Brain magnetic resonance imaging findings in relapsing neuromyelitis optica.

BACKGROUND

Some studies showed abnormalities in brain magnetic resonance imaging (MRI) of relapsing neuromyelitis optica (R-NMO) from 12 to 46%. These abnormalities are described as compatible/non-compatible with multiple sclerosis (MS).

OBJECTIVE

To describe the abnormal brain MRI lesions in R-NMO with imaging studies conducted with more sensitive white matter change techniques.

METHODS

Thirty patients with R-NMO were selected. All MRI brain studies were performed with a 1.5-T Siemens MRI system according to the Standardized MR Imaging Protocol for Multiple Sclerosis from the Consortium of MS Centers Consensus Guidelines.

RESULTS

Brain MRI images were evaluated in 29 R-NMO cases because in one case the MRI images were not appropriate for the study. Of these 29 brain MRI studies, 19 cases (65.5%) had at least one or more lesions (1-57) and 10 were negative (34.4%). Brain MRI findings in 19 cases were characterized in T2/fluid-attenuated inversion-recovery (FLAIR) by the presence of subcortical/deep white matter lesions in 16 (84.2%) cases (1-50), most of them <3 mm and without juxtacortical localization. Periventricular lesions were observed in 13 (68.4%) cases, but morphologically they were not oval, ovoid or perpendicularly orientated. Infratentorial lesions, all >3 mm, were observed in 4 (21.05%) cases without cerebellar involvement. T1 studies demonstrated absence of hypointense regions. Optic nerve enhancement was observed in 6/19 patients (31.5%). None of the brain MRI abnormalities observed were compatible with Barkhof et al. criteria of MS.

CONCLUSIONS

This study, based on a Cuban patient population, with long duration of disease, good sample size and detailed characterization by MRI, demonstrated the brain MRI pattern of R-NMO patients, which is different from MS.