Senate Republican Leader Mitch McConnell's office released an update about the 81-year-old Kentuckian's health after he froze in front of cameras last week for the second time in as many months.

The note from Brian Monahan, the Capitol Hill attending physician, says there is no evidence of a stroke, seizure disorder or movement disorder like Parkinson's disease.

The Republican leader's office had attributed the two frozen moments to "lightheadedness," and Monahan indicated that it's "not uncommon" for victims of concussion to feel lightheaded. McConnell suffered a concussion and broken ribs after falling at a Washington hotel and his hitting his head in March, sidelining him from the Senate for nearly six weeks.

The note comes as the Senate returns to session Tuesday after a five-week recess and as GOP senators are expected to face questions about whether they believe the Republican leader can continue leading his conference as he has for the past 16 years -- longer than any party leader in Senate history.

McConnell is expected to make floor remarks about Senate business after the chamber opens at 3 p.m. ET and meet with his leadership team at 5 p.m. for the first time since before the summer break.