Alzheimer’s Disease? Dementia? Confusion Still Reigns.

People ask me a lot of questions, but the one I hear most often is, “What’s the difference between Alzheimer’s disease and dementia?” The simple answer to the question is that dementia is a syndrome (not a disease) that can have many causes. Alzheimer’s is a specific disease with a defined but poorly understood etiology that causes 60 to 80% of cases of dementia. But there are other possible causes. 

Seems simple enough, but… 

This distinction has actually been kind of hard to nail down for a long time. Is someone’s dementia caused by Alzheimer’s disease? We don’t know for sure until the autopsy. Until then, all we know with certainty is the person had dementia. So the two terms were used interchangeably for a long time, even among medical professionals. 

As we noted in Beating the Dementia Monster, medical science tried to sort things out in 2011 in a group of interested organizations calling themselves the National Institute on Aging-Alzheimer’s Association workgroups. They tried to standardize the clinical spectrum, describing it as “preclinical Alzheimer’s disease” (AD), “mild cognitive impairment (MCI) due to AD” (or “prodromal AD”), and “dementia due to AD.” They combined these clinical syndromes with biomarkers for amyloid and neurodegeneration that were present at the time. And so, in 2015, on examining my cognitive test performance and MRI biomarker evidence, I was told that I had MCI, most likely due to Alzheimer’s disease. (Earlier in 2015, using pre-2011 terminology, a neurologist recorded that I had “early stage senile dementia, likely of the Alzheimer’s type.”) 

And so, even today, I hear people, even medical professionals, using the terms interchangeably. Some have noted that this confuses people, especially when it’s important to talk to patients and their families about dementia. They further note that something should be done to improve clarity here. 

I recently received a “Special Communication” from JAMA Neurology. (JAMA is Journal of the American Medical Association.) It reported on the work of another work group chartered to bring further clarity to discussion of dementia, along with Alzheimer’s disease and all of the other causes of the cognitive impairment syndromes. The article was entitled, “A New Framework for Dementia Nomenclature.” 

I read the article and saw how an emerging new paradigm could help medical professionals talk to one another … if they all adopt it. But I didn’t think it was so much a “new framework” as an evolution of the old one we described in Beating the Dementia Monster. However, I was uncertain about how it would help doctors talk to their patients, since it seems to be evolving into something even more complicated. 

The framework revolves around this table whose design is intended to yield a disease label. 

You can see that it brings in more considerations, such as the possibility of diseases other than Alzheimer’s disease causing the dementia. So it will likely help the professionals talk to each other (provided they do a better job of adopting it than they did the last one in 2011). 

On the other hand, I’ll be waiting to see if this will actually help patients and their families understand what is overtaking them.