Dr Hala Samir Sweed M.B.B.Ch, MSC, MD Consultant Geriatrician Associate Professor of Geriatrics and Gerontology Faculty of Medicine- Ain Shams University – EGYPT Member of IAGG

Clock drawing test (CDT) has well established correlations with other cognitive tests including the Mini Mental Status Exam (MMSE)

CDT has consistently shown general sensitivity rates of 81- 95%; an above-average percentage for cognitive screening tools

Schramm et al, 2002

Subjects with VaD have been found to executive functioning considerably more deteriorated than those with AD.

Inzitari & Pantoni , 1998

Examples of ECFs include goal selection, planning, motor sequencing, and selective attention. All are required by clock drawing.

Royall et al,1998

Thus, patients with VaD might be expected to have poorer performance in CDT. However, studies have shown controversy results ;

Wiechmann, et al, (2010)

Witoonpanich, et al, (2010)

Matioli and Caramelli, (2010)

Heinik, et al, (2002)

Moretti et al, (2002)

DT-MRI is a promising technique to explore the anatomical basis of human cognition and its disorders

Bozzali et al, (2002) Chen et al., (2009) Stahl et al, (2007) Sugihara et al, (2004) Kantarci et al, (2001)

CDT may correlate with radiographic findings of cerebral structures identified as having a role in executive function.

Samton et al, (2005)

Tranel et al, (2008)

To assess the clock drawing testing (CDT) and diffusion tensor magnetic resonance imaging (DT-MRI) differences between probable Alzheimer’s dementia (AD) and vascular dementia (VaD) and the CDT correlation with the DT-MRI .

Study Population

Elderly patients presenting at the Geriatric outpatient clinic

Study Duration;

6months

Tools of assessment

Full medical and personal history.

Functional assessment------------Activities of Daily Living questionnaire (ADL).

Mood assessment----------------

Geriatric depression scale 15 items (GDS-15).

Tools of assessment

Cognitive assessment------------

DSM-IV criteria

Mini-mental status examination (MMSE)

Hachinski ischemic index (HIS)

The Clock Drawing Test (CDT) (Shulman et al, 1993)

Tools of assessment

Laboratory investigations

DT- MRI------30 elderly

Apparent diffusion coefficient (ADC)

Fractional anisotropy (FA)

15 ROIs

92 elderly

89 elderly

completed the

study

58.4% females

(n=52/89)

41.6% males

(n=37/89)

3 excluded

Controls

n=49

Alzheimer's D

n= 25

Vascular Dementia

n=15

Age 64.94±4.77 74.40±4.71

*t=8.103 p=0.000

**t=1.572 p=0.124

72.10±4.25

*t=5.185 p=0.000

Gender F/ M 26/23

53.1%/ 46.9%

19/6

76%/ 24%

*X2=0.078 p=0.047

**X2=0.089 p=0.062

7/8

46.7%/ 53.3%

*X2=0.771 p=0.445

Years of Education 7.84± 4.79 7.76± 4.19

*t=0.068 p=0.946

**t=0.539 p=0.593

7.00± 4.54

*t=0.599 p=0.552

ADL

Dependent

Assisted

Independent

7 14.3%

11 22.4%

31 63.3%

7 28%

15 60%

3 12%

*X2=17.758 p=0.000

**X2=0.640 p=0.726

3 20%

9 60%

3 20%

*X2=9.469 p=0.009

Controls

n=49

Alzheimer's D

n= 25

Vascular Dementia

n=15

GDS 2.71±2.10 3.48± 2.31

*t=1.433 p=0.156

**t=0.592 p=0.558

3.93± 2.40

*t=1.901 p=0.062

MMSE 27.37±1.64 15.90±2.91

*t=21.765 p=0.000

**t=1.927 p=0.061

17.73±3.01

*t=16.057 p=0.000

Hachiniski score 2.04± 0.84

**t=25.300 p=0.000

9.00± 0.85

CDT 1.18±0.39 4.16±0.69

*t=23.757 p=0.000

**t=3.280 p=0.002

5.00±0.93

*t=23.152 p=0.000

Spacing error 5 20%

**X2=11.111 p=0.001

11 73.3%

A B Figure (1) showing CDT of two patients A (VaD) and B (AD) both

have a MMSE score of 21/30, with evidence of spacing error in VaD’s clock drawing.

Controls

n=10

Alzheimer's D

n= 10

Vascular Dementia

n=10

Age 70.20±5.73 71.60±3.06

*t=0.681 p=0.504

**t=0.278 p=0.784

72.00±3.37

*t=0.856 p=0.403

Gender F/ M 7/3

70%/ 30%

8/2

80%/ 20%

*X2=0.268 p=0.605

**X2=0.966 p=0.326

6/4

60%/ 40%

*X2=0.220 p=0.639

Years of Education 10.60± 5.08 7.70± 2.63

*t=1.603 p=0.126

**t=0.066 p=0.948

7.60± 4.00

*t=1.466 p=0.160

ADL

Dependent

Assisted

Independent

0 0%

1 10%

9 90%

4 40%

5 50%

1 10%

*X2=13.067 p=0.001

**X2=1.865 p=0.394

3 30%

7 70%

0 0%

*X2=16.500 p=0.000

Controls

n=10

Alzheimer's D

n= 10

Vascular Dementia

n=10

GDS 3.00±2.54 3.50± 2.79

*t=0.418 p=0.681

**t=0.173 p=0.0.865

3.30± 2.36

*t=0.274 p=0.787

MMSE 27.90±1.64 16.80±2.35

*t=13.320 p=0.000

**t=1.454 p=0.163

18.60±3.13

*t=8.766 p=0.000

Hachiniski score 1.90± 0.99

**t=18.515 p=0.000

8.80± 0.63

CDT 1.30±0.48 3.90±0.74

*t=9.303 p=0.000

**t=2.242 p=0.038

4.80±1.03

*t=9.707 p=0.000

Spacing error 2 20%

**X2=5.300 p=0.021

7 70%

Figure (2) showing the DTI-MRI cuts of 3 patients A) A subject with normal cognitive function, B) patient with propable AD and C) a patient with VaD. The ROI being placed at the medial temporal lobe and figures show high ADC and reduced FA in patients with dementia compared to the control.

Normal AD

Normal VaD

AD VaD

AD VaD

CDT differs among VaD and AD with a range of radiological correlations.

Larger studies are needed to confirm the use of CDT as a discriminative tool between VaD and AD.

DT-MRI is a sensitive and discriminative technique for the evaluation of patients with cognitive impairment including probable AD and VaD

Reference ranges need to be set through larger studies.