A New Dementia Test Raises More Questions Than Answers


Our understanding of disease mechanism is changing, in a way that makes early diagnosis more valuable. Dementia has a very long preclinical phase — up to 20 years, in some cases — where scans and blood tests can detect subtle changes but symptoms are not yet visible.

Two proteins begin to appear in the brain of patients with dementia in this window: tau and amyloid. Researchers have struggled for years to decipher the exact role they play, but now some think they have the answer. In dementia and Alzheimer’s patients, amyloid forms tangles and plaques in the spaces between brain cells. the theory so that once it grows to a certain level, it causes tau protein — which is usually part of the scaffolding of neurons — to convert from a normal to a toxic state. That is what causes most symptoms, by killing cells and interfering with the ability of neurons to send clear signals.

In June 2021, the The FDA granted expedited approval to aducanumab, the first new drug for Alzheimer’s disease in 18 years. It is designed to attach to amyloid molecules and make it easier for the immune system to clear them. But this is a controversial approach, because previous drug treatments aimed at clearing amyloid have failed to make a big difference.

In the emerging theory of dementia, however, the timing of intervention can be very important. With better early detection, medications like aducanumab can be given when they still have time to make a difference. “If you remove amyloid at a very early stage, that’s probably when the real benefit happens,” Koychev said. If amyloid is removed from the brain before it triggers tau to become toxic, perhaps the most severe side effects can be delayed or avoided altogether.

Easy-to-use digital tests can be combined with brain scans and blood tests to help researchers create a map of exactly how amyloid and tau proteins are associated with disabilities. mentally — and whether cleaning it makes a difference. Instead of a blanket method of screening everyone, Koychev suggests targeting those in the most at-risk groups with regular assessments.

He noticed, however, that there were many disagreements in the field, and there were serious skepticism if the new drug for Alzheimer’s works as expected. But it has revived research after Habibi called a “long drought period” in a field that was late with cancer in terms of investment and interest from pharmaceutical companies. Dening believes that’s because of a combination of factors — the stigma of the disease, the age of the people most commonly infected with it, and a fatalist “well, that’s the same thing that happens when you get older” attitude.

Things eventually changed as a large and wealthy demographic group moved into the age bracket where risk was highest. Trials like the ICA are targeted at them, but Koychev hopes they will also “democratize access to brain health.”

Because they are only digital and semi-supervised, they can be taken anywhere you get the iPad. That means they can reach people who are no longer in traditional situation studies, which are often inhabited by groups of volunteers who do not accurately reflect the underlying population. They can also be retrieved more frequently, to create a picture of an individual’s cognitive performance over time — Cognetivity has a separate iPhone app called OptiMind designed for home-tests. aims to do that.

We may still lack good treatments for dementia and Alzheimer’s disease, but the ability to recognize them early can change our attitude toward them, which in itself can improve our understanding and stimulate investment in those. solution we need. “Brain health can be something that people watch and watch over, just like you take care of your physical health,” Koychev said.


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