Question: Does drawing a clock really prove whether or not I have Alzheimer’s disease?
Answer: Only time will tell!
One of the most important parts of the physician’s examination for Alzheimer’s disease and dementia is the cognitive testing. This is a series of questions that tests a patient’s memory, orientation, concentration, language and other brain functions to determine if they have been affected by disease.
Some patients get frustrated by the types of questions the doctor may ask, because they can seem too simplistic, or might not appear to have any connection with diagnosing a memory problem. But most physicians are simply administering a standardized series of questions that have been developed specifically for the purpose of diagnosing dementia and have been validated in millions of patients over many years.
For example, “What day of the week is it?” tests orientation; “Repeat the following words now, and tell me them in five minutes” tests immediate and short-term memory; “Take this paper in your right hand, fold it in half, and place it on the ground” tests comprehension, one aspect of language function. The beauty of performing these standardized tests is that the patient’s scores can be compared to “normal” scores for people of a similar age and educational background. The score does not provide a diagnosis in and of itself, but along with other aspects of the patient’s history and examination, can provide physicians with the information they need to diagnose dementia.
So what’s with clock drawing? Drawing a clock, putting in all the correct numbers and being able to correctly set the hands at a given time, is actually a remarkably sensitive test of a number of cognitive functions including memory, comprehension, spatial abilities, and what is referred to as “executive” function.
Some researchers have suggested that the clock drawing test alone can help with diagnosing dementia, aid in determining what is causing the dementia, and even provide clues into how the illness will progress. If you are over 80 years of age in Ontario and planning to renew your driver’s license, you may be surprised to learn that the written examination will include a clock drawing test. This is based on research that has suggested that performance on the clock-drawing test actually corresponds to driving ability.
