The Economist November 13th 2021 pp79-80|Science&technology|Diagnosing dementia|”Knowing the worst” “It is becoming easier, cheaper and quicker to diagnose dementia”
Read The Economist for all the details
Summary offered by 2244
Image from nia.nih.gov
55 million people worldwide are living with dementia but only one-in-four have “been...diagnosed with the condition.” Reasons for the low level of making an official diagnosis include; the idea that dementia is a normal part of human ageing, that dementia is “incurable” and that those with hints of dementia are afraid it’s “a sentence of brain-death, and so do not seek help.”
New tools may improve the ability to make a diagnosis and there are hopes that “some forms of dementia…[may have]...more effective treatments.” “Alzheimer’s disease (AD)…[accounts] for 60-80% of [dementia] cases.”
Currently expensive imaging using MRI (magnetic resonance imaging), PET (positron-emission tomography) combined with a needle-based extraction of a small amount of brain fluid (CSF cerebrospinal fluid) are needed to help diagnose AD. These tools assess the size of the brain and the build-up of beta-amyloid and tau that accumulate in the brains of those with AD.
Such technology, being expensive, is not widely available and patients often are reluctant to undergo these imaging protocols and CSF-sampling procedures. Researchers are now proposing to measure beta-amyloid (ba) and tau (t) from simple blood samples although how these blood levels compare to brain levels is still being evaluated. Reportedly “adding age and the presence of a form of the APOE gene” increases the predictive value of ba and t combined to 94% accuracy” in making the diagnosis of AD.
Others are investigating the use of “passive tests” using ECG caps (electroencephalographic) to identify AD even before outward signs and symptoms are noticeable. “Machine-learning and AI are enabling big improvements in cognitive testing” some of which have been adopted by “some regions of Britain’s National Health Service…America’s” FDA “and by regulators in the” EU.
Another area of research has been retrospective studies of “how people use words” as they develop dementia or not. Ajay Royyuru (IBM) says language assessment “suggests that changes over time can be used to predict…[who]...will acquire dementia, seven and a half years before they are diagnosed even with mild cognitive impairment (MCI). Today more than ever massive amounts of data from smartphones…”could help earlier detection of dementia.”
With the ability to make an earlier diagnosis of dementia we will need effective therapies. “In June the FDA approved Aduhelm, the first drug to treat Alzheimer’s”...using “a monoclonal antibody shown to reduce accumulations of beta-amyloid (ba). Lastly, with an ageing population worldwide, those with dementia will be increasing to “80m by 2030 and more than 140m by 2050.”