Optic perineuritis in polyarthritis nodosa

Abstract

A 52-year-old male patient with polyarthritis nodosa (PAN) was referred to our neurology outpatient clinic. His main symptom was paroxysmal alternating bilateral blindness. Subsequently, he developed retro-orbital pain. Neurological examination including funduscopy was normal and laboratory tests showed no relevant abnormalities. MRI orbits showed remarkable perineural thickening and contrast enhancement of the optic nerve sheaths with sparing of the central optic nerve. These findings are pathognomonic for the clinical-radiological diagnosis of optic perineuritis (OPN). The patient was treated with high-dose immunosuppressants and had a good clinical outcome. Rapid diagnosis of OPN is important because early treatment is associated with a better outcome.

Keywords: neuro-opthalmology; neurology.

Figure 1

A 52-year-old man with optic perineuritis in polyarthritis nodosa. Coronal T2-weighted fat-saturated spin-echo MR image showing both normal optic nerves with left intraconal fat stranding.

Figure 2

A 52-year-old man with optic perineuritis (OPN) in polyarthritis nodosa (PAN). The upper left image shows an axial T1-weighted fat-saturated spin-echo MR image with gadolinium showing a normal left optic nerve intraconal fat stranding. The right upper image shows a sagittal T1-weighted fat-saturated spin-echo MR image with gadolinium with focal thickening and enhancement of the optic nerve sheath. Bottom left and right images: Coronal T1-weighted fat-saturated spin-echo MR with gadolinium showing focal enlargement and enhancement of the left optic nerve sheath (the ‘doughnut sign’) with intraconal fat stranding. Due to unfortunate angulation, the image of the right optic nerve is suboptimal; however, this optic nerve sheath appears to be normal.