Clinicoradiological comparative study of Aquaporin-4-IgG seropositive neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody associated disease (MOGAD): A prospective observational study and review of literature

Brain and Spine Magnetic Resonance Imaging (MRI) Characteristics of a Pediatric Cohort With MOGAD

Background and ObjectivesMyelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently defined demyelinating disorder with an age-related phenotypic spectrum. At disease onset, there is considerable clinical overlap between MOGAD and other demyelinating conditions, and it remains difficult to identify MOGAD radiographically. This study aims to further describe neuroimaging findings in the brain and the spine at presentation and throughout relapses in children with MOGAD.MethodsWe present a retrospective cohort study including all children presenting to a single center between 2010 and 2020 with acute demyelination who were positive for serum MOG-IgG antibodies and negative for serum aquaporin-4 antibodies. For each patient, magnetic resonance imaging (MRI) scans of the brain and spine at presentation and on each relapse were reviewed and categorized in a blinded fashion by 2 pediatric neuroradiologists.ResultsSixteen patients met the inclusion criteria. Four had diffuse and bilateral fluid-attenuated inversion recovery signal in the white matter, but only on initial presentation. The area postrema was never affected. All 5 patients with optic neuritis had pre-chiasmatic (but not chiasmatic) involvement on presentation. The brachium pontis was involved in 3 patients on initial presentation, and in 8 patients at any time. Eleven patients demonstrated spinal cord involvement, and the cervical, thoracic, and lumbar regions were involved at similar frequencies.DiscussionThe radiographic features of MOGAD in children appear to reflect their presenting demyelinating syndromes. However, certain features, such as diffuse fluid-attenuated inversion recovery hyperintensities and expansile fluid-attenuated inversion recovery signal in the brachium pontis, may be more frequent in MOGAD compared with other demyelinating disorders.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD): Insights into pathogenesis and biomarkers of prognosis

MOG antibody-associated disease (MOGAD), an inflammatory demyelinating pathology, is typically associated with the clinical phenotypes acute disseminated encephalomyelitis (ADEM), optic neuritis (ON), or transverse myelitis (TM). The mainstay of diagnosis is detection of antibodies targeting oligodendrocyte-expressed MOG (MOG-IgG). MOG-IgG-mediated demyelination occurs via complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), enhanced cognate T-cell CNS infiltration and activation, and oligodendrocyte cytoskeleton disruption, but the exact role of the immune system in MOGAD is still poorly understood. The disease course is either monophasic or relapsing, with relapsing course affecting approximately two-thirds of individuals. Neurological disability accumulates with relapse and may manifest as visual, motor, sensory, and cognitive deficits. Thus, accurate disease course prediction is of paramount importance. Prognostic biomarkers, implemented at a global scale, have the potential to guide timely therapeutic decisions to limit relapse-associated disability accrual while simultaneously avoiding unnecessary immunosuppression in monophasic individuals. This review explores recent insights in the understanding of MOGAD pathogenesis as well as advances in prognostic biomarkers of relapsing course and disease activity.

MOGAD: A comprehensive review of clinicoradiological features, therapy and outcomes in 4699 patients globally

