Barnes et al developed a tool for predicting progression from mild cognitive impairment to probably Alzheimer's disease. This can help to identify a patient who may benefit from an intervention. The authors are from the University of California San Francisco, the Jewish Home of San Francisco and the Alzheimer's Disease Neuroimaging Initiative.
Patient selection: adult with mild cognitive impairment
Outcome: probable Alzheimer's disease
Parameters:
(1) Functional Assessment Questionnaire (FAQ, 0 to 30 with higher scores associated with greater functional impairment)
(2) middle temporal cortical thickness on MRI scan in mm
(3) hippocampal subcortical volume on MRI scan in cubic millimeters
(4) Alzheimer's disease assessment scale (ADAS) cortical subscale (0 to 70 with higher scores indicating worse cognitive function)
(5) clock drawing test (0 to 5, with 5 normal)
|
Parameter |
Finding |
Points |
|
FAQ |
0 |
0 |
|
|
1 to 6 |
2 |
|
|
>= 7 |
3 |
|
middle temporal cortical thickness |
> 2.624 mm |
0 |
|
|
<= 2.624 mm |
1 |
|
hippocampal subcortical volume |
>= 3132.5 cu mm |
0 |
|
|
< 3132.5 cu mm |
1 |
|
ADAS cognitive |
< 14.33 |
0 |
|
|
14.33 to 18.67 |
2 |
|
|
> 18.67 |
3 |
|
clock test |
4 or 5 |
0 |
|
|
0 to 3 |
1 |
total score =
= SUM(points for all 5 parameters)
Interpretation:
• minimum score: 0
• maximum score: 9
• The higher the score the greater the risk of progression to probably Alzheimer's disease.
|
Total Score |
Risk |
Percent (3 Years) |
|
0 to 3 |
low |
6% |
|
4 to 6 |
moderate |
53% |
|
7 to 9 |
high |
91% |
Performance:
• Diagnostic accuracy was measured with Harrell's c = 0.78.
Specialty: Neurology
