The way people draw on paper could detect early signs of Alzheimer’s disease.
Those with dementia pause for longer when drawing, use the pen at a jerky speed and are more erratic in how hard they press down, a study has found.
Researchers recruited 144 people, including 27 with early-stage Alzheimer’s disease, 65 with mild cognitive impairment and 52 people of a similar age who had neither.
They found an algorithm, judging 22 different measures of drawing style, correctly identified these people with 75 per cent accuracy. Published in the Journal of Alzheimer’s Disease, the study found consistent differences in how people drew in the tasks.
Researchers recruited 144 people, including 27 with early-stage Alzheimer’s disease, 65 with mild cognitive impairment and 52 people of a similar age who had neither (file image)
Professor Tetsuaki Arai, senior author of the study from the University of Tsukuba in Japan, said: ‘Our results pave the way for better screening tests for cognitive impairments.’ Drawing tests are already used to diagnose Alzheimer’s. But traditionally these tests analyze red flags for dementia such as slower thinking speed.
Detecting mild signs of mental impairment early on could prevent or delay someone developing dementia.
The new study looked at factors like how often people paused, the speed of their drawing and how they held the pen.
Unusually, researchers measured these features across five separate tasks.
These included the three tests above, plus analysis of how people wrote a sentence and did a more complicated version of the line-drawing test, connecting letters and numbers, such as one followed by A and two followed by B.
The study, published in the Journal of Alzheimer’s Disease, found consistent differences in how people drew across all five tasks, which were done using a pen and a digital tablet rather than a pen and paper.
Researchers could detect people with Alzheimer’s or mild cognitive impairment through longer pauses when people were drawing, less smoothness in their drawing speed and greater variability in the pressure they put on the pen.
The way people draw on paper could detect early signs of Alzheimer’s disease (file image)
The accuracy of the various tests, in detecting people who had Alzheimer’s, mild cognitive impairment or neither, varied from 53 per cent when people were judged writing a sentence, to 67 per cent for the more tricky line-drawing task.
But overall, the accuracy for all five together was 75.2 per cent.
It is important to detect mild cognitive impairment, which often starts with mild memory problems like forgetting recent events or repeating the same question.
Picking this up early could prevent or delay someone going on to get dementia.
The study found 27 measurements of drawing style could tell the difference between mild cognitive impairment and Alzheimer’s disease, although the algorithm also wrongly classified 12 healthy people as having mild cognitive impairment when they did not.
Drawing provides clues to whether someone has early Alzheimer’s disease because changes in the brain can affect both memory and how we control our movements.
Researchers already look at how hard people press when drawing to diagnose Parkinson’s disease and Huntington’s disease, but the technique has rarely been used for dementia.
Professor Arai said: ‘We were surprised by how well the combination of drawing traits extracted from multiple tasks worked by capturing different, complementary aspects of cognitive impairments.
‘The three-group classification accuracy of all five tests was 75.2 per cent, which was almost 10 per cent better than that of any of the tests by themselves.’