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is one of the most common antibody-mediated CNS disorders. Optimal diagnostic and prognostic biomarkers remain unclear. Our aim was to clarify these biomarkers and therapeutic outcomes internationally. We reviewed articles from 2007 to 2022 and identified 194 unique cohorts encompassing 4699 paediatric and adult patients from 31 countries. Where phenotypes were specified, the most common initial presentation overall was optic neuritis (ON; paediatric 34 %; adults 60 %), during which 71 % had papilloedema on fundoscopy. The most common phenotype at latest follow-up was relapsing ON (20 %). Only 47 % of patients with 6-24 months of follow-up exhibited a relapsing course, while this proportion was much higher (72 %) when follow-up was extended beyond 5 years. Despite a similar relapse rate, the time to first relapse was much shorter in paediatric than adult patients (6 vs 17 months). Adult MRI-Brain scans performed at onset were more frequently normal than in paediatric patients (50 % vs 27 %). Abnormal MRI scans showing involvement of deep grey matter, cortico-subcortical, periventricular lesions, leptomeningeal enhancement, H-shaped spinal cord lesions, and bilateral optic nerve abnormalities were more common in paediatric patients compared to adults. Conversely, adults demonstrated higher frequencies of eccentric spinal cord lesions and intraorbital involvement. CSF analysis demonstrated intrathecally restricted oligoclonal bands in 12 %, elevated protein in 35 %, and pleocytosis in 54 %. Peripapillary retinal nerve fibre layer (pRNFL) thickness, measured acutely, frequently demonstrated swelling (weighted-median 145 μm; normal 85-110). Most cohorts demonstrated notable pRNFL atrophy at latest follow-up (weighted-median 67 μm). pRNFL thickness was significantly lower when measured at or after six months following ON onset, compared to measurements taken within the first six months following ON onset (p < 0.001). Therapeutic and outcome data was available for 3031 patients with a weighted-median disease duration of 32 months. Acute immunotherapy was initiated in 97 %, and maintenance immunotherapy in 64 %, with considerable regional variation. Expanded Disability Status Scale (EDSS) scores and visual acuities improved from nadir to latest follow-up in most patients. A negative correlation was noted between follow-up pRNFL thickness and latest follow-up visual acuity (r = -0.56). Based on this unprecedented global aggregation of MOGAD patients, we reveal a higher proportion of relapsing patients than previously recognised. While commonly used measures like EDSS show significant recovery, they underestimate visual disability following optic neuritis, the most frequent clinical presentation. Our findings suggest that RNFL thickness, especially when measured at least 6 months post-ON, may serve as a more sensitive biomarker for long-term visual impairment.

Quality of life in patients with myelin oligodendrocyte glycoprotein antibody associated disease compared to patients with AQP4-IgG positive neuromyelitis optica spectrum disorders: A Korean multicenter study

BACKGROUND

Little is known about the quality of life (QOL) of patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). We compared QOL and associated factors in patients with MOGAD and aquaporin4 IgG (AQP4-IgG) positive neuromyelitis optica spectrum disorder (NMOSD).

METHODS

This multicenter questionnaire study compared the QOL of 41 patients with MOGAD and 78 with AQP4-IgG positive NMOSD. Patients who were positive for AQP4-IgG or MOG antibodies were included. WHO Quality of Life Scale Brief Version was used to assess QOL in physical, psychological, social, and environmental domains. QOL, sleep quality, pain, fatigue, and depression were compared between the two groups. The factors associated with QOL in each group and the entire cohort were analyzed.

RESULTS

The proportion of patients with poor QOL was not significantly different between MOGAD (51.22 %) and AQP4-IgG positive NMOSD (58.97 %, p = 0.054). In the MOGAD group, the pain score (β=-1.032, p = 0.001) and depression score (β=-0.694, p = 0.007) were negatively associated with physical and psychological QOL, respectively. Sleep quality was negatively associated with physical (β=-1.506, p = 0.034) and psychological (β =-2.064, p = 0.033) QOL. When the entire cohort was analyzed, a positive MOG antibody was independently associated with worse psychological QOL (β=-8.998, p = 0.013) compared to positive AQP4-Ab after adjustment for sleep quality, depression, fatigue, and pain.

CONCLUSIONS

The overall QOL of the patients of MOGAD was comparable to that of AQP4-IgG positive NMOSD. Patients with MOGAD were experiencing sleep disorder, fatigue, and depression at similar degrees to those of patients with AQP4-IgG positive NMOSD. Further consideration of sleep quality and psychological QOL is required to improve QOL in patients with MOGAD.

Clinico-radiologic Spectrum and Outcome of Pediatric Acquired Demyelinating Disorders of Central Nervous System: A Retrospective Indian Tertiary Care Hospital Cohort

BACKGROUND

Pediatric acquired demyelinating syndrome (ADS) constitutes a group of treatable disorders with acute neurologic dysfunction. Neuroimaging has played a significant role in diagnosis of ADS. We describe clinico-radiologic spectrum, outcomes, and comparison of the groups: acute disseminated encephalomyelitis (ADEM), neuromyelitis optica spectrum disorder (NMOSD), clinically isolated syndrome (CIS), multiple sclerosis (MS), and myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD).

