Optic chiasm involvement in AQP-4 antibody–positive NMO and MOG antibody–associated disorder

Background: Optic neuritis (ON) is often the presenting symptom in inflammatory central nervous system demyelinating disorders. Objective: To compare the frequency and pattern of optic chiasm involvement in patients with aquaporin-4-immunoglobulin G (AQP4-IgG)-associated ON to patients with myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG)-associated ON. Methods: Retrospective review of all patients evaluated at Mayo Clinic, Stanford University and Ramathibodi Hospital who were found to have: (1) ON, (2) either MOG-IgG or AQP4-IgG by cell-based assay, and (3) magnetic resonance imaging (MRI) at the time of ON. MRI was reviewed for contrast enhancement of the optic chiasm and the pattern of involvement. Results: One hundred and fifty-four patients (74 AQP4-IgG and 80 MOG-IgG) were included. Among patients with AQP4-IgG-ON, 20% had chiasmal involvement, compared with 16% of patients with MOG-IgG-ON ( p = 0.66). In patients with chiasmal involvement, longitudinally extensive optic nerve enhancement (from orbit extending to chiasm) was identified in 54% of MOG-IgG-ON patients, compared with 7% of AQP4-IgG-ON patients ( p = 0.01). Conclusion: Chiasmal involvement of MOG-IgG-ON and AQP4-IgG-ON occur at more similar frequencies than previously reported. Furthermore, MOG-IgG-ON chiasmal involvement is more likely to be part of a longitudinally extensive optic nerve lesion.

Asymptomatic optic nerve lesions

ObjectiveTo evaluate the frequency of asymptomatic optic nerve lesions and their role in the asymptomatic retinal neuroaxonal loss observed in multiple sclerosis (MS).MethodsWe included patients with remitting-relapsing MS in the VWIMS study (Analysis of Neurodegenerative Process Within Visual Ways In Multiple Sclerosis) (ClinicalTrials.gov Identifier: 03656055). Included patients underwent optical coherence tomography (OCT), optic nerve and brain MRI, and low-contrast visual acuity measurement. In eyes of patients with MS without optic neuritis (MS-NON), an optic nerve lesion on MRI (3D double inversion recovery [DIR] sequence) was considered as an asymptomatic lesion. We considered the following OCT/MRI measures: peripapillary retinal nerve fiber layer thickness, macular ganglion cell + inner plexiform layer (mGCIPL) volumes, optic nerve lesion length, T2 lesion burden, and fractional anisotropy within optic radiations.ResultsAn optic nerve lesion was detected in half of MS-NON eyes. Compared to optic nerves without any lesion and independently of the optic radiation lesions, the asymptomatic lesions were associated with thinner inner retinal layers (p < 0.0001) and a lower contrast visual acuity (p ≤ 0.003). Within eyes with asymptomatic optic nerve lesions, optic nerve lesion length was the only MRI measure significantly associated with retinal neuroaxonal loss (p < 0.03). Intereye mGCIPL thickness difference (IETD) was lower in patients with bilateral optic nerve DIR hypersignal compared to patients with unilateral hypersignal (p = 0.0317). For the diagnosis of history of optic neuritis, sensitivity of 3D DIR and of mGCIPL IETD were 84.9% and 63.5%, respectively.ConclusionsAsymptomatic optic nerve lesions are an underestimated and preponderant cause of retinal neuroaxonal loss in MS. 3D DIR sequence may be more sensitive than IETD measured by OCT for the detection of optic nerve lesions.

Lesions of the nervous system associated with relapsing polychondritis

Three clinical cases are described including two of relapsing polychondritis with lesions in the central and peripheral nervous system (one of long-standing aseptic lymphocytic meningitis and one of cranial neuropathy of 2, 5, 7, and 8 pairs) and the third case of the optic nerve lesion with amblyopia. The two former cases were successfully treated with high doses of corticosteroids, the third one with moderate doses of the same medications. The data from the current literature concerning variants of clinical manifestations, methods for diagnostics and treatment of neurologic manifestations of relapsing polychondritis are discussed.