South Carolina judge DeAndrea Benjamin, and voted to advance the nomination of Western Pennsylvania judge Cindy K. Chung. Neither vote was tied, with some Republicans supporting the women in both cases. The Senate has not yet announced when the confirmation vote will be for Chung.

The Senate's next scheduled vote is Monday at 5:30 p.m.

As well wishes poured in from Democrats and Republicans on Thursday afternoon, it was unclear when Fetterman might be released from the hospital.

Fetterman suffered a stroke May 13, three days before the Democratic primary. He had a procedure to implant a pacemaker and defibrillator in his chest and remained in the race but largely off the trail for months as he recovered. Oz made Fetterman's health a major part of his campaign, accusing Fetterman, who was slow to release details about his stroke, of not being transparent enough about his health and questioning his fitness to serve.

Fetterman insisted throughout the campaign that he was on the road to a full recovery. A statement released by his primary care doctor in October said Fetterman was continuing to recover well from the stroke and had no work restrictions.

Since his inauguration in January, Fetterman has kept the full schedule of a freshman senator, participating in his first Senate hearings, flying on Air Force One to Philadelphia for an appearance withBiden last week, and attending the State of the Union on Tuesday. In a PhiladelphiaI nquirer interview lastmonth, his wife, Gisele, said her husband's only lingering issue from the stroke was auditory processing challenges.

Fetterman's impaired speaking ability causes him to repeat words and sometimes use them in the wrong order. This issue was not the result of any decline in cognitive skills, according to his campaign. He underwent months of rehabilitation exercises to improve his speaking ability, and has relied on closed-captioning devices to help him communicate in the Senate.