METHODS

Retrospective review of 70 children with ADS at a tertiary care hospital over 15 years (2008-2023) was performed. Diagnosis was assigned as per International Pediatric Multiple Sclerosis Study Group criteria 2016. Fisher's exact and chi-square tests were applied.

RESULTS

Thirty-nine boys and 31 girls aged 8.2 ± 4.0 years with CIS (n = 27), ADEM (n = 16), NMOSD (n = 13), MS (n = 1), and MOGAD (n = 13) were included. Clinical syndromes with positive significant association included polyfocal symptoms, encephalopathy in ADEM, optic neuritis (ON) in MOGAD, brainstem, area postrema syndrome in NMOSD. MOGAD presented with atypical presentations like prolonged fever (PF; 76.9%) and aseptic meningitis (23%). Seropositivity for myelin oligodendrocyte glycoprotein immunoglobulin-G was 62% and for NMO-IgG 2.6%. Neuroimaging of MOGAD showed lesions predominantly in basal ganglia/thalami (69.2%), optic nerve (46.2%), and cerebellum (46.2%). Imaging patterns between ADEM and MOGAD were comparable except for more ON (p = 0.004), spinal cord (p = 0.01), and cerebellar lesions (p = 0.03) in MOGAD. Area postrema lesion was unique to NMOSD. All patients received immunotherapy, of whom 91.4% (n = 64) had good recovery, 8.6% (n = 6) had functional limitation on modified Rankin scale at discharge, and 12 (17.1%) relapsed.

CONCLUSION

The largest group was CIS. Seropositivity of MOG was high with atypical presentations like PF and aseptic meningitis. Specific neuroimaging patterns correlated with ADS categories. Short-term outcome with immunotherapy was favorable in spite of relapses.

The distinction of area postrema syndrome between MOGAD and NMOSD

Background and objectives

Both myelin oligodendrocyte glycoprotein-IgG associated disorders (MOGAD) and neuromyelitis optica spectrum disorder (NMOSD) are demyelinating diseases of the central nervous system. They present similar clinical manifestations such as optica neuritis, myelitis and area postrema syndrome (APS). The distinctions of optica neuritis (ON) and myelitis between them have been elaborated to great length while their differences in APS remain to be elucidated. We aim to report the frequency of APS in patients with MOGAD as well as NNOSD patients, and to compare the characteristics of APS between patients with MOGAD and those with NMOSD.

Methods

Seven MOG-IgG positive APS patients were retrospectively identified between 2017 and 2022. APS phenotypes have been previously described. The similarities and differences between MOGAD and NMOSD patients with APS was compared, including the frequency and duration of APS between the two diseases, and their incidences of accompanied subtentorial lesions have also been described and compared.

Results

We reviewed a cohort of 218 MOG-IgG-positive patients, and 396 patients with NMOSD. 200 MOGAD patients and 332 NMOSD patients were included in this study. In the cohort, seven patients with MOG-IgG-positive antibody presented with APS were analyzed, four of whom had disease onset with APS. Of the 332 patients with NMOSD, 47 had APS attacks while 31 had APS at disease onset. In patients with MOGAD, 2 had nausea, 3 had vomiting, 5 had hiccups, and 1 patient presented with all three symptoms above. In patients with NMOSD, 70.2 % had nausea, vomiting and hiccups at the same time during APS attacks. Apart from the medulla oblongata, other subtentorial regions were also affected in 6/7 MOGAD patients while 14/47 NMOSD patients had other subtentorial regions involved. During an APS attack, the incidence of concomitant lesions in the brainstem and other regions was significantly greater in MOGAD than in the NMOSD cohort (P = 0.008*).

Conclusion

APS is a rare, but not isolated clinical manifestation of MOGAD. APS happened more frequently with other supratentorial and subtentorial lesions in MOGAD. The symptoms of NVH (nausea, vomiting, hiccups) tended to happen respectively in MOGAD compared with NMOSD. The phenotype or mechanism of APS in MOGAD may differ from that in NMOSD.

Role of serostatus in pediatric neuromyelitis optica spectrum disorders: A nationwide multicentric study

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) are immune-mediated inflammatory disorders of the central nervous system (CNS) mostly presenting as optic neuritis and acute myelitis. NMOSD can be associated with seropositivity for aquaporin 4 antibody (AQP4 IgG), myelin oligodendrocyte glycoprotein antibody (MOG IgG), or can be seronegative for both. In this study, we retrospectively examined our seropositive and seronegative pediatric NMOSD patients.

