What do Albert Einstein, Bill Gates, John F. Kennedy and Oprah Winfrey all have in common? Widespread fame. And now new research suggests that middle-aged Americans who fail to recognise or name them and their like may suffer from a specific type of early onset dementia.
Called primary progressive aphasia, this particular form of dementia tends to initially strike men and women between the ages of 40 and 65. It is principally known for disrupting language skills, making it difficult for patients to understand or find the right words when trying to articulate their thoughts.
With that in mind, investigators believe they have devised a simple, cheap and easy-to-administer screening test that can accurately unearth evidence of the disease based on a patient's inability to verbally identify photos of well-known faces.
"Although several [other] tests assess knowledge of famous faces, many contain stimuli unfamiliar to younger individuals who are seeking neurologic treatment for early dementia," said study author Tamar Gefen, a clinical psychology doctoral candidate at the Northwestern University Feinberg School of Medicine, in Chicago.
"[Our] test includes images of faces, like Oprah, that are appropriate for a younger generation," Gefen said. "And [ours is] the first study to look at face identification difficulties in a particular group of individuals with primary progressive aphasia, a disease that strikes early and destroys slowly a person's ability to communicate, speak, understand and write."
Gefen and her colleagues discussed their observations in the 13 August issue of the journal Neurology.
To test the potential of photo recognition as a dementia screening tool, the authors focused on 30 patients (60% of whom were female) already diagnosed with primary progressive aphasia, as well as 27 healthy patients.
On average, study participants were roughly 62 years old. All were asked to look at a series of 20 black-and-white images downloaded from the Internet. All depicted so-called cultural icons, including Lucille Ball, Princess Diana, Martin Luther King Jr., Elvis Presley and Muhammad Ali. About half of the images were of people who are still alive. About two-thirds were of men, and about a quarter were of black celebrities.
Participants were first asked to try to provide the full name of the person in each image. Partial credit was given for offering just the first or last name. If no part of the name could be recalled, participants were instead asked to offer some form of detailed and relevant description concerning the celebrated person at hand.
At the same time, MRI brain scans were taken of everyone in the study in the hopes of mapping brain irregularities linked to primary progressive aphasia.
Those who were healthy fared much better overall than those with primary progressive aphasia.
Whereas 93% of the healthy group was able to successfully put a name to a famous face, the same was true of just 46% of the primary progressive aphasia patients.
And although 97% of the healthy group was able to recognise or describe the icons on view, the same was true of just 79% of the dementia group.
What's more, brain scan analyses revealed that those who had difficulty with name recall were more likely to have experienced brain-tissue loss in the left temporal lobe region of their brains, while those with difficulties in face recognition had suffered brain loss on both sides of the same region.
"We hope," Gefen said, "that this tool can be incorporated into a battery of tests to be used for younger patients who specifically complain of difficulties naming a person's face."
Catherine Roe, an instructor in neurology at the Washington University School of Medicine, in St. Louis, took a cautious view of the findings.
"To help us know how to use this test as a screening tool," Roe said, "more research needs to be done to figure out whether this test distinguishes all people with dementia from people without dementia or whether it distinguishes only people with one particular type of early-onset dementia from people without dementia."
Cheryl Grady, a senior scientist with the Rotman Research Institute at the Baycrest Center in Toronto, seconded the need for follow-up work. But she nonetheless described the work as "intriguing" and praised "the updating of such a test for middle-aged adults".
"[But] I would say that a lot more studies need to use this test before we will know how sensitive it is or whether it is more sensitive to early disease than other fairly sensitive tests," Grady said.
In research, the more true positive results a test produces, the more "sensitive" the test is considered.
For more on primary progressive aphasia, visit the U.S. National Aphasia Association.