For patients over the age of 50, a routine physical exam at the doctor's
office typically covers a wide spectrum of medical biomarkers with one
glaring exception, cognitive health. Unless there have been unusual
mental changes or challenges in their daily life, tests of a patient's
attention, memory or brain processing speed is usually not part of a
To detect the early, subtle signs of mild cognitive impairment (MCI)
which may lead to forms of dementia, including Alzheimer's disease,
there is a need for a standardized test that can alert physicians to a
possible cognitive decline. Last week, research from the Florey
Institute of Neuroscience and Mental Health in Australia reported that a
brief, online set of cognitive tests, commercially known as Cognigram,
can detect early signs of MCI and Alzheimer's.
Cognigram has been developed by Cogstate, a leading medical technology
company specialising in cognitive assessment and training. Cognigram is
available to primary care physicians to provide a dementia test at the
point of care in Canada through an exclusive agreement with Merck
Canada. More than 580 primary care physicians have registered to use
Cognigram and 20 testing centres are now live.
To evaluate the functional health of a human brain, physicians need to
observe performance on several key domains. To assess the state of sub
cortical brain regions including the basal ganglia as well as cortical
regions such as the prefrontal and parietal cortices, tests of attention
and reaction time are used. Learning and working memory depend on normal
functioning of the hippocampus and temporal lobe (for pattern
separation) and prefrontal cortex and anterior cingulate (for working
By grouping these two domains, attention/reaction and learning/memory,
into composite scores, the research team, led by Paul
Maruff PhD, Chief Science Officer of Cogstate, was able to compare
test results with traditional hallmarks of MCI and AD.
"The presence of a relatively greater impairment in cognitive functions
dependent on cortical and limbic brain regions (i.e., learning and
working memory) with relatively subtle impairment in motor and attention
functions is consistent with neuropsychological models of AD which
emphasize that cognitive impairment characteristic of both prodromal and
clinically classified AD is disruption to memory and executive
function," said Dr Maruff.
To test this, they recruited volunteers from the Australian Imaging,
Biomarkers and Lifestyle (AIBL) Study, dividing them into three groups;
653 healthy adults, 107 with amnesic MCI (where the primary symptom is
memory loss), and 44 with AD. They were all asked to complete the four
tests of the Cogstate brief battery, also known as Cognigram,
and the speed and accuracy of the results were recorded.
All of the Cogstate tests use a deck of playing cards as their focus
point. No knowledge of any card games is required, patients simply
answer a yes/no question about what and when cards are shown to them.
For the attention/reaction composite, volunteers completed the Detection
task, pressing a certain key on a computer keyboard as soon as a card is
turned over, as well as the Identification
task, answering yes or no if a card turned over is the color red.
For the learning/working memory composite, two additional tests were
used. The One
Card Learning task asks, "Have you seen this card before in this
task?" To test immediate recall, the One
Back test asks if the card displayed is the same as the immediately
As hypothesized by the research team, the results showed that both the
MCI and the AD groups performed significantly worse on both composites
than the healthy adults. Also, the AD group's learning/memory score was
significantly lower than the MCI group, demonstrating the presence and
progression of the memory decline caused by the disease.
To be a reliable diagnostic tool for physicians, the test battery needs
to be able to show consistent results over time. The Cognigram testing
was repeated four times in three months and showed statistically similar
results across all groups.
The full study can be accessed online at BMC
"We are excited about the results of this study," said Maruff. "The
Cogstate brief battery has been found to be sensitive to amyloid related
cognitive change in many trials. This study shows for the first time,
that a version of the test designed specifically for clinical practice;
the Cognigram battery, has excellent sensitivity and specificity to mild
Dan Peterson, +1-203-773-5010
Ben Oliver, +61 3 9866 4722