METHOD

Data were collected from all participating centres nationwide. Patients diagnosed with NMOSD were divided into three subgroups according to serology: AQP4 IgG NMOSD, MOG IgG NMOSD, and double seronegative (DN) NMOSD. Patients with at least six months of follow-up were compared statistically.

RESULTS

The study included 45 patients, 29 female and 16 male (ratio:1.8), mean age 15.16 ± 4.93 (range 5.5-27) years. Age at onset, clinical manifestations, and cerebrospinal fluid findings were similar between AQP4 IgG NMOSD (n = 17), MOG IgG NMOSD (n = 10), and DN NMOSD (n = 18) groups. A polyphasic course was more frequent in the AQP4 IgG and MOG IgG NMOSD groups than DN NMOSD (p = 0.007). The annualized relapse rate and rate of disability were similar between groups. Most common types of disability were related to optic pathway and spinal cord involvement. Rituximab in AQP4 IgG NMOSD, intravenous immunoglobulin in MOG IgG NMOSD, and azathioprine in DN NMOSD were usually preferred for maintenance treatment.

CONCLUSION

In our series with a considerable number of double seronegatives, the three major serological groups of NMOSD were indistinguishable based on clinical and laboratory findings at initial presentation. Their outcome is similar in terms of disability, but seropositive patients should be more closely followed-up for relapses.

Neuromyelitis optica spectrum disorder with AQP4-IgG presenting as area postrema syndrome and progressing to myelitis: A rare case report

Key Clinical Message

Neuromyelitis optica spectrum disorders can less commonly present with area postrema syndrome progressing to myelitis. Management involves intravenous glucocorticoids, plasma exchange, and preventive immunotherapy.

Abstract

Neuromyelitis optica spectrum disorders can less commonly present with area postrema syndrome progressing to myelitis. The majority of patients have positive AQP4-Ab. Diagnosis is based on clinical and imaging findings. These patients can be treated with intravenous glucocorticoids, plasma exchange, and preventive immunotherapy.

Pediatric myelin oligodendrocyte glycoprotein antibody-associated disease in southern China: analysis of 93 cases

Objective

To study the clinical features of children diagnosed with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in southern China.

Methods

Clinical data of children diagnosed with MOGAD from April 2014 to September 2021 were analyzed.

Results

A total of 93 children (M/F=45/48; median onset age=6.0 y) with MOGAD were involved. Seizures or limb paralysis was the most common onset or course symptom, respectively. The most common lesion locations in brain MRI, orbital MRI, and spinal cord MRI were basal ganglia and subcortical white matter, the orbital segment of the optic nerve, and the cervical segment, respectively. ADEM (58.10%) was the most common clinical phenotype. The relapse rate was 24.7%. Compared with the patients without relapse, relapsed patients had a longer interval from onset to diagnosis (median: 19 days VS 20 days) and higher MOG antibody titer at onset (median: 1:32 VS 1:100) with longer positively persistent (median: 3 months VS 24 months). All patients received IVMP plus IVIG at the acute phase, and 96.8% of patients achieved remission after one to three courses of treatment. MMF, monthly IVIG, and maintaining a low dose of oral prednisone were used alone or in combination as maintenance immunotherapy for relapsed patients and effectively reduced relapse. It transpired 41.9% of patients had neurological sequelae, with movement disorder being the most common. Compared with patients without sequelae, patients with sequelae had higher MOG antibody titer at onset (median: 1:32 VS 1:100) with longer persistence (median: 3 months VS 6 months) and higher disease relapse rate (14.8% VS 38.5%).

Conclusions

Results showed the following about pediatric MOGAD in southern China: the median onset age was 6.0 years, with no obvious sex distribution difference; seizure or limb paralysis, respectively, are the most common onset or course symptom; the lesions of basal ganglia, subcortical white matter, the orbital segment of the optic nerve, and cervical segment were commonly involved in the CNS MRI; ADEM was the most common clinical phenotype; most had a good response to immunotherapy; although the relapse rate was relatively high, MMF, monthly IVIG and a low dose of oral prednisone might effectively reduce relapse; neurological sequelae were common, and possibly associated with MOG antibody status and disease relapse.

