Who is Parkinson's expert Dr. Cannard and why did he visit the White House 8 times?

Parkinson's expert Dr. Kevin Cannard visited the White House eight times in eight months, heightening concerns surrounding President Biden's health.

Cannard describes himself on his LinkedIn page as a "Neurology specialist supporting the White House Medical Unit" who has worked in various capacities at Walter Reed Hospital in Bethesda, Maryland, since 1998. The Maryland-based doctor was thrust into the spotlight after news broke of his repeated visits to the White House last week, with Cannard previously maintaining a low profile outside the medical world. 

"[Cannard’s] practice encompasses both general neurology as well as movement disorders as part of the residency training program at Walter Reed," a biography for Cannard on a networking platform for medical professionals reads. "He has over 30 years of experience in the use of botulinum toxin for the treatment of movement disorders, spasticity, and pain syndromes to include headache. The first 20 years of his medical career was spent on active duty in the U.S. Army, retiring as a Colonel in 2008. He has been a civilian physician at Walter Reed ever since."