CDT neuro psychological test

1. CLOCK DRAWING
TEST
MADE BY :
Dr. KHANSA HAQ NAWAZ & IQRA AZAM

2. DEVELOPMENT
CDT

3. HISTORY
• MacDonald Critchley's well-known textbook from 1953,
The Parietal Lobes, is often cited as the first mention of the
CDT, its recorded use actually stretches back more than a
century to 1915. A review of the literature shows that the
CDT began as a test for aphasia-related disorders and
constructional apraxia until its entry into contemporary
cognitive screening in the 1980s when it primarily became a
cognitive screen. Its usage took off in 1989 with over 2000
publications since.

4. HISTORY(CONT...)
• Clock Drawing Test performance was originally used as an
indicator of constructional apraxia. During World War II, it
was employed in studies of soldiers who were victims of head
trauma and had possible focal lesions in the occipital and
parietal lobes. Goodglass and Kaplan conducted the first
systematic study of the CDT as part of the Boston Aphasia
Battery.

5. OBJECTIVE
• The Clock drawing test (CDT) is a brief cognitive task that
can be used by physicians who suspect neurological
dysfunction based on history and physical examination.
• The Clock Drawing Test (CDT) is a simple neuropsychological
screening instrument that is well accepted by
• patients and has solid psychometric properties. Several
different CDT scoring methods have been developed, but no
• consensus has been reached regarding which scoring method
is the most accurate.

6. ADMINISTRATION
• The procedure of the CDT begins with the instruction to the
participant to draw a clock reading a specific time (generally
11:10).

7. INSTRUCTIONS
Draw an analogue clock on the pre- draw circle page.
Instructor repeat instructions again and again.
Patient is allow to take as much time he needs to complete.

8. INTERPRETATION
• There are several types of scoring the clock drawing test,
they are qualitative and semi quantitative.
• such as:
• Watson et al.
• Shulman et al.
• Sunderland et al. etc

9. SUNDERLAND ET AL
SCORING METHOD

10. SCORING METHOD
• Sunderland et al. 1989 A PRIORI
• criteria for evaluating clock drawings.
• Cut off score = 5 or less indicates impairment.

11. SCORING METHOD
• 10 - 6 Drawing of clock face with number and circle
generally intact
• 10 Hands in correct position (i.e. Hours hand approaching 3
o'clock)
• 9 Slight errors in placement of hands.
• 8 More noticeable errors in placement of hour and minute
hands.

12. SCORING METHOD
• 7 Placement of hands is significantly off course.
• 6 Inappropriate use of clock hands (i.e. use of digital display
or circling numbers despite repeated instructions).

13. SCORING METHOD
• 5 - 1 Drawing of clock face with circle and numbers is NOT
intact.
• 5 Crowding of numbers at one end of the clock or reversal of
numbers. Hands may still be present in some fashion.
• 4 Further distortion of number sequence. Integrity of clock
face is now gone (i.e. numbers missing or placed outside of
boundaries of the clock face).

14. SCORING METHOD
• 3 Numbers and clock face no longer obviously connected in
the clock drawing. Hands are not present.
• 2 Drawing reveals some evidence of instructions being
received but only vague representation of a clock.
• 1 Either no attempt or an uninterpretable Effort Is made.

15. BENIFITES OF THE CDT
• The way a client draws a clock face can provide an assessor
with insight into the severity of dementia and it only takes
two minutes to administer.
• It is also appropriate in multiethnic populations due to the
‘universal’ nature of the clock.
• The CDT can complement other screening tests, especially
those, which do not include an item to assess frontal lobe
impairment.

16. CRITICISM
• The properties of any screening test should not only include
ease of administration and acceptability but ease of scoring
and, if used sensibly as a first stage in disease identification,
there should be a high sensitivity and positive predictive
value. Specificity and negative predictive value are less
important in this respect, unless the screening method is
itself lengthy, aversive or expensive, none of which apply to
any of the forms of the CDT.

17. CRITICISM
• It seems to this reviewer that, while the CDT is often
proposed as a means of identifying patients with early stages
of dementia who might benefit from specific treatment, it
has largely been validated in groups of patients with
established diagnoses. Or worse still, validated in patients
whose ‘dementia’ is only established by scores on other
screening tests.

18. REFERENCES
• Rouleau I, Salmon DP, Butters N, Kennedy KC, McGuire K.
Quantitative and qualitative analyses of clock drawings in
Alzheimer’s and Huntington’s disease. Brain Cogn. 1992;18:70-
87.
• Freedman M, Leach L, Kaplan E, Winocur G, Shulman KI, Delis
CD. Clock Drawing: a neuropsychological analysis. New York:
Oxford University Press;1994.
• Shulman KI. Clock-drawing: is it the ideal cognitive screening test?
Int J Geriatr Psychiatry. 2000;15:548-61.
• Aprahamian I. O Teste do Desenho do Relógio no rastreio
diagnóstico