Doctors who've figured out how to image the brain's waste-disposal system think they may have stumbled upon a potential way to diagnose Alzheimer's and other dementias -- possibly years before the diseases ensue.
Stony Brook doctors have mapped the intricate disposal system in rats and now are considering human imaging studies that focus on a vast system that stretches throughout the inner labyrinths of the brain.
Using a special type of MRI, Dr. Helene Benveniste zeroed in on the brain's glymphatic system, a specialized network involved in flushing obstructive dead-cell particles and other debris out of the organ.
Despite glitches that can occur in the network, "the glymphatic system has been overlooked in the human brain," for its role in Alzheimer's, Benveniste said.
She and her colleagues hypothesize that when blockages pervade the network, Alzheimer's and other forms of dementia are likely because two key brain-damaging proteins, beta amyloid and tau, are free to wreak havoc in the organ.
Beta amyloid leads to plaques in the brain, a hallmark characteristic of Alzheimer's disease; tau causes the so-called tangles by damaging vital brain cells.
Together the two underlie the so-called plaques and tangles theory of Alzheimer's disease.
"If the amyloid and tau don't get flushed away, they will contribute to buildup," Benveniste said Friday.
"This technique provides a three-dimensional view of the glymphatic pathway that captures movement of waste and solutes in real time," she said.
If further studies prove the hypothesis, Benveniste's imaging technique could be used to predict not only Alzheimer's, but other dementing illnesses, such as chronic traumatic encephalopathy -- CTE -- a degenerative brain disease of athletes with a history of repetitive head injuries.
"Football players, boxers, soldiers, anyone who has had repetitive head trauma will have damage in the brain," said Benveniste, noting people with CTE also have evidence of plaques and tangles.
She said imaging the glymphatic superhighway could provide a simpler way of diagnosing dementias than doctors now have.
Currently, the diagnosis of Alzheimer's is an involved process that includes verbal, number and memory testing as well as PET scans and a range of others tests. The most definitive test for Alzheimer's remains an autopsy.
Dr. Adam M. Brickman, an assistant professor of neuropsychology at the College of Physicians and Surgeons at Columbia University, called the Stony Brook brain-imaging studies intriguing.
This week, he and a team of researchers from Columbia's Taub Institute for Research on Alzheimer's and The Aging Brain, announced that tiny damaged blood vessels, which lead to so-called white matter hyperintensities in the brain, may also be a key contributor to Alzheimer's disease.
Micro-vascular damage is yet another new way of thinking about the genesis of the disorder, he said.