If a person's brain size starts to shrink, it could mean that within a decade they may start presenting symptoms of Alzheimer's disease, researchers from Massachusetts General Hospital, Harvard Medical School revealed in the journal Neurology. Rush University researchers were also involved in this study.
This new discovery adds compelling evidence to Alzheimer's slow and gradual emergence. Experts say it could help health care professionals and scientists identify individuals at risk before damage occurs.
The authors used magnetic resonance imaging (MRI) scans to measure the thickness of the cerebral cortex - part of the brain - in 65 individuals. Cortex thinning is a characteristic of Alzheimer's disease. The cortex is the outer part of any organ, which in this text refers to the outer portion of the cerebrum (brain).
They divided the study participants into three groups and worked out how many eventually developed Alzheimer's symptoms:
- High thickness measurements - none of these people went on to develop Alzheimer's disease
- Average thickness measurements - 20% of these people went on to develop Alzheimer's disease
- Low thickness measurements - 55% of these people went onto develop Alzheimer's disease
"By focusing on cortical regions known to be affected in AD dementia, subtle but reliable atrophy is identifiable in asymptomatic individuals nearly a decade before dementia, making this measure a potentially important imaging biomarker of early neurodegeneration."
The Alzheimer's Society, UK, wrote in a communiqué:
"We have known for some time that changes in the brain can happen a long time before a person starts showing symptoms. Research such as this is helping us build on our understanding of where these changes happen and how early. However, while these latest results are significant, it is a small sample size and we are still some way from being able to say for certain which people will go on to develop Alzheimer's.
Alzheimer's disease, also known as Senile dementia of the Alzheimer Type (SDAT), or simply Alzheimer's is a progressive neurologic brain disease which leads to irreversible loss of neurons and loss of memory, reasoning, intellectual functions - all of which eventually become severe enough to make social and occupational functioning impossible.
As the disease progresses, plaques and tangles develop in the structures of the brain, causing its cells to die. Alzheimer's patients also have abnormally low levels of brain-neurotransmitters, chemicals involved with the transmission of messages in the brain.
Alzheimer's, which gets worse with time, is the most common form of dementia. There is no current cure, although some therapies may help slow down its progression and alleviate symptoms. It is a terminal disease (causes death). Approximately 4.5 million Americans and 417,000 British people have Alzheimer's.
"Alzheimer-signature MRI biomarker predicts AD dementia in cognitively normal adults"
B.C. Dickerson, MD, T.R. Stoub, PhD, R.C. Shah, MD, R.A. Sperling, MD, R.J. Killiany, PhD, M.S. Albert, PhD, B.T. Hyman, MD, PhD, D. Blacker, MD, ScD and L. deToledo-Morrell, PhD
Written by Christian Nordqvist