Clinical and radiologic approach to 'typical' versus antibody-related optic neuritis

Optic chiasm involvement in multiple sclerosis, aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein-associated disease

BACKGROUND

Optic neuritis (ON) is a common feature of inflammatory demyelinating diseases (IDDs) such as multiple sclerosis (MS), aquaporin 4-antibody neuromyelitis optica spectrum disorder (AQP4 + NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). However, the involvement of the optic chiasm (OC) in IDD has not been fully investigated.

AIMS

To examine OC differences in non-acute IDD patients with (ON+) and without ON (ON-) using magnetisation transfer ratio (MTR), to compare differences between MS, AQP4 + NMOSD and MOGAD and understand their associations with other neuro-ophthalmological markers.

METHODS

Twenty-eight relapsing-remitting multiple sclerosis (RRMS), 24 AQP4 + NMOSD, 28 MOGAD patients and 32 healthy controls (HCs) underwent clinical evaluation, MRI and optical coherence tomography (OCT) scan. Multivariable linear regression models were applied.

RESULTS

ON + IDD patients showed lower OC MTR than HCs (28.87 ± 4.58 vs 31.65 ± 4.93; p = 0.004). When compared with HCs, lower OC MTR was found in ON + AQP4 + NMOSD (28.55 ± 4.18 vs 31.65 ± 4.93; p = 0.020) and MOGAD (28.73 ± 4.99 vs 31.65 ± 4.93; p = 0.007) and in ON- AQP4 + NMOSD (28.37 ± 7.27 vs 31.65 ± 4.93; p = 0.035). ON+ RRMS had lower MTR than ON- RRMS (28.87 ± 4.58 vs 30.99 ± 4.76; p = 0.038). Lower OC MTR was associated with higher number of ON (regression coefficient (RC) = -1.15, 95% confidence interval (CI) = -1.819 to -0.490, p = 0.001), worse visual acuity (RC = -0.026, 95% CI = -0.041 to -0.011, p = 0.001) and lower peripapillary retinal nerve fibre layer (pRNFL) thickness (RC = 1.129, 95% CI = 0.199 to 2.059, p = 0.018) when considering the whole IDD group.

CONCLUSION

OC microstructural damage indicates prior ON in IDD and is linked to reduced vision and thinner pRNFL.

The Treatment of Acute Optic Neuritis

Despite the high incidence of optic neuritis (ON), and the growing number of therapeutic options for the long-term treatment of diseases associated with ON including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody associated disease (MOGAD), there are still only limited therapeutic options for treating an acute event of optic neuritis. These include steroids, plasma exchange (PLEX) and intravenous immunoglobulin (IVIG). High-dose steroids remain the mainstay of acute treatment. However, evidence is emerging that when optic neuritis is accompanied with certain atypical features that suggest a more unfavorable outcome this mandates special consideration such as early addition of other therapeutic agents or tapering the steroid very slowly. This review will distinguish between typical and atypical neuritis and discuss acute treatment options.

[Neurological involvement of sarcoidosis: current diagnostic and therapeutic strategies]

Neurosarcoidosis (NS) is a rare but severe form of sarcoidosis. NS is associated with significant morbidity and mortality. Mortality is about 10% at 10 years with more than 30% of patients who have a significant disability. The most frequent features are cranial neuropathy (the facial and optic nerve most commonly affected), cranial parenchymal lesions, meningitis, spinal corn abnormalities (20-30%) and more rarely peripheral neuropathy (approximately 10-15%). The challenge of diagnosis is to eliminate other diagnoses. Atypical presentations should make to discuss the need for cerebral biopsy in order to highlight the presence of granulomatous lesions while eliminating alternative diagnosis. Therapeutic management is based on corticosteroid therapy and immunomodulators. There are no comparative prospective study to allow us to define the first-line immunosuppressive treatment and the therapeutic strategy in refractory patients. Conventional immunosuppressants such as methotrexate, mycophenolate mofetil and cyclophosphamide are commonly used. Data on the efficacy of anti-TNFα (including infliximab) in refractory and/or severe forms are increasing during the last ten years. Additional data is necessary to assess their interest in first line in patients with severe involvement and a significant risk of relapse.

