Hoping to reassure his colleagues that he is physically able to continue as minority leader, Senator Mitch McConnell released a letter on Tuesday from the attending physician of Congress declaring that an examination and tests had ruled out a stroke or seizure as causes of his recent on-camera medical episodes.
In the letter, Dr. Brian P. Monahan, the Navy rear admiral who serves as the on-site doctor in the Capitol for members of Congress and the Supreme Court, said his examination of Mr. McConnell, Republican of Kentucky — along with a brain M.R.I., an electroencephalogram study and a neurological consultation — had found no sign of a seizure disorder or stroke.
Both possibilities and others have been raised by medical professionals who watched video of Mr. McConnell inexplicably freezing up during a news conference last week as well as a similar episode at the Capitol in July.
“There is no evidence that you have a seizure disorder or that you experienced a stroke, TIA or movement disorder such as Parkinson’s disease,” the letter said, using a shorthand for transient ischemic attack, a kind of mini stroke. “There are no changes recommended in treatment protocols as you continue recovery from your March 2023 fall.”
Mr. McConnell and his aides have attributed both alarming medical episodes to lightheadedness stemming from a concussion he suffered after a serious fall at a Washington hotel in March, as well as being dehydrated at the time of his appearances. Dr. Monahan cited a similar reason when he issued a letter after Mr. McConnell’s incident last week before having examined him or conducted any tests.
With the Senate returning on Tuesday after the extended August break, Republicans gathered for the first time since Mr. McConnell’s latest public incident, which has raised quiet questions about his ability to lead Senate Republicans and spurred speculation about a possible succession. The release of the second medical note from the Capitol physician appeared to be an effort to head off any real action regarding his leadership and to show colleagues he was not hiding the true extent of his medical condition.
As he entered the Senate chamber on Tuesday, Mr. McConnell did not respond to questions from reporters about his health, but he obliquely addressed it on the floor as he talked about the busy schedule he kept in Kentucky during the past month.
“Now one particular moment of my time back home has received its fair share of attention in the press over the past week, but I assure you August was a busy and productive month for me and my staff back in the commonwealth,” he said as he ticked off events from his recess schedule.
Democrats made it a point to welcome Mr. McConnell back.
“I’m glad to see him back and doing well,” said Senator Chuck Schumer, Democrat of New York and the majority leader.
So far, few senators have publicly called for any discussion of Mr. McConnell’s health, and most Republicans who have spoken have been supportive of him.
But on Tuesday evening, Senator Josh Hawley of Missouri, who supported an unsuccessful challenge to Mr. McConnell last year by Senator Rick Scott of Florida, raised questions.
“I don’t know; I’m concerned about it,” Mr. Hawley said. “There were 11 of us who didn’t support him a few months ago. If you’re asking me if I’m concerned about his health: yeah, of course.”
Senate Republicans are scheduled to gather on Wednesday for their first private luncheon since July and Senator John Cornyn, Republican of Texas and a close ally of Mr. McConnell, said he expected the party leader to discuss his health status.
“I’m confident there’ll be some conversations or meetings,” said Mr. Cornyn, who added he welcomed the new letter from the Capitol physician and the additional medical information.
“He feels good,” Mr. Cornyn said about Mr. McConnell. “He feels like he’s up to his job. But these two episodes, which obviously rattled everybody — it’s just taking longer than I think he anticipated to recover from the concussion.”
After last week’s incident, Mr. McConnell called numerous senators to try to allay fears about his health. He told them that the incidents were clearly side effects of his fall and had only happened twice, though each time had been in front of television cameras present to record his remarks to the media.
Dr. Monahan rarely speaks in public about his job — and almost never about the medical condition of a member of Congress — strongly suggesting that the pair of brief statements he has written up about Mr. McConnell’s condition over the past few days were solicited by the senator.
“He wouldn’t have released the letter if he didn’t want that issue to be laid to rest,” Mr. Cornyn said on Tuesday of Mr. McConnell.
An internal medicine, hematology and medical oncology doctor, Dr. Monahan has served as the attending physician since 2009, when he was nominated to the post by President Barack Obama.
Kayla Guo contributed reporting.