The health problems of ailing Sen. Dianne Feinstein are more serious than previously disclosed, including a case of encephalitis, according to a report Thursday.

The 89-year-old Ms. Feinstein, who returned to the Senate last week after a lengthy hospitalization for shingles, is suffering from vision and balance impairments and facial paralysis, The New York Times reported, citing two people familiar with her diagnosis.

The six-term lawmaker also has the previously unreported case of encephalitis, a swelling of the brain that can cause memory or language problems, confusion and other ill effects.

Absent from the Senate since February, Ms. Feinstein is using a wheelchair and appears “shockingly diminished,” the report said.

Ms. Feinstein told CNN on Thursday that she does not have encephalitis, saying it “really has never been diagnosed.”

“It was a really bad flu,” she said. “I’m doing better, thank you.”

The senator’s office did not address the report beyond issuing a statement in her name.

“I’m back in Washington, voting and attending committee meetings while I recover from complications related to a shingles diagnosis. I continue to work and get results for California,” the statement said.

Democratic leaders needed Ms. Feinstein, a member of the Senate Judiciary Committee, to return to Washington to help confirm some of President Biden’s judicial nominees. She helped Democrats this week advance the nomination of Nancy Abudu, who was confirmed Thursday as the first Black woman to serve on the Atlanta-based 11th U.S. Circuit Court of Appeals. Republicans accused the nominee of being an “anti-police activist.”

Senate Majority Whip Richard J. Durbin of Illinois said Thursday he was unaware of Ms. Feinstein having contracted encephalitis.

“You can tell that her right eye is affected by it,” Mr. Durbin told CNN. “My mother went through something similar. It’s really a painful experience.”

Even before her hospitalization, Ms. Feinstein was the subject of calls for her resignation due largely to concerns about her cognitive abilities.

Upon her return to the Capitol last week, she apparently forgot that she had been gone.

“I haven’t been gone,” she told a reporter. “I’ve been working. No, I’ve been here. I’ve been voting. Please, either know or don’t know.”

Ms. Feinstein has announced she won’t run for reelection in 2024, but some in her own party have urged her to retire early.

Rep. Katie Porter, California Democrat who is running for the Senate seat in 2024, said Thursday that “change is overdue” and that Congress must change its policy to address “infirm” lawmakers such as Ms. Feinstein and Sen. John Fetterman, Pennsylvania Democrat.

“Look, we just had Sen. Fetterman who was in the hospital for a couple months” being treated for depression after a stroke, Ms. Porter said on CNN. “We’ve had senators who have had children. And so I think we do need to have some policies like every other workplace in America, to think about, what are you going to do when someone becomes infirm, either for the short term or the long term?”

• Dave Boyer can be reached at dboyer@washingtontimes.com.