Should Aquaporin-4 Antibody Test Be Performed in all Patients With Isolated Optic Neuritis?

BACKGROUND

Optic neuritis (ON) may be the initial manifestation of neuromyelitis optica spectrum disorder (NMOSD). Aquaporin-4 antibody (AQP4 Ab) is used to diagnose NMOSD. This has implications on prognosis and is important for optimal management. We aim to evaluate if clinical features can distinguish AQP4 Ab seropositive and seronegative ON patients.

METHODS

We reviewed patients with first episode of isolated ON from Tan Tock Seng Hospital and Singapore National Eye Centre who tested for AQP4 Ab from 2008 to 2017. Demographic and clinical data were compared between seropositive and seronegative patients.

RESULTS

Among 106 patients (120 eyes) with first episode of isolated ON, 23 (26 eyes; 22%) were AQP4 Ab positive and 83 (94 eyes; 78%) were AQP4 Ab negative. At presentation, AQP4 Ab positive patients had older mean onset age (47.9 ± 13.6 vs 36.8 ± 12.6 years, P < 0.001), worse nadir VA (OR 1.714; 95% CI, 1.36 to 2.16; P < 0.001), less optic disc swelling (OR 5.04; 95% CI, 1.682 to 15.073; p = 0.004), and higher proportions of concomitant anti-Ro antibody (17% vs 4%, p = 0.038) and anti-La antibody (17% vs 1%, p = 0.008). More AQP4 Ab positive patients received steroid-sparing immunosuppressants (74% vs 19%, p < 0.001) and plasma exchange (13% vs 0%, p = 0.009). AQP4 Ab positive patients had worse mean logMAR VA (visual acuity) at 12 months (0.70 ± 0.3 vs 0.29 ± 0.5, p = 0.051) and 36 months (0.37±0.4 vs 0.14 ± 0.2, p = 0.048) follow-up.

CONCLUSION

Other than older onset age and retrobulbar optic neuritis, clinical features are non-discriminatory for NMOSD. We propose a low threshold for AQP4 Ab serology testing in inflammatory ON patients, particularly in high NMOSD prevalence populations, to minimize diagnostic and treatment delays.

Clinical and diagnostic spectrum of optic neuritis: A single-center retrospective study of disorders associated with multiple sclerosis, anti-aquaporin-4 and anti-myelin oligodendrocyte glycoprotein antibodies

OBJECTIVE

Optic neuritis (ON) is an immune-mediated optic neuropathy associated with multiple immune-mediated neurological conditions. Our aim was to characterize the clinical and diagnostic features of first or initial episodes of ON associated with multiple sclerosis (MS)-associated (typical) and antibody-related (atypical) ON.

METHODS

Retrospective, single institution, medical record review. We analyzed demographic, clinical, laboratory, and radiographic findings of 139 patients who presented with first episodes of MS-associated ON (MS-ON), aquaporin 4 antibody-associated ON (AQP4-ON), and myelin oligodendrocyte glycoprotein antibody-associated ON (MOG-ON) between January 2015 and October 2019 without preceding diagnosis. Simple hypothesis testing assessed differences between groups were performed.

RESULTS

Of 139 patients (109 [79 %] women; 29 [21 %] men; mean age 47 [SD, 14] years), 106 had MS-ON, 25 had AQP4-ON, and 8 had MOG-ON. Patients with MOG-ON had the highest recurrence rate (88 %) relative to MS-ON (28 %) and AQP4-ON (56 %) patients (P < .001). Patients with AQP4-ON had the highest mean visual functional system scores (4.3 [SD, 1.8]) relative to MS-ON (2.0 [SD, 1.9]) and MOG-ON patients (2.8 [SD, 2.0]) (P < .001).

CONCLUSION

Patients presenting with initial episodes of ON exhibit a range radiographic and laboratory feature depending on the underlying associated disease. Understanding the variable characteristics of typical (MS-associated) and atypical (antibody-associated) ON may help physicians accurately diagnose and effectively treat ON.

