Gauging the size of the brain ventricles – the fluid-filled cavities in the brain – and the surrounding dead brain tissue with the help of magnetic resonance imaging scans may help doctors diagnose Alzheimer's disease much earlier than standard diagnostic tests, the Canadian researchers claim.
For the research the researchers performed brain scans using the magnetic resonance imaging technique on 504 individuals over the age of 70 enrolled in the Alzheimer's Disease Neuroimaging Initiative (ADNI), a multi-site trial co-sponsored by the National Institutes of Health and the pharmaceutical industry, both at baseline and six months later.
They were then categorized into three groups; one had no cognitive impairment, second, some cognitive impairment and third, who were already diagnosed with Alzheimer's.
On examination researchers found a direct association between ventricledefine enlargement and Alzheimer's - ‘as the ventricles enlarge, the surrounding brain tissue dies’.
In individuals with no cognitive impairment the ventricle growth rate was noticed at about 1.5 per cent over six months and the brain tissue shrank during the normal aging process.
In seniors who exhibited early signs of cognitive difficulties, the ventricle growth rate was about 3.5 per cent over six months, researchers gauged.
However, in the third group with people already diagnosed with the disease at the commencement of the study, the ventricle enlargement was maximum and fastest. It grew at 5.5 per cent per six months.
Moreover, patients who had Alzheimer's at the commencement of the study had 60 per cent faster expansion of ventricles compared to people with mild cognitive impairment, researchers found.
Alzheimer's disease, the most common cause of dementia is a degenerative and terminal disease with no known cause. Typically being characterized with progressive symptoms like confusion, anger, mood swings, language breakdown and long-term memory loss, the diagnoses of the disease relies on neuro-cognitive assessments, such as testing of memory, ability to problem solve, count, etc.
With no definitive diagnoses available until after death when an autopsy helps reveal the presence of amyloid plaques and ‘tangles’ in brain tissue, the new research suggests links between ventricle size and onset of Alzheimer’s aiding early detection.
"These findings mean that, in the future, by using magnetic resonance imaging (MRIdefine) to measure changes in brain ventricle size, we may be able to provide earlier and more definitive diagnosis," said Robert Bartha, who is also an Associate Professor in the Schulich School of Medicine & Dentistry in Medical Biophysics.
"In addition, as new treatments for Alzheimer's are developed, the measurement of brain ventricle changes can also be used to quickly determine the effectiveness of the treatment," Bartha added.
The results of the study feature in the Friday’s online edition of the journal Brain.
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