Quantitative MRI analysis of the brain after twenty-two years of neuromyelitis optica indicates focal tissue damage.
BACKGROUND
The long-term effect of neuromyelitis optica (NMO) on the brain is not well established.


METHODS
After 22 years of NMO, a patient's brain was examined by quantitative T1- and T2-weighted mono- and biexponential diffusion and proton spectroscopy. It was compared to 3 cases with short-term NMO and 20 healthy subjects.


RESULTS
Although routine T1- and T2-weighted images appeared to be normal, quantitative T1-, T2- and diffusion-weighted magnetic resonance imaging identified areas with high diffusivity and altered relaxation time in 'normal appearing white matter' (NAWM). In such abnormal NAWM regions, biexponential diffusion analysis and quantitative spectroscopy indicated extracellular edema and axonal loss, respectively. Repeated analysis 6 months later identified the same alterations. Such patchy alterations were not detectable in the NAWM of the 3 cases with short-term NMO, and they were also not quantitatively different from the controls.


CONCLUSIONS
After NMO of 22-year duration, metabolic changes, altered diffusivity and magnetic resonance relaxation features of patchy brain areas may suggest tissue damage in NAWM that persist for at least 6 months.
Diagnostic Center of Pecs, University of Pecs, Pecs, Hungary.
Mihaly
M
Aradi
Edit
E
Koszegi
Gergely
G
Orsi
Gabor
G
Perlaki
Anita
A
Trauninger
Arnold
A
Toth
Attila
A
Schwarcz
Zsolt
Z
Illes
D000328:Adult; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009471:Neuromyelitis Optica / Q000175:diagnosis*; D011522:Protons; D013057:Spectrum Analysis; D055815:Young Adult
D011522:Protons