Differences in the involved sites among different types of demyelinating optic neuritis in traditional MRI examination: A systematic review and meta-analysis

Background

Magnetic resonance imaging (MRI) plays a significant role in assessing optic neuropathy and providing more detailed information about the lesion of the visual pathway to help differentiate optic neuritis from other visual disorders. This study aims to systematically review the literature and verify if there is a real difference in lesion location among different demyelinating optic neuritis (DON) subtypes.

Methods

A systematic search was conducted including 8 electronic databases and related resources from the establishment of the database to August 25th, 2020. We classified DON into 5 subtypes and divided the visual pathways into five segments mainly comparing the differences in the involved visual pathway sites of different subtypes.

Results

Fifty-five studies were included in the analysis, and the abnormal rate was as high as 92% during the acute phase (within 4 weeks of symptom onset). With respect to lesion location, the orbital segment of the optic nerve was the most frequently involved (87%), whereas optic tract involvement was very rare. Involvement of the orbital segment was more common in myelin oligodendrocyte glycoprotein antibody-related optic neuritis (MOG-ON) (78%) and chronic relapsing inflammatory optic neuropathy (CRION) (81%), while the lesion was found to be located more posteriorly in neuromyelitis optica spectrum disorder-related optic neuritis (NMOSD-ON). With respect to lesion length, approximately 77% of MOG-ON patients had lesions involving more than half of the optic nerve length.

Conclusions

MRI examination is recommended for DON patients in the acute phase. In MOG-ON, anterior involvement is more common and the involved length is mostly more than 1/2 of the optic nerve length, whereas posterior involvement, intracranial segment, optic chiasm, or optic tract, is more common in NMOSD-ON.

Prospero registration number

CRD42020222430 (25-11-2020).

Chronic Relapsing Inflammatory Optic Neuropathy (CRION)

Purpose of review

This review highlights the epidemiology, clinical and radiologic characteristics of chronic relapsing inflammatory optic neuropathy (CRION) and treatment modalities.

Recent findings

Summary

CRION is an inflammatory optic neuropathy that is characterized by a chronic and relapsing course, that is characterized by pain associated with subacute vision loss. It is favorably responsive but highly dependent on corticosteroids with frequent relapses in the setting of steroid tapering. Additional diagnostic biomarkers and further studies are required to better diagnose and treat this rare but potentially debilitating condition.

Clinical characteristics of optic neuritis phenotypes in a 3-year follow-up Chinese cohort

To evaluate the clinical characteristics of optic neuritis (ON) with different phenotypes. This prospective study recruited patients with new-onset ON between January 2015 and March 2017 who were followed-up for 3 years. They were divided into the myelin oligodendrocyte glycoprotein-seropositive (MOG-ON), aquaporin-4-seropositive (AQP4-ON), and double-seronegative (seronegative-ON) groups, and their clinical characteristics and imaging findings were evaluated and compared. Two-hundred-eighty patients (405 eyes) were included (MOG-ON: n = 57, 20.4%; AQP4-ON: n = 98, 35.0%; seronegative-ON: n = 125, 44.6%). The proportion of eyes with best-corrected visual acuity > 20/25 at the 3-year follow-up was similar between the MOG-ON and seronegative-ON groups; the proportion in both groups was higher than that in the AQP4-ON group (p < 0.001). Relapse rates were higher in the MOG-ON and AQP4-ON groups than in the seronegative-ON group (p < 0.001). Average retinal nerve fiber layer (RNFL) thickness at 3 years was similar between the MOG-ON and AQP4-ON groups (63.41 ± 13.39 and 59.40 ± 11.46 μm, p = 0.476) but both were thinner than the seronegative-ON group (74.06 ± 11.14 μm, p < 0.001). Macular ganglion cell-inner plexiform layer (GCIPL) revealed the same pattern. Despite RNFL and GCIPL thinning, the MOG-ON group’s outcome was as favorable as that of the seronegative-ON group, whereas the AQP4-ON group showed unsatisfactory results.

