One of Our Greatest Hopes for Alzheimer’s Treatment Appears Ineffective

New Study Challenges Common Alzheimer’s Treatment Approach

For years, scientists have focused on the clumps of sticky proteins in the brains of Alzheimer’s patients as a possible treatment avenue. However, a recent study suggests this might be misguided.

It appears that simply removing amyloid-beta clumps may not actually rejuvenate critical brain functions.

Notably, the brain’s waste-clearing system, known as the glymphatic system, doesn’t seem to recover after these clumps are cleared. In fact, this system is already known to be compromised in Alzheimer’s patients, typically aiding in the removal of excess amyloid-beta through cerebrospinal fluid (CSF) waves.

This study originated from researchers at Osaka Metropolitan University in Japan, who evaluated the new Alzheimer’s drug lecanemab on 13 individuals diagnosed with the disease. They employed magnetic resonance imaging (MRI) scans to observe its impact on the brain.

“Even when amyloid-beta is reduced by lecanemab, the glymphatic system may not bounce back in the short term,” notes medical researcher Tatsushi Oura from Osaka Metropolitan University.

The findings further emphasize the complex nature of Alzheimer’s, which is linked to numerous potential risk factors and symptoms. The exact causes of the disease remain unclear; it’s likely that a range of triggers are involved.

While the accumulation of amyloid-beta and another protein called tau are recognized indicators of Alzheimer’s, the relationship between them is still a mystery. Scientists are still trying to figure out whether these proteins cause the disease, are generated by it, or perhaps both.

In this research, lecanemab did succeed in lowering amyloid-beta levels, but the glymphatic system’s functionality showed no improvement after three months. Essentially, the drug doesn’t seem to reverse the damage done by Alzheimer’s regarding the brain’s waste management mechanisms.

“Disease-modifying therapy can lessen plaque levels and slow cognitive decline but does not restore lost functions, likely due to already established neuronal damage and issues with the clearance system,” the researchers assert in their published work.

This study offers more depth to the increasingly intricate understanding of Alzheimer’s and how it might be addressed. Past research has also suggested that removing plaques may not significantly enhance Alzheimer’s symptoms, leading some experts to theorize that the plaques could actually be a byproduct of the disease rather than its root cause.

Earlier trials indicated that lecanemab can decelerate the progression of Alzheimer’s, but its effectiveness seems to be highest at earlier stages of the disease. Thus, researchers are concentrating on detecting dementia signs as early as feasible.

This brief study involved a limited participant pool, so the researchers aim to broaden their investigation—looking at how lecanemab affects different stages of Alzheimer’s and over extended periods.

“In the future, we want to consider factors like age, disease stage, and the extent of white matter lesions to better understand the relationship between changes in the glymphatic system due to lecanemab treatment and treatment outcomes,” Oura adds.