A multicenter (1)H-MRS study of the medial temporal lobe in AD and MCI.
OBJECTIVE
The need for biological markers of Alzheimer disease (AD) is constantly increasing. Proton magnetic resonance spectroscopy ((1)H-MRS) studies have provided consistent evidence for a reduction of the neuronal marker N-acetylaspartate (NAA) in patients with AD. Within the German Competence Network on Dementia, we conducted a (1)H-MRS study in patients with mild dementia and mild cognitive impairment (MCI) at four sites to investigate the multicenter feasibility of (1)H-MRS.


METHODS
In total, 130 patients with dementia (98 AD, 32 non-AD), 136 subjects with MCI (70 of AD type, 66 of non-AD type), and 45 unimpaired control subjects were included. Single-volume (1)H-MRS of the left medial temporal lobe was performed at long and short echo times. Metabolites were quantified and metabolic ratios were determined.


RESULTS
We found a significant reduction of NAA concentration in patients with AD as compared to healthy volunteers and compared to patients with MCI of AD type. NAA/Cr (creatine/phosphocreatine) was also lower in patients with AD compared to control subjects. NAA, choline compounds, and Cr were lower in patients with AD compared to patients with non-AD dementia.


CONCLUSIONS
We demonstrated the multicenter feasibility of proton magnetic resonance spectroscopy ((1)H-MRS) of the medial temporal lobe in mild dementia and mild cognitive impairment, which is a prerequisite for the application of (1)H-MRS in large-scale clinical trials. Since the concentration measures of the metabolites are adjusted for brain tissue volume, these findings are indicators of biochemical pathology beyond brain atrophy.
Jessen
F
F
Department of Psychiatry, University of Bonn, Germany. Jessen@uni-bonn.de
Gür
O
O
Block
W
W
Ende
G
G
Frölich
L
L
Hammen
T
T
Wiltfang
J
J
Kucinski
T
T
Jahn
H
H
Heun
R
R
Maier
W
W
Kölsch
H
H
Kornhuber
J
J
Träber
F
F
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D003072:Cognition Disorders / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000378:metabolism / Q000473:pathology*
D015415:Biomarkers; D001224:Aspartic Acid; C000179:N-acetylaspartate