In a new study, researchers find that a clock drawing test for detecting cognitive dysfunction should be conducted routinely in patients with high blood pressure.
People with high blood pressure who have impaired cognitive function are at higher risk of developing dementia within five years.
However, cognitive function is not routinely measured in patients with high blood pressure.
In the current Heart-Brain Study, the team evaluated the clock drawing test to detect cognitive impairment in 1,414 adults with high blood pressure.
The average blood pressure was 144/84 mmHg, average age was 60 years, and 62% were women.
In the clock drawing test, patients were given a piece of paper with a 10 cm diameter circle on it.
They were asked to write the numbers of the clock in the correct position inside the circle and then draw hands on the clock indicating the time “twenty to four.”
Patients were scored as having normal, moderate, or severe cognitive impairment.
The researchers found a higher prevalence of cognitive impairment with the clock drawing test (36%) compared to another standard cognitive test MMSE (21%).
Three out ten patients who had a normal MMSE score had an abnormal clock drawing result. The disparity in results between the two tests was greatest in middle aged patients.
The researchers suggest that the ability to draw the numbers of a clock and a particular time is an easy way to find out if a patient with high blood pressure has cognitive impairment.
Untreated high blood pressure could silently and progressively damage the arteries in the subcortex of the brain and stops communication between the subcortex and frontal lobe.
This disconnect could lead to impaired ‘executive functions’ such as planning, visuospatial abilities, remembering details, and decision-making.
The clock drawing test is known to evaluate executive functions.
It is important because identifying these patients provides the opportunity to intervene before dementia develops.
The study author is Dr Augusto Vicario of the Heart and Brain Unit, Cardiovascular Institute of Buenos Aires, Argentina.
The study is presented at ESC Congress 2018.
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Source: ESC Congress 2018.
