During his lecture for the IOA’s 2023 Sylvan M. Cohen Annual Retreat, Jason Karlawish, MD, co-director of the Penn Memory Center shared his thoughts on how and why society and the field of aging research has reached the current state of nomenclature of Alzheimer’s Disease and dementia and the problems that exist within this nomenclature.
Dr. Karlawish started his lecture titled " “The Nomenclature of Alzheimer’s Disease: Too Many Ideas in One Word” by discussing the current state of nomenclature for Alzheimer’s Disease and other diseases that result in cognitive impairment. Dr. Karlawish lays out two hypothetical scenarios, one in which a patient experiences a drastic loss of weight, anemia, fatigue, etc. They go to see a doctor, receive an MRI and are found to have a cancerous tumor. The patient will go back to their family, and when the patient communicates their diagnosis to their family, everyone will clearly understand conceptually what cancer is and that it's an umbrella term consisting of various types and stages. In the second scenario the patient may have problems with repetitive questions, struggling to find common words, struggling to multi-task, etc. This patient gets diagnosed with Alzheimer’s Disease, yet unlike the first scenario the diagnosis may not be understood by those who the patients tell their diagnosis too.
Dr. Karlawish describes the current state of affairs for the nomenclature of Alzheimer’s Disease and related dementias to be an “intellectual cacophony”, which could be described as a discordant mixture of sounds that aren’t harmonious. This is the description used due to the lack of a universal term to concisely describe the problem at hand. Dr. Karlawish uses the example of mild cognitive impairment (MCI) vs Alzheimer’s Disease at which he explains that about 40 years ago when the term MCI was coined dementia was a requirement for an Alzheimer’s Disease diagnosis. At that point what differentiated MCI vs Alzheimer’s Disease was the degree of cognitive decline experienced. In the modern day there is better differentiation with the discovery of various neurodegenerative disorders that are associated with dementia as one of the symptoms. These disorders are called Alzheimer’s Disease and Related Disorders (ADRD’s). This raises two questions, 1) what makes these “related disorders” disorders and not diseases? and 2) why are all these disorders defined in relation to Alzheimer’s?
Dr. Karlawish explains this by going back in history to the National Alzheimer’s Plan that was signed in 2011. The first draft of this plan defined Alzheimer’s Disease as dementia and included a variety of neurodegenerative disorders including lewy body diseases and frontotemporal lobar degeneration. The plan utilized Alzheimer’s Disease as an umbrella term for all diseases that result in dementia. This shows that historically Alzheimer’s was viewed as the predominant form of dementia and at one point even being the only disease resulting in dementia in adults. Modern research delineates Alzheimer’s Disease from other diseases resulting in dementia due to pathological, clinical, and causative differences. This terminology was even seen in the development of the National Alzheimer’s Association in which there was a debate on whether to emphasize only Alzheimer’s in the name of the organization or to be more broad and utilize Alzheimer’s Disease and Related Disorders to capture dementia-causing disorders. The organization was originally The Alzheimer’s Disease and Related Disorders Association until after a few years the board ultimately decided to change the name publicly to the National Alzheimer’s Association.
Dr. Karlawish doesn’t use this historical example to bash either side of the nomenclature debate but to emphasize that maybe “we should be more Australian than French”. Dr. Karlawish explains this phrase in which France utilizes Alzheimer’s Disease as an umbrella term while in Australia they use dementia as the umbrella term that includes Alzheimer’s Disease. Dr. Karlawish further explains his methodology that we should be treating the various disorders that cause debilitating cognitive impairments instead of just one disease state that isn’t all encompassing. In the current moment we have furthered our understanding as a nation regarding what Alzheimer’s Disease is and how it delineates from other forms of dementia. Dr. Karlawish concludes his talk by stating that the current nomenclature used in the state of Alzheimer’s and dementia comes from a time period where the nomenclature coaligned with the current state of knowledge regarding these conditions. However, we are at a different period where we have more knowledge, specifically that there are a variety of neurodegenerative diseases that result in dementia, not just Alzheimer’s Disease. Dr. Karlawish suggests shifting our language to include these diseases in our nomenclature by using the umbrella term, dementia. Dr. Karlawish emphasizes the importance of changing our nomenclature by stating, “we have a national focus on tackling this problem and I think we ought to use the clearest language to tackle it”.