Diffuse white matter damage is absent in neuromyelitis optica.
OBJECTIVE
Neuromyelitis optica (NMO) is an idiopathic mostly relapsing inflammatory disease with attacks on the optic nerves and spinal cord. Whether NMO is a separate disease or a subtype of classic multiple sclerosis (MS) is unclear. Clinically, CSF and MR imaging parameters and histopathologic data suggest that the normal-appearing white matter (NAWM) may be affected in MS but not in patients with NMO. Therefore, we hypothesized that the NAWM in NMO is normal.


METHODS
We studied prospectively 8 patients with clinically definitive NMO or remitting longitudinal extensive transverse myelitis (LETM) and 8 healthy controls. Ratios of N-acetylaspartate to creatine (Cr) and choline to Cr and the absolute concentrations of the metabolites were measured by chemical shift imaging with a (1)H-MR spectroscopy operating at 3T. All patients with clinically definitive NMO and LETM were found to be positive for NMO-immunoglobin G with a commercially available test.


RESULTS
The metabolic pattern of the NAWM of patients with NMO showed no difference compared with age- and sex-matched healthy controls.


CONCLUSIONS
Diffuse white matter damage is absent in NMO.
Aboul-Enein
F
F
Department of Neurology, SMZ-Ost Donauspital, Vienna, Austria. fahmy.aboul-enein@chello.at
Krssák
M
M
Höftberger
R
R
Prayer
D
D
Kristoferitsch
W
W
D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000175:diagnosis*; D011446:Prospective Studies; D055815:Young Adult