Pulsations driving brain’s cleaning system completely different in Alzheimer patients: study

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Finnish Researchers have been able to describe in detail how the pulsations of the cerebral arteries maintaining the brain’s cleaning system differ in Alzheimer’s disease patients, according to a recent research report published on the scientific journal Brain.

Significant pulsation changes were found especially in the areas of the brain associated with memory functions, said the report.

“Both the propagation speed of the pulse waves and their direction differ in Alzheimer’s patients in comparison to healthy controls. In certain parts of the brain, including the hippocampus and parietal lobes, the direction of propagation of pulse waves was reversed compared to healthy individuals. These parts of the brain play a major role in memory functions,” said Zalan Rajna, the head researcher of the study from Oulu University, in a Monday news release.

A brain’s cleaning system, the glymphatic system, activates during deep sleep. If disturbances occur in the system, waste material starts to accumulate in the brain, leading to premature brain degeneration. The driving force of the glymphatic system is created as a result of the heartbeat, respiratory movement, and pulsation of the blood vessels.

In Alzheimer’s disease, two kinds of waste materials in particular are accumulated in the brain, beta-amyloids and tau proteins, and these cause the brain to deteriorate, weakening memory functions and data processing abilities. Research has shown that in Alzheimer’s disease, harmful amyloid plaque is formed not only around the brain tissue but also around the cerebral arteries, stiffening them.

“We observed that upon arrival, the pulse propagation is abnormal in Alzheimer’s patients: too fast in small vessels and too slow in large ones,” Rajna said.

It remains uncertain whether the accumulation of amyloid plaque in the brain of an Alzheimer patient is caused by abnormal pulsation or whether the plaque accumulated around the arteries causes the abnormal pulsation.

The finding is crucial for understanding the dynamic brain mechanisms leading to Alzheimer’s disease and, in the long term, for the prevention and treatment of the disease, said the university.

Although there is currently no treatment for Alzheimer’s disease and its progress cannot be stopped, the disease can be prevented by maintaining good cardiovascular health and ensuring sufficient, high-quality sleep.