A leading neurologist said it's a 'fact' that President Biden suffers from a degenerative brain condition - claiming he could 'diagnose him from across the mall.'

Dr. Tom Pitts, a New York-based specialist, appeared on NBC to give his devastating take on the president's neurological health in the wake of several notable gaffes, culminating in a disastrous debate performance in June.

Biden, 81, stumbled in answering questions, trailing off and appearing unfocused. That came after years of allegations of ill-health, including being forgetful and falling over amid reports his close team keeps his health issues out of public view. 

'His motor symptoms are degenerating,' Pitts said. 'He has Parkinsonisms. That is a fact. He has degeneration of the brain. Show me the MRI. Show me he doesn't. Put your money where your mouth is. He definitely has it.'

Parkinsonisms is an umbrella term for degenerative brain conditions that include Parkinson's.

White House Press Secretary Karine Jean-Pierre has fiercely denied Biden is being treated for Parkinson's disease, outside his regular checkups. 

Jean-Pierre confirmed Biden had been examined three times by a neurologist but refused to say why a specialist visited the White House eight times in eight months, citing privacy and security concerns.  

Pitts, a Columbia University graduate and a New York-based specialist board certified four times over, was asked his thoughts on the president's condition.

On his various online profiles, Pitts does not mention any expertise in Parkinson's . He describes his expertise on LinkedIn as being in headaches, multiple sclerosis and other brain-related conditions, but not Parkinson's.