Last Thursday, Jan. 21, I sat perched at a laptop, my eyes fixated on a pair of black-and-white images on the screen. Every few seconds, a new set of images appeared. Some depicted everyday items, such as a teddy bear or ice cream cone. Others looked more abstract, like Rorschach ink blots.
At some point during this cognitive assessment test, certain pictures start popping up again. In most cases, people pay more attention to the novel images than to the pictures they’ve seen before. The exception? People who are at risk of developing Alzheimer’s disease in the next three to six years tend to fixate equally on both images—new and old alike.
This simple eye-tracking test, developed by a digital health startup called Neurotrack, has the potential to change the way we detect and treat a disease that afflicts more than five million Americans. It assesses what researchers call recognition memory, which depends on the integrity of the brain’s hippocampal region—one of the first areas to falter in people with Alzheimer’s.
Getting an Alzheimer’s diagnosis typically requires a huge battery of neurological and cognitive tests. The trouble is that most people don’t think to see a doctor until they or their loved ones suspect their memory is fading. By that time, neurons in their brain have died, causing irreversible brain damage. Yet clinical trials for experimental Alzheimer’s therapies have traditionally sought out participants with a diagnosis. Experts think many Alzheimer’s drug trials have failed because the tests were conducted on people with brain damage that was too advanced, costing pharmaceutical companies billions of dollars in the process.
Earlier diagnosis could help studies enroll the right people—those who seem healthy but are actually on the verge of cognitive decline. In addition to Neurotrack’s eye-tracking test, promising options for earlier diagnosis include analyzing spinal fluids and performing positron emission tomography (PET) brain scans to detect a key red flag for Alzheimer’s—amyloid-beta protein in the brain, which can accumulate decades before cognition declines. Researchers hope that once they’re able to identify people at risk for the disease, companies may be able to develop new drugs that slow or stop its progress.
Better drugs could also lead to “better quality of life for the patient, which would ultimately lower health care costs,” says Samir Kaul, the founding managing director of Khosla Ventures. Khosla is the lead investor for Neurotrack’s $6.5 million in new funding, announced Jan. 27. If it passes muster in ongoing studies, Neurotrack’s online test could be a cheap, easy, non-invasive way to detect Alzheimer’s in advance of symptoms.
The Palo Alto, California-based company is inviting physicians to offer the eye-tracking test to their patients. It’s also developing a personalized lifestyle program for prospective patients. The program will be based on emerging research in Finland and elsewhere suggesting that diet, exercise, cognitive training, sleep and stress management could preserve brain health and help prevent Alzheimer’s.
Neurologist Richard Isaacson uses Neurotrack’s Web-based tool, along with other tests, to evaluate cognition in patients at the Alzheimer’s Prevention Clinic at Weill Cornell Medicine in New York. So far, more than 300 people—most of them cognitively healthy with a family history of Alzheimer’s—have taken the digital eye-tracking test. “The holy grail of Alzheimer’s prevention is having a test that can diagnose a person before they’re symptomatic,” says Isaacson.
Neurotrack’s long-term goal is to be “a place where people can find out if they’re at risk for cognitive decline and have a solution for dealing with it in the absence of a drug, or maybe in addition to a drug,” CEO Elli Kaplan tells Quartz. Before co-founding the company in 2012, Kaplan spent 20 years working at the White House, analyzing foreign policy and economic issues for the State and Treasury departments. She also held positions at Goldman Sachs and multiple startups. Kaplan has a personal connection to her company’s mission: she lost two grandparents to Alzheimer’s disease.
The efficacy of Neurotrack’s original half-hour cognitive assessment test was explored in a five-year study published in 2013 in the American Journal of Alzheimer’s Disease and Other Dementias. The study followed 92 older adults—32 with mild cognitive impairment, and 60 with normal cognitive functioning—who took the half-hour office test. Test scores successfully predicted who in the normal group later became impaired and which of the mildly impaired would later develop Alzheimer’s.
Preliminary data suggests the five-minute online test done on a home computer works as reliably as the expensive office setup. However, we won’t know for a few years whether the shorter test can accurately predict who will go on to develop Alzheimer’s.
The eye-tracking tool is also being tested alongside PET and MRI scans and other early-Alzheimer’s tests in ongoing studies at Brown University, Emory University’s Alzheimer’s Disease Research Center, Harvard University, New York University’s Langone Medical Center, Stanford University, and Weill Cornell Medicine.
“Ultimately our vision is to become the new standard of care for early diagnosis of Alzheimer’s,” says Kaplan. “But we’ve got a long way to go.”