Alzheimer’s disease could be detected using a simple online test.

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), which can pinpoint the areas of brain degeneration, a symptom of the disease.

“One of the areas know to degenerate in Alzheimer’s disease is a region called the cholinergic basal forebrain, implicated in memory and attention. It has been unclear whether loss of function in this brain area causes the cognitive changes seen early in Alzheimer’s disease,” says Associate Professor Elizabeth Coulson, who coordinated the study.

The researchers examined the cognitive changes in rodent models with basal forebrain degeneration.

“Surprisingly, the mice behaved normally on most of the cognitive tests, however, on a recall navigation task akin to ‘dead reckoning’, the mice became disorientated,” Associate Professor Coulson said.

This demonstrated that recall navigation tasks rely heavily on cholinergic neurons.

Current Alzheimer’s disease treatments act to enhance the function of these cells but drugs work only as long as the cells are healthy.

“It is already known that Alzheimer’s disease patients, and even people with memory complaints, perform poorly on both real space and computerised recall navigation tasks,” says Associate Professor Coulson.

“The significance of our work is that 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.”

The findings are currently being validated in humans by Associate Professor Coulson in collaboration with researchers from the Czech Republic, the team who developed the human recall navigation tasks.

Volunteers are asked to navigate a simple arena on a computer monitor touch screen and are, in some cases, required to have a brain MRI.

Associate Professor Coulson says the diagnostic tool could be in wide use as early as 2015.

She says that, to begin with, patients would be tested at a memory clinic but that the online nature of the examination means it could one day be undertaken at home.