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

Abstract

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.

Chiasmatic lesions on conventional magnetic resonance imaging during the first event of optic neuritis in patients with neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein‐associated disease in a Latin American cohort

“…Previous studies [19][20][21][22][23]30] reported posterior lesions in between 35% and 80% of the studied cases. Furthermore, longitudinally extensive optic nerve involvement was reported in 13%-100% [19][20][21][22][23] of NMOSD-ON patients.…”

“…Additionally, MRI is crucial to exclude differential diagnoses as well as for the evaluation of inflammatory lesions during follow-up [17]. While brain MRI lesions in both NMOSD and MOGAD have been described [9][10][11][12][13][14][15][16][17][18], only a few previous studies have evaluated the radiological features of NMOSD-ON versus MOGAD-ON, focusing on optic chiasm involvement [19][20][21][22][23].…”

“…By contrast, MOGAD-ON is associated with the optic nerve sheath or extends into the orbital fat with gadoliniumenhancing lesions more than half of the length of the optic nerve in 80% of patients [19,24]. Optic chiasm lesions on MRI have been reported in up to 64% of NMOSD-ON patients seropositive for AQP4-ab, while in MOGAD-ON they were reported in up to 16% [19][20][21][22][23]. Thus, frequency rates vary widely between distinct populations worldwide.…”

Optic Neuritis in the Era of NMOSD and MOGAD: A Survey of Practice Patterns in Singapore

“…97 In the brain, there can be poorly demarcated "fluffy" deep white matter, juxtacortical, brainstem or cerebellar peduncle lesions. 38,61,62 A recent study by Tajfirouz et al 98 comparing 74 NMOSD and 80 MOGAD patients reported chiasmal involvement in 20% and 16% respectively (P ¼ 0.66). Chiasmal involvement in MOGAD was also more likely to be part of a longitudinally extensive optic nerve lesion.…”

Increasing role of imaging in differentiating MS from non-MS and defining indeterminate borderline cases

“…In MOGAD, long lesions have a tendency to affect the anterior segment of the nerve and co-occur with optic nerve swelling on fundoscopy, while AQP4-Ab optic neuritis has a predilection for posterior segments and the optic chiasm [40,44]. Optic chiasm lesions also occur in MOGAD where they are usually a part of the longitudinally extensive involvement of the whole nerve starting www.journals.viamedica.pl/neurologia_neurochirurgia_polska in the orbit [46]. Longitudinally extensive lesions of the optic nerve are rare in MS [47,48].…”