Clock-Drawing Test to diagnose Alzheimer’s

Did you know…?

The Clock-Drawing Test is a simple and fairly quick method that can help diagnose Alzheimer’s and other types of cognitive deterioration.

But what does it consist of?

Firstly, the patient is asked to draw a clock with all the hours, and the hands pointing at a specific time. Ideally, the patient would draw a sphere, place the numbers in order and have the hands pointing at said time.

However, that simple task involves various cognitive areas, such as short-term memory, understanding and planning, and thought-hand coordination.

Moreover, there are three ways of carrying out the Clock-Drawing Test that vary in difficulty. For instance, the patient can have a blank page so that they will have to start it from scratch. Another option is to hand them a paper where the sphere has already been drawn. Lastly, they can get both an image of a clock and a blank page to copy it.

Furthermore, the Clock-Drawing Test is evaluated according to the 4 main elements in it:

• Sphere: score goes from 0 to 2 depending on how circular or asymmetric the sphere is.
• Numbers: score goes from 0 to 4 and takes into account the order of the numbers and their location inside or outside the sphere.
• Hands: score goes from 0 to 4 considering their proportion, their location in the sphere and whether they are pointing at the time asked.

Generally speaking, a final score of 7 (out of 10) or below can be a sign of cognitive deterioration. If this is the result, it is always best practice to talk with a specialized doctor before making any decision.

Despite its simplicity, a large part of the scientific community agrees that this test is an efficient method of screening for cognitive difficulties.