Bilateral optic nerve, chiasmal enhancement may indicate neuromyelitis optica

This retrospective review of magnetic resonance images from six patients with neuromyelitis optica and 11 patients with multiple sclerosis found a trend toward more posterior involvement of the optic nerve in the patients with neuromyelitis optica, with chiasmatic enhancement exclusively seen in these patients.

The authors know of no prior systematic comparison of imaging of acute optic neuritis in securely diagnosed neuromyelitis optica versus multiple sclerosis.

No significant differences were observed in the presence, degree, or type of signal alteration and contrast enhancement of the affected nerve segments between neuromyelitis optica and multiple sclerosis patients.

Since previous research indicates that simultaneous bilateral disease is rare in multiple sclerosis and due to the findings of the current study, the authors suggest that simultaneous bilateral optic nerve enhancement or chiasmal enhancement on MRI in a monocularly symptomatic patient should warrant careful evaluation for neuromyelitis optica.