Serial proton MR spectroscopy of contrast-enhancing multiple sclerosis plaques: absolute metabolic values over 2 years during a clinical pharmacological study.
OBJECTIVE
The time courses of total creatine (Cr), N-acetylaspartate (NAA), choline (Cho), and myo-inositol have not previously been investigated in the follow-up of contrast-enhancing multiple sclerosis (MS) plaques. Therefore, over a period of 2 years, we compared the absolute concentrations of these metabolites between patients treated with a placebo or 15 +/- deoxyspergualin (DSG) and between clinical groups with relapsing-remitting or secondary-progressive MS.


METHODS
Sixteen patients, recruited from a pharmacological study of DSG, and 11 healthy control subjects were investigated by a stimulated-echo acquisition mode sequence (TR/TE = 3000/20). The selected volume initially contained a contrast-enhancing plaque, which was followed up for a period of 2 years.


RESULTS
In contrast-enhancing plaques, Cho was significantly elevated and showed a significant reduction after both 3 and 12 months. The initially normal Cr significantly increased between 3 and 12 months, and was negatively correlated with plaque volume on T1-weighted MR images. NAA initially showed normal values, a significant decrease at 1 month, and a slow recovery over 2 years. Myo-inositol did not show a clear tendency. The placebo group did not differ from the treated group, nor did the relapsing-remitting group differ from the secondary-progressive group.


CONCLUSIONS
The contradictory time courses of Cr and NAA show that an absolute quantification in proton MR spectroscopy in MS is necessary to avoid a false interpretation of reduced NAA/Cr ratios. The increase in Cr is probably due to remyelination. The initial dip and later recovery of NAA seem to be related to diminishing edema and remyelination.
Mader
I
I
Department of Neuroradiology, University Hospital, Tübingen, Germany.
Roser
W
W
Kappos
L
L
Hagberg
G
G
Seelig
J
J
Radue
E W
EW
Steinbrich
W
W
D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001921:Brain / Q000473:pathology; D002794:Choline / Q000032:analysis; D003401:Creatine / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D006146:Guanidines / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007089:Image Enhancement; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D007294:Inositol / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000175:diagnosis / Q000188:drug therapy*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis / Q000188:drug therapy*
D006146:Guanidines; D007166:Immunosuppressive Agents; D001224:Aspartic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline; C037258:gusperimus