Serial MRI and CSF biomarkers in normal aging, MCI, and AD.
OBJECTIVE
To compare the annual change in MRI and CSF biomarkers in cognitively normal (CN), amnestic mild cognitive impairment (aMCI), and Alzheimer disease (AD). Comparisons were based on intergroup discrimination, correlation with concurrent cognitive/functional changes, relationships to APOE genotype, and sample sizes for clinical trials.


METHODS
We used data from the Alzheimer's Disease Neuroimaging Initiative study consisting of CN, aMCI, and AD cohorts with both baseline and 12-month follow-up CSF and MRI. The annual change in CSF (total-tau [t-tau], Abeta(1-42)) and MRI (change in ventricular volume) was obtained in 312 subjects (92 CN, 149 aMCI, 71 AD).


RESULTS
There was no significant average annual change in either CSF biomarker in any clinical group except t-tau in CN; moreover, the annual change did not differ by clinical group in pairwise comparisons. In contrast, annual increase in ventricular volume increased in the following order, AD > aMCI > CN, and differences were significant between all clinical groups in pairwise comparisons. Ventricular volume increase correlated with concurrent worsening on cognitive/functional indices in aMCI and AD whereas evidence of a similar correlation with change in CSF measures was unclear. The annual changes in MRI differed by APOE epsilon4 status overall and among aMCI while annual changes in CSF biomarkers did not. Estimated sample sizes for clinical trials are notably less for MRI than the CSF or clinical measures.


CONCLUSIONS
Unlike the CSF biomarkers evaluated, changes in serial structural MRI are correlated with concurrent change on general cognitive and functional indices in impaired subjects, track with clinical disease stage, and are influenced by APOE genotype.
Vemuri
P
P
Aging and Dementia Imaging Research Laboratory, Department of Radiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
Wiste
H J
HJ
Weigand
S D
SD
Knopman
D S
DS
Trojanowski
J Q
JQ
Shaw
L M
LM
Bernstein
M A
MA
Aisen
P S
PS
Weiner
M
M
Petersen
R C
RC
Jack
C R
CR
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000134:cerebrospinal fluid* / Q000235:genetics / Q000473:pathology; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000235:genetics / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D001057:Apolipoproteins E / Q000235:genetics; D015415:Biomarkers / Q000134:cerebrospinal fluid; D001921:Brain / Q000473:pathology*; D003072:Cognition Disorders / Q000134:cerebrospinal fluid* / Q000235:genetics / Q000473:pathology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D012016:Reference Values; D012044:Regression Analysis; D012720:Severity of Illness Index; D016875:tau Proteins / Q000134:cerebrospinal fluid*
D016229:Amyloid beta-Peptides; D001057:Apolipoproteins E; D015415:Biomarkers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins