A new type of dementia, previously misdiagnosed as Alzheimer’s Disease, has been discovered to be prevalent in the oldest of old persons.
Perhaps a third of elderly people earlier thought to have Alzheimer’s Disease may have had Limbic-predominant age-related TDP-43 encephalopathy “LATE” instead, which has some symptoms in common with Alzheimer’s Disease although with a more gradual decline in memory. LATE is associated with the accumulation of TDP-43 protein in the brain, unlike Alzheimer’s Disease which is linked to amyloid and tau proteins.
Researchers might in future be better able to develop suitable diagnostic tests and targeted treatments for this specific type of dementia. The newly recognised existence of LATE, and its probable role as a confounding variable in Alzheimer’s drug trials, may perhaps account for the failure to discover effective pharmacological treatments for Alzheimer’s Disease to date; decades worth of carefully conducted and expensive clinical trials might simply have been barking up the wrong tree, in part.
In the meantime, further exploratory research is required:
“Development of a disease biomarker would augment observational studies seeking to further define the risk factors, natural history, and clinical features of LATE, as well as eventual subject recruitment for targeted therapies in clinical trials”.
Roberts, M. (2019). New type of dementia identified. London: BBC Health News, April 30th 2019.
This relates to:
Nelson, PT. Dickson, DW. [and] Trojanowski, JQ. [et al] (2019). Limbic-predominant age-related TDP-43 encephalopathy (LATE): consensus working group report. Brain. April 30th 2019. [Epub ahead of print].
Further discussion, from NHS Behind the Headlines:
New type of dementia identified. London: NHS Digital (previously NHS Choices); Behind the Headlines, May 1st 2019.
This discovery has been rated (by BBC journalists) to be perhaps one of the top medical breakthroughs in 2019:
Gallagher, J. (2019). ‘Man on the Moon’ moment – the year’s big breakthroughs. London: BBC Health News, December 31st 2019.