Comparison of clinico-radiological profile, optical coherence tomography parameters, and outcome in MOGAD and Neuromyelitis optica spectrum disorder subtypes: A prospective observational study

Objectives

The objectives of the study were to compare the clinico-radiological profile, optical coherence tomography (OCT) parameters and outcome in Myelin Oligodendrocyte Glycoprotein-IgG-associated disorders (MOGAD) and Neuromyelitis Optica Spectrum disorder subtypes.

Materials and Methods

This prospective study involved collection of data regarding neurological assessment, neuroimaging, cerebrospinal fluid analysis, OCT parameters, treatment and outcome. Disease severity and disability were assessed using Expanded Disability Status Scale and modified Rankin scale. Patients were categorized into aquaporin-4 (AQP4+), MOGAD, and double negative (DN; both AQP4 and MOG negative).

Results

Among 31 patients included, 42% were AQP4+, 32.2% were MOGAD, and 25.7% were DN. The median age at onset was comparable (AQP4+ vs. MOGAD vs. DN = 28 years vs. 24.4 years vs. 31.5years; P = 0.31). Females predominated in AQP4+ compared to MOGAD group (76.9% vs. 30%; P = 0.02). Majority of patients (73.5%) had a relapsing course with a median of two (range = 1-9) relapses. Ninety-nine demyelinating events occurred: Transverse myelitis (TM) in 60/99 (60.6%), optic neuritis (ON) in 43/99 (43.4%), area postrema (AP) syndrome in 20/99 (20.1%), and optico-spinal syndrome in 10/99 (10.1%). ON was common in MOGAD than AQP4+ patients (58.6% vs. 32.1%; P = 0.03). Spinal cord and brain lesions on magnetic resonance imaging (MRI) were seen in 90.3% and 54.8% patients, respectively. A significantly higher proportion of AQP4+ patients showed longitudinally extensive transverse myelitis as compared to MOGAD group (69.2 % vs. 20 %; P = 0.04), specifically involving dorsal cord (92.3% vs. 50%; P = 0.02). MRI brain lesions, especially involving AP, was frequent in DN than MOGAD (47.1% vs. 6.9%; P = 0.003) and AQP4+ (47.1% vs. 18.9%; P = 0.03) patients. AQP4+ group showed significant nasal RNFL thinning on OCT (P = 0.04). Although 6-month good functional outcome was better in MOGAD than DN and AQP4+ (80% vs. 71.4% vs. 41.7%) groups, they were comparable (P = 0.13).

Conclusion

Nearly three-fourth of our patients showed a relapsing course, with TM being the most common clinical presentation. AQP4+ group showed female preponderance, frequent dorsal cord longitudinally extensive transverse myelitis, less frequent ON, and greater nasal RNFL thinning compared to MOGAD group. MRI brain lesions were more common in DN patients. All three groups exhibited good response to pulse corticosteroids and showed a comparable functional outcome at 6-month follow-up.

Elevated serum levels of bone morphogenetic protein-9 are associated with better outcome in AQP4-IgG seropositive NMOSD

Lymphatic drainage in the central nervous system is regulated by meningeal lymphatic vasculature, and recurrent neuroinflammation alters lymphatic vessel remodeling. Patients with aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4 + NMOSD) were reported to demonstrate worse outcomes compared with patients with anti-myelin oligodendrocyte glycoprotein-associated disorders (MOGAD). This study aimed to investigate the serum cytokines relevant to vascular remodeling after attacks and their prognostic role in patients with AQP4 + NMOSD. This study measured the serum levels of 12 cytokines relevant to vascular remodeling, including bone morphogenetic protein-9 (BMP-9) and leptin, in 20 patients with AQP4 + NMOSD and 17 healthy controls (HCs). Disease controls included 18 patients with MOGAD. Serum and cerebrospinal fluid interleukin-6 levels were also measured. Clinical severity was evaluated with Kurtzke's Expanded Disability Status Scale (EDSS). Compared with HCs, patients with AQP4 + NMOSD showed higher BMP-9 (median; 127 vs. 80.7 pg/mL; P = 0.0499) and leptin levels (median; 16,081 vs. 6770 pg/mL; P = 0.0224), but not those with MOGAD. Better improvement in EDSS at 6 months was associated with baseline BMP-9 levels in patients with AQP4 + NMOSD (Spearman's rho =  - 0.47; P = 0.037). Serum BMP-9 is upregulated at relapse and may contribute to vascular remodeling in AQP4 + NMOSD. Serum BMP-9 levels could predict clinical recovery 6 months after the attack.

