Two new techniques allow detecting Alzheimer's much before symptoms

BarcelonaAlthough there is no cure yet, science is tightening the siege on neurodegenerative diseases, such as Alzheimer's and multiple sclerosis, and there are increasingly more and better diagnostic tools and new treatments that slow their progression. This Friday, the prestigious journal The Lancet published two investigations on new techniques that allow detecting Alzheimer's, which is the most common form of dementia, long before the first symptoms appear. They are a simple blood test, which has been shown in other studies to be a great tool for early diagnosis and is already used in hospitals, and a new brain scanner that improves the results of the technique currently used in the United States and Europe. The sooner the disease is identified, the sooner strategies can be deployed to delay its course, which is why it is essential to have early diagnosis tools.

Alzheimer's is characterized by the unusual accumulation inside and outside neurons of a peptide (a protein fragment) called beta-amyloid and a protein known as tau. It is not known why this happens, but it is very likely what causes cells to malfunction

and the brain to atrophy little by little. Measuring the levels of these proteins in the blood has become a way to track changes that indicate whether a person will develop the disease. Now, research from the University of California has determined that a single test can detect signs of the accumulation of these proteins in the brains of people who have not yet developed symptoms. Higher levels of these proteins are associated with worse cognitive performance and accelerated decline in adults, according to this research.

To reach these conclusions, researchers measured the levels of beta-amyloid and tau in the blood of 1,350 adults without dementia in the United States, with an average age of 61 years. Elevated levels were associated with worse cognitive performance, both in terms of information processing speed and executive function, which is what allows the brain to plan, focus attention, and adapt to new challenges. The authors emphasize that early identification opens a window of opportunity to reduce risk factors for Alzheimer's such as a sedentary lifestyle, smoking, and poor sleep hygiene, among others, which would allow delaying the onset of cognitive decline and the development of symptoms.

The second investigation published by the journal was led by professionals from the University of Pittsburgh Medical Center, who have discovered a new brain imaging test that can detect tau protein before symptoms appear. Furthermore, it improves the diagnostic imaging technique currently used in clinical practice in the United States and Europe, according to the study's authors. To determine this, they compared the current standard test, called Flortaucipir, and the new test, named MK6240, in a trial with 682 participants aged between 50 and 89 years. In people without symptoms, but with the presence of beta-amyloid in the brain, the new test detected tau in 15% of cases, while the standard method only identified it in 6%. The authors argue that using more sensitive tests can improve early detection and better identify patients more likely to develop symptoms.

Combating multiple sclerosis

Besides the two publications on Alzheimer's, this Friday The Lancet also echoes research on multiple sclerosis and, more specifically, on ocrelizumab, a medication already prescribed to patients with initial symptoms of this disease. Most clinical trials have failed to identify effective treatments for patients with advanced forms of multiple sclerosis, but, according to the study, this drug not only delays the course of symptoms and, therefore, the progression of patients' disability, but also does so for those who have been ill for a long time. This leads the authors to believe that this medication may benefit a broader group of patients than those currently receiving the drug.

So far, the effects of ocrelizumab in patients over 55 years old, with more advanced disabilities, such as using a wheelchair, are unknown, as they were not candidates to receive the drug until now. The researchers included over a thousand adults with primary progressive multiple sclerosis, aged between 18 and 65 years and with varying levels of disability – from mild to quite advanced – to receive the drug every six months or a placebo.

In the group of patients with advanced disability, the medication significantly reduced the risk of worsening, such as the progressive loss of function in the upper extremities and hands. For the authors of the research, maintaining upper limb function is crucial for these wheelchair-bound patients, as it allows them to maintain independence and a better quality of life. In short, they argue, this drug can benefit more patients than current ones.