Brain magnetic resonance imaging scans that measure gray matter shrinkage can determine how fast early Alzheimer's disease will progress to dementia, according to a study published in the journal Neurology.
Researchers tracked 130 people aged 40 to 64 with mild cognitive impairment alongside 97 healthy volunteers over an average follow-up period of about two years. During the monitoring period, approximately 65 percent of participants with early Alzheimer's disease saw their condition progress into dementia.
To evaluate structural changes in the brain, scientists developed a specialized magnetic resonance imaging marker that measures reduced gray matter thickness across eight brain regions. These specific areas are directly responsible for memory, speech, and thinking. The researchers found that greater tissue atrophy in these regions correlated with a faster onset of dementia.
For every increase in the degree of gray matter atrophy by one standard deviation, the probability of progressing from mild cognitive impairment to dementia increased by 1.24 times. The diagnostic indicator proved more accurate at predicting disease progression than evaluating a patient's initial clinical symptoms.
Brain region atrophy and clinical impact
Mild cognitive impairment is an early phase of memory loss or cognitive decline in individuals who maintain their independence in daily activities. Alzheimer's disease is a progressive neurological disorder that gradually damages brain cells, serving as the most common cause of dementia worldwide. Gray matter contains neuronal cell bodies, synapses, and dendrites that process information and govern memory, speech, perception, and decision making.
Researchers said that in the future, this brain scan analysis could help doctors assess the rate of dementia progression in a specific patient in advance. They noted that the tool could help medical providers determine when an individual faces the risk of losing personal independence.
Diagnostic tools and dementia prevention
Magnetic resonance imaging is a non-invasive medical imaging technique that uses magnetic fields and radio waves to generate detailed images of internal brain structures. The medical journal Neurology is the official peer-reviewed journal of the American Academy of Neurology, publishing research across clinical neurology and neuroscience.
The findings build on earlier research into neurodegenerative risk factors. In a previous study, scientists reported that hormone replacement therapy reduces the risk of dementia and Alzheimer's disease in women.
