Barnes et al developed a tool that can help to identify a patient with mild cognitive impairment who may progress to Alzheimer’s disease. The study was performed by the Alzheimer’s Disease Neuroimaging Initiative.
Patient selection: mild cognitive impairment
Outcome: probable Alzheimer’s disease
Parameters:
(1) Functional Activities Questionnaire (FAQ) of Pfeffer et al (range 0 to 30)
(2) middle temporal cortical thickness in mm, based on quartiles
(3) hippocampal subcortical volume in cubic mm, based on quartiles
(4) Alzheimer’s Disease Assessment Scale (ASAS) cognitive subscale, total score (range 0 to 70)
(5) clock test score (range 0 to 5, 5 normal)
|
Parameter |
Finding |
Points |
|
FAQ |
0 |
|
|
|
1 or 6 |
2 |
|
|
7 to 30 |
3 |
|
middle temporal cortical thickness |
> 2.624 mm (highest 2 quartiles) |
0 |
|
|
<= 2.624 mm (lowest 2 quartiles) |
1 |
|
hippocampal subcortical volume |
> 3132.5 cubic mm (highest 2 quartiles) |
0 |
|
|
<= 3132.5 cubic mm (lowest 2 quartiles) |
1 |
|
ADAS cognitive score |
<= 14.33 (lowest quartile) |
0 |
|
|
14.34 to 18.67 |
2 |
|
|
>= 18.68 (highest 2 quartiles) |
3 |
|
clock test |
>= 4 |
0 |
|
|
< 4 |
1 |
where:
• For imaging studies there was overlap at breakpoints.
total score =
= SUM(points for all 5 parameters)
Interpretation:
• minimum score: 0
• maximum score: 9
• The higher the score the greater the risk of deterioration.
|
Score |
3-Year Conversion to Alzheimer’s Disease |
|
0 to 3 |
6% |
|
4 to 6 |
53% |
|
7 to 9 |
91% |
Performance:
• Harrell’s c was 0.78 (0.74 when corrected for optimism).
Specialty: Neurology