Case Report: Interferon-Alpha-Induced Neuromyelitis Optica Spectrum Disorder

Background and Objectives

To describe a new case of neuromyelitis optica spectrum disorder (NMOSD) induced by the administration of interferon-alpha (IFNα) and to raise awareness of this rare drug-induced disease of IFNα treatment.

Methods

A single case study and comprehensive literature review of eight cases.

Results

A 24-year-old man was diagnosed with cerebral venous thrombosis and essential thrombocythemia. He had been undergoing IFNα treatment (IFNα-2b, 3 million IU per day) without any side effects for 18 months, at which point the patient developed persistent hiccups, nausea, urinary retention, and numbness. Spinal magnetic resonance imaging revealed a longitudinal abnormality extending from the medulla to the entire spinal cord. The patient was positive for anti-aquaporin-4 antibody (AQP4-IgG) in both the serum and cerebrospinal fluid (CSF), which confirmed the diagnosis of NMOSD. Thus, recombinant IFNα-2b was suspended immediately. Because his condition did not improve after 6-day treatment of methylprednisolone pulse therapy (1,000 mg for 3 days, then 500 mg for 3 days), intravenous immunoglobulin (0.4 g/kg/day for 5 days) was administered. The patient gradually improved. Low-dose prednisolone and mycophenolate mofetil were subsequently administered as a long-term treatment. The patient was discharged with subtle limb numbness and their expanded disability status score (EDSS) was 1. At the 1-year follow-up, the patient had not relapsed and tested negative for AQP4-IgG. We further identified the eight patients with IFNα-induced NMOSD. The median onset age was 59 years, and the median time of IFNα exposure was 18 months. Optic neuritis was the most common initial symptom (five, 55.6%), followed by myelitis in three patients and area postrema syndrome in one patient. More than half (five, 55.6%) of the patients were monophasic. After IFNα discontinuation and immunotherapy, most (seven, 77.8%) patients remained relapse-free. However, only one patient was free of sequelae.

Conclusion

This study highlights the potential pathogenic risk of NMOSD of IFNα treatment. Given the high disability rates of this rare drug-induced disease, it is crucial to monitor the early manifestations of NMOSD during IFNα treatment.

Progressive Retinal and Optic Nerve Damage in a Mouse Model of Spontaneous Opticospinal Encephalomyelitis

Neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein-antibody-associated disease (MOGAD) are antibody mediated CNS disorders mostly affecting the optic nerve and spinal cord with potential severe impact on the visual pathway. Here, we investigated inflammation and degeneration of the visual system in a spontaneous encephalomyelitis animal model. We used double-transgenic (2D2/Th) mice which develop a spontaneous opticospinal encephalomyelitis (OSE). Retinal morphology and its function were evaluated via spectral domain optical coherence tomography (SD-OCT) and electroretinography (ERG) in 6- and 8-week-old mice. Immunohistochemistry of retina and optic nerve and examination of the retina via RT-qPCR were performed using markers for inflammation, immune cells and the complement pathway. OSE mice showed clinical signs of encephalomyelitis with an incidence of 75% at day 38. A progressive retinal thinning was detected in OSE mice via SD-OCT. An impairment in photoreceptor signal transmission occurred. This was accompanied by cellular infiltration and demyelination of optic nerves. The number of microglia/macrophages was increased in OSE optic nerves and retinas. Analysis of the retina revealed a reduced retinal ganglion cell number and downregulated Pou4f1 mRNA expression in OSE retinas. RT-qPCR revealed an elevation of microglia markers and the cytokines Tnfa and Tgfb. We also documented an upregulation of the complement system via the classical pathway. In summary, we describe characteristics of inflammation and degeneration of the visual system in a spontaneous encephalomyelitis model, characterized by coinciding inflammatory and degenerative mechanisms in both retina and optic nerve with involvement of the complement system.