Senate Republican leader Mitch McConnell shows “no evidence” of a seizure disorder or a stroke, a congressional physician said Tuesday amid growing concerns about the 81-year-old lawmaker’s health and capacity to lead the chamber’s Republicans before the 2024 elections.

Brian Monahan, the Capitol’s attending physician, said he had examined McConnell since the senator froze last week for more than 30 seconds during a public appearance. The examination included a brain MRI and EEG, Monahan said in a letter released by McConnell’s office.

“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,” Monahan said in the letter, which didn’t offer a medical opinion on the cause of the episode.

McConnell returned to the Capitol hours later as the Senate resumed work after a month-long break, smiling and ignoring reporters’ questions on his health as he walked in and out of the Senate chamber.

He delivered an eight-minute speech on the Senate floor, briefly alluding to a “particular moment” during the August break that “received its fair share of attention.” He didn’t otherwise address the episode as he detailed his August itinerary.

The Republican leader, a consummate dealmaker, could play a pivotal role in a looming standoff with hard-line House conservatives threatening to shut down the government as soon as Oct. 1 unless President Joe Biden and Democrats agree to deep spending cuts and other concessions.

Read More: McConnell’s Frailty Casts Pall Over GOP Ahead of 2024 Election

No Senate Republican has suggested he step aside, and McConnell’s lieutenants in the Senate have continued to back the leader. Senate Republicans will meet privately on Wednesday.

McConnell abruptly stopped and stared ahead for more than 30 seconds after a reporter’s question Wednesday about a potential 2026 re-election run during an appearance in Covington, Kentucky. It was the second such public episode in as many months.

In July, McConnell froze for about 20 seconds during a news conference on Capitol Hill. He was led away for a few minutes but then returned to the microphones and said he was “fine” and able to do his job. He suffered a concussion and broken rib in a March 8 fall at a fundraiser in Washington and didn’t return to the Senate until mid-April.

A McConnell ally said last week the leader has maintained his normal political schedule including phone calls, meetings and fundraisers since returning to work.

Yet the conservative National Review called in an editorial last week for McConnell to step down, saying he had “noticeably aged” in recent months and the two recent incidents affect “his ability to function as the leading representative of his caucus.”

Dick Durbin, the Senate Democrats’ second-ranking leader, indicated McConnell linked the recent episodes to the concussion he suffered in March in a conversation the two recently had.

“He said the concussion had lasting effects on him,” Durbin said. “As he said, he’s gone through every examination and passed.”

--With assistance from Steven T. Dennis.

(Corrects timing of National Review editorial, in eleventh paragraph.)