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When there is doubt about an older person’s cognitive abilities, doctors may perform what is called the clock test. What does it consist of? Here is the detail.
Alzheimer’s disease, like other neurodegenerative dementias, develops gradually over time. If you notice the presence of certain early signs of the disease, it is possible to carry out certain tests, including that of the clock.
What is the clock test?
The clock test is a simple tool for assessing a patient’s cognitive abilities and detecting the possible start of cognitive decline in the elderly. It takes place in two stages, which must be quickly completed by the test subject.
The first part of the test therefore consists, for the patient being evaluated, of drawing a clock, freehand, with its twelve digits. Once this first part has been completed, the second consists, for the patient, of drawing the needles according to the precise time indicated by the doctor carrying out the test.
A test widely used throughout the world
This clock test makes it possible to assess different cognitive functions, such as spatial orientation, visuospatial memory or executive or gestural functions. It is also part of the MoCA test, for Montreal Cognitive Assessment (MoCA).
This more general test lasts 10 minutes and includes a part where the patient must draw a clock. It was created in 1996 for healthcare professionals to identify mild cognitive dysfunction, a precursor to dementia, and exists in more than 100 languages and dialects.
Only a doctor – usually a geriatrician – can evaluate this test and draw initial conclusions. The specialist will observe certain essential criteria of the test, such as the formation of a circle, the positioning of the figures or their size, in relation to the whole. The ability to position the needles in the right place is also a determining factor.
However, although it represents a first indicator, the clock test is in no way the means to make a definitive diagnosis. Even included in the MoCa test, as highlighted by Dr. Christophe Trivalle, geriatrician at Paul-Brousse hospital, interviewed in a previous article. “This test is not very efficient but can be carried out as a sort of clearing, to detect memory disorders. It is made up of several questions calling on memory, but also on spatial and temporal orientation or even to fluency”.
You have understood: to truly make a diagnosis of dementia, this test is a first step, which must necessarily be supplemented by other, more in-depth examinations and biological analyses.
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