Optic neuritis classification in 2021

Optic neuritis (ON) can be associated with inflammatory disease of the central nervous system or can be isolated, with or without relapse. It can also be associated with infectious or systemic disease. These multiple associations based on a variety of clinical, radiological, and biological criteria that have changed over time have led to overlapping phenotypes: a single ON case can be classified in several ways simultaneously or over time. As early, intensive treatment is often required, its diagnosis should be rapid and precise. In this review, we present the current state of knowledge about diagnostic criteria for ON aetiologies in adults and children, we discuss overlapping phenotypes, and we propose a homogeneous classification scheme. Even if distinctions between typical and atypical ON are relevant, their phenotypes are largely overlapping, and clinical criteria are neither sensitive enough, nor specific enough, to assure a diagnosis. For initial cases of ON, clinicians should perform contrast enhanced MRI of the brain and orbits, cerebral spinal fluid analysis, and biological analyses to exclude secondary infectious or inflammatory ON. Systematic screening for MOG-IgG and AQP4-IgG IgG is recommended in children but is still a matter of debate in adults. Early recognition of neuromyelitis optica spectrum disorder, MOG-IgG-associated disorder, and chronic relapsing idiopathic optic neuritis is required, as these diagnoses require therapies for relapse prevention that are different from those used to treat multiple sclerosis.

MRI Characteristics of NMO, MOG and MS Related Optic Neuritis

Acute isolated optic neuritis can be the initial presentation of demyelinating inflammatory central nervous system disease related to multiple sclerosis (MS), neuromyelitis optica (NMO) or myelin oligodendrocyte glycoprotein antibody disease (MOG-AD). In addition to the well-characterized brain and spinal cord imaging features, important and characteristic differences in the radiologic appearance of the optic nerves in these disorders are being described, and magnetic resonance imaging (MRI) of the optic nerves is becoming an essential tool in the differential diagnosis of optic neuritis. Whereas typical demyelinating optic neuritis is a relatively mild and self-limited disease, atypical optic neuritis in NMO and MOG-AD is potentially much more vision-threatening and merits a different treatment approach. Thus, differentiation based on MRI features may be particularly important during the first attack of optic neuritis, when antibody status is not yet known. This review discusses the optic nerve imaging in the major demyelinating disorders with an emphasis on clinically relevant differences that can help clinicians assess and manage these important neuro-ophthalmic disorders. It also reviews the utility of optic nerve MRI as a prognostic indicator in acute optic neuritis.

Vision improvement in severe acute isolated optic neuritis after plasma exchange treatment in Chinese population: a prospective case series study

Background

Plasma exchange (PE) is often considered as an effective treatment for neuromyelitis optica spectrum disorder (NMOSD) and several inflammatory demyelinating disorders of the central nervous system. This study aimed to evaluate the visual outcomes of Chinese patients with severe acute isolated optic neuritis (ON) who received PE therapy after high-dose intravenous methylprednisolone (IVMP) treatment.

Methods

Thirty-seven acute isolated ON patients experiencing their first attack of severe visual impairment without neurological disability were recruited. All subjects received five cycles of double-filtration plasmapheresis. Visual acuity (VA) was documented at onset, 1 day before PE treatment, at each cycle of PE therapy and at the 1-month follow-up visit.

Results

This study included 26 female (70.3%) and 11 male (29.7%) subjects, and 18 subjects (48.6%) had bilateral involvement. The time window between onset and PE treatment was 27.3 ± 12.7 days (range: 6-53 days). Mean VA (logMAR) of the studied eyes at onset, 1-day before PE treatment/after IVMP and after the fifth PE treatment were 3.41 ± 1.50, 2.61 ± 1.64 and 1.66 ± 1.52, respectively (p < 0.001). Nineteen eyes (51.4%) showed no light perception at the onset, and 17 eyes (45.9%) improved to Snellen VA >20/800 after IVMP and PE treatments, among which five eyes (13.5%) recovered to Snellen VA 20/20 (p < 0.001). Predictors of good visual outcome included body mass index [odds ratio (OR) = 0.734, p = 0.044], serum AQP4 antibody-positive status (OR = 0.004, p = 0.001), bilaterality (OR = 0.042, p = 0.008) and time window from onset to PE therapy per 1 day (OR = 0.79, p = 0.002).

Conclusion

This study revealed that PE treatment effectively improves the visual outcomes of patients experiencing their first attack of severe acute isolated ON after high-dose IVMP treatment. Better visual outcomes can be achieved with early PE treatment.