Clock Drawing Test

Resources for the Comprehensive Geriatric Assessment based

Proactive and Personalised Primary Care of the Elderly

Purpose : Screening test for cognitive dysfunction secondary to dementia, delirium, or a range of neurological and psychiatric illnesses

Admin time : x min. variable

User Friendly : High

Administered by: Healthcare Provider

Content : Template for Clock Drawing Test, showing a blank circle as a clock face. Scoring instructions. Interpretation guide. Scoring examples.

Author : (Shulman KL , 1986)

Clock Drawing Test

Why

The clock drawing test (CDT) has been proposed as a quick screening test for cognitive dysfunction secondary to dementia, delirium, or a range of neurological and psychiatric illnesses (Cucinotta D, 2004).

The CDK can be effectively administered to resistant and non-compliant older persons, (Freund B, 2005)

How

Provide patient with a piece of paper with a pre-drawn circle of approximately 10 cm in diameter.
Indicate that the circle represents the face of a clock and ask the patient to put in the numbers so that it looks like a clock.
Ask the patient to add arms so that the clock indicates the time "ten minutes after eleven."

Scoring

The choice of a scoring system ultimately depends on the specific needs and goals of the clinician or researcher.

Score Card

The clock is divided into eighths, beginning with a line through the number 12 and the center of the circle.

If the 12 is missing, its position is assumed to be counterclockwise from the 1 at a distance equal to that between the 1 and 2.

Any straight edge may be used to divide the clock into eighths.

The scoring template shows the clock circle, already divided in to eighths.

A scoring template, drawn on a see-through sheet of plastic, is placed over the patient's drawing.

Alternatively, a scoring template drawn on paper, is placed under the patient's drawing so that the scoring template clock shows through the patient's drawing paper above it.

One point each is given for the numbers 1, 2, 4, 5, 7, 8, 10, and 11 if at least half the area of the number is in the proper octant of the circle relative to the number 12.

One point each is given for an obvious short hand pointing at the 11 and an obvious long hand pointing to the 2.

The difference in the length of the hands must be obvious at a glance.

A score of :

10 suggests that cognitive impairment (CI) is unlikely.

8 or 9 must be interpreted clinically.

<8 indicates CI

<5 indicates prominent impairment.

In medically stable patients, scores remain stable from one day to the next (Watson Y, 1993).

Scoring examples :

Applications

The CDT can used to supplement information obtained from other tests such as :

MMSE (Ferrucci L, 1996)
7 Minute Neurocognitive Screening Battery (Solomon PR, 1998)
Rey-Osterreith Comp[lex Figure (Osterreith P, 1994)
Symbol Digits Modalities test (Mendez MF, 1992)

The CDT has been used to :

establish problems with executive functions indicating the need for a formal driving evaluation (Freund B, 2005).
screen for executive control dysfunction in sub-cortical strokes or vascular pathology, as in hypertension or diabetes (Munshi M, 2006), and hypothyroidismy (Royall DR, 1998)
predictiion of post-operative delirium (Fisher BW, 1995)
prediction of functional outcome in hip fracture patients (Adunsky A, 2002)

Specific brain dysfunctions have been associated with specific CDT abnormalities :

ischemic vascular dementia (Libon DJ, 1996)
Huntington’s disease (Rouleau I, 1992)
correlation with gray matter volumes in the bilateral superior temporal regions (Heinik J, 2000)
thinning of the posterior cingulate and right middle frontal gyrus (Ahn HJ, 2011)
correlation with fronto-lobar dysfunction (Moretti R, 2002)
right parietal (Suhr J, 1998)
right posterior (Freedman M, 1994)
bilateral prefrontal (Salmon E, 2009)
temporal (Boxer AL,2003)
temporal-parietal (Forster S, 2009)
frontal (Teipel SJ,2006)

In Alzheimer's disease the CDT has been used to :

differentiate Alzheimers Disease from cerebral vascular disease (Heinik J, 2002)
track progression (Royall DR, 1998)
determine the degree to which executive function decline affects gait (Sheridan PL, 2003)

The CDT can be effectively administered to resistant and non-compliant older persons, (Freund B, 2005)

Strengths and weaknesses

The strength and weakness of the clock-drawing test lies in the number of cognitive, motor and perceptual functions required simultaneously for successful completion.

Successful completion of the task requires

visual memory (Colombo M, 2009)
visuo-spatial abilities (Nagahama Y, 2005).
orientation, conceptualization of time (Lam LWC, 1998)
executive function (Estaban-Santillan C, 1998).
auditory comprehension, motor programming, numerical knowledge, semantic instruction, inhibition of distracting stimuli, concentration and frustration tolerance (Shulman KI, 2000)

The executive function required for clock-drawing involves control functions shared by independent living skills.

The completely normal clock means that a number of functions are intact and suggests that the patient may be able to continue independently.

A grossly abnormal clock is an indicator of potential problems warranting further investigation or resource allocation (Royall DR, 1996) .

While the grossly abnormal clock demands immediate attention, questions regarding the importance of minor errors remain.

Serial clock drawing can be used to follow a progressive dementing process, or recovery from a toxic delirium (Shulman KI, 2000).

Minor clock errors are suggestive of a dementing process. They also highlight the placement of the arms as the most abstract feature of clock drawing, and therefore useful in early dementing processes (Estaban-Santillan C, 1998).

An advantage of the CDT over many other cognitive measures is its lack of reliance on verbal abilities, and in patients with aphasia or other loss of verbal expression. (Spreen O, 1998),

making it a useful screening tool for dementia in non-English speaking populations (Cacho J, 1996).

High intra- and inter-rater reliability has been demonastrated across clinicians and non-clinicians (Kozora E, 1994).