Analysis of cerebral structural changes in systemic lupus erythematosus by proton MR spectroscopy.
OBJECTIVE
To determine whether cerebral atrophy in systemic lupus erythematosus is associated with decreased levels of the neuronal marker N-acetyl-aspartic acid.


METHODS
Two groups of patients with systemic lupus erythematosus were studied, those with significant atrophy (n = 11) and those without significant atrophy (n = 10), using proton MR spectroscopy on a 1.5-T imaging unit. The solvent-suppressed, short-echo, volume-localized proton spectroscopy technique showed typical brain metabolites, including N-acetylaspartate, creatine/phosphocreatine, and choline-containing compounds.


RESULTS
The N-acetylaspartate-to-creatine/phosphocreatine ratio was smaller in those patients with significant cerebral atrophy (1.68 +/- 0.27) than in those patients with minimal or no atrophy (2.17 +/- .30). The degree of atrophy was negatively correlated with the N-acetylaspartate-to-creatine/phosphocreatine ratio. The choline-to-creatine/phosphocreatine ratio was not significantly altered in systemic lupus erythematosus patients with atrophy.


CONCLUSIONS
These data suggest that cerebral atrophy in systemic lupus erythematosus is associated with neuronal dropout (or damage), which results in decreased N-acetylaspartate ratios. A change in choline ratios is not implicated in the biochemical changes associated with cerebral atrophy. Proton MR spectroscopy may be useful in correlating brain metabolites with cerebral structural changes in patients with autoimmune diseases.
Sibbitt
W L
WL
Center for Non-Invasive Diagnosis, University of New Mexico School of Medicine, Albuquerque 87131.
Haseler
L J
LJ
Griffey
R H
RH
Hart
B L
BL
Sibbitt
R R
RR
Matwiyoff
N A
NA
D000293:Adolescent; D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001284:Atrophy; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010725:Phosphocreatine / Q000378:metabolism
D010725:Phosphocreatine; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline