What’s the Difference Between a Neurological Exam and a Cognitive Exam? A Neurologist Explains

The ongoing controversy surrounding Joe Biden’s fitness for office has led many to call for the president to have a cognitive exam.

The 81 year old told ABC News’ George Stephanopoulos on Friday that he has “a cognitive test every single day” as the leader of the free world and presumptive Democrat nominee, but he refused to agree to undergo an independent medical evaluation that includes neurological and cognitive testing.

But what exactly would those tests entail? On Tuesday’s show, Megyn was joined by Dale Bredesen, MD, author of The End of Alzheimer’s, to discuss how cognitive conditions are diagnosed and what the president could do to show he does not have any neurological disorders.

Neurological vs. Cognitive Exams

The terms ‘neurological exam’ and ‘cognitive test’ have been thrown around quite a bit these days and seem to be used interchangeably, but Dr. Bredesen said they are not one in the same. “They are actually part of the same thing,” he shared. “A neurological exam includes a cognitive exam, but it also includes other things, like strength, sensation, balance.”

When it comes to the cognitive exam specifically, Dr. Bredesen explained that the test looks at different areas of the brain to see “how is your memory doing,” “how are you doing with respect to your executive function,” “how are you with your orientation,” “do you know the day,” “do you know the year,” “do you know where you are,” “how are you doing with your verbal skills,” “can you read,” can you repeat,” “how are you doing with your spatial skills.”

One exercise, he noted, may involve having a patient draw an analog clock and place the hands at a specific time. “It’s actually surprising how early you may see changes in that based on the parts of the brain that are affected,” Dr. Bredesen added.

Advancements in Testing

There have been “tremendous” advancements in the last few years, according to Dr. Bredesen, when it comes to neurological and in age-related testing. “Everybody’s got their opining, everybody’s got their ideas… [but] the reality is you don’t need to speculate,” he said. “There are specific tests that can be done very easily today.”

For those concerned about Alzheimer’s disease (the most common type of dementia), Dr. Bredesen said p-tau217, GFAP, and neurofilament light are promising new blood tests. “They are actually quite good and quite sensitive,” he explained. “P-tau217, in particular, is specific for Alzheimer-related conditions, and so it will see it before you have major symptoms.”

When it comes to Parkinson’s disease and Lewy body dementia – two conditions Biden has been speculated to show symptoms of – Dr. Bredesen said Syn-One is “a simple skin biopsy” that is now available, and there are additional options coming down the pike. “There is, coming, a wonderful test where you literally can take a small amount of sweat and you can look with mass spectrometry at a specific pattern of molecules that has turned out to be closely related to whether you have Lewy body disease, Parkinson’s or not.” 

He also said there is “specific imaging” in PET scans one can look at, including fluorodopa uptake, in the case of Parkinson’s disease.

What We Know About Biden

While White House physician Dr. Kevin O’Connor insisted in a letter as recently as Monday that Biden underwent “an extremely detailed neurologic exam” as part of his annual physical that “was again reassuring in that there were no findings which would be consistent with any cerebellar or other central neurological disorders, such as stroke, Parkinson’s, or ascending lateral sclerosis, nor are there any signs of cervical myelopathy,” the specifics of the test are not known.

“If they took such an exam – any of the ones you just mentioned – and it showed the president didn’t suffer from any of those, it would be very simple to do and very simple to release to the public to quell some of the fears,” Megyn asked Dr. Bredesen.

“Absolutely,” he said. “The reality is that instead of all the speculation… it would be very easy to look at those specific tests and know exactly where you stand.”

You can check out Megyn’s full interview with Dr. Bredesen by tuning in to episode 832 on YouTube, Apple Podcasts, or wherever you like to listen. And don’t forget that you can catch The Megyn Kelly Show live on SiriusXM’s Triumph (channel 111) weekdays from 12pm to 2pm ET.