Table 1.

Comparative chart of optic nerve (ON) MRI in inflammatory demyelinating diseases (IDDs) of the CNS. AQP4-NMOSD: Aquaporin 4-antibody Associated neuromyelitis optica spectrum disorder; LEON: longitudinally extensive optic neuritis; MOG-ON: myelin oligodendrocyte glycoprotein antibody associated optic neuritis.

MRI	MS	AQP4-NMOSD	MOG-NMOSD
Optic nerve (Range) [74,76,77]	Unilateral Short segment 13 mm (8–36 mm) Median # segments: 1 (1–4 mm)	Bilateral LEON, median length 26 mm (range 14–46 mm) Three segments (1–8) Posterior predominance with chiasma and optic tract involvement Milder swelling than MOG-ON Rare twisting	Bilateral LEON Anterior predominance Perineural sheath swelling Tilting & twisting of the optic nerve