Alzheimer’s disease could be detected using a simple online test, according to scientists at the Queensland Brain Institute (QBI) at the University of Queensland (UQ).
Alzheimer's disease patients, known to show specific memory impairment, are currently diagnosed using a range of cognitive tests as well as magnetic resonance imaging (MRI) scans, which can pinpoint the regions of brain degeneration, a symptom of the disease.
“One of the areas know to degenerate in Alzheimer's disease is a region called as the cholinergic basal forebrain, implicated in memory and attention. It has been unclear whether loss of function this brain area causes the cognitive changes seen early in Alzheimer's disease,” says QBI researcher Associate Professor Lizzie Coulson, who coordinated on the study.
In the study, researchers at the University of Queensland examined the cognitive changes in rodent models with basal forebrain degeneration mimicking Alzheimer's disease.
“Surprisingly, the mice behaved normally on most of the cognitive tests. However on a recall navigation task akin to ‘dead reckoning’, the mice become disorientated,” A/Prof. Coulson said.
This demonstrated recall navigation tasks rely heavily on cholinergic neurons, which are known to deteriorate early in Alzheimer’s patients. Current Alzheimer's disease treatments act to enhance the function of these cells, but the drugs only work for as long as the cells are healthy.
“The significance of the finding is that it is already known that Alzheimer's disease patients, and even people with memory complaints perform poorly on both real space and computerized recall navigation tasks,” says A/Prof. Coulson.
“By asking patients to perform these navigation tasks, doctors may be able to detect symptoms of Alzheimer’s disease much sooner and more cheaply than the MRI tests,” she said.
“We envision this test could also help to identify patients who would benefit from early administration of current Alzheimer's disease treatments.”
A/Prof. Coulson, in collaboration with a team from the Czech Republic who developed the human recall navigation tasks, are currently validating the findings in humans. Volunteers are asked navigate a simple arena on a computer monitor touch screen. Some subjects also have a brain MRI.
A/Prof. Coulson says the diagnosis tool could be widely used as early as 2015. Patients would perform the online test at a memory clinic, but the examination could one day be undertaken on their home computer says Coulson.
The paper, Lesions of the basal forebrain cholinergic system in mice disrupt idiothetic navigation, published in the journal PlosOne, was funded by the Queensland Government NIRAP (National and International Research Alliances Program) and the National Health and Medical Research Council of Australia
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