Evidence of biochemical and biomagnetic interactions in Alzheimer's disease: an MEG and MR spectroscopy study.
BACKGROUND
Several neuroimaging studies have shown reliable differences between Alzheimer's disease (AD) patients and age-matched controls. However, few studies have demonstrated the interactions between neuroimaging methods for the diagnoses of AD.


OBJECTIVE
In this study, we try to elucidate the complementary nature of magnetoencephalography (MEG) and magnetic resonance spectroscopy (MRS) examinations in the assessmentof AD.


METHODS
Ten patients fulfilling the NINCDS-ADRDA criteria of probable AD, and 10 elderly individuals with no history of neurological or psychiatric illness serving as age-matched controls participated in the study. All patients and controls received an MRS, MEG and neuropsychological assessment. MEG data were obtained in the context of a working memory task, previously utilized in a similar sample of patients.


RESULTS
The AD group showed a reduced number of activity sources over left temporoparietal areas during the late portion of the evoked magnetic field (between 400-800 ms), as well as a bilateral temporoparietal increase in creatine and myoinositol concentrations, and in the myoinositol/N-acetyl-aspartate ratio. The combination of the variables 'number of dipoles during the late portion of the evoked magnetic field' and 'myoinositol/N-acetyl-aspartate ratio' accounted for 65% of the variance of the Mini Mental State Examination scores.


CONCLUSIONS
These results highlight the importance of assessing the complex brain pathology underlying AD by utilizing multiple brain examination modalities in a coordinate approach.
Maestú
F
F
Centro de Magnetoencefalografía, Facultad de Biología, Universidad Complutense, Madrid, España. cmeg@rect.ucm.es
García-Segura
J
J
Ortiz
T
T
Montoya
J
J
Fernández
A
A
Gil-Gregorio
P
P
Campo
P
P
Fernández
S
S
Viaño
J
J
Portera
A
A
D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism* / Q000503:physiopathology* / Q000523:psychology; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D015415:Biomarkers; D001923:Brain Chemistry / Q000502:physiology; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D007294:Inositol / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D015225:Magnetoencephalography; D008297:Male; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology
D015415:Biomarkers; D001224:Aspartic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003401:Creatine