Noninvasive Test Could Reveal Early Alzheimer's Disease

Noninvasive tests for the detection of Alzheimer’s disease are a viable option, according to research published online December 22, 2014 in Nature Nanotechnology.

Researchers from Northwestern University developed a noninvasive magnetic resonance imaging (MRI) test in order to develop a viable method for the early detection of Alzheimer’s disease. The scientists paired an MRI with a magnetic nanostructure (MNS) and an antibody that sought out the Alzheimer’s disease biomarker, the amyloid beta brain toxins. The group of toxins in the brain showed up as dark areas in MRI scans because of the associated nanostructures. This technology aims to detect something different than other Alzheimer’s disease scanners — instead of plaques, it detects the amyloid beta oligomers. This is beneficial because the plaques occur in the brain at a later stage of Alzheimer’s disease progression when therapeutic intervention is typically very late in the disease onset. The amyloid beta oligomers are currently believed to be an early cause of Alzheimer’s disease and subsequent memory loss.

An additional result of the study, although it was not a primary endpoint, demonstrated that the MRI probe may improve memory. This was accomplished by binding the toxins which preventing them from causing further damage to the brain.

“We have a new brain imaging method that can detect the toxin that leads to Alzheimer’s disease,” lead neuroscientist William L. Klein, PhD, who first identified the amyloid beta oligomer in 1998, said in a press release. “Using MRI, we can see the toxins attached to neurons in the brain,” Klein said. “We expect to use this tool to detect this disease early and to help identify drugs that can effectively eliminate the toxin and improve health.”

The researchers first used animal models to test their hypothesis and demonstrate their findings. In animals without models of Alzheimer’s disease, the presence of toxins was noted in the MRI scans of the hippocampus part of the brain. However, there were no dark areas noted in the hippocampus of the animals without mice models of Alzheimer’s disease.

“Noninvasive imaging by MRI of amyloid beta oligomers is a giant step forward towards diagnosis of this debilitating disease in its earliest form,” co corresponding author and materials scientist Vinayak P. Dravid, PhD continued in the press release. “This MRI method could be used to determine how well a new drug is working. If a drug is effective, you would expect the amyloid beta signal to go down.”

Human brains with and without Alzheimer’s disease were also tested, using samples from the school’s Cognitive Neurology and Alzheimer’s Disease Center. There was a presence of large dark areas, including those that indicated the occurrence of amyloid beta oligomers, in the MRI scans from brains with the disease.