According to a recent study published in Neurology, even for individuals without brain amyloid plaques, cognitive impairment is linked to shrinking in the hippocampal region of the brain, which is in charge of memory.
A person with cognitive impairment experiences difficulties with memory, acquiring new information, focusing, or making decisions that impact their day-to-day activities.
There are several levels of cognitive impairment. People with moderate impairment can still do their daily tasks while starting to detect changes in their cognitive abilities.
Severe impairments can cause a person to lose their capacity to write, speak, and comprehend meaning or significance, making it impossible to live independently.
"These results suggest that neurodegenerative diseases other than Alzheimer's are contributing to this decline, and measuring the hippocampus volume may help us evaluate these causes that are currently difficult to measure."- Bernard J. Hanseeuw, study author
He continues by saying that this may make it easier to forecast who would react to these new medications and how quickly people's cognitive deterioration would progress.
At the beginning of the investigation, one hundred twenty-eight participants in the research, whose average age was 72, were free of cognitive or memory issues.
Throughout the survey, the participants had a variety of brain scans to determine the volume of the hippocampus and the number of tau tangles and amyloid plaques in their brains, as another indicator of Alzheimer's disease is the tau protein.
People with Alzheimer's have brains that aggregate between their neurons to form amyloid plaques, which are hard, intractable deposits of beta-amyloid proteins. Most tau protein is present in brain cells or neurons.
Stabilization of the interior microtubules is one of tau's many vital roles in healthy brain cells. Tau is a little protein with a short name but with a big reputation due to its connection with several cognitive conditions.
The subjects underwent annual cognitive tests for an average follow-up period of seven years.
A higher rate of hippocampal atrophy has been linked to a faster rate of cognitive deterioration. Examining every biomarker, the researchers discovered that hippocampal shrinkage was linked to cognitive impairment regardless of tau and amyloid levels.
Merely reducing the hippocampus area explained 10% of the variation in cognitive deterioration.
According to Hanseeuw, these findings highlight the complexity of dementia and its varied etiology. They also imply that dementias other than Alzheimer's disease could be linked to hippocampal atrophy and cognitive loss.
- Neurology. Association of pathological and volumetric biomarker changes with cognitive decline in clinically normal adults: Harvard Aging Brain Study
- CDC. Cognitive Impairment: A Call for Action, Now!
- BrightFocus Foundation. Amyloid Plaques and Neurofibrillary Tangles.
- BrightFocus Foundation. Tau Protein and Alzheimer’s Disease: What